The American Heartworm Society and Association of Shelter Veterinarians’ 2024 Shelter Heartworm Management Practices Survey [Abstract]

Abstract

Introduction

The Association of Shelter Veterinarians (ASV) and American Heartworm Society (AHS) have a long-standing collaboration to develop and deliver evidence-based recommendations for heartworm prevention, diagnosis, and treatment in animal shelters. The 2024 Shelter Heartworm Management Practices Survey aimed to collect data from shelters across North America to address the ongoing growing challenges and concerns related to the disease and its impact on community animal welfare.       

Methods

The 2024 survey comprised a total of 58 questions, most of which mirrored those from previous versions. Shelter veterinarians across North America were invited to respond electronically through SurveyMonkeyⓇ. Responses were reviewed and analyzed using descriptive statistical methods.

Results

A total of 135 responses were received. Responses were distributed across private humane societies/SPCA (49%), municipal shelters (27.5%), public-private partnership shelters (18.6%), breed/species-specific rescues (2%), and foster-based organizations (1%). Respondents were geographically spread across the midwestern (30.4%), southeastern (29.4%), western (26.5%), and northern (14.7%) United States. The majority of shelters employed full-time veterinarians (86.3%). Most shelters (77%) provide monthly heartworm preventives for dogs, primarily using oral ivermectin products per product label (50%), followed by oral milbemycin (33%). Over three quarters (76.2%) of the shelters tested dogs over the age of six months for heartworms, often during intake and/or at veterinary examination (68.8%), with antigen testing as the primary diagnostic method (96.4%). Treatment was offered to all heartworm-positive dogs in 66.1% of the shelters, while 22.9% of the shelters made treatment decisions based on adoptability (48.1%) and resources (25.9%). The primary adulticide treatment was a 3-dose melarsomine protocol (70.5%), followed by a 2-dose melarsomine protocol (22.9%). Among shelters implementing these protocols, doxycycline or minocycline were commonly used as an adjunct treatment. In 49.5% of shelters, dogs were routinely sedated or anesthetized during injection administration. Heartworm-positive dogs were typically housed in the shelter (67%) or in foster homes (49.5%) and made available for adoption during treatment. Exercise restrictions were applied in 80.6% of shelters, starting at the time of diagnosis (55.8%) and continuing for several weeks after the last melarsomine injection (89.6%). Anxiolytics or psychotropic medications were used in 58.2% of cases during the restriction period. Heartworm prevention was provided by 49.1% of respondents that admitted cats and 25.9% of those that admitted ferrets.

Conclusion

These survey results highlight the challenges shelters have faced and the improvements made over the past five years, offering further insights for targeted operational and educational improvements about heartworm disease in animal shelters.

Financial Support and Conflict of Interests

This work was supported by the Association of Shelter Veterinarians and the American Heartworm Society, a grant was provided by Maddie’s Fund, Pleasanton, CA. Dr. Lucy Fuller serves on the Board of Directors of the Association of Shelter Veterinarians, and Dr. Uri Donnett serves on the Board of Directors of the American Heartworm Society.