Pet Connection

Skin Deep

Staph infections in dogs can be difficult to eradicate without appropriate, consistent treatment

By Kim Campbell Thornton

Andrews McMeel Syndication

I was scratching my dog, Harper, beneath the chin a few weeks ago and felt a couple of unusual bumps. I couldn’t really get a good look at them because they were hidden beneath her wavy, mid-length coat. A few days later, they had multiplied.

Our veterinarian diagnosed a staph infection based on the appearance of the bumps and the prevalence of that type of bacteria on canine skin. Usually it doesn’t cause any problems, but licking, scratching, trauma or metabolic changes can cause staph populations to grow out of control. He prescribed a course of antibiotics and daily baths with medicated shampoo for a week.

Staph -- short for staphylococcus -- infections are common in dogs, says William H. Miller, a veterinary dermatologist at Cornell University College of Veterinary Medicine in Ithaca, New York. In rare instances, staph infections can be triggered by an immunodeficiency in which the skin’s protective barrier is weakened, but more typically they follow damage to the skin by some underlying disease.

“Allergies are the primary culprit,” he says. “Everyone has bacteria and yeast on their skin surface, and they typically do no harm as long as the individual’s skin and immune system are normal. With allergy, the skin is easily damaged by licking and scratching, and that sets up the perfect climate for infection with the animal’s own bacteria.”

The most common signs are hair loss and itching. If you have a shorthaired dog, you may notice small, red, raised bumps, known as papules, or pimples, also called pustules. These are hidden in dogs with thick, dense coats -- unless they appear on less-furry areas, such as the belly. As the infection progresses, you may see more hair loss -- caused by the dog scratching the itchy area -- and scaling, or flaky skin. Harper’s infection was localized to her neck, but dogs with widespread infections can suffer intense itchiness.

A variety of skin disorders cause pustules in dogs, but infection is the No. 1 cause, Dr. Miller says. Staph infections can be tentatively diagnosed simply by looking at the lesions, but cytology -- examining the pus in the pustule microscopically -- is required to confirm it. If the bacteria present are round -- cocci -- it is most likely a staph infection, but a bacterial culture is necessary to be certain the bacteria are staph.

“Although that is a valid reason to do a culture, the real benefit of a culture is to identify which antibiotics can be effective in treating the infection,” Dr. Miller says. “If the bacteria are susceptible to the antibiotic being used, the drug has to be used at the correct dosage to kill the bacteria, and it must be used long enough to kill all the bacteria.”

Treatment can take weeks to months, depending on the extent of the infection and whether it is superficial or descends far down the hair follicle. Topical treatments such as ointments, mousses, sprays and shampoos can help to shorten the course of treatment. Dogs should be treated until the lesions disappear, plus a few extra days to ensure that the deep part of the infection is wiped out. Stopping treatment too soon can cause infection to recur, this time with antibiotic-resistant bacteria.

Infections can’t be transmitted, but bacteria or yeast can be transferred from one animal to another through proximity. Owners themselves may transfer the microbes if they pet an animal with abnormal skin and then pet another animal without first washing their hands. If you know that one pet has a skin infection, hand hygiene is important to prevent spreading it to other animals in the home.

Take treatment seriously.

“For any number of reasons, we are seeing more and more cases of resistant bacteria, and some are so resistant that we have few or no antibiotics that can be used,” Dr. Miller says. “In some cases, the animal has to be euthanized because we have no effective means of treating the infection.”

Q&A

Eye disease

common in cats

Q: My cat has been diagnosed with anterior uveitis. What can you tell me about this eye problem?

A: You probably first noticed that your cat’s eye was painful because he was squinting or tearing up, his eyeball was inflamed and his third eyelid -- that thin membrane at the inner corner of the eye -- was swollen. Sometimes the eye appears unusually enlarged. We usually see it in middle-aged or older male cats, but any cat can be affected.

Those signs can indicate inflammation of the uvea, the pigmented middle layer of the eyeball made up of the iris, the ciliary body and the choroid. Cats with uveitis may be extremely sensitive to light or show other signs of pain, such as pawing at the eye.

Possible causes include underlying infectious diseases such as feline immunodeficiency virus, feline leukemia virus and feline infectious peritonitis; trauma; cataract formation; and cancer. Sometimes the cause is unknown.

Signs of uveitis can mimic those of other eye diseases or injuries, and puncture wounds of the eye can go unnoticed when they occur, so uveitis can be a challenge to diagnose. A thorough history; physical exam to detect underlying viral, bacterial or fungal diseases; and eye exam are all important. Tell the veterinarian about any cat fights, pointy plants or other ways a cat’s eye may have been unknowingly injured. Imaging such as radiography or ultrasonography may be necessary as well.

Uveitis can result in gradual blindness or irreversible complications such as glaucoma and cataracts if it’s not caught early or goes untreated. Depending on the cause, your veterinarian may prescribe topical and systemic corticosteroids, NSAIDS and other drugs to control inflammation and pain and treat underlying causes if known. If the underlying cause is treatable, cats with anterior uveitis can have a good outcome. -- Dr. Marty Becker

Do you have a pet question? Send it to askpetconnection@gmail.com or visit Facebook.com/DrMartyBecker.

THE BUZZ

Ticks weather winter,

bite pets year-round

-- Don’t assume winter weather means your dog or cat is safe from disease-carrying ticks. Contrary to popular belief, ticks do fine in winter, coming out on sunny days for a blood meal and burrowing beneath leaf litter or snow to shelter from extreme cold. Both human and veterinary forecasts predict that 2019 will be a big year for ticks. Ask your veterinarian about the prevalence of tick-borne diseases in your area and whether your pet needs year-round prevention from the blood-sucking arachnids. If you see a tick on your pet, use tweezers or a tick removal device to grasp the tick as near to the skin as possible, and tug firmly. It’s better to remove it yourself than to wait and have the veterinarian do it because ticks can transmit disease in only a few hours.

-- California legal beagles have added new laws regarding pets and pet ownership that went into effect this month. Judges can now determine who gets custody of family pets during a divorce, taking into consideration factors such as who spends the most time caring for the pet. And pet stores can no longer sell dogs, cats or rabbits obtained from breeders but must instead offer animals from shelters or rescue groups. Stores must also post the names of the organizations that provided the animals.

-- Love watching the glitter drift down in snow globes? Be careful to display them where pets can’t knock them over and break them. The liquid inside some imported snow globes may contain ethylene glycol, or antifreeze, according to the Pet Poison Helpline. As little as a teaspoon of the highly toxic liquid can cause acute kidney failure and death. Signs of poisoning include acting drunk or uncoordinated, excessive thirst and lethargy. Immediate treatment is essential to save the pet’s life. -- Dr. Marty Becker, Kim Campbell Thornton and Mikkel Becker

ABOUT PET CONNECTION

Pet Connection is produced by a team of pet-care experts headed by "The Dr. Oz Show" veterinarian Dr. Marty Becker and award-winning journalist Kim Campbell Thornton. They are affiliated with Vetstreet.com and are the authors of many best-selling pet-care books. Joining them is dog trainer and behavior consultant Mikkel Becker. Dr. Becker can be found at Facebook.com/DrMartyBecker or on Twitter at DrMartyBecker. Kim Campbell Thornton is at Facebook.com/KimCampbellThornton and on Twitter at kkcthornton. Mikkel Becker is at Facebook.com/MikkelBecker and on Twitter at MikkelBecker.

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