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DENVER/Oct. 31, 2023 – A new paper published in Frontiers of Veterinary Science revealed a concerning finding: Less than 40% of dogs in the longitudinal Golden Retriever Lifetime Study were on preventive heartworm medications at baseline. This is a troubling discovery, as heartworm disease is a serious and potentially fatal condition that is preventable in dogs.  

This study, funded by Morris Animal Foundation and conducted by researchers at Lincoln Memorial University, investigated what factors predict heartworm preventive medication use in the golden retrievers in the Study cohort. The team unearthed critical factors associated with a reduced likelihood of dogs being on heartworm prevention, including dogs in the highest quartile of height, sexually intact dogs and dogs receiving supplements. Conversely, dogs receiving other vaccines or diagnosed with an infectious disease or an ear, nose, or throat health condition during their health checkups in the last year were likelier to receive heartworm preventives.  

Dr. Lauren Wisnieski, Associate Professor of Public Health and Research at Lincoln Memorial University and the study’s principal investigator, emphasized the scarcity of studies examining the prevalence of prophylactic use in dogs. She said this recent project is especially crucial as climate change has extended mosquito season in certain states, making year-round vigilance imperative. 

Heartworm larvae are deposited onto a dog’s or cat’s skin during a mosquito bite, where they undergo maturation, sometimes for several months. Despite advances in understanding heartworm disease, including improved diagnostic tests and safer, more effective treatments, heartworm disease remains a significant health threat for pets in all 50 states. 

Heartworms can grow to a foot long and cause lasting damage to the heart, lungs and other organs. While treatment is possible, it can be financially costly for the owners and often means a long recovery, if successful, for the pet. 

“This data can help inform how veterinarians talk to clients,” Wisnieski said. “It can also help identify populations that have risks of nonadherence. Prevention is a cheaper alternative to the financial burden of treating heartworm disease later.”   

Wisnieski said now that she and her team have preliminary data, they will work on broadening their research scope. This expansion will encompass diverse dog breeds, those given supplements, the impact of cost on preventive use and the effect of the human-animal bond.   

About Morris Animal Foundation 
Morris Animal Foundation’s mission is to bridge science and resources to advance the health of animals. Founded in 1948 and headquartered in Denver, it is one of the largest nonprofit animal health research organizations in the world, funding nearly $160 million in more than 3,000 critical animal health studies to date across a broad range of species. Learn more at  

Media Contact: Annie Mehl