Arthritis, also sometimes referred to as degenerative joint disease (DJD) or osteoarthritis (OA), refers to the inflammation and weakening of one or more joints. It can be caused by a number of things, such as trauma, physical abnormalities, joint infections, genetic predispositions and immune system problems. Arthritis is painful, slowly progressive and almost always permanent. It can contribute to stiffness, pain, lameness, joint deformities and loss of normal function, depending on the number and location of joints involved and the age and general health of the affected animal. Arthritis is less common and usually milder in cats than in dogs. Fortunately, there are several things that owners can do to help arthritic cats (and dogs) lead full and fairly pain-free lives, including weight management, dietary and lifestyle changes, surgical procedures and use of various approved medications and supplements.
Causes of Feline Arthritis
Arthritis refers to inflammation of one or more joints. It can be degenerative or inflammatory, and each of these general categories involves several sub-categories or types. The nomenclature can be confusing, because all arthritis involves some degree of inflammation. However, the primary cause of “degenerative” arthritis is not inflammation, while the main cause of “inflammatory” arthritis is. Regardless of cause or type, the end results of arthritis are the same: moderate to crippling pain and loss of normal joint function. Here’s a general overview of arthritis in cats.
I. Degenerative (noninflammatory) Arthritis. Degenerative or noninflammatory arthritis, also called degenerative joint disease (DJD) and osteoarthritis (OA), is the most common type of arthritis in domestic cats. It’s an inevitably progressive and irreversible disease of slow joint and cartilage deterioration.
A. Primary. Primary degenerative arthritis is uncommon in cats.
B. Secondary. Most of the time, degenerative feline arthritis develops secondary to another inciting event or condition, such as acute or chronic trauma, which interferes with the biomechanical forces on affected joints. Physical injury – especially to the cartilage that connects joint bones (articular cartilage) - causes chemicals called inflammatory mediators to be released. These substances break down the connective cartilage matrix faster than it can be rebuilt, which leads to joint degeneration and lots of pain. The events that trigger the release of these chemicals typically fall into one of two categories: 1) abnormal forces on normal joints; or 2) normal forces on abnormal joints. Degeneration and collapse of the joint space damages the joint’s mechanical integrity and causes bone remodeling. As the joint breaks down, bony outgrowths form, intensifying the cat’s discomfort.
1. Abnormal forces on normal joints can be caused by sprains, fractures, obesity, aging, poor nutrition, trauma and many other things.
2. Normal forces on abnormal joints can be caused by elbow and hip dysplasia, osteochondrosis dissecans, patellar luxation, ununited anchoneal process, fragmented coronoid process, cranial cruciate ligament rupture and other congenital or genetic conformational defects.
II. Inflammatory Arthritis. Inflammatory arthritis, also called inflammatory joint disease, can be infectious or noninfectious.
A. Infectious. Infectious inflammatory arthritis is caused by bacteria, fungi, viruses, rickettsia or other microscopic organisms. Tick-borne diseases, like Rocky Mountain Spotted Fever, Lyme Disease and Ehrlichiosis, can contribute to infectious arthritis. Bacterial joint infections can be innocuated by injections, joint taps, surgical procedures, animal or reptile bites and other open or penetrating wounds. Fungal, viral and rickettsial causes of infectious arthritis are uncommon in cats.
B. Noninfectious. Noninfectious inflammatory arthritis usually involves the immune system and affects multiple joints. For some reason, the cat’s immune system attacks its own cartilage and joints.
1. Erosive. Noninfectious arthritis can erode joints and cartilage, causing severe leg and paw deformities. Rheumatoid arthritis, plasmacytic-lymphocytic synovitis and systemic lupus erythematosus can contribute to erosive noninfectious arthritis.
2. Nonerosive. Noninfectious arthritis can also cause inflammation and pain without eroding joint and cartilage tissue. This isn’t common in cats.
Feline arthritis is hard to prevent. The progression of degenerative arthritis can be delayed if the cause is resolved. Weight management is probably the most important factor. Obese cats should be on a calorie-restricted diet under veterinary supervision. Supplements can help manage arthritis pain and may delay joint damage. Affected cats should always have a comfortable sleeping area that doesn’t require excessive jumping to reach.
Arthritis – especially the degenerative form of this inflammatory joint disease – is fairly common in domestic cats. Fortunately, arthritis is not particularly difficult to diagnose. In most cases, owners bring their aging cats to a veterinarian because they have noticed that they are stiff, reluctant to rise and are just generally starting to slow down. They may have problems jumping up onto furniture, grooming themselves or getting into and out of the litter box. The doctor will ask the owner about the cat’s general health, when its current symptoms started and whether they have waxed and waned, stayed about the same or steadily gotten worse. After taking a thorough history, the veterinarian will carefully examine the cat, paying particular attention to its limbs, back and joints. She will be looking for swelling, heat and signs of discomfort. A complete physical examination will help to localize the site of the joint inflammation. Usually, the cat’s history, presenting symptoms and physical examination results will point to a tentative diagnosis of arthritis.
After the history and physical examination are completed, the typical initial data base for aging feline patients includes taking blood and urine samples and submitting them to a laboratory for blood work and a urinalysis. These routine tests usually don’t provide much diagnostic information about the overall condition of cats with arthritis or the causes of their discomfort, although they can help rule out other possible causes, such as joint infections, and may provide valuable information about the cat’s geriatric baseline health. Radiographs, commonly called X-rays, are a very effective tool for identifying and assessing the degree of arthritis; they can show changes in the joint capsules, soft tissue thickening and mineralization, narrowing of joint spaces, joint effusion (fluid build-up), changes in the cartilage that connects bones in joints, other bony changes, intra-articular calcified bodies (osteophytes) and other physical changes that are known to be associated with this disease. Unfortunately, the degree of abnormalities that can be seen on radiographs does not necessarily correlate to the severity of the cat’s clinical disease or to how poorly it feels. Another procedure, called bone nuclear scintigraphy, can help the veterinarian localize arthritic sites. Sampling and analysis of synovial fluid, which is the fluid lining and lubricating the inside of the joint capsule, can help determine the degree of inflammation and whether the joints are infected. Magnetic resonance imaging (MRI) and computed tomography (CT) are also available in specialized referral clinics and veterinary teaching hospitals to visualize joint incongruity, physical cartilage changes and the overall extent of the cat’s arthritis.
Arthritis in cats is almost always progressive and irreversible. Fortunately, there are a number of ways to manage this condition and help most affected animals maintain a good and relatively pain-free quality of life.
Effects of Arthritis – From the Cat’s Point of View
Arthritis is a painful, progressive, usually permanent joint disease that unfortunately is fairly common in companion cats. While it is most frequently seen in older, obese cats, arthritis can also strike younger animals, especially those with a genetic predisposition to developing the disease. Arthritic cats experience varying degrees of stiffness, soreness, lameness and pain in one or more of their inflamed joints. They feel worse when they get up in the morning or try to stand after taking a nap. Cold, damp weather can increase their discomfort. Because arthritis is almost always irreversible, most arthritic cats get more painful over time. In severe cases, this condition can become debilitating and even crippling.
Symptoms of Arthritis – What the Cat’s Owner May See
The symptoms of feline arthritis usually appear gradually and worsen slowly over time. Outward signs of arthritis are not specific to this disease and can mimic those of many other disorders. The first signs are often so mild that even the most observant owners may miss them. Eventually, most owners of arthritic cats will notice that their companion isn’t acting or feeling right. The signs of arthritis include:
Intermittent lameness (less common in cats than dogs)
Reluctance to rise or move
Stiffness, especially after vigorous exercise or prolonged periods of rest
Swollen joints; may be warm and tender
Difficulty entering and exiting the litter box
Visible joint deformities
Sleeping more than usual (prolonged periods of rest)
Exercise intolerance; disinterest in physical activity
Aggression when joints are touched
Abnormal stance when walking (pelvis tucked under; using hind legs with exaggerated care)
Cats at Increased Risk
There is no breed or gender predisposition that increases a cat’s chance of developing arthritis, although it most commonly affects aging animals. In fact, degenerative arthritis reportedly affects roughly 90% of cats over 12 years of age. Free-roaming outdoor cats have a greater risk of traumatic injuries that can contribute to arthritis, and obese cats definitely are predisposed. Genetics are thought to be influential as well.
Goals of Treating Feline Arthritis
The goals of treating arthritis are to relieve pain and inflammation, improve mechanical joint function, slow progression of the disease and stimulate the body’s ability to repair affected joints.
Surgical and non-surgical options are available to help manage arthritis, both of which can dramatically improve a cat’s comfort and quality of life. Surgery is usually a last resort, because it can be painful and exacerbate other symptoms that are already associated with the disorder.
Non-surgical treatment options include:
Nonsteroidal anti-inflammatory medications (NSAIDs), to reduce inflammation and pain
Chondroprotective agents, to promote heathy cartilage repair (polysulfated glycosaminoglycans, glucosamine, chondroitin sulfate, hyaluronan, Vitamin C, omega 3 and 6 fatty acids and MSM, among others)
Opioids, to relieve pain
In many cases, dietary modification and weight loss alone will decrease the discomfort associated with arthritis, since obese arthritic cats tend to suffer more than fit ones. Moderate exercise can stimulate cartilage repair an help delay joint degeneration and muscle atrophy. Physical therapy, including hydrotherapy (water exercises) and passive flexion and extension of affected limbs, can be incorporated into long-term management of arthritis, although most cats resist hydrotherapy fairly strenuously. Less traditional techniques may or may not benefit arthritic cats by helping to ease pain, increase circulation, speed healing and promote wellness, comfort and relaxation. These include: massage therapy to stimulate blood flow and reduce stress, acupuncture, acupressure, chiropractic adjustment, and use of herbal or other non-regulated supplements (“homeopathic remedies”). Many of these adjunct remedies have not been scientifically studied in a well-controlled manner to assess their benefit to arthritic cats. Chiropractic manipulation of animals with musculoskeletal abnormalities is highly controversial.
Surgical treatment options include:
When a cat’s joints have become so severely damaged that non-surgical treatment options don’t resolve its discomfort, surgical options may be considered.
Arthroscopy is the most minimally-invasive surgery currently available for arthritic animals and can be used to repair damaged shoulders, elbows, stifles (knees) and ankle joints. The surgeon makes small cuts over the joint and inserts tiny cameras to assess joint damage and plan surgical repair, which may also be done through the incisions with specialized instruments.
Elbow and hip replacements may be available for cats at specialized hospitals, although they are rarely done. These surgeries are expensive and require a long recovery time (approximately 2-3 months).
Damaged wrist, toe, limb and spine joints can be fused surgically using metal implants.
Prognosis for Cats with Arthritis
Although arthritis is progressive and irreversible, non-surgical and surgical therapies often help affected cats live a fairly normal life. The prognosis for cats with arthritis really depends on its cause. If the condition is caught early and is not exacerbated by age or obesity, the prognosis is usually excellent. Overweight and old arthritic cats are not good surgical candidates. Arthritis caused by immune or inherited conditions tends to worsen with time, although medical and life style modifications certainly still can enhance the cat’s quality of life. A veterinarian is the best one to give owners an idea of what they can expect from the various management options.
Anemia is defined as a deficiency or reduction in the normal number or concentration of red blood cells - called erythrocytes or “RBCs” that are circulating in a cat’s blood stream. As a general rule, adult cats are anemic when they have less than 5 million RBCs in 1 milliliter of blood or when the overall RBC percentage in their blood is less than 25%.
Causes of Feline Anemia
There are three general causes of anemia in cats: blood loss, destruction of RBCs and inadequate RBC production. The first two categories are called regenerative anemia; the last is considered non-regenerative.
Blood loss reduces the number of circulating red blood cells because it decreases total blood volume. It can be caused by trauma, surgery, blood clotting abnormalities, ulcers, blood-sucking parasites (fleas, ticks, lice, hookworms), cancer and many other disorders or conditions.
Destruction of RBCs (or an abnormally short RBC lifespan), also called hemolytic anemia, reduces the concentration of red blood cells in the bloodstream rather than total blood volume. Autoimmune hemolytic anemia is uncommon in cats but occasionally occurs when a cat’s immune system attacks its own red blood cells for no known reason. Non-immune-mediated hemolytic anemia happens when something else destroys a cat’s RBCs, such as parasites, hereditary diseases or exposure to toxins.
Inadequate RBC production is the most common form of feline anemia. This serious condition often is attributable to some underlying disease such as feline leukemia, infectious peritonitis, bone marrow cancer, kidney failure, administration of certain drugs and enzyme abnormalities.
How Anemia Affects Cats and What Owners May See
Red blood cells carry oxygen from the lungs throughout the body. Normally, as they age or are damaged, RBCs break down and are either recycled to the bone marrow to be incorporated into new RBCs or processed and excreted by the liver. Anemic cats don’t have enough red blood cells to transport sufficient oxygen to their tissues and organs, which causes them to become oxygen-starved. Affected cats get weak, tired and lethargic. They develop exercise intolerance, elevated heart rate, bounding irregular pulses, pale mucous membranes, confusion, appetite loss, rapid breathing and ultimately collapse. Feeding a high-quality diet, preventing traumatic injuries, keeping current on vaccinations and following sound veterinarian-approved methods to keep parasites at bay can all help to reduce the occurrence of anemia in companion cats.
Diagnosis and Treatment
Veterinarians usually can diagnose anemia in cats by simple, fairly inexpensive routine blood tests that analyze the numbers and concentration of their circulating red blood cells. Sometimes, more advanced blood work and possibly bone marrow evaluation can be helpful to identify what is actually causing the cat’s anemia. Because the causes of feline anemia are so varied and often unrelated, it is really important to determine why a cat is anemic before deciding on and going down a treatment path.
Anaphylactic shock is an exaggerated allergic reaction to a foreign substance, such as a drug, insect saliva or toxin, which a cat comes into contact with. That substance is called an “allergen.” In people, we usually think of anaphylaxis as being caused by bee stings. In companion animals, anaphylaxis can be caused by insect stings and also by many other, and happens within minutes of exposure to the offending allergen.
Preventing Anaphylactic Shock
The only way to prevent anaphylactic shock is to keep the cat away from the allergen that stimulates its immune system to become hyperactive and overreact. Of course, if the owner doesn’t know that her cat is allergic to a particular substance or item, this can be difficult at best. Once a cat does have an anaphylactic reaction, contact with the offending allergen will continue to cause the cat to have severe reactions in the future. Occasionally, anaphylactic shock happens on the very first exposure to an allergen. It is extremely important for owners to take their cat to a veterinarian immediately if they suspect that the animal may be going into anaphylactic shock. Without prompt and proper medical treatment, cats with anaphylactic reactions can deteriorate rapidly. Serious anaphylactic reactions can be fatal.
Symptoms of Anaphylactic Shock – What the Cat’s Owner Sees
Anaphylactic shock in cats is a true medical emergency that must be treated immediately to prevent probable death, which can occur within a matter of hours after exposure to the offending allergen. Owners of affected cats may notice one or more of the following signs if their cat is in or going into anaphylactic shock:
Excitement, agitation or restlessness
Severe inconsolable itchiness, especially around the head and neck
Swelling around the head and neck
Raised red areas (wheals) associated with the areas of itchiness or swelling
Difficulty breathing (dyspnea)
Pale gums and other mucous membranes (abnormal pallor)
Excessive salivation (often profuse)
Changes in mental acuity or clarity
Depression; appears to be moping or sedated
Seizures, tremors, shaking, trembling
Cardiovascular failure (fast or slow heart rate)
Poor pulse quality (weak or thread pulses)
Most affected cats are between 6 and 24 months of age, although the reason for this age association is not well understood. Anaphylactic shock typically can be effectively treated with epinephrine injections and additional support, but these treatments must be given within a matter of minutes once the symptoms begin. It is a good idea for owners to have their local veterinary clinics and the shortest way to get to them mapped out ahead of time, so that they are well-prepared to get their bellowed companion to the hospital as quickly as possible for any type of potential medical emergency, including anaphylactic shock.
Intensive veterinary attention and hospitalization are almost always necessary to save the life of an animal in anaphylactic shock; this condition should not – and usually cannot – be successfully treated by owners at home. At the veterinary clinic, after a taking a preliminary history from the cat’s owner while performing a perfunctory physical once-over, the medical team will start a number of emergency treatments – even before any advanced diagnostic testing is done. Rapid supportive and medical treatment is the main and perhaps only thing that can help most cats survive from this potentially devastating condition.
The anal sacs in cats, also referred to as “scent glands,” are basically pockets on either side of the anus, each of which is about the size of a pea. They are lined with glandular tissue that secretes a smelly discharge which contributes to territorial marking and is expressed during times of fear or anxiety. Anal sac disease occurs when one or both of the two anal glands become inflamed, infected, abscessed, blocked or impacted with fluids that normally are expressed when the cat defecates (or “poops”). This condition occurs rather frequently in both cats and dogs. However, cats tend to develop anal sac impactions, while dogs seem to be predisposed to developing anal sac infections or abscesses. Impaction occurs when anal sac secretions build up in and become dried, hard and pasty.
How Cats Get Anal Sac Disease
Normally, a cat’s anal sacs are emptied when it defecates (“poops”), as a simple result of pressure from fecal matter passing through the rectum and out the anus. Anal sac secretions are typically fairly thick, creamy-colored and very smelly, and they normally coat the cat’s stool. Anal sac problems can develop for a number of reasons. One of the most common causes of feline anal sac disorders is being fed a diet that is too low in fiber. A fiber-rich diet results in well-formed, voluminous stools, which tend to naturally express the anal glands when the cat has a bowel movement. Basically, firm feces squeeze the anal sacs and cause them to express their contents. A cat’s stool won’t be solid and well-formed if its diet doesn’t contain enough fiber. Obesity and lack of exercise can also contribute to impacted anal glands, as can chronic diarrhea and poor muscle tone.
Symptoms of Anal Sac Disease in Cats – What the Owner Sees
Owners of cats with anal sac problems will see a fairly consistent series of signs. Their cats will scoot, lick and bite at their rear end and take other steps to try and relieve the discomfort, pain and itchiness that is associated with this condition. Certainly, there are a number of things other than anal sac disorders that can cause cats to rub and lick at their rectal area, such as inhalant or food allergies, internal parasites like tapeworms, and tumors. Nonetheless, most cats empty their anal glands naturally whenever they have a bowel movement. They also normally express their anal glands during exercise. When the anal sacs are impacted, this normal emptying doesn’t occur. When the anal glands fail to empty, most cats will scoot their rear ends along the ground, which helps to squeeze and empty the anal sac secretions. If this is unsuccessful, affected cats tend to become increasingly uncomfortable. They start straining and excessively licking and biting at their anal area. If left untreated, cats with anal sac disorders may develop a rash around their anus due to self-trauma. Some cats chase their tails and/or undergo changes in temperament when their anal sacs are impacted. Cats that require constant manual anal gland emptying should be thoroughly assessed by a veterinarian to make sure that there is no underlying medical cause for this problem.
A definitive diagnosis of anal sac disorders is made when a veterinarian digitally palpates the cat’s anal sacs. The veterinarian will examine the area by gently placing a finger inside the cat’s rectum. If impaction is present, the veterinarian will feel small hard masses in the anal sacs. At this point, the veterinarian must apply a good amount of pressure to the anal sacs to express the plugged-up material, which usually is a thick, pasty, brown ribbon-like material. Anesthesia or heavy sedation is often necessary due to the pain associated with this procedure. If it appears that the anal sacs are infected, most veterinarians will send the expressed anal sac material to a laboratory for further examination, and also will put the cat on a course of broad spectrum oral antibiotics.
Goals of Treating Anal Sac Disease in Cats
The main goals of treating anal sac problems in companion cats are to empty any impactions in the anal sacs, control and resolve any infections, relieve the cat’s discomfort and assess whether the cat has any cancerous tumors or other masses that may be contributing to its symptoms. Anal sacs become impacted when the liquid secreted by their glandular lining stays inside the anal pockets for an inordinately long period of time and becomes dried, hard and pasty. This build-up of anal sac secretions blocks the outflow that usually accompanies each bowel movement.
Allergies, also called hypersensitivity reactions, occur when a cat’s immune system overreacts to something it comes into contact with in the environment. Allergies can affect the skin, stomach, intestinal lining and many other areas. Feline allergies may be mild or may cause extreme discomfort, agitation, depression and a predisposition to secondary bacterial infections. They can be difficult to diagnose, and even more difficult to treat. Unlike dogs and people, cats with allergies usually don’t get watery eyes and have bouts of sneezing. Instead, allergies tend to affect their skin.
Causes of Feline Allergies
Allergies are caused by something in the environment, called an “allergen,” that a cat’s immune system targets as being foreign. Common feline allergens are flea saliva, insect bites, parasites, pollen, dust mites, mold, grasses and certain ingredients in food. The best way to prevent allergies in cats is to keep them from coming into contact with the particular allergens that are causing them to have an allergic reaction.
Symptoms of Feline Allergies
The most common symptoms of feline allergies are skin irritation, itchiness, restlessness, agitation, depression, relentless grooming, ingested hair balls, hot spots, skin rashes, ear infections, coughing, vomiting, wheezing and diarrhea. The itchiness caused by allergies may be all over the cat’s body, or it may be localized around the ears, neck and groin. Hair loss is also common. Many cats with allergies develop crusty scabs and sores on their skin. Secondary bacterial and yeast skin infections often develop around these areas and cause additional inflammation, irritation and discomfort. Many of these symptoms are seasonal. Owners may notice that their cat’s allergies are worse during the Spring and Summer months. If food allergies are the culprit, the signs may be a bit different. Instead of skin problems, cats with food allergies often develop gastrointestinal symptoms that include vomiting, diarrhea and weight loss.
Diagnosing Allergies in Cats
Feline allergies are diagnosed by assessing the cat’s symptoms and medical history, together with evaluating the results of blood tests and response to treatment. A skin patch test can be performed to identify the specific allergens that are causing the cat’s symptoms. Cats with allergies have a very good prognosis. Once the offending allergens are identified and removed from the cat’s environment, the symptoms and irritations of allergies should decline dramatically.
Treating Feline Allergies
Fortunately, there are a number of ways to treat allergies in cats. The best way is to remove the offending allergens from the cat’s immediate environment. Prescription medications that suppress the immune system, and special shampoos, are also available to help with allergies. Most cats with allergies can be well-managed and lead a full, comfortable life.
Addison’s disease, medically called hypoadrenocorticisim, is a condition that occurs when one or both of a cat’s adrenal glands aren’t functioning properly and don’t produce enough of several essential adrenal hormones. Cats with Addison’s disease become weak and relatively inactive, especially when they are going through periods of stress. They develop stomach-aches, nausea, vomiting, diarrhea, weight loss, depression and other unpleasant symptoms, which typically come and go in waves. Some cats with Addison’s disease collapse without warning. Their levels of circulating electrolytes, such as glucose, potassium, sodium and chloride, become imbalanced, which can lead to dehydration and other severe problems. Owners who notice that their cat isn’t feeling well for no apparent reason should consult with a veterinarian. A simple blood test can confirm whether or not a kitty has Addison’s disease. Fortunately, this disorder is manageable through the use of hormone replacement therapy.
Symptoms of Addison’s Disease - What the Owner Sees
Cats with Addison’s disease may or may not show any observable signs of illness. When they do, their symptoms are notoriously non-specific and often come and go for no apparent reason. They can include:
Inactivity; lack of energy
Lack of appetite (inappetance, anorexia)
Vomiting (uncommon but can occur))
Increased thirst and consumption of water (polydipsia; uncommon but can occur)
Increased production and output of urine (polyuria; uncommon but can occur)
Sudden collapse (fairly common)
These vague symptoms can be caused by any number of things other than Addison’s disease. However, even though it isn’t common in cats, Addison’s should be on the list of differentials for a feline pal that just isn’t acting like its normal bouncy self. The good news is that feline Addison’s disease is fairly easy to diagnose by a series of simple blood tests. It also is relatively easy to treat, or at least to manage, by adrenal hormone replacement therapy.
Causes of Addison’s Disease in Cats
Addison’s disease is the common name for what medically is known as hypoadrenocorticism. It occurs when one or both of a cat’s paired adrenal glands, which sit just above each kidney, do not make and secrete enough essential adrenal hormones into the cat’s bloodstream. The adrenal glands primarily produce steroid hormones. Addison’s is uncommon in companion cats. When it does occur, it usually is caused by atrophy, or wasting, of the adrenal gland or glands due to something wrong with the cat’s immune system. In other words, something stimulates the cat’s immune system to start attacking its own tissues. Why this happens is still a medical mystery. Some authorities suggest that overdoses of corticosteroid drugs, cancer (neoplasia), physical trauma to the pituitary gland, mineralization of the pituitary gland, abnormal internal bleeding (hemorrhage), infection and/or granulomatous disease all may contribute to feline Addison’s disease. Granulomatous diseases are those that involve the formation of granulomas, which are actively growing tumor-like masses or nodules that develop when wounded tissue is healing.
Diagnosing Addison’s Disease in Cats
After taking a history and performing a physical examination, most veterinarians presented with a kitty that “just ain’t doing right” will recommend taking a blood sample and submitting it for routine blood work, which is referred to as a complete blood count (CBC) and serum chemistry profile (chem panel). They probably will also recommend taking a urine sample and performing a urinalysis. Routine blood and urine test results can show a great deal about the function of a cat’s vital organs, but typically will not be completely diagnostic of Addison’s disease. Based on the results of those tests, the veterinarian may suggest chest X-rays (radiographs), an abdominal ultrasound and/or other tests. The most reliable way to diagnose Addison’s disease is by conducting an ACTH stimulation test. This involves taking an initial blood sample and having a laboratory assess the levels of a hormone called cortisol in the cat’s blood. Then, a different hormone that normally is made by the pituitary gland, called ACTH, is administered to the cat by intravenous or intramuscular injection (by “giving the cat a shot”). Finally, the vet will take 2 more blood samples, approximately 30 and 60 minutes after giving the ACTH injection. The lab will evaluate those samples for the levels of post-ACTH-administration cortisol in the cat’s blood. Cats with Addison’s disease will have little if any increase in their circulating blood cortisol levels, while cats that don’t have Addison’s disease should have significantly elevated cortisol levels.
How aggressively a veterinarian and owner will treat cats with Addison’s disease will depend in large part on the individual cat’s clinical status. Acute Addisonian episodes are true medical emergencies and require immediate veterinary intervention, even before diagnosis of the disease is confirmed. Waiting for a definitive diagnosis may result in death. Emergency treatment includes placing the cat on intravenous fluids (usually normal saline) and giving injections of corticosteroids. While dogs often show marked improvement within 24 hours of treatment, cats tend to have a much slower response to therapy and may remain weak and listless for 3 to 5 days or more, despite appropriate stabilization and treatment. ACTH stimulation testing should then be done. This involves a simple series of blood tests and injection of a hormone that normally stimulates production of adrenal hormones. Cats with Addison’s disease won’t respond normally to injection of ACTH. Once the cat’s fluid levels are restored and its hormone levels are stabilized, and after it has recovered from any other adverse effects of the disease, the owner can take their kitty home. Long-term treatment of Addison’s disease typically involves life-long oral supplementation with adrenal corticosteroid hormones, the choice of which will be made by a veterinarian based upon whether the cat’s disease is primary or secondary. Addison’s patients should have regular urine and blood tests to monitor the level of adrenal hormones and other substances circulating in their blood. If elevated potassium levels persist, the cat may need additional drug therapy.
Prognosis and Outcome for Cat’s with Addison’s Disease
The prognosis for cats with Addison’s is excellent, as long as their owners are conscientious about daily treatments and take them to the veterinarian for regular periodic monitoring. Good communication between owners and their veterinarians is essential to successful treatment of this uncommon feline disease.
Dogs, like other carnivores, have a pair of small sacs on either side of their anus (commonly called the “butt hole”), which is the end of the digestive tract. These anal glands produce a smelly, yellowish-gray to brownish pasty material, which normally is expelled when a dog poops or when it is startled or frightened. This is often attributed to territorial marking. The actual cause of anal sac problems is not well-understood. Anal sac “disease” happens when the sacs become inflamed, impacted, infected, irritated, abscessed or affected by tumors. Dogs with anal sac problems can’t properly eliminate the fragrant material that their glands normally produce. This causes lots of itchiness, pain and general discomfort. Unfortunately, anal sac problems are fairly common in domestic dogs.
Causes of Canine Anal Sac Disease
The underlying causes of anal sac problems are not fully understood. Several predisposing factors have been suggested, including obesity, bouts of diarrhea, poor muscle tone around the anus, chronically soft feces and excessive or retained anal glandular secretions. Normally, the paired anal sacs act as reservoirs for secretions from the glandular tissue that lines them. Changes in the amount or character of those secretions, or changes in muscle tone or the consistency of a dog’s stool, can plug the anal sacs and cause them to overfill, sometimes to the point of rupturing. This causes pressure, inflammation and irritation. It also promotes abnormal overgrowth of bacteria that normally are present inside the sacs, which in turn increases the chances of infection, impaction and formation of pus-filled abscesses. Both benign and malignant tumors of the anal sacs can also occur, causing symptoms similar if not identical to those caused by more temporary and treatable problems. Why tumors develop in the area around the anus (the “perianal” area) is not known, but they are fairly common in domestic dogs.
Prevention of Anal Sac Disease
One of the best ways to prevent anal sac disease is to feed dogs a high quality diet that is low in saturated fats and has enough indigestible dietary fiber to reduce the frequency of loose or sloppy stools and increase fecal bulk. Anal sac secretions can’t be evacuated naturally unless there is a sufficient amount of firm, formed feces passing through a dog’s rectum. Obese or overweight dogs should be put on a weight loss regimen, because excess weight has been associated with anal sac problems. Routine manual expression of the anal sacs by veterinarians, veterinary technicians, groomers or owners should not be necessary in normal dogs. In fact, chronic manipulation of the anal sacs can damage their sensitive tissues and increase the risk of more serious problems. However, in certain situations, it may become necessary to manually express a dog’s anal glands. Good routine hygiene can help prevent the accumulation of bacteria and other infectious microorganisms around the anal area. Unfortunately, given the current state of medical knowledge, there is no way to prevent perianal tumors. Research into the causes and treatment of cancer remains in the forefront of both human and veterinary medicine. A veterinarian is the best person to assess a particular dog’s anal sac health and discuss appropriate management protocols with its owner.
Anal sac problems are fairly common in domestic dogs. Fortunately, they are not particularly difficult to diagnose. Owners usually bring their affected dogs to the veterinary clinic because they have been licking at their rear end and scooting their butts across the floor. They may also complain about a nasty smell coming from their dog’s rear and bad breath. The veterinarian will take a history from the owner about the dog’s general health, including when the current symptoms showed up and whether they have gotten worse or stayed about the same over time. The veterinarian will also perform a thorough physical examination. She will inspect the anal area visually and digitally (by hand). The digital rectal examination involves inserting a finger into the dog’s anus and physically expressing, or squeezing out, the contents of both anal sacs for further evaluation. This procedure can be painful, depending on the severity of the dog’s condition. Sedation or general anesthesia may be needed to complete the rectal examination. Normal anal sac secretions are clear to pale yellowish or grayish brown. Impacted anal sacs become plugged with a thick, pasty material; inflamed sacs often contain a creamy yellow or thin greenish secretion. Abscessed anal sacs typically discharge a reddish-brown material containing pus and blood, accompanied by a fever and obvious swelling and redness around the anal area. The veterinarian’s initial evaluation of the perianal area and the anal sac secretions will give her a good idea about the dog’s condition.
Most veterinarians will draw blood and urine samples. The results of routine blood work (a complete blood count and serum chemistry panel) and a urinalysis are usually normal in dogs with anal sac disorders, unless the sacs are infected. Some dogs will anal sac tumors will have elevated blood levels of parathyroid hormone-related protein and calcium. The veterinarian may recommend radiographs (X-rays) of the chest and pelvis, and possibly an abdominal ultrasound, to look for evidence of metastasis (spread of cancerous cells), especially to the lymph nodes. Samples of the anal sac contents will be examined microscopically through a process called “cytology.” Anal saccular secretions can be cultured to look for infectious microorganisms. However, culture results can be difficult to interpret, due to the normal presence of a so many different bacteria (“normal flora”) in that region. If a mass is found, it can be sampled by a fine needle aspirate or, more diagnostically, by a tissue biopsy. The sample will be sent to a laboratory for detailed evaluation, to confirm or rule out cancer.
Most anal sac disorders in companion dogs are not especially serious and are not hard to diagnose, especially since the area involved is so isolated and accessible. Nonetheless, it is important for owners to take these problems seriously and to seek veterinary assessment and advice when they notice that something is amiss in their dog’s perianal region.
Effects of Anal Sac Disease – From the Dog’s Point of View
Canine anal sac disorders are relatively common. The anal sacs are paired structures located on either side of a dog’s anus (the terminal end of the digestive tract through which feces is expelled). Normally, the anal sacs secrete a very smelly substance when a dog defecates, which probably acts as a form of territorial marking. When these sacs become irritated, inflamed, impacted or infected – which can occur for a number of reasons – their contents can’t drain normally, although the glandular tissue lining the sacs continue to produce the substance. The discomfort, itchiness and pain suffered by dogs with impacted anal glands can range from quite mild to extremely severe. Affected animals will be uncomfortable, at best.
Symptoms of Anal Sac Disease – What the Owner Sees
Dogs with anal sac disorders usually show signs of physical discomfort in the area around their anus, called the “perianal” or “perineal” region. The region may be swollen and red, both of which are recognized signs of inflammation and irritation. Blood and/or pus may be seen on the dog’s feces or on the skin and hair around its anus; this is more common in long-haired breeds and when an anal sac abscess has ruptured. Owners may notice one or more of the following signs if something is wrong with their dogs’ anal sacs:
Licking and biting at the perianal area (can be intermittent or relentless)
Straining to defecate (tenesmus)
Scooting the rear end along the floor, grass or ground in a sitting position
Reluctance to sit still
Fresh blood on fecal material
Pus on fecal material (pus is a protein-rich inflammatory byproduct made of cells (leukocytes), a thin liquid (liquor puris) and cellular debris; it usually is a sign of bacterial infection)
Visible swelling and redness around the anus
Open, weeping wounds adjacent to the anus, with or without the presence of pus or blood
Foul odor coming from the anal area
Bad breath (halitosis; from licking the rear end)
Fever, if infection is present
If a dog has anal sac tumors, its owner may (or may not) notice a visible mass or bulge near the dog’s anus.
Dogs at Increased Risk
Small breed dogs develop anal sac disorders more commonly than do larger breeds – particularly Miniature Poodles, Toy Poodles and Chihuahuas. Long-haired dogs and fat animals are at a higher risk, as well. Older female dogs are particularly predisposed to developing anal sac tumors, which may or may not be malignant or even visible to the naked eye. Dogs suffering from chronic diarrhea, soft feces and/or poor rectal muscle tone, regardless of the cause of those conditions, are predisposed to anal sac disease, as well.
When an owner suspects that his dog may have something unusual going on in the area around its anus, he should take his pet to a veterinarian as soon as possible. In most cases, an anal sac problem is not an emergency. However, if ignored, the condition can quickly get worse and become increasingly difficult to treat. The goals of treating anal sac disease are to relieve the dog’s discomfort and pain, unplug and empty impacted sacs, reduce inflammation, eliminate associated infections, heal abscessed areas and remove identifiable tumors.
The first and most urgent treatment for a dog with impacted anal sacs is to manually – and very gently - express the contents of the sacs. This should be done by a veterinarian or by a skilled veterinary technician. In cases that recur frequently, the dog’s owner can be taught how to perform this procedure at home. However, most owners find the process offensively smelly and unpleasant and prefer that somebody else handle it outside of their presence. If an infection is present, the veterinarian will flush the anal sacs with sterile saline or another appropriate substance and apply an antibiotic or antibiotic-and-steroid medication directly into the affected areas. It is almost always necessary to use heavy sedation, and sometimes general anesthesia, for those procedures. Anal sac abscesses often rupture. They are treated the same way, using saline, antibiotics and topical steroid treatments. If an abscess is present but has not yet ruptured, hot packs can be applied to the area several times a day, to help bring the abscess to a head. The veterinarian can then lance the abscess to establish a route for drainage, which will greatly reduce the dog’s discomfort. A full course of broad spectrum oral antibiotics are often recommended for dogs with anal sac disease. Some dogs have chronic recurrent anal sac problems. In those dogs, long-term treatment includes managing the dog’s weight, increasing the amount of insoluble fiber in its diet and making sure that it gets an adequate amount of physical exercise. In severe cases, the anal sacs can be removed surgically by a procedure called an “anal sacculectomy.” Identified tumors can also be surgically removed, if necessary.
With appropriate treatment, the outlook for dogs with non-malignant anal sac disease is good. Most dogs respond well to non-surgical medical management of the condition. When the anal sacs are surgically removed, because of cancer or for some other reason, the prognosis becomes more guarded. Dogs may develop fecal incontinence after an anal sacculectomy, or if a lot of scar tissue has built up from recurrent problems. If no treatment is undertaken, the prognosis for a return to normalcy is guarded to grave.
“Black skin disease,” also called Alopecia X, growth-hormone-responsive alopecia and adrenal sex-hormone imbalance, is a hormonally-influenced, progressive loss of hair and darkening of skin in adolescent and young adult dogs. It’s a form of patterned baldness, meaning that affected animals lose hair evenly on both sides of their body. Outer guard hairs usually fall out first, revealing an increasingly dry, “cottony” undercoat. It then falls out symmetrically, and the balding skin darkens. In extreme cases, fur is left only on the dog’s head and paws. Little is known about what causes black skin disease. Obesity, hormonal imbalances, allergies and genetics have all been suggested as contributors. Black skin disease may be a combination of several different disorders, making diagnosis and treatment that much more difficult. Fortunately, it doesn’t seem to be itchy, painful or otherwise affect a dog’s health. Black skin disease is mostly a cosmetic issue for owners.
Causes of Black Skin Disease in Dogs
Little is known about this condition or its cause. Factors such as obesity, hormonal imbalances, allergies and genetics have all been suggested as contributors. One theory is that affected dogs have a genetic predisposition to some sort of hormonal imbalance, which somehow affects the function of cells at the level of the hair follicle. Another hypothesis is that there is some inherited defect in the normal hair growth cycle. It may be that Alopecia X is not a single disease at all but rather a combination of several, making diagnosis and treatment that much more difficult.
Preventing Black Skin Disease
Preventing Alopecia X is not realistic at this time, because the cause of the condition is so poorly understood. Certainly, weight management can remove obesity as a contributing factor. Because stress seems to exacerbate the signs of Alopecia X, owners should do their best to remove stressors from their dogs’ environment. Castration or spaying, dietary management and other hormonal or environmental management protocols may help to relieve the effects of stress and thereby reduce the hair loss and pigmentation changes associated with this disorder.
Alopecia X does not appear to affect a dog’s health. It seems to be a purely cosmetic issue for owners of affected animals, and benign neglect is often the recommended “treatment” of choice. Other conditions can be confused with Alopecia X. Currently, there are no medical tests to definitively diagnose this disorder. A veterinarian must rule out a number of other problems, particularly hypothyroidism and hyperadrenocorticism (Cushing’s disease), before concluding that Alopecia X is the cause of symmetrical baldness. This is called making a diagnosis by exclusion.
Alopecia X, sometimes called black skin disease, is difficult to diagnose. Many other conditions can be confused with Alopecia X, and currently there is no medical test that can definitively diagnose this condition.
Faced with a dog whose hair is thinning gradually and symmetrically, a veterinarian will want to perform a thorough physical examination and take a detailed history from the owner. Because this condition can mimic so many others, diagnosis can only be made by ruling out other possible causes – called diagnosis by exclusion. Some disorders that can look like Alopecia X include hypothyroidism, hyperadrenocorticism (Cushing’s disease), functional tumors of the gonads, infection and/or inflammatory disease of the sebaceous glands (sebaceous adenitis) and other forms of hair follicle dysplasia.
Veterinarians can take a skin biopsy and submit it to a pathology laboratory for analysis. In cases of Alopecia X, the results of this test typically are non-specific and provide little assistance in development of a treatment protocol.
Alopecia X is a cosmetic condition that does not appear to adversely affect a dog’s health in any way, other than possibly creating an increased chance of sunburn damage to the exposed areas. Most dogs characteristically retain hair on their heads and legs. Re-growth of hair is highly variable and difficult to predict.
Symptoms of Black Skin Disease
“Black skin disease” is a phrase used to refer to a form of hair loss (alopecia) in dogs that seems to be caused or at least influenced by hormonal imbalances. The term more commonly used by veterinarians and breeders for this condition is Alopecia X. Affected dogs typically have normal hair coats as puppies. They begin to develop signs of hair loss and hyperpigmentation (darkened skin) in adolescence to early adulthood, usually by three years of age, although signs may appear at any time. Dogs with this disorder lose their long, outer “guard” hairs first. Most cases start with gradual thinning of hair on the back of the hind legs and along the top of the back. Hair loss also occurs commonly under the tail, on the belly and around the genitals. The soft, fuzzy secondary coat becomes exposed. This is referred to as a “puppy coat” and suggests why Alopecia X is sometimes referred to as “wooly coat syndrome.” Over time, even the puppy-coat falls out, leaving the skin bald. The hairless areas tend to spread but normally are not itchy, painful or prone to infection. Darkening of the skin generally follows the hair loss. Some dogs never re-grow their coats; if they do, the hyperpigmented skin usually peels away, exposing fairly normal-looking skin underneath.
Alopecia X is a progressive condition that typically follows a reliable course. This includes:
Gradual loss of color and lushness of the coat (presumably from a loss of melatonin)
Gradual and symmetrical loss of outer guard hairs
Increasingly dry, “cottony” undercoat
Hyperpigmentation of the skin
In extreme cases, hair loss can progress until fur is only present on the dog’s head and paws. Normally, the skin discoloration follows the hair loss in patches beginning along the back and hind legs, but in some cases the skin darkens more broadly. The darkening may appear as small flecks of black skin, or the skin may become solid black. Some dogs will re-grow their coat partially or temporarily. No generalized signs of illness are associated with Alopecia X. If your dog has hair loss and also shows changes in appetite or thirst (increased or decreased eating or drinking), acts depressed or shows other signs of systemic illness, there probably is another underlying cause of the alopecia.
Dogs At Increased Risk
Alopecia X has been diagnosed in dogs of all ages and breeds, regardless of their spay/neuter status. However, it seems to occur in males and in certain breeds more frequently than others. Nordic breeds are overrepresented, including the Pomeranian, Chow Chow, Alaskan Malamute, Siberian Husky and Elkhound, among others. Toy and Miniature Poodles are also overrepresented. All coat colors seem to be equally affected.
Alopecia X is a form of symmetrical pattern baldness and skin hyperpigmentation seen primarily in Nordic breeds and Toy or Miniature Poodles. While it is purely a cosmetic condition, many owners find it unpleasant to have a progressively balding pet. Treatment protocols for Alopecia X are at best a trial and error approach, since the underlying cause of this disorder is not known. The overall therapeutic goal is to restore the dog’s coat and, hopefully, prevent recurrence of hair loss.
Most hormone-based hair losses look alike. Before treating a dog suspected to have Alopecia X, a veterinarian will try to rule out diseases that mimic Alopecia X, especially Cushing’s disease and hypothyroidism. If Alopecia X is caused by hormonal imbalances as is suspected, then hormone therapies can be helpful. The first step in treatment is to spay or neuter intact dogs. There are many health and behavioral benefits to sterilization in addition to helping manage the symptoms of Alopecia X. Many dogs will re-grow most if not all of their coat after they are spayed or neutered because of the hormonal changes associated with those procedures. Unfortunately, hair re-growth is not always permanent.
If the affected dog has been neutered or spayed and several months pass without its coat returning, the veterinarian may recommend oral melatonin therapy as the next treatment step. Melatonin is a nutritional supplement; it is not regulated by the Federal Drug Administration, and there can be significant differences in the amount or quality of melatonin found in different brands. Melatonin is readily available over-the-counter in tablet form at health food stores and vitamin retail outlets, as well as at some supermarkets. Current research suggests that melatonin should be given to dogs with Alopecia X orally for at least two or three months. About 50% of dogs reportedly show improvement in hair growth within 6-8 weeks. Once hair growth has stabilized, if it does, the dose of melatonin typically is gradually tapered to a once-a-week dose. It is possible that the treatment can eventually be discontinued, although hair loss may recur. A veterinarian is the best person to recommend any treatment option, including the appropriate dose of melatonin for an affected dog. Please note that melatonin can cause drowsiness and sedation in dogs and in people. It also can affect diabetes, which underscores the importance of having a veterinarian rule out all other diseases that may be causing the dog’s hair loss before classifying the cause as Alopecia X.
If alteration and melatonin do not help, there are some other treatment options to consider. These carry additional potentially adverse side effects and should be discussed with a veterinarian so that the possible benefits of improved cosmetic appearance can be weighed against the possible risks of treatment.
Methyltestosterone therapy (one form of hormone therapy) is often the next treatment option. Testosterone therapy should only be implemented after baseline blood testing, and periodic blood work should be done to monitor levels of this hormone if it is given, as it can be toxic to the liver. This treatment can also cause increased aggression in dogs.
Lysodren, also called mitotane or OP’ddd, is another possible treatment. Lysodren is most often used to treat Cushing’s disease (hyperadrenocorticism). Lysodren acts by eroding the outer layers of the adrenal gland, thereby limiting the amount of adrenal hormones made and distributed throughout the body. Lysodren can be helpful in cases of Alopecia X, because the adrenal gland also is responsible for producing sex hormones. Dogs with Alopecia X do not have Cushing’s disease, and they do not have an overabundance of corticosteroids. Lysodren can cause abnormally low circulating corticosteroid levels, creating a steroid deficiency known as “Addison’s disease,” or hypoadrenocorticism. Dogs treated with Lysodren should have regular blood tests to monitor their hormone levels.
Another option involves giving injections of growth hormone, as some authors suggest that Alopecia X may be caused by a deficiency of this hormone. Growth hormone is a genetically engineered product which is difficult to come by commercially but may be available through veterinary or other academic teaching laboratories and institutions. Administration of growth hormone can contribute to diabetes, so the dog’s blood sugar levels must be carefully monitored if this treatment approach is used. Reports suggest that a 6-month course of growth hormone therapy may produce good results for several years in dogs with Alopecia X.
Other treatments that have been tried include administration of prednisone, anipryl, ketoconazole, leuprolide, cimetidine and other medications. Essentially, each of the above treatments is an attempt to re-start the hair follicle growth cycle. Obviously, since the exact cause of Alopecia X is unknown, there is no one treatment approach that will work for every affected dog. In cases where the hair loss is mild, shampoos which contain soothing ingredients can help calm the symptoms. Again, owners should consult with a veterinarian about which, if any, treatment protocols are best in any given case.
Very often, the best treatment for Alopecia X is no treatment at all – which in medical jargon is called “benign neglect”. While the condition may be unsightly, if it is not harming or bothering the dog, then no treatment is medically necessary. Many dogs with Alopecia X live long, happy lives completely unaffected by their hair loss. They develop their own special look, and are adored by their owners for their uniqueness.
Hair loss, technically called “alopecia,” is broadly defined as any deficiency in a dog’s normal hair coat. Alopecia doesn’t refer only to hair loss; it also includes coat defects from failure of hair to grow in the first place. Many medical conditions involve hair loss, including color dilution alopecia, seasonal flank alopecia, alopecia X (“black skin disease”), acanthosis nigricans, follicular dysplasia, congenital hypotrichosis, pattern baldness and pituitary dwarfism. Some have a genetic component. External parasites, fungal and bacterial skin infections, certain drugs, hormonal/endocrine imbalances such as Cushing’s Disease, Addison’s Disease, hypothyroidism, hyperthyroidism, allergies, stress, poor nutrition, lactation and cancer can all cause hair loss, with or without redness, itchiness, scabbing, scaling or bleeding. Because hair loss typically is associated with an underlying medical disorder, annual veterinary examinations can help identify and manage the problem before it becomes out of hand. These tests are especially important for older dogs.
Causes of Canine Alopecia
There is no particular age or sex predisposition to the development of alopecia, although certain dog breeds do seem at increased risk for certain kinds of alopecia. Doberman pinschers and many other breeds are prone to developing color dilution alopecia. Recurrent seasonal flank alopecia tends to occur in Boxers, Bulldogs, and Airedale terriers. Alopecia X (also called adrenal reproductive hormone imbalance and sometimes called “black skin disease”) occurs more commonly in plush-coated breeds such as the Pomeranian, Chow chow, Keeshond, and Miniature poodle, and also in Arctic breeds (Samoyed, Siberian husky, Alaskan malamute).
Some of the more common causes of alopecia in dogs are described below.
External parasites are notorious for causing alopecia in dogs. Fleas, ticks, lice and mites can all cause intense itching and scratching which leads to hair loss. Parasites can also physically damage the hair follicles, and allergic reactions to the parasites can cause hair loss as well. Demodectic mange (caused by various species of mites that live within the hair follicles) causes localized to generalized hair loss with redness and mild scaling.
Fungal infections of the skin (called “dermatophytosis”) can cause partial to complete alopecia with scaling and with or without associated redness. Some fungal infections are zoonotic, which means that they have the potential to cause skin lesions in people.
Bacterial skin infections – especially those caused by Staphylococcal species – can cause alopecia with redness, crusting and circular patterns of hair loss. Bacterial folliculitis is the most common cause of multifocal alopecia in dogs.
Several different endocrine disorders commonly contribute to alopecia. Hyperadrenocorticism (Cushing’s disease, or iatrogenic hyperadrenocorticism caused by veterinary corticosteroid administration), hypoadrenocorticism (Addison’s disease), hypothyroidism, hyperthyroidism, hyperestrogenism (in females) and hypoandrogenism can all result in some form of alopecia if the underlying condition is not controlled. Many dogs have focal hair loss around the genital and flank regions following spay or neuter procedures. Testicular neoplasia (cancer) can also cause hormonally-based alopecia.
Immune-mediated reactions to certain foods, chemicals, pollens, grasses and many other potential allergens are among the most common causes of hair loss in dogs.
Some types of alopecia have a genetic basis. These include: acanthosis nigricans, Alopecia X (also called adrenal reproductive hormone imbalance and sometimes simply “black skin disease”), follicular dysplasia, color dilution mutant alopecia, congenital hypotrichosis, pattern baldness and pituitary dwarfism, among others.
Reactions to Medication or Injections
Drug reactions can lead to hair loss. For example, chemotherapeutic treatments for cancer commonly cause alopecia. Hair loss often occurs at injection sites, usually caused by an inflammatory reaction to the substance that was injected. Rabies vaccines have been known to cause patchy hair loss around the injection site 2 to 3 months after being given.
Stress and Nutritional Deficiencies
Nutritional deficiencies and other causes of stress can cause alopecia. Bitches that are nursing puppies often “blow their coat” – a type of alopecia probably caused by the nutritional, physical. and emotional strain associated with whelping and lactation. Dogs that are especially anxious or high-strung, have psychological or behavioral disorders (separation anxiety, etc.), or who have abusive backgrounds may also lose hair as a result of stress.
Certain breeds or family lines of dogs have an increased risk of developing alopecia. For example, small-breed dogs with plush coats and certain Arctic breeds are prone to developing Alopecia X, also known as adrenal reproductive hormone imbalance or black skin disease. Doberman pinschers are genetically predisposed to color dilution alopecia. Responsible breeders will eliminate affected dogs from their breeding programs.
Many cases of alopecia in dogs are caused by external parasites. Using preventative parasite control will reduce or eliminate parasitic infestation and the alopecia that often accompanies it. Owners of dogs that live in (or frequently visit) areas infested with fleas and ticks should regularly use flea and tick repellents, even if their dogs have not yet become infected by those parasites. Maintaining a clean and hygienic environment will also reduce the risk of alopecia associated with fleas, ticks, lice and mites.
Hair Loss Due to Underlying Medical Conditions
Alopecia is often caused by an underlying medical condition. Annual veterinary examinations with regular blood and urine tests will help identify underlying endocrine, hormonal, immune-mediated or other medical conditions that can cause or contribute to alopecia. These tests are especially important for older dogs. Spaying and neutering of companion animals can also greatly reduce the risk of alopecia.
Nutrition and Other Prevention
Hair loss cannot always be prevented, nor can it always be “cured.” However, providing a safe, clean, stress-free environment and a high-quality diet with free access to fresh water will go a long way to helping companion animals maintain a healthy hair coat.
How Alopecia Affects Dogs
Alopecia is one of the more common complaints of dog owners. How alopecia affects a dog depends upon the underlying cause of the condition. Hair loss (or failure to grow) can occur anywhere on the body of a dog of any age, breed or gender, including on the face, around the eyes, on the back, near the base of the tail or on the flank. The hair abnormality may occur on its own without any apparent cause or other clinical signs. Alternatively, the absence of hair may be accompanied by scratching, redness, pustules or other skin changes. Alopecia can appear symmetrically in discrete but well distributed patches, or it can have no pattern at all.
Symptoms of Alopecia
One of the most baffling things about alopecia is the vast number of ways that it can present. It can occur acutely or be slowly progressive. It can happen in isolation or with localized or generalized hair loss but no other clinical signs. The skin may appear normal, and the dog may act completely normal as well. Some cases of alopecia never progress. The affected dog simply loses hair, and the hair does not grow back. In other cases, hair loss may spread across the body and become generalized, or it may become patchy.
Symptoms In Addition to Hair Loss
When hair loss is accompanied by other clinical signs, owners usually notice itching, scratching, chewing and changes to the appearance or condition of the skin itself. The skin in areas of hair loss can become red, irritated and inflamed, or it can darken. In many cases, the affected skin becomes crusty, thickened, and raised. It can also become thinner. Sometimes, the skin becomes oily and greasy, and pustules or other skin lesions can develop. In severe cases, dogs can develop blisters, weeping sores and hot spots, which are prone to developing secondary bacterial infections.
Which clinical signs a particular dog develops depends upon the underlying cause of the alopecia. The specific signs are important to help the veterinarian establish a correct diagnosis.
Alopecia is usually a sign of an underlying disorder, which must be diagnosed accurately in order for effective treatment to begin. If the hair loss is accompanied by scratching, pustules, hot spots or other lesions, it may be appropriate to apply topical medications to manage and hopefully alleviate the discomfort caused by these conditions even before the actual cause of the alopecia is determined. The veterinarian may prescribe ointments, creams, lotions, shampoos or other soothing treatments to calm any inflammation associated with alopecia. She also may recommend oral or topical antibiotics, antihistamines and/or anti-inflammatories as part of an initial treatment regimen.
There are a number of topical medications to treat alopecia caused by external parasites. Flea and tick control, and shampoos or other products that kill mites, lice or fungi, are generally quite effective in resolving parasitic alopecia, although it can take weeks to months for the hair to grow back completely.
Alopecia Due to Endocrine Disorders or Hormonal Imbalance
Alopecia caused by endocrine or hormonal abnormalities is managed by treating the underlying disorders. For example, alopecia associated with hyperthyroidism or pituitary dwarfism can be treated with lifelong hormone replacement medication. Spaying and neutering can be successful treatments for hair loss caused by certain other hormonal imbalances, or even stress.
There are a number of treatment options for alopecia caused by immune-mediated reactions. These include medicated shampoos, topical and oral anti-inflammatories and antihistamines, and corticosteroid therapy. Of course, if a veterinarian can identify the cause of the reaction and remove the allergen from the dog’s environment, allergic alopecia should resolve in short order.
Essential fatty-acids, Vitamin D, and oral melatonin supplementation have been found to be safe and variably effective in stimulating hair regrowth and improving overall coat condition in dogs.
The prognosis for recovery from alopecia is good in most cases, if the underlying cause of hair loss is identified and treated. If the skin has suffered extensive scarring, hair regrowth will be more limited.