Itchy Skin: Searching for the Cause
Causes for itchy skin include external parasites such as fleas and mites, allergies, and bacterial infections. (Please refer to the section on fleas for a full description of control methods and flea related conditions on your pet). Other less common external parasites include mites and lice. These are best diagnosed by your veterinarian. A skin scraping must be analyzed to identify and treat these pests effectively. Please notify your veterinarian if you have any itchy rash-like lesions as some of these parasites may bite humans as well.
The most common skin allergies seen in our area are caused by fleas, food, or inhalant sources. Flea allergy is discussed in the section on fleas. Food allergies usually manifest as itchy skin that is not seasonal (appears all year) and may flare up with diet changes or treats. In cats, it may show as vomiting as well. The skin lesions vary in their severity, and are generally widespread over the entire body although there are exceptions to this. Inhalant allergies may also show symptoms of widespread itchy skin and may be accompanied by runny red eyes; red itchy ears; and a seasonal appearance of symptoms. The best method to diagnose one allergy source from another is either a blood sample or skin patch test evaluated by your veterinarian or veterinary dermatologist.
Contact allergies can also cause itchy skin. These include substances such as fresh cut grass, carpet deodorizing products, detergents, etc. Contact allergies usually show symptoms of red skin and itch on the skin in direct contact with the offending substance.
Infected skin is very itchy, and is usually a result of bacterial over growth on the skin after the skin has been irritated or inflamed over several hours to days. This happens when a pet continues to itch and irritate an area. These "hot spots" of infected skin will appear very red to greenish, often are hairless, and should be seen by your veterinarian for treatment.
Some pets have very greasy, flaky skin (called seborrhea) which is itchy and has a tendency toward infections. This can be very difficult to control, but with diligence it is possible. Many of these pets also have allergies, and thyroid hormone imbalances. It is best to consult your veterinarian for testing if your pet has these symptoms. Dry flaky skin alone may be a symptom that indicates a variety of conditions ranging from external parasites, to simple dry skin.
Itchy Skin Treatments
Treatment for any of the above-mentioned causes of itch varies from pet to pet depending on the severity of the itch and the location of any skin lesions. With the exception of external parasites, many of the itchy skin conditions are never fully curable, but instead we work toward maintaining the comfort of the pet. There are many options available, including the care of specialists in veterinary dermatology located locally.
External parasites are treated following identification, which may require a skin scraping. Different parasites are treated with different products, so consult your veterinarian for guidance. Fleas are by far the most common external parasite seen in our area. Control is outlined in the flea section.
Allergic skin conditions, depending on the source of the allergy, are treated with many different products and medicines, including: food trials, fatty acid supplements, antihistamines, shampoos and cream rinses, and cortisone in various forms. If serum or skin testing has been completed, allergy injections may be given and provide relief for itchy skin. Contact allergies are treated similarly, but also require avoidance of the offending substance such as new flooring, cedar bedding, grass, carpet products, and detergents.
Hair Loss
Hair loss in pets is rarely due to aging! Usually, hair loss is a result of itching or rubbing at the skin and pulling the hair out or breaking it off close to the skin level. Hair loss can be due to compulsive grooming or licking. It is also seen with fungal infection (as in ringworm) or in the presence of a mite infestation called Demodex (also known as red mange). Ringworm and Demodex usually do not cause significant itch or discomfort. Other causes for hair loss, without associated itchy skin, include many of the endocrine (or hormonal imbalance) diseases. Cushing's disease (hyperadrenocorticism), hypothyroidism, are the most common endocrine diseases associated with hair loss.
Ringworm is caused by a fungal infection of the skin. This is found in kittens most frequently, but can affect older cats and dogs. Ringworm is contagious to humans, but people seem to have different susceptibility to this infection. This infection can be difficult to eliminate. Some casescan take up to 8 weeks of intensive treatment. Diagnosis is based on the results of a fungal culture or by using a Wood's lamp to identify the presence of the fungus on the pet's coat. Treatment includes treatment of the home, isolation of the pet during treatment, wearing protective clothing when handling the pet, and both oral and topical medication.
Demodex is diagnosed with a skin scraping performed by your veterinarian to identify the mites. This type of mange is not thought to be contagious in most cases but is caused by an overgrowth of the mites due to a compromised immune system. The mites multiply in the hair follicles causing hair loss. Treatment is aimed at reducing the population of these mites to a normal level using a topical and sometimes oral medication.
Endocrine disease must be diagnosed by your veterinarian, usually via blood testing and a thorough physical exam. Treatment depends on the symptoms and the extent of abnormalities found on the blood analysis. In most cases, hair coat changes revert back to normal with treatment.