Scratching Beneath the Surface of Allergic Skin Disease

Author: Texas A&M College of Veterinary Medicine & Biomedical Sciences

Spring is coming, and it’s bringing allergy season with it. While you may suffer from all of the excess pollen in the air, your pets may also be affected by seasonal allergies, or they could be allergic to a more permanent feature of their environment.

There are several causes of allergic skin disease in pets, including biting insects, diet, and environmental factors. If the allergies tend to get worse during certain times of the year, external parasites, biting insects, or environmental factors tend to be the more likely culprits.

Dr. Alison Diesel, a clinical associate professor in dermatology at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, has advice for pet owners who may be noticing some extra itching from their dog or cat.

“The most common cause of allergic skin disease worldwide is fleas,” Diesel said. “The saliva that is injected when a flea bites can cause an allergic reaction in sensitive dogs and cats.”

Diesel said it is common for pets to be allergic to environmental factors such as mold, dust (as well as the associated dust mites), or pollens from weeds, grasses, and trees.

“A common misconception is that dogs and cats can have allergies to things like cleaners or laundry detergents,” she added. “This is something that is essentially never seen.”

While itching is the main indicator of allergic skin disease, Diesel said to watch for more than just scratching, because biting, licking, rubbing, rolling, head shaking, and scooting can also indicate that a pet is feeling itchy. Cats also may show excessive grooming behaviors, which can result in bald patches and hairballs.

“It is important to remember that other things, such as infections and parasites, can also cause the same symptoms,” Diesel said. “These first need to be investigated before jumping on the allergy train. Contact your pet’s veterinarian to help determine what may be causing the itch observed.”

A veterinarian can also help determine if the amount of itching is normal or excessive. Diesel said the Texas A&M Small Animal Hospital uses a scale of one to 10 to help rate a pet’s itching level.

“If the animal’s scratching is disrupting their normal behavior, their sleeping habits, or their owner’s sleeping habits, this is considered to be too much itching,” she said.

More extreme signs of itching—such as hair loss, red skin, scratch marks, and rashes—also indicate that the pet is itching more than a normal amount.

Once the cause of the allergy is determined, treatment can begin. Diesel said that flea prevention is the first step for any pet with allergic skin disease.

“Even when fleas are not seen, this is very important,” she said. “Even a small amount of flea saliva that is injected into a sensitive patient can cause a massive allergic response.”

She said other treatments include medications, special shampoos, topical products, dietary changes, and allergy immunotherapy, which involves giving the pet allergy injections or oral drops. The severity of the itch, duration of the itching, and other health conditions will determine which treatment is the best choice.

Diesel also said that some human antihistamine medications can be given to pets, but a veterinarian should always be consulted first. Pet dosages are very different from human dosages, and some decongestant medications may be toxic.

Some veterinarians, like Diesel, specialize in allergic skin disease. If your primary veterinarian cannot stop the itching, a veterinary dermatologist may be able to do further testing and prescribe different treatment options.

Pets deserve to spend each day as comfortable as possible, free from itching and pain. Now that spring is almost here, make sure you watch out for any of the symptoms of allergic skin disease in your dog or cat.

Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University. Stories can be viewed on the web at vetmed.tamu.edu/pet-talk. Suggestions for future topics may be directed to editor@cvm.tamu.edu.