Allergic Reactions

Allergic reactions (anaphylaxis) are exaggerated or inappropriate responses to foreign particles (allergens). They occur when the body’s immune system has an unusually strong response, or hypersensitivity to a substance that entered the body. Just about anything can cause one, but since things like pollen, dander, etc. float in the air and are easily inhaled, their results are often seen. Often allergens find their way into bodies in other ways. Bee stings and insect bites inject substances directly into the skin, where an immediate reaction can occur. Rarely, an animal can be allergic to a drug or vaccination. Even certain foods can cause reactions.

Most times a foreign substance will simply be carried away and expelled form the body by the immune system. Occasionally though, the immune system will overreact to it and produce chemicals like histamines which can cause the problems (hence why people take antihistamines for allergies). Animals can have various responses. Dogs and cats may show swelling and/or bumps on the skin (hives), either locally around the bite area or all over the body, especially on the face. Some pets may have trouble breathing, or intense itching about the face. You may see vomiting, diarrhea, or salivating.

Sometimes internal organs, such as the liver (in dogs), can be affected. In the most severe cases, an animal can go into anaphylactic shock, which simply means the allergic reaction is serious enough to cause shock-like symptoms (collapse, pale gums, etc) which requires immediate medical attention. It should be noted that previous exposure to the allergen could increase the chances of a reaction. In other words, just because a pet does not react to one exposure, doesn’t necessarily mean it won’t react on subsequent exposures (ex: repeat vaccinations).

So, while allergic reactions are uncommon, they do happen, and owners should be alert for the signs of them. Some responses can become serious within minutes. Keep a close eye on your pet when it’s outdoors, or anywhere insects may be. Watch closely after any vaccination or medications are given, especially a second course of injections. Veterinarians watch for immediate reactions, but sometimes these can be delayed, and show no signs until you get home. If you see any possible signs of reaction, call your veterinarian or emergency clinic for more information.