Topical treatments for pyoderma

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According to recent updates to the “Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis,” topical therapy is now the first line treatment of choice for superficial bacterial folliculitis, or pyoderma.^1,2 As Jason B. Pieper, DVM, MS, DACVD, assistant professor at Iowa State University explained in his lecture at the 2025 Veterinary Meeting & Expo (VMX) in Orlando, Florida, the first step in the treatment of pyoderma should be topical therapy.¹

Pyoderma is a bacterial infection of the skin. It is divided based on the how deep the infection is in the skin and consists of surface, superficial, and deep pyoderma, with surface pyoderma being the most common form of the infection.¹

"Now one thing I will say…is superficial pyoderma does involve the hair follicles because again, the epidermis kind of goes down and surrounds….the hair shaft…with the hair follicle, so even infections down in that area are still considered a superficial pyoderma,” explained Pieper during his session.¹

When thinking about topical therapy for a pyoderma case, it is important to consider both the active ingredient that will be used and what the best formulation for the patient’s individual case is; as well as the frequency of the topical application, how labor intensive the therapy is, and what the realistic client compliance will be.¹

Ingredients

Chlorhexidine

The antiseptic chlorhexidine is the most widely available antimicrobial, according to Pieper. It is effective against viruses, bacteria, and fungi and can work synergistically with other ingredients like miconazole. Addressing concerns over antimicrobial resistance to this ingredient, Pieper explained that there has been no documented clinical resistance to this antiseptic to date.

He also noted that higher concentrations of chlorhexidine are not always better than lower concentrations, citing a 2013 study on chlorhexidine shampoos in 0.8, 2, 3, and 4% concentrations that found larger zones of bacterial growth inhibition in shampoos with 2 and 3% chlorhexidine compared to the shampoos containing 0.8 and 4% chlorhexidine.^1,3

Benzoyl Peroxide

This ingredient has antibacterial, keratolytic, degreasing, and follicular flushing activity. “People use this for acne, so again, cleaning out the hair follicles and kind of breaking up the oils, stuff like that,” said Pieper.

However, benzoyl peroxide can cause excessive drying of the skin, which lead to increased pruritus. It could also potentially bleach fabrics like bedding. Additionally, the ingredient has a low number of formulations.

Sodium hypochlorite

Sodium hypochlorite is similar to chlorhexidine in its effectiveness against bacteria, viruses, and fungi. “Historically people have talked about in human medicine using something called a Dakin’s solution. And what they would do is that they would go ahead and take bleach, dilute with water, put some baking soda in there, boil it to neutralize it, things like that, and…they would use it for children and do baths with some really resistant infections,” said Pieper. However, as Pieper explained, its drying effect is the concern.

“There is one study out there with just bleach and water, which is kind of what we think of with sodium hypochlorite, that did not show it to be drying when they used it, so that’s a nice benefit with this compared to say, benzoyl peroxide,” he added. There is a shampoo with salicylic acid (Command) that is available, said Pieper. Studies have shown that this shampoo is effective, according to his session.

Accelerated hydrogen peroxide

This ingredient is widely used for decontamination. It works well against gram-positive bacteria, some gram-negative bacteria, and dermatophytes, according to Pieper. He explained that there is a veterinary shampoo available with this ingredient in a one-gallon container that could be an effective option for decontamination.

Formulations

Considering the formulation that will be used for the patient is crucial, as it is important to consider which formulation will be best for the patient, location of the infection, formulation efficacy, and compliance. “There’s nothing worse than giving [patients] a product and they don’t use it at all—it’s not going to work at all,” said Pieper.

Shampoo

One of the oldest formulations, shampoo is labor intensive but is effective for generalized disease. As Pieper explained, shampoos have the ability to reach lesions that may have not been noticed. For shampoos, a contact time of 10 minutes is recommended, explained Pieper.

Spray

Although sprays can be easily applied, application can also be difficult with patients that have a thick haircoat. Moreover, compliance can be an issue with this type of formulation, as many cats and dogs are fearful of sprays.

“A lot of studies have shown that you’re going to need to apply that 1-2 times a day,” said Pieper, explaining that patients will need to be distracted after application to prevent treatment removal. Although relatively labor-intensive, sprays are useful for generalized lesions if wide areas are covered, as well as for small areas.

Ointment

This formulation is available in a range of combination medications, including steroids. “I typically think of them as your triple threat-type product,” said Pieper, explaining that ear medication ointments can work really well.

Ointments also work well for localized lesions. This formulation will also be applied 1-2 times a day.

Wipes

Wipes are a newer type of formulation. Applied 1-2 a day, these work best for localized lesions, especially in areas that are difficult to reach, according to Pieper. “I like them for paws, especially kind of those bulldog paws to get that kind of cheesy stuff in between,” he said. “It works really well to…get in there, wipe it out, and physically remove that debris.” He noted that the liquid in the wipes will also leave residual product in the area.

Mousse

This formulation is the newest formulation, explained Pieper. Mousse is best for multifocal, as well as generalized lesions, depending on the dog, their coat length, thickness, affected area, etc. It is applied a few times a week, depending on the patient. According to Pieper, mousse is a “great alternative to bath.” However, some products can irritate ulcerated lesions.

References

1. Pieper JB. Updates in pyoderma: Diagnosis and treatment. Presented at: Veterinary Meeting & Expo; Orlando, FL. January 25-29, 2025.
2. Hillier A, Lloyd DH, Weese JS, et al. Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases). Veterinary Dermatology. 2014;25(3):163. doi:10.1111/vde.12118
3. Kloos I, Straubinger RK, Werckenthin C, Mueller RS. Residual antibacterial activity of dog hairs after therapy with antimicrobial shampoos. Veterinary Dermatology. 2013;24(2):250. doi:10.1111/vde.12012