Canine parvovirus treatment receives conditional approval

The U.S. Department of Agriculture (USDA) has granted a conditional license for the first therapeutic solution to treat canine parvovirus (CPV).

Canine Parvovirus Monoclonal Antibody—Elanco's first monoclonal antibody treatment—is a single, intravenous dose used to treat clinical signs caused by parvo in sick puppies and dogs, regardless of vaccination status.

Canine parvovirus treatment receives conditional approval
The Canine Parvovirus Monoclonal Antibody decreases mortality and may provide faster resolution of the symptoms, thus limiting the need for hospitalization and is less physically and emotionally taxing than traditional supportive therapy, according an announcement from Elanco. (Photos courtesy of Elanco)

The treatment can be administered to dogs 8 weeks or older with CPV, according to a May 2 Elanco announcement. It is expected to be available to veterinarians for direct purchase through Elanco, pending individual state approvals.

CPV is a highly contagious virus that can affect all dogs, but unvaccinated dogs and puppies younger than 4 months old are the most at risk, resulting in a fatality rate greater than 90% if left untreated.

The virus affects dogs' gastrointestinal tracts and is spread by direct dog-to-dog contact and contact with contaminated feces, environments, or people. This makes treatment especially important in animal shelters where parvovirus can quickly spread through puppies and young dogs in large numbers.

Dr. Kristin Zersen, assistant professor of emergency and critical care at Colorado State University College of Veterinary Medicine & Biomedical Sciences' Veterinary Teaching Hospital, said, "With traditional treatments, there can be unpredictable outcomes with potentially high costs. With the Canine Parvovirus Monoclonal Antibody, puppies may feel better faster and go home sooner."

Canine parvovirus treatment receives conditional approval

No specific drug is available that will kill the virus in infected dogs, and treatment is intended to support the dog's body systems until the dog's immune system can defeat the viral infection. Treatment has generally consisted of intensive care efforts to combat dehydration by replacing electrolyte, protein and fluid losses, controlling vomiting and diarrhea, and preventing secondary infections. Treatment in private practice settings can cost up to several thousand dollars and last for days, making it an unaffordable option for many pet owners.

In the treatment efficacy study, none of the 28 puppies treated with the Canine Parvovirus Monoclonal Antibody died and all had significantly faster times to resolution of vomiting, inappetence, and lethargy.

Dr. Jeanette O'Quin, associate professor in the Department of Veterinary Preventive Medicine at The Ohio State University College of Veterinary Medicine, said if treatment works as well in practice as it did in the research trials, "then it could have huge impacts on how we treat parvo. Shortening the time that intensive treatment is needed could make treatment more affordable for clients. Even shortening hospitalization by a single day could significantly reduce costs of supportive care and make treatment accessible to more people."

Dr. O'Quin says she sees great potential for the use of monoclonal antibodies in treating canine parvovirus.

"For this product to also be effective in improving access to care among those who can't afford parvo treatment, it will also need to be affordable," she added.

A version of this story appears in the July 2023 print issue of JAVMA.