Allergic, parasitic, and viral skin disease treatment toolkit

“The first step to healthy skin for pets is a healthy diet.”

Most veterinarians understand the basics of preventing and controlling feline and canine skin issues, but today’s pet health professionals should strive to be aware of the multitude of product and treatment options for managing skin issues when they arise.

Most methods to diagnose parasitic skin disease are through fecals or biopsies, said Paul Calhoun, DVM, a veterinarian with Animal Medical Center of Hattiesburg in Mississippi. The latest treatment methods are monthly preventatives that are applied topically or systematically, topical baths, or dips, he added.

“The first step to healthy skin for pets is a healthy diet,” said Dr. Calhoun. “Low-quality food that does not satisfy your pet’s nutritional needs could result in a dull coat and dry skin,” he said. “Best practices are to identify changes in skin color, hair loss, and clinical signs such as itching—all symptoms that should be examined by a veterinarian. Also, wellness exams twice yearly are very important to help evaluate skin changes, such as lumps and bumps.”

The best practice for skin care is prevention, said Jeff Werber, DVM, a veterinarian in Los Angeles.

“For dogs, itching and scratching is the No. 1 sign of allergic skin disease and, if left untreated, it can lead to open sores and wounds that can become infected,” he said. “If veterinarians see signs of allergies, I encourage them to consider treatments like Apoquel to ensure their dog doesn’t cause a self-inflicted wound from excessive rubbing or itching.”

Dr. Werber is seeing more fatty acid supplements in response to skin issues, as pet owners are paying more attention to their pet’s diets.

“It’s common for pet owners to try over-the-counter remedies first, including antihistamines and dips, 
but these treatments rarely provide relief, which is 
why a veterinarian is needed,” he said. “Apoquel 
will provide fast and safe relief for symptoms associated with allergies triggered by food, fleas, or contact allergens, as well as atopic dermatitis. It works quickly.”

An evolution has occurred in topical treatments for parasitic skin diseases in the past decade, and while topical treatments are still popular, more oral treatments administered once a month or once every three months are available for dogs, said Acacia Roman, a tech services veterinarian at Vetiquinol in Fort Worth, Texas.

“As there are variable options for treatment, selection will depend on several factors, including species, toxicity, bathing frequency, budget of the owner, compliance, preference, and time to work,” she said. “In most cases, my clients typically tend to prefer the oral route for their dogs. Oral options for cats is very limited and the topical option is preferred.”

Stopping the itch

Itching is the single greatest reason for veterinary visits, yet millions of dogs continue to suffer because their owners underestimate the severity or frequency of their dogs’ itching, said Victor Oppenheimer, DVM, director of Hospital de Animales Perla del Sur in Ponce, Puerto Rico.

“If veterinarians notice signs of allergic dermatitis—frequent or constant scratching, licking, biting, scooting, and/or rubbing—I encourage them to educate dog owners about allergic skin disease and look at ways to treat the itch at its source,” he said.

The main trend in skin health centers around stopping pets from scratching—and stopping the itch, he said.

“Most of the skin problems are multifactorial; there may be a hormonal, unknown allergy, immunological problems, as well as other components,” he said. “This makes it frustrating for the owners as well as the veterinarian because there is not always a single injection or tablet that solves the problem.”

However, recent medications are trying to control the itch by reducing the activity of the cells that trigger the itching, he said.

“On the alternative medicine side, those of us who are experts in Class 2, not Class 3 or 4, cold laser treatment, can manipulate systems involved with no secondary effects,” he said. “This treatment can reduce scratching by at least 50 percent.”

Dr. Oppenheimer agreed that Apoquel is one of the newest drugs that can stop itching with minimal side effects, adding that it’s a great choice when there isn’t a definitive diagnosis.

“If the problem is due to ectoparasites like fleas and ticks, Bravecto, Nexguard, and Simparica are exceptional drugs,” he added. “They last one to three months, and as they have new ingredients, there is a low chance for resistance.”

Viral skin diseases

Histiocytic skin disease, if not metastatic, may respond to surgical excision and/or systemic immunosuppressive drugs, such as cyclosporine A, said Roman.

The most common canine and feline viral skin diseases she has seen are papilloma-type and usually regress spontaneously.

“Skin lesions caused by other viruses may be treated with antiviral medications depending on the case,” she said.

According to Calhoun, cats and dogs are seen periodically with papillomavirus, diagnosed via histopath.

“Feline herpes is seen with respiratory signs, as is calicivirus,” he said. “Feline leukemia also causes skin disease.”

One of the latest options for diagnosis is in-home blood tests, which can provide clients with faster results.

Making noise

The availability of new treatments to manage pruritus in atopic dogs is a game changer, according to Roman.

“We have used glucocorticoids to alleviate the clinical signs of atopic dermatitis,” she said. “The introduction of JAK inhibitor oclacitinib as well as monoclonal antibodies—caninized anti-cIL-31—to our tool box to our manage atopy in dogs, give us the opportunity to provide relief to the pruritic patient with few side effects while we manage this life-long disease multimodally.”

Another game changer is the treatment of generalized demodecosis with oral isoxazoline drugs such as Nexgard and Bravecto instead of the daily oral ivermectin or topical amitraz topical dips, Roman added.

New tech is aiding with skin health issues, as well. Oppenheimer referred to his use of Class 2 cold lasers.

“It is frequency specific,” he said. “This means that I can select specific treatments for the skin, such as increased circulation, reduction in inflammation, eliminate common bacteria, and other microorganisms so that there’s is actually a cure and not just control of the skin disease. It works. Class 2 cold laser is the future of medicine.”

Feline skin care

Cats are usually the exception to all the rules when it comes to skin health.

“The main problem owners have with cats is medicating them without being scratched or bitten,” Oppenheimer said. “There is a product called Convenia, which is an injection for bacterial infections and abscesses.”

Veterinarians should tell their pet parents to groom their cat weekly, especially if they go outside, as it will help them notice any scratches that may have broken the skin barrier, which will help veterinarians anticipate bacterial infections, he added.

Calhoun said hair loss is the most common sign of skin disease in cats.

“Additionally, there can be changes in skin color and texture,” he said. “Many internal concerns, such as liver disease, kidney disease, and parasites could all cause poor skin conditions.”

Grooming matters

For both dogs and cats, veterinarians should advise pet owners to regularly groom breeds whose coats require it to remove mats and undercoat, routinely brush their pet to reduce shedding, and bathe dogs when necessary—but not with human shampoos, said Oppenheimer.

“A dog’s skin has a pH of 7 to 8, which is neutral to alkaline, and human skin has a pH of 5.5, which is acidic,” he said. “Using human shampoos on pets isn’t healthy. However, shampoos specifically formulated for pets, such as those containing oatmeal, can soothe, calm, and moisturize pets’ skin, owners can bathe them weekly.”

While it seems simplistic, reminding owners to engage in general brushing is important for several reasons, Oppenheimer said.

“Brushing spreads the skin’s natural protective oils across the surface,” he said. “Consistent grooming also increases circulation and blood flow, which help maintain healthy skin. Following these basic steps will prevent most of the skin diseases that are caused by poor grooming.”


When it comes to skin health issues, it’s important for veterinarians to talk with owners before they start using any product on their pet.

“Most veterinary clinics carry quality, effective products to treat skin issues,” Calhoun said. “Additionally, annual blood testing is important in order to detect internal changes of organs such as kidney and pancreas.”

It’s important to always consider “rational antimicrobial use” to choose an efficacious antibiotic therapy while preventing antibiotic resistance, Roman said.

“In addition, topical medicated products can be of benefit when treating skin infections or pruritic conditions,” she said. “Seba-Hex by Vetoquinol is an option for pyoderma, folliculitis, and seborrhea. Using topical products may reduce the need for oral antimicrobial use in numerous conditions.”

“Apoquel has helped a lot of dogs, but you still need to implement good parasite control, including flea prevention, and you still need to ID the potentially underlying adverse reactions.”

—Jeanne B. Budgin, DVM, DACVD, president of the American Academy 
of Veterinary Dermatology

“In addition to judicious use of oral antimicrobials, I often recommend liberal use of topical antimicrobials—such as shampoos, sprays, and other formulations—as adjunctive or sole therapy for skin infections. Topical therapy can be helpful to prevent infection recurrence as we determine and control the underlying allergy. With recurrent or relapsing infections, culture and susceptibility of the skin is often indicated to base appropriate antimicrobial therapy. I also recommend strict ectoparasite control for any pruritic patient. This means flea control and therapies to rule out pruritic superficial mites—such as scabies in our small animal patients and fly control in our large animal patients.”

—Christine Cain, DVM, DACVD, assistant professor of dermatology and allergy at the Matthew J. Ryan Veterinary Hospital at the University of Pennsylvania

“The most common allergies I see in my practice are caused by environmental conditions, starting with pollen. Dust mites are a really big one, as are grasses, weeds, mold, and any and all of the above. Rounding out the top three causes are flea hypersensitivity and cutaneous adverse reaction to food.”

—Christine Zewe, DVM, a resident in dermatology at Cummings School
of Veterinary Medicine at Tufts University

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