New Research Adds Support to Change Heartworm Protocol

Phase 2 Study calls for fighting both the mosquito and the heartworm

San Antonio, August 5, 2016 -- AVMA Convention -- Phase 2 of a groundbreaking study by John McCall, MS, PhD, demonstrates an even greater need to change the approach in fighting the rising incidence of heartworm infection in #dogs. The new data shows that blocking transmission from dogs to mosquitoes, and from mosquitoes to dogs, using repellents/insecticides and macrocyclic lactone preventives is part of a multi-modal approach. The data will be discussed at a press conference briefing Saturday August 6, presented as a poster session on Sunday August 7 at the American Association of Veterinary Parasitologists Annual Meeting and as an educational session at the AVMA on Monday August 8. #FightHeartworm #veterinary

Phase 1 of McCall’s research showed the value of topical repellent insecticidal products in a “double defense” protocol for protecting dogs against the vector – the mosquito and use of a preventive against heartworm disease. The study was presented at the Western Veterinary Conference in March 2016. Phase 2 of McCall’s study further supports using a topical parasiticide to repel and kill mosquitoes, rather than relying solely on an oral heartworm preventive. These two studies combined send a powerful message regarding the efficacy of a double defense protocol.

“This second phase of the Ceva sponsored investigation uncovers an important benefit of the mosquito repellency feature of Vectra® 3D,” says Elizabeth Hodgkins, Veterinary Relations Director for Ceva Animal Health. “This research shows that Vectra® 3D, by repelling and killing mosquitoes that may transmit the disease, adds an extra layer of protection along with the heartworm preventive.  This is exciting news, and reinforces the new "Double Defense" protocol – Vectra® 3D and a heartworm preventive - for protecting dogs from mosquitoes and heartworm disease transmission.”

McCall’s Phase 2 findings included:

  • The overall anti-feeding efficacy of Vectra 3D was 98.5 percent.
  • No worms were found in the Vectra 3D and heartworm preventive treated group.
  • The combination of Vectra 3D for mosquito control and a heartworm preventive had superior efficacy for protecting dogs against heartworm infection compared to a heartworm preventive alone in Phase 2 of the study.

John McCall is a professor emeritus in the Department of Infectious Diseases at the University of Georgia College of Veterinary Medicine. His work in the Phase 2 study proves that Vectra® 3D, a topical parasiticide, plays a leading role in the double defense protocol by repelling and killing mosquitoes. (See the full details on the design and results of the new study at

 “This is a new area to explore in veterinary medicine, and I am very excited about the results. After fighting heartworm the same way for decades, it’s time for a new approach,” McCall says, “and that includes fighting the mosquito as well as the heartworm.”

This new protocol comes as the incidence of heartworm disease continues to increase nationally. In just two years, from 2013-2015, there was a 166 percent increase in reported positive heartworm cases, according to the Companion Animal Parasite Council (CAPC). Additionally, the American Heartworm Society (AHS) has tracked the geographic spread of heartworm disease to all 50 states and its increased prevalence in several regions of the country.

“The AHS stresses the importance to pet owners of giving a heartworm preventive year-round to prevent the serious and often deadly consequences of heartworm disease,” says Tom Nelson, AHS executive board member and co-author of the society’s guidelines for the prevention, diagnosis and management of heartworm infection. “The multimodal approach, like on the human side, is something we need to embrace more in veterinary medicine and we need to look at how we can decrease the exposure to the infection.”

For the past several years, most veterinarians relied on a unimodal strategy to protect dogs by prescribing oral medications, but vector control has received little attention.

“We’ve really neglected the other parasite that’s involved in the heartworm life cycle, and that’s the mosquito,” says Susan Little, DVM, PhD, and Regents Professor of Parasitology at Oklahoma State University. “Now we can implement a double defense approach and actually use something that repels and kills mosquitoes, in addition to the heartworm preventive.”

Ceva Animal Health will continue its extensive campaign to educate the veterinarian community on the groundbreaking research. A shareable infographic showcasing the dangers of mosquitos and how the Double Defense Protocol can help protect your dog can be found here. #FightHeartworm #veterinary

*Do not use Vectra 3D on Cats. 

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