Pet Allergies

By: Morris Nejat, MD
Last Reviewed on: September 6, 2005
When it comes to pet allergies, man's best friends may often be his worst enemies. Numerous times a day, I see patients who are concerned that they may be allergic to their pets, and it often turns out that they are. But before you make the family dog the scapegoat for allergy symptoms, you must be sure not to wrongfully accuse an innocent pet.

Diagnosis of Animal Allergy
If you suffer from symptoms such as sneezing, runny nose and itchy, watery eyes, you can only know for certain you have an allergy by undergoing a specific test. In my practice, I start by asking questions about symptoms, history of allergy, environmental exposures and family history to get a good picture of your situation. To help determine whether an allergy is involved, I usually perform one of two types of skin testing: a skin prick test, which involves making a small break on the surface of the skin to introduce an extract of a specific allergen (any substance, including animal dander, that can cause an allergic reaction); or an intracutaneous test, where an allergen extract is injected into the skin. If you develop swelling and redness in the area, that indicates you have an allergy. On the other hand, if skin testing is negative, a blood test can confirm whether the animal in question is the source of the allergy. Too often I have seen a family get rid of a beloved family pet without adequate confirmation. They find out down the road that they were wrong and it wasn't Fluffy or Rover that was making little Johnny wheeze, but rather his teddy bear.

Treatment of Animal Allergy
Once an animal allergy has been diagnosed, it is important to understand what aspect of the animal you are allergic to. Below is a list of common animal allergies and the best steps for addressing each.

Cat Allergy: People who are allergic to cats have a reaction to the cat's saliva and dander (dead skin cells). However, typical allergic symptoms do not result from direct contact with your pet. Instead, when the cat grooms itself by licking its fur, it deposits saliva, which dries leaving behind the protein antigen and loosens dead skin cells. These allergens (saliva and dander) are very lightweight and are easily airborne. Once in the air, the antigens can spread to clothes, furniture, carpeting or any other household item.


Once cat allergy is confirmed, the best way to decrease allergy symptoms is to remove the cat from the home. If you decide to keep your cat, however, you should at least try to keep it out of the bedroom or off the bed. Washing the cat once a week may help reduce the amount of cat allergen in the house

However, relatively high concentrations of cat antigen can remain, even months after the cat is removed. Therefore, it is important to clean or replace the carpeting, furniture, and any other material that may harbor the cat saliva antigen. Many of the products available to clean home furnishings have been shown to have little effect on the presence of cat allergen .

There are less dramatic means to improve or eliminate cat allergy symptoms other than getting rid of your pet. These means include the use of medications and allergy immunization.

Dog Allergy: Patients allergic to dogs are allergic to the dog's saliva and dander. However, an allergy to dogs is easier to manage than a cat allergy because dogs are often kept outside, or at least out of bedrooms, and they get regular baths.

As with a cat allergy, the best way to address a dog allergy is to remove the animal from the home, but medications or allergy shots are other options.


Horse Allergy: People with this allergy may often think they are reacting to pollen or mold because their symptoms arise outdoors. These patients are usually allergic to horse hair and dander, and treatment includes horse avoidance, medication and/or allergy shots to decrease the immune system's sensitivity to horse allergen.

Rodent Allergy: People become allergic to rodents, including mice, rats and guinea pigs, due to frequent exposure to the animals; those most at risk include veterinarians, laboratory technicians and anyone who lives in close quarters with rodents (such as pet owners and those who live in rodent-infested homes).

The rodent's urine has a high concentration of protein, which is the primary trigger for allergic reactions. The urine is often sprayed rather than deposited, thereby increasing human exposure. After the urine dries, its proteins become airborne and are inhaled, leading to allergy symptoms.

Rabbit Allergy: Again, people with continual exposure to the animal?veterinarians, lab workers and pet owners?are at risk. The rabbit's urine is the common allergen.

Cockroach Allergy: Roaches, especially the German cockroach, are a common pest in crowded cities worldwide. Recent studies have shown that, in inner cities, exposure to roach droppings is a major risk factor for allergies and asthma. Avoidance consists of roach baits and traps, extermination and proper housekeeping. This includes not leaving food or water out in open containers, and washing and drying dishes after each meal. Emptying areas of standing water, such as the refrigerator draining pan, and wiping down sinks can help deny roaches any water source. Though the pests can go for weeks without food, they won't last long without water, which is why they are often found around kitchens or bathrooms. Unfortunately, though, one can't encourage cleanliness in their neighbors. People who don't improve with avoidance measures can be treated with medications and allergy immunization.

Dust Mite Allergy: Dust mites are too small to be seen with the naked eye. They are eight-legged and sightless, and they eat the dead skin cells we all shed. Most patients allergic to dust mites are actually allergic to the dust mite feces, which release allergens very rapidly. The dust mite fecal pellets are similar to pollen grains in three major ways:

the fecal particles size
the quantity of allergen carried
the rate of protein release
Dust mites become a part of our environment and lifestyle. Since they are entirely dependent on humidity for water, they tend to live in places that "store" moisture, including carpets, sofas, mattresses and clothing. As humidity levels fall, dust mites dig deeper into these sanctuaries, where there is more moisture. So even in very dry conditions, it may take months for dust mites to die and for their allergen dissipate. Protecting you and your family from dust mite allergies comes down to one important rule: make your home inhospitable to the pests! Washing your bedding at least once a week and buying dust mite encasements are important steps.

Conclusion

The medications used to treat animal allergy are similar to those used for other allergies, such as hay fever and asthma. These include antihistamines, nasal steroid sprays and asthma pills and sprays. You and your allergy specialist should discuss which of these medications would best suit your symptoms. Allergy shots, another treatment option, work by gradually building your immune system's tolerance to the culprit allergen. This process usually begins with weekly injections and ends after three to five years of therapy, with a good chance of no recurring allergy symptoms. Although roaches and dust mites may not be your idea of pets, getting rid of these creatures may significantly improve your tolerance of the pets you love.