Skin Problems in Cats
By Jessica Vogelsang, DVM
Skin problems are one of the most common reasons cats are brought to the veterinarian. Itchy skin, compulsive chewing and hair loss are just some of the ways cats react when their skin is inflamed. Here are seven of the most common skin problems diagnosed in felines:
Like many warm-blooded mammals, cats are susceptible to the itchy bite of the common flea. In addition to being a pesky nuisance for cats and people, fleas are a transmission vector for other parasites such as tapeworms.
While most cats respond to a flea bite by itching and scratching, some cats can exhibit a hypersensitivity reaction to flea saliva and have extreme itching from as little as one bite. A wide array of topical, oral, and environmental products exist to kill fleas. It’s important to remember that for every flea you spot on your cat, another nine are out in the environment, so it’s vital to treat furniture, bedding and carpeting in order to combat a flea infestation.
Ear mites, also known by their scientific name Otodectes cynotis, are one of the most skin-crawling parasites of the feline world (pun intended). Although most commonly seen in young cats (where they are infected from their parent), ear mites can be found in cats of any age.
Cats infected with ear mites may show only mild symptoms of ear canal irritation, though many cats appear extremely itchy, pawing and scratching at their ears and shaking their head until they burst blood vessels and form a hematoma in their pinna. The ear canals are filled with a thick, reddish or black crusty discharge.
Ear mites are readily diagnosed at the veterinarian by examining the crusty discharge under a microscope and checking for the mites. Topical treatments and ear drops resolve the infection, but because ear mites are very contagious to other cats all felines in the household should be treated at the same time even if only one cat appears symptomatic.
Ringworm, also known as dermatophytosis, is a fungal infection very common in cats. Ringworm fungus infects the superficial layers of the skin and nails. The most common species of ringworm fungus, Microsporum canis, is zoonotic, meaning it can be transmitted between cats, dogs and people.
Unlike the easily-spotted raised red circle seen in people with ringworm, the lesions may be more difficult to detect in cats. The skin may appear scaly and have round thickened patches of skin with hair loss. Patchy hair loss on the body is also common. The lesions are most commonly seen on the head, chest, along the back and on the forelegs. The lesions are not usually itchy.
Ringworm can be diagnosed by identifying the fungus through a culture sent to the lab, or sometimes can be found using a special ultraviolet lamp at the veterinary clinic. Ringworm is treated with a combination of topical antifungal shampoos and oral antifungal agents; treating the environment including furniture, bedding, combs and bowls is important because the fungal spores can remain dormant in the environment for months.
Environmental allergies, or atopy, is more common in the cat than you may realize. Like us, cats can develop an allergy to just about any environmental allergen such as dust, mold, grass, pollen or even other animals. Affected cats rub at their face, scratch their ears and armpits, and may over-groom themselves, resulting in a patchy appearance as they chew off their fur.
A full exam is necessary because atopy presents very similarly to food allergies and other skin conditions in the cat. Your veterinarian may recommend allergy testing if he or she suspects atopy. While atopy can be managed with oral medications, injections and avoidance of the allergen, it is considered a lifelong, chronic condition.
Pyoderma, or a bacterial infection of the skin, is a very common secondary condition in cats. A cat who is itching and grooming due to parasites, fungus or allergies can cause trauma to the skin, which allows the bacteria in the environment to take over and create a secondary infection.
In addition to causing itchiness, pyoderma can appear as hair loss, peeling layers of skin, small pustules, or spreading reddened lesions. Once pyoderma is diagnosed by the veterinarian, antibiotics will treat the bacterial infection. If the underlying cause of the itchiness is not addressed, the infection may recur.
Food allergies are the third most common form of allergic disease in the cat, trailing atopy and flea allergies. Food allergies can develop at any age and can occur in response to any food product, but the most common offenders are beef, dairy, and seafood.
While the clinical signs of itchiness mimic that of the other types of allergies, cats with food allergy are itchiest on their head and neck. A small number, 10 to 15 percent, may also have GI signs such as vomiting or diarrhea. Many cats also have secondary bacterial infections which must be treated with antibiotics.
While history and clinical signs may point in the direction of food allergy, putting your cat on a strict hypoallergenic elimination diet for eight to ten weeks is the only way to definitively diagnose a food allergy. Once the allergy is confirmed and the specific allergen pinpointed by introducing proteins one at a time, the cat can transition to a diet that does not include the offending item.
Much like a hormonal pre-teen, cats can develop blackheads on their chin. These blackheads, also called comedones, accumulate on the chin of affected cats for reasons we don’t fully understand. It occurs in all breeds and ages of cat, and affects males and females in equal proportions. The comedones can be asymptomatic or can cause itching and hair loss in the affected regions.
Your veterinarian may do a skin scraping of the area to rule out other problems such as mites. Treatment involves clipping the hair and cleaning the area with a follicle-flushing shampoo containing benzoyl peroxide; in cases with secondary bacterial infection, antibiotics may be indicated.
Cats are notorious for hiding their symptoms of discomfort and many medical conditions cause the exact same physical symptoms. If your cat is itchy, experiencing hair loss, or has any unusual lesions on her skin, get her checked out by the vet. With appropriate treatment, she’ll be feeling better in no time.
Think your cat might have something? Here are some more signs to help determine if your cat is sick.