Allergies can vary in severity and cause various symptoms. According to the Mayo Clinic, allergies occur when the immune system reacts to a foreign substance by producing antibodies.
These antibodies identify a particular allergen as harmful, even when it isn’t. Allergies can cause reactions in the skin, breathing passages and digestive system.
Thousands of people experience allergies to foods, pets and environmental factors. Pets also can be susceptible to allergies. Allergies can be found in cats and dogs, according to PetMD. They also may be present in other animals. People who notice their companion animals scratching, chewing or licking themselves more than normal may find their pets have allergies. Some pets may experience gastrointestinal issues as well.
The pet care information site Pet Cube says common allergens for pets can include: