Allergies in Dogs and Cats

Dogs commonly get allergies, cats occasionally get allergies, and both manifest them differently than people. In dogs, allergies most commonly cause skin and ear problems, while in cats allergies involve the skin but rarely the ears. Licking of the feet, frequent scooting or licking the rear, recurrent ear or skin infections, hair loss, and itching can all be signs of an allergy.

There are three basic causes of allergies in dogs:

1. Fleas

2. Food

3. Environmental (includes pollens, grasses, molds, dust mites).

Dogs can also have a contact allergy, but this is rare. Flea allergies are the most common allergy in dogs. Because it is the flea saliva that dogs are allergic to, one bite can be enough to cause dogs to itch non-stop, lose hair, and get welts all over their back (think of a person with an allergy to bees). Thus you may not see fleas on the dog with a flea allergy. Cats hide evidence of fleas very well because they groom themselves so frequently, and because they rarely scratch like dogs do (their tongue is more effective).

A second cause of allergies is food. Dogs and cats can react to either the protein or carbohydrate in foods. Switching brands of food thus won't resolve food allergies, unless you completely avoid the offending ingredient. Common allergic ingredients include beef, dairy, chicken, eggs, wheat, and corn, but can also include lamb or other sources. It can take the body 8-12 weeks to recover from a food allergy, and these allergies develop commonly between 6 months to 3 years of age. Even small amounts of the offending ingredient can cause a significant flare of itching and infection.

A third allergen includes environmental sources. There typically will be a seasonal pattern to the allergy, depending on the source. Environmental sources also can develop between 6 months and 3 years of age, but also later in life as well. Sometimes these allergies develop when moving to new areas as dogs are exposed to new pollens and grasses. Some allergies will worsen as the pet ages, and become itchy year-round.

Treatment involves clearing any infection (bacterial and yeast) and trying to address the underlying allergy. If the allergen is not removed, the animal will continue to erupt with infections. To treat flea allergies, the animal must be on a topical product that will kill the adult fleas. Oral products require the flea to bite, thus not preventing the problem.

Fleas survive year-round in our mild climate here, and their eggs hatch at various times depending on the temperature and humidity; thus flea preventatives must be applied year-round to treat flea allergies. Discuss with your vet the most effective flea products and proper application.

Food allergies require either a novel diet or a hydrolyzed diet. A novel diet has a new protein and carbohydrate which your pet has never had before, without any of the offending ingredients. A hydrolyzed diet has the protein broken down to a level not recognized by the immune system. Be aware that bones, dog treats, and human food could all elicit a reaction.

Environmental allergies are difficult because we cannot remove the inciting cause. Thus treatment relies upon controlling infections and reducing the body's response, similar to how we treat our allergies. Your veterinarian can discuss with you many different treatment options. Wiping off the coat with a wet towel can help remove pollens on the coat, and frequent bathing with a medicated shampoo can help soothe the coat. It is important to remember that bathing will remove essential oils from the skin and depending on its condition, this could be good or result in dryness if not restored with
conditioners.