My cat seems to be scratching a lot lately. I thought it could be fleas but I’m not seeing any signs. What else could it be?
Last week I discussed the many causes of pruritus (itching and scratching) in dogs and cats. Today I will review the most common cause of pruritus, allergies.
What is an allergy?
An allergy is a state of over-reactivity or hypersensitivity of the immune system to a particular substance that we call an allergen. Most allergens are proteins. The allergen may be of insect, plant or animal origin and may be eaten (food allergy), inhaled (hayfever in people and atopy in pets), or touched (poison ivy in people).
The most common symptom associated with allergies is itching. Another common allergy is an inhalant allergy called atopy. The main cause of inhaled allergens are trees, weeds, grass pollens, house dust mites and molds. Many of these allergies occur seasonally such as ragweed and grass pollens. However, others such as mold, mildew, and house mites can be year round. When humans inhale these allergens, the allergy manifests mainly with respiratory signs such as runny eyes, running nose and sneezing. But in dogs and cats the result is usually itchy skin.
Next week we will discuss two main causes of allergies, food and fleas.
Thomas Schaeberle, VMD