Itchy dogs and cats: Canine and feline allergies explained Published June 29, 2010 By Capt. Sherri Daye, DVM, MRCVS RAF Feltwell Veterianry Treatment Facility RAF FELTWELL, England -- Does your dog or cat scratch themselves silly? Do they wake you in the middle of the night scratching and licking at their skin? Do they have an ear infection that keeps coming back, even after you treat it? Are they starting to go bald? If so, then read on, several things can cause dogs and cats to be pruritic ("itchy"). Some of the more common causes are: Parasites. Parasites, such as fleas or mites can cause your pet to itch. Some animals are allergic to fleas and can become extremely pruritic with just one flea bite. The best way to protect your pet and you from fleas is to apply an overt the counter flea preventative to all of your pets monthly. Note: Use caution when applying OTC products to your pet. Some OTC products vary in efficacy and safety. Also, cats can be very sensitive to some insecticides. Never apply an insecticide product to a cat unless the label specifies it is safe for use in cats. As for mites, your veterinarian can do some simple tests to determine if your pet suffers from mites, and can then prescribe appropriate medications to eliminate the mites. Allergies: Just like people, pets can be allergic to a variety of things--including fleas, certain types of food, dust mites, other animals, and many other things found in the environment. Allergies are basically the immune system over-reacting to "normal" things ("allergens"). Whereas most people with allergies suffer sneezing and stuffy noses, often dogs' and cats' allergies manifest in their skin. Only about 15 percent of atopic animals show respiratory signs (rhinitis and asthma). Basically, rather than showing hay fever -like symptoms, Fluffy and Fido tend to get itchy skin, dermatitis and recurrent ear infections. Food allergies: Many pets suffer from allergies to ingredients commonly found in most pet foods, such as fish, beef, chicken, and wheat. These allergies can develop at any time during their life (reports of food allergies first occurring have been made for animals from 2 months old to 14 years old.) Symptoms often include dermatitis (itchy, infected skin) and otitis (ear infections), but can also include diarrhea and vomiting. Most commonly, food allergies occur in younger (less than 2 years old) animals. The best way to determine if your pet suffers from food allergies is to perform a diet trial in which they receive only hypoallergenic food (such as prescription diet ZD or a food with novel proteins--kangaroo and potato for example) for 8-12 weeks. If they show improvement, they may remain on the hypoallergenic food for life. If they don't show significant improvement, then the next step would be to find out what else they may be allergic to. Atopy: Allergies to substances inhaled in the environment (like pollens and dust mites) can also make your pet very pruritic. Allergic inhalant dermatitis affects about 10 percent of dogs. It most commonly occurs in dogs and cats less than 5 years old, but has been found to first occur in some older animals as well. Often the symptoms are seasonal, but not always - depending on what the animal is allergic to. The best way to determine if your pet suffers from atopy is to first rule out parasite and food allergy as the cause of their itching. Once those differential diagnoses are ruled out, then your veterinarian may perform allergy testing on your pet. There are two types of allergy testing - intradermal (in which small amounts of allergens are injected into the skin) and serological (in which a blood sample is drawn and sent to the laboratory for testing.) Your veterinarian can discuss the pros and cons of each, and together you can determine which best suits your pets' needs. Once a diagnosis of atopy has been made there are a few different possible treatments, the simplest of which is to administer an antihistamine (such as diphenhydramine, aka Benadryl). Be sure to discuss dosages with your vet before giving any OTC antihistamine to your pet. Another possible treatment for atopy is the administration of an immunosuppressant such as cyclosporine. Cyclosporine works well in many animals, but can have some negative side effects such as decreasing the immune system too much, so it is important to follow up with your veterinarian for regular tests while your pet is on an immunosuppressant. A third possible treatment for atopy is immunotherapy, or hyposensitization (aka "allergy shots"). Immunotherapy consists of a long-term series of subcutaneous (under the skin) injections of small amounts of the offending allergen, in an attempt to desensitize your pet to that substance. While there are other diseases that can cause itchy skin, parasites and allergies are the most common. If your pet is having skin or ear problems, it is important to have it thoroughly examined by your veterinarian. Be sure to let them know the details of the problems - things like how long your pet has been experiencing symptoms, if it has experienced similar symptoms in the past, and if so, when? The answers to these questions can be very helpful in diagnosing the cause for your pet's scratching. What to know: If you would like to schedule an appointment at the RAF Feltwell Veterinary Treatment Facility, call DSN 226-7097 (COM 01638 52 7097).