Allergies commonly cause sneezing, watery eyes, coughing, or asthma in people. We may not be affected ourselves, but we likely know someone close who is, and because so many people suffer, the Asthma and Allergy Foundation of America (AAFA) sponsors National Asthma and Allergy Awareness Month each May.
While allergies affect many humans, they are also a prominent problem in pets, causing itchy skin, inflammation, and chronic infections. Allergies affect people and pets in different ways, so Providence Vet answers your most common questions about allergies in pets.
Question: What is a pet allergy?
Answer: Allergies are the result of an immune system gone haywire, and reacting to everyday substances (i.e., food, pollen, or mold) that the system identifies as foreign invaders. The immune system is highly complex, and the pathways involved can be immediate or delayed, but ultimately will lead to an inflammatory response that in pets is concentrated in the skin, ears, anal glands, and gastrointestinal tract.
Question: What are allergy signs in pets?
A: The hallmark allergy sign in pets is itching, which may manifest as the pet scratching, chewing, or licking. Other signs may include:
- Chronic skin infections
- Chronic ear infections
- Red, thickened, scaly, or dark-pigmented skin
- Hair loss
- Vomiting and diarrhea
- Weight loss
Q: What is causing my pet’s allergies?
A: Pets can be allergic to fleas, food, and many environmental substances. Environmental allergies are the most common, but most allergic pets have multiple allergen triggers, with crossover into several categories.
- Fleas — Flea allergy dermatitis (FAD) is caused by flea bites, with or without an infestation, and characteristically results in hair loss and inflammation at the tail base.
- Food — Allergies can develop to protein or carbohydrate sources in a pet’s diet, with allergens most often correlating to the most common pet food ingredients (i.e., chicken, beef, fish, egg, and dairy).
- Environment — Pets can be allergic to pollens, grasses, molds, dust mites, other insects, other pets, or humans.
Q: Do grains or gluten cause allergies in pets?
A: Not necessarily—gluten allergy is found only in Irish setters, so is unlikely to cause your pet any problems. Food allergies are generally uncommon, and a dietary protein is usually the culprit if they do occur. A grain allergy, or an allergy to another non-grain carbohydrate or vegetable, is still possible, but unless your pet has a specific, pre-existing, uncommon food allergy, a grain-free diet will not help, because they are not inherently hypoallergenic, despite being marketed as such.
Q: How are allergies diagnosed in pets?
A: When allergies first manifest, a few simple tests can rule out other problems.
- Skin scraping — Superficial skin samples can rule out demodex and sarcoptes mites.
- Fungal culture — This test can rule out ringworm, which is common in cats.
- Skin cytology — This microscopic examination of skin cells can show bacteria or yeast overgrowth, or inflammation signs.
- Blood work — Blood work can help rule out endocrine disorders that lead to skin issues (i.e., hypothyroidism, Cushing’s syndrome).
- Food trial — To rule out the possibility of food contributing to allergy signs, pets should complete a 6- to 8-week food trial, during which pets eat a prescription or home-made diet consisting of one protein and one carbohydrate they have never eaten before, balanced with fats, minerals, and vitamins. If the pet improves on the trial, and regresses after being challenged with individual ingredients from the original diet, a food allergy is likely.
- Treatment trials — When tests are normal and clinical signs point to allergies, the pet can be treated, which may require trial and error. If multiple treatment options fail, the pet may be referred to a specialist to rule out less common skin conditions.
Q: How are allergies treated in pets?
A: Treatment depends on severity, seasonality, and causative allergens, and may include:
- Flea treatment — Monthly flea preventives and environmental control can reduce the possibility of flea-allergy flare-ups.
- Diet — For food allergies, some detective work is required to figure out which foods cause flare-ups, and then, once determined, these foods must be avoided. Fatty acid supplements or a prescription diet formulated for skin health may also be helpful.
- Medications — Antihistamines, anti-inflammatories, and immunosuppressants reduce the immune response and itch, and antibiotics or antifungals can help with secondary infections. Topical medications are used for ear infections and localized skin infections.
- Bathing — Medicated shampoos reduce the skin’s microbial populations and soothe inflammation.
- Immunotherapy — Allergy shots, given orally or under the skin, desensitize pets to their specific allergens as determined by a blood test. However, this treatment works in only 60% to 70% of pets with environmental allergens.
Q: Can I prevent allergies from developing in my pet?
A: Probably not. Veterinarians still aren’t sure why allergies develop, in humans or pets. They know that genetics play a role, and researchers are looking into the role of gut and skin bacteria (i.e., the microbiome) in immune function and disease. If the gut health theory rings true, specific probiotic strains could help prevent or treat future allergies, but that knowledge is likely many years away. For now, feed your pet a high quality, balanced diet, and ask your veterinarian for recommendations if you are interested in supplements that promote skin health.
If your itchy pet needs allergy relief, or if you’re not sure what’s causing their itch and discomfort, schedule an appointment with your Providence Vet team. We can help.