Topical bacteriophage therapy for staphylococcal superficial pyoderma in horses: a pilot study

The University of Florida College of Veterinary Medicine is currently recruiting horses with bacterial skin infections for a clinical research trial to determine if topical bacteriophage therapy can help clear infections without side effects.

Inclusion & exclusion criteria: Horses with Staphylococcus aureus skin infections if they have compatible clinical signs of skin infection. The clinical diagnosis will be confirmed by cytological, microbiological (culture), and bacterial identification (MALDI TOF). There is no age, breed or sex requirement. Horses cannot receive any systemic or topical antibiotic therapy within a week before bacteriophage administration. Horses with known comorbidities will be allowed to stay on systemic therapies as long as no changes have been made in the 4 weeks prior to bacteriophage application.

Treatment: Participants will have 2.5 mLs of a topical bacteriophage product applied to a small area chosen by the investigator once daily. Participants will also have 2.5 mLs of a placebo product applied to a separate small area chosen by the investigator once daily. The handler applying the products will not know which product is the treatment and which product is the placebo. The horse will be examined on the first day of treatment, at day 7, day 14, day 21 and day 28 of treatment by the primary investigator of this study. Tape specimens and culture swabs will be collected at all visits for microscope evaluation, culture, and bacterial identification. The topical product and placebo product will be replenished at each weekly visit as well. These visits will be done at the horse’s primary location as long as it is within a 1 hour driving distance from the University of Florida hospital. Otherwise, the horse can be brought to the University of Florida for follow up.

Cost: The study will pay for the topical products to be applied, skin cytology and culture and sensitivity. No additional costs will be covered.

Contacts: You can contact our Large Animal Hospital at (352) 392-2229 or email: to schedule an appointment with Clinical Trials. Dr. Kalie Marshall is the Principal Investigator.

Background: In the future, this product could help horses (and other species) suffering from skin infections. Skin infections are common in horses, especially those with underlying allergies. Allergies cause a breakdown in the skin barrier allowing for an overproduction of bacteria which in turn leads to skin infections. In recent years, the emergence of bacterial resistance to antibiotics has been shown in humans and animals. Therefore, a novel treatment, such as the bacteriophages in this study, that will not require the use of antibiotics could be extremely beneficial. Bacteriophages are viruses that specifically infect and kill bacteria, but do not harm or otherwise affect horses. They are safe to use, specific to the bacteria of interest, and found everywhere in the environment.

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Boehringer Ingelheim

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