Vet's Orders: Why Can't My Pet Stop Scratching?

Dr. Chiara Hoskin, BVSc

Why pets itch:

Skin complaints are among the most frequent reasons pet parents seek veterinary care. Clinically, itchy skin and secondary hair loss can be categorized into three primary differentials: skin parasites, allergies, and secondary infections.

Pests (Parasites):

Fleas: These are the classic offenders, often causing pets to lose hair specifically on their lower back, right near the tail. In pets that are allergic, even one single bite can set off a massive reaction.

Mites: These are tiny, microscopic critters. Some types, like Demodex, are common in young or sick pets and usually cause patchy hair loss on the face and feet. Others, like Scabies, are highly contagious and cause intense itching, especially around the ears and elbows. Another type, Cheyletiella, causes dry, scaly skin on the back that looks like "walking dandruff" and can spread between pets and even to humans.

Allergies:

Food Allergies: You might be surprised to learn that a pet can develop a food allergy at any stage of their life, even if they’ve been eating the same food for years. It often looks like a skin rash, hair loss, or recurring ear infections.

Environmental Allergies: Just like us, pets can be allergic to things in the air, like pollens or dust. It’s actually more common than food allergies, and many pets unfortunately suffer from both at the same time.

Infections:

Bacteria and Yeast: Even if the original cause of the itch was a flea or an allergy, the cycle of scratching often creates small breaks in the skin where bacteria and yeast thrive. Once these infections set in, they keep the itch going long after the original problem is addressed. This shows up as red, crusty, or raw skin, pimples, or even thickened, "elephant-like" skin caused by yeast overgrowth.