If you’ve ever asked yourself, “How do I know what my dog is allergic to?”—this blog post is for you. Our resident Veterinary Dermatologist Dr. Anthea Schick helps decode three types of allergies and what to look for.
Skin and ear problems are common in dogs, and they’re one of the most frequent reasons that owners bring their pets to the veterinarian. While there are many different reasons why a pet will lick, rub, scratch, and chew, the most common is allergies. Allergies are defined as a chronic condition involving an abnormal reaction to an ordinarily harmless substance called an allergen. Allergens can trigger a response that starts in the immune system and results in an allergic reaction.
When dogs are allergic, instead of sneezing and hay fever, they mostly show their allergies in their skin and ears. Allergic dogs are basically like people with eczema. But in order to better understand what your dog is suffering from, it helps to break down some allergy basics.
3 TYPES OF ALLERGIES
Environmental Allergy: Just like people, dogs (and cats) can be allergic to pollen, dust, and molds. Allergic dogs may scratch all over—especially at their armpits, belly, ears, and paws. They may also have recurrent skin and ear infections and lick their paws. The signs usually start between 6 months to 5 years of age. Also take note if this reaction happens during a particular season, like Spring or Fall.
Food Allergy: Animals with a food allergy can show very similar signs as pets with environmental allergies, but the itching is not seasonal. Animals can develop a food allergy at any time in their life—even if they have been eating the same food all along. In fact, one of the most common food allergens is chicken. Besides itchiness, food-allergic dogs may also have ear or skin infections. The symptoms of a food allergy usually do not improve much with anti-itch medications.
Parasite Allergy: Fleas cause itching and hair loss due to the irritation caused by their bites, secondary bacterial infections, or to a flea bite allergy. Animals will often itch and lose hair on their back near their tail. In flea-allergic animals, even one flea bite can cause a reaction. Mange mites (sarcoptes or scabies mites) can also cause intense allergic reactions and extreme itch. Scabies may cause hair loss and crusts to form on ears and elbows. Scabies mites can be very difficult to find, and, if suspected, should be treated even if skin samples don’t reveal mites.
HOW TO IDENTIFY THE ALLERGY
If you can’t easily figure out what type of allergy your dog has, there are things you can do to help pinpoint the problem.
Some parasites, like fleas and ticks, are usually easy to find since they are visible to the naked eye. Other skin parasites can be tricky to find. Demodex mites live inside hair follicles and can usually be found by veterinarians with skin scrapings. Skin scraping involves using a dull blade or medical skin spatula to scratch the skin to acquire samples of skin cells and any parasites that may be present. Scabies (sarcoptes) mites can be very hard to find and might be present even if skin scrapings are negative. There are several other types of parasites, like Cheyletiella (also called walking dandruff) and a variety of species of lice, that you’ll also need help from your vet to detect. Luckily, there are newer prescription parasite medications that treat them all!