What can make your dog and cat have their hair fall out leaving a bald spot. Usually around ears on the face?

Ringworms:

* Caused by a type of fungus called a dermatophyte

* Highly contagious to both animals and humans

* Spreads through direct contact with an infected animal or object, or through contact with contaminated soil or surfaces

* Can be more common in the ear area if your dog or cat is scratching or rubbing excessively

Otodectes cynotis (ear mites):

* Microscopic mites that live on the skin of the ear canal

* Cause intense itching and irritation

* Can lead to secondary bacterial infections and hair loss

Demodex:

* A type of microscopic mite commonly found on dogs and cats' skin

* Some animals have higher numbers without any symptoms, though they may be more susceptible to other skin infections

* Certain factors like a compromised immune system or certain medications can cause demodex mites to overpopulate, causing hair loss

Bacterial and Fungal Infections:

* Various types of bacteria and fungi can cause skin infections in dogs and cats leading to hair loss around ears and face.

Food and Environmental Allergies:

* Allergies can cause intense itching, biting and scratching which may lead to hair loss.

Cushing's Disease:

* Common in dogs and rare in cats, Cushing's disease leads to excessive production of the hormone cortisol which suppresses hair growth.

Alopecia Areata:

* An autoimmune disease that results in the immune system attacking hair follicles, leading to sudden bald spots.

It is important to consult a veterinarian for a proper diagnosis and appropriate treatment. The vet may recommend diagnostic tests, skin scrapings, and treatment based on the underlying cause. Self-treatment or delay in seeking veterinary care may worsen the condition.