Allergies in pets
Allergies are the result of the immune system reacting to a benign protein (think pollen or chicken) as though it were a disease-causing entity. The symptoms allergy sufferers experience are the body’s immune system attacking the protein. In humans, these manifest most commonly as sniffling and sneezing or an itchy face. More frightening symptoms, normally seen in people allergic to bee stings and certain types of food, are anaphylactic reactions. This involves a shock-like reaction that affects the whole body as quickly as seconds within contact and can be fatal.
Any animal can have allergies.
In dogs and cats, allergy symptoms differ from those most often seen in people. Dogs will most often express mild allergies by licking or chewing on their feet, rubbing their face, or chewing on their skin. As allergies become more severe, dogs may experience hair loss, open wounds from self-trauma, diarrhea and vomiting.
Cats will often groom excessively (sometimes to the point of baldness) or have chronic diarrhea or vomiting.
Allergies can also cause respiratory illness like coughing or asthma. Because of the underlying threat of valley fever in southern Arizona, any case of coughing needs to be taken seriously.
Asthma, most often seen in cats, can be caused by allergies. Asthma is a dangerous narrowing of the bronchial passages of the lungs. Asthma causes coughing, shortness of breath, exercise intolerance, and open-mouthed breathing. Asthma is extremely dangerous.
Any pet can have an anaphylactic reaction. These are usually sudden and unexpected. They can cause the airways to become compromised and, although exceptionally rare, they are veterinary emergencies. Most anaphylactic reactions are caused by insect stings or ingestion of a substance.
Dogs seem to groom themselves in front of owners, while cats may do it in secret. The most common signs of licking in dogs is fur discoloration (white or tan fur may begin to look orange; this is often seen inside the thighs or on feet). Cats may get bald spots that lead owners to conclude that the fur is falling out. A common place for fur-pulling in cats is the belly.
Treatment of allergies is two-fold – addressing the symptom(s) and addressing the underlying cause(s).
There are several classes of of drugs and treatments that are commonly used for allergies.
Antihistamines work by suppressing the body’s release of histamines, which cause itching and inflammation. Antihistamines may work in seasonal or mild allergies. Most of the antihistamines that we use have limited side effects.
Immune suppressants suppress the immune system. This has the effect of possibly increasing susceptibility to other illnesses, including infections like valley fever.
Immune suppressants are the most effective treatment for allergies. This class of drugs includes such things as steroids, and can have differing and severe side effects, especially if used often or improperly.
Two newer forms of immune suppressants are the brand name drugs Atopica and Apoquel.
Atopica can take up to a month to take effect and has been very successful in treating allergies in many cases. Atopica is generally safer than steroids. However, it is slower acting, not always effective, and can be costly for owners.
Apoquel at the time of this writing (October 2014) has been on the market since the spring of 2014. It is quickly effective, has few side effects, is less costly than Atopica, and at this time available in extremely limited quantities due to unanticipated demand.
Food allergies are more often the cause of skin lesions in cats than in dogs, but in all cases an underlying food allergy cannot be ruled out. For the treatment of food allergies, a food trial is often necessary. Food allergies can be completely addressed through exclusive feeding of novel protein or hydrolyzed protein foods.
Hyposensitization or allergy shots are also sometimes used. Hyposensitization releases small amounts of the offending allergen(s) into the pet’s body (usually through injections) in an effort to “train” the immune system into seeing these proteins as benign. Allergy shots are made specifically for the needs of each individual pet. Treatment can take up to a year for improvement of symptoms.
Cats with asthma are often treated with anti-inflammatory and immunosuppressant drugs, and can benefit from treatment that directly affects the inflammation of the lungs through targeted treatments through inhaled medications.
Shampoos, sprays and supplements also have a place in a multimodal approach to allergy treatment.
Allergic pets can get secondary bacterial and fungal infections that complicate treatment.
Allergies at this time are largely thought to be partly heritable, meaning that some lines of dogs and cats may have a higher likelihood of developing allergies.
Complications to allergies include secondary diseases that can exacerbate skin health such as hypothyroidism and Cushing’s disease. Obesity has also been linked to higher incidence of allergies in pets. Certain breeds are more likely to suffer from allergies or other skin diseases. Weight does seem to play a role in some pets’ allergies, and a slender pet is healthier all-around and on many different fronts. We wholeheartedly recommend keeping pets slim throughout their lifetimes through a balanced use of food and exercise.
In recent studies on piglets, some connection has been made between the cleanliness of the piglets’ surroundings and their susceptibility to allergies. The research, though preliminary at this point, seems to point to the idea currently gaining favor that excessively clean and disease and parasite-free habitats create a hypervigilance in the immune system that may translate to an increased possibility of acquiring allergies.
While we certainly do not condone allowing your pet to become infected with treatable diseases or parasites, we certainly believe that exposure and socialization, especially in a safe manner as puppies and kittens, may help prevent future allergies.
The most important thing to know about your allergic pet is that things are constantly changing. Allergies and your pet’s reactions to them will change over time. What works today may not work tomorrow and symptoms may wax and wane with the seasons or with travel. The best predictor of successful treatment is owner vigilance. Owners who pay attention to the changing course of their pet’s illness and who are proactive with treatment often have better results as well as fewer secondary infections and issues.