How to Diagnose and Treat Bacterial Skin Infections in Cats

Bacterial skin infections in cats, also known as pyoderma, can be caused by either environmental or internal factors. The staph infection is the most common cause of bacterial skin infections.^[1] At home, you may be able to diagnose your cat’s symptoms by examining its skin for lesions, pustules, and sores. Your doctor will be able to confirm or disconfirm your diagnosis with examinations, cultures, and blood tests. Treatment depends on the severity of the infection. If it is a mild infection, topical antibiotics and medicated shampoos may be prescribed. If it is more serious, oral antibiotics in addition to topical ones will be prescribed.

EditSteps

EditLooking for Symptoms

Examine your cat’s skin. A bacterial skin infection can occur on any part of the cat’s body, including its face and nose. Thoroughly check your cat’s whole body by running your hands over its fur as if you are petting it. Feel and examine the skin for itchy, red skin lesions, pustules (pimples), hair loss, open draining sores, and epidermal collarettes, i.e., a circular lesion with a circular rim containing scales or peeling edges.^[2]
- Skin folds can develop bacterial skin infections as well. If your cat has skin folds, make sure to look under the skin folds for lesions, pustules, and sores.
- Bites and scratches from other animals can also cause skin infections and abscesses. Monitor these closely.
Monitor your cat’s itching. Try to determine if your cat began itching before or after the infection developed. If your cat began itching before the infection developed, then the cause of the infection is most likely environmental. If your cat began itching the affected area after it developed, then the cause of the infection is most likely due to internal factors.^[3]
Check to see if your cat has a fever. Cats who have deep pyoderma, a severe skin infection, may have open draining sores and a fever. Signs of a fever in cats are a loss of appetite, as well as depressed, lethargic, quiet, and withdrawn behavior. A cat with a fever may or may not feel warm to the touch.^[4]
- Other symptoms include vomiting, diarrhea, pale gums, and weakness.
Consult your vet. Because it is difficult to differentiate between a bacterial and fungal infection, you will need to take your cat to the vet once a problem is identified. Your vet will also be able to test whether the infection is caused by environmental factors or internal factors. The vet is not able to prescribe medication until they have performed an examination. The tests may include:^[5]
- A microscopic examination of the pustules and/or discharge.
- Antibiotic sensitivity and culture tests to pinpoint the bacteria causing the infection. This can include skin scrapings and fungal cultures to rule out fungal infections and microscopic parasites.
- Food trials and allergy testing to exclude food allergies as the cause.
- The use of a flea comb to examine the skin and hair for lice and fleas.
- Blood tests to identify any internal causes.

EditTreating Your Cat

Clip the hair around the affected area. This is necessary in order to maintain the cleanliness of the infected area and to treat it. Use grooming scissors to trim the hair to about half of an inch around the area. Make sure to clean the scissors with soap and water before and after using them.^[6]
- Many vet offices are happy to clip the cat's hair prior to a visit.
Administer oral antibiotics. First wrap your cat in a towel. While sitting on the floor, place your cat between your knees. Gently, but firmly, place one hand on top of your cat's head. Your thumb should be on one side of its jaw and your fingers on the other side. Then, place the syringe at the corner of your cat's mouth behind the canine tooth. Slowly administer the medication in small intervals so your cat has time to swallow.^[7]
- Depending on the severity of the infection, your doctor may prescribe topical antibiotics, oral antibiotics, or both.
- It is important that you finish the whole prescription unless your vet instructs otherwise.
- Common oral antibiotics are Clavulanic acid-amoxicillin (Clavamox), Cefovecin (Convenia), Clindamycin, and cephalexin.
Use medicated shampoos. Mix one part of medicated shampoo to five parts of water. Then, in a bathtub or basin, carefully wet your cat with warm water using a cup or hose. Make sure not to get water in its eyes, ears, or nose. Lightly massage the shampoo into your cat's hair in the direction of its hair growth. Finish by thoroughly rinsing your cat with a cup.^[8]
- Medicated shampoos, like Clinical Care, and shampoos that contain benzoyl peroxide are a great way to treat and clean infected areas on cats that have mild infections.
- These products may also help prevent future bacterial skin infections.
Consider possible causes. Bacterial skin infections can be caused by the environment, for example, allergens, chemical toxins, fleas, parasites, and mites. They can also be caused by internal problems such as food intolerance or allergies, hypothyroidism, hyperadrenocorticism, hormone imbalances, cancer, and gland diseases. If the problem continues or recurs, try to identify possible causes in the environment or in the cat's diet. If additional symptoms appear, consult a vet to see if there is an underlying health problems.
- Allergies to pollen, mold, pine needles or other substances are huge contributors to skin conditions. Try to remove these from the environment to see if your cat's condition improves.
Monitor your cat’s recovery. If your cat’s symptoms worsen, if it develops new symptoms, or if you do not see an improvement within a week, then contact your vet. Call the vet and describe your cat’s symptoms and recovery process. Your vet will most likely ask you to come in for an additional appointment.^[9]
- The vet may run more examinations, cultures, and blood tests.