Ear Infections in Dogs and Cats

Which Bacteria and Yeast Cause an Ear Infection?

Dogs usually have yeast (Malassezia) and bacterial infections (Staphylococci, Pseudomonas). Dogs that swim typically develop Pseudomonas, and dogs with increased cerumen (earwax) typically have Malassezia. Dogs with hypothyroidism typically have Staph ear infections. Less commonly, dogs have bacterial infections caused by Corynebacteria, Enterococci, E. Coli, Streptococci, and Proteus.

Cats usually have yeast (Malassezia) infections, but don't usually have bacterial infections. Occasionally bacteria (Mycoplasma and Bordetella) are found in cats with middle ear infections, but it is unclear that these bacteria actually cause the infection.

Recommended Pet Medications for Treating Ear Infections:

Zymox Otic Enzymatic Solution with Hydrocortisone

Zymox Otic Enzymatic Solution Hydrocortisone Free

Tresaderm

Otomax

What if the Infection Causes the Ear Drum to Rupture?

Eardrums can heal in 3-4 weeks when the cause of the rupture is addressed. In the meantime, do not put any medications or flushing solutions in the ear that were not prescribed by the veterinarian.

Which Pets are Most at Risk for Ear Infections?

• Activity: Swimming
• Ear microenvironment: Parasites, increased cerumen, increased hair, narrow canals
• Endocrine disease: Hypothyroidism
• Environment: Humidity
• Trauma: Exuberant ear cleaning
• Chronic respiratory infection: Herpes or calici viruses may predispose cats to ear infections by weakening the immune system

Dog Breeds Most Likely to Develop Ear Infections Because of Allergies:

• Any pet with hot spots (flea allergy dermatitis)
• Cocker Spaniels
• Labrador Retrievers
• Schnauzers
• Setters
• West Highland Terriers
• Wheaten Terriers

Dog Breeds Most Likely to Develop Ear Infections Because of Ear Canal Skin Characteristics:

• Basset Hounds
• Beagles
• Cocker Spaniels
• Labradors
• Setters
• Shar Peis
• Springer Spaniels

Dog Breeds Most Likely to Develop Ear Infections Because of Thick Hair In the Ear Canal:

• Lhasa Apsos
• Maltese
• Pekingese
• Poodles
• Schnauzers
• Shih Tzus
• Spaniels

How Significant are Allergies to Pets With Ear Infections?

Approximately 80% of dogs with allergies develop otitis. In dogs and cats, symptoms caused by allergies to food, inhaled proteins, or contact materials—for example, corn, pollen, and grass—are different than allergic symptoms in people. People with allergies often have itchy, runny eyes or a runny nose. Dogs and cats are more likely to develop heat and inflammation of the ears, head, neck, and feet than of the eyes and nose. Heat and inflammation in the ears predisposes pets to increased yeast growth and chronic itchy, smelly otitis.