Horse Allergies

This page reviews secondary" cat allergens, and reviews why we are concerned when individuals have allergies to horses, rabbits, or severe allergies to eggs or meat.   

Most folks with cat allergy tend to react to a small protein called Feline allergen #1 (Fel d1). This is the commonest cause of cat allergies.  Most people are allergic to more than one cat allergen, though usually not severe. 

Severe allergies to horses, rabbits, dogs, or food allergies to pork, beef, or egg are a concern.  Most  individuals with these allergies will react to very low Siberians. We can safely place kittens in about 40% of these situations. 

Horses are a significant sources of animal allergens. Half of folks with prolonged contact with horses develop reactions.  Anaphylaxis from exposure to horse albumin or lipocalin can occur in children without warning, though minor symptoms (asthma, itching, eczema) are usually present first. Carrying Childrens Chewable Benadryl  when allergic children visit horses can reduce reactions.

Allergens share commonalities between different species. For example: Albumin is a protein made by all animals. It holds fluids in the bloodstream and carries vitamins and enzymes throughout the body.  Albumin made by cats has the same functions as albumin made by dogs, horses, and people, but the structure of albumin is slightly different in each species.  

Our immune system can react to albumins from different animals. There are about 6 different epitopes (latch points) on albumin. Different species can have similar or different epitopes. Our immune system is highly adaptable, so each person reacts to allergens in a different way.  

Pretend a PaperMate Pencil and Papermate Pen are two different albumins, and the latch-points “epitopes” are the writing tip, barrel, shirt clip, and eraser.  If your immune system latches onto the shirt clip of the Pencil, you will react to the Pen.  If my immune system latches to the writing tip of the Pencil, I don’t react to the Pen. 

Looking at the three commonest cat allergens, you can see why cross reactions can occur. 

Fel d 1 ~ Cat uteroglobin: does not seem to share epitopes with other animals.

Fel d 2 ~ Cat serum albumin: shares epitopes with Dog and Horse, and Pork and Beef.

Fel d 4 ~ Cat lipocalin: shares epitopes with Horse, Boar, Mouse, Cow

Folks with allergies to horses, dogs, rabbits, or food allergies to pork, egg, and beef tend to react to low Fel d1 Siberians.  The cross-reactive allergens listed above are the primary cause.  Because of this risk, we suggest fur tests and then spend time with a known low allergen Siberian. 

© Meredith Lundberg 2015