Gazette Vet: Pollen Primer


By Dr. John Andersen, DVM

We Virginians are blessed with extraordinary spring seasons each year and this year seems particularly beautiful to me. I get great pleasure stepping out on my patio each morning and observing everything coming back to life. Daffodils, tulips, and bluebells are in bloom along with dogwood, cherry, and redbud trees. The grass is thick, deep green, and freshly mowed. Roses are leafing out, boxwoods are fluffing up, and deciduous trees are waking. Then I look at my patio table that is covered with a thick layer of yellow pollen and I sneeze.

Our pets are afflicted by the same environmental and seasonal allergies that we often suffer from, and this is most obvious during season changes like right now. But while we humans tend to suffer from sneezing, a runny nose, and itchy eyes, our pets instead get skin and ear infections related to allergies.

This doesn’t intuitively make sense; why aren’t they sneezing? How in the world is all this pollen causing my dog to have ear infections? Or causing my cat to have scabs all over her head and neck? The answer is simply that they are different than us.

When a person steps outside on a heavy pollen day, they are surely exposed head to toe. But we are usually clothed and we sure do like to shower and wash our hands a lot. So for the most part, allergens (like pollen, dust, and mold) seem to cause problems when we inhale them and when they encounter our eyes. If we are allergic to these airborne particles and exposed, there are immune cells in our nose, throat, and eyes that release histamine and other compounds that cause inflammation and hence the sneezing, runny nose, itchy eyes.

Occasionally we see dogs and cats sneeze and have red eyes from allergies, but this is not common and it is rarely severe. We don’t really know why they don’t get similar “hay fever” signs like us. They are simply different.

The main difference in how dogs and cats are affected by allergies is that they have skin reactions. When they are exposed to pollens and allergens, even by inhaling them, it tends to cause histamine release in their skin and ears. This leads to pink, itchy skin. And we also know that dogs can get a lot of allergen exposure through their skin directly. So when they walk on that freshly mowed grass, or are walking around with pollens caught in their fur coats, the skin inflammation is only worsened. With prolonged allergy exposure, the skin will stay inflamed and they will start producing more oils and having dandruff.

Meanwhile, like us, dogs and cats have bacteria and yeast that colonize every square inch of their skin and ears. In health, these occur in balance and do not cause problems and are not noticed. With warm, moist, inflamed skin and ears, these bugs are loving it and start to overgrow and misbehave and cause skin and ear infections.

Specifically, allergic skin disease in pets looks like:

• Dogs with “dirty,” smelly, itchy ears. Dogs do not normally produce ear wax and rarely get dirt in their ears. They also rarely get ear mites. So if you see black waxy discharge or any type of discharge in your dog’s ears, they likely have a yeast infection and need some medication. Cleaning their ears alone will rarely resolve these infections once they have started.

• Dogs who are itchy and chew/lick at their feet. Is your dog recently waking you up at night chewing at herself and licking her feet? When you scratch her neck, does she now reflexively itch with her back leg? Is she just scratching herself all day long? If so (and if you are using proper flea prevention!), she probably has allergies.

• Dogs who have scabs, rashes, or hair loss. These often occur over their back, under their bellies, and on the insides of their legs. These are usually a result of hair follicle infections secondary to the allergies.

• Dogs who have skin that has become darkly pigmented, thickened, and smelly. This is usually the result of yeast infection on the skin, a result of allergies. Usually it is most prominent on their bellies and feet.

• Dogs with “hot spots,” circular areas of raw, moist, skin infection. These are usually around their cheeks and head and are very sensitive.

• Cats with small scabs and sores over their head and neck. These are rarely fight wounds or bug bites, and more likely to be hair follicle infections that have scabbed over.

• Cats who are licking the hair off their belly or sides. These cats are itchy and obsessive-compulsive.

Allergies are rarely easy. I probably spend more time with client education about allergies than any other disease. This is because we will rarely cure their allergies, much like I’ll probably always have ragweed allergies. It becomes important to understand these allergies and your pet’s particular allergy pattern in an effort to best manage them over time.

Some pets are managed with regular bathing and antihistamines. Bathing is probably the most under-utilized tool—I recommend bathing itchy dogs on a weekly basis if possible, it makes a huge difference! Some pets need a steroid course to decrease the allergic inflammation and antimicrobials to treat the skin infections. It is hard to get allergic pets to any kind of “maintenance” plan until we’ve gotten the skin back to normal first. Allergy testing and allergy shots are also good tools, but are more expensive and take time to work.

Fortunately, most pet allergies are manageable without everyone going crazy. Spending a lot of time with your veterinarian is very important here. So get out there, enjoy the spring, and call your vet if you’ve got an allergic pet.