Keywords
1. Heartworm prevalence in Colorado
2. Dog importation impact
3. Animal shelter disease prevention
4. Dirofilaria immitis transmission
5. Veterinary heartworm guidelines
A mounting concern has gripped the veterinarian community in Colorado as recent studies reveal a significant rise in the prevalence of heartworm (Dirofilaria immitis) cases among domestic canines. The period between 2013 and 2017 saw an alarming 67.5% increase in heartworm incidence in dogs in the state. This escalation is thought to be linked to the substantial importation of dogs from other states, particularly those with higher instances of the disease. These findings have been well documented in the research published in “Parasites & Vectors” (DOI: 10.1186/s13071-019-3473-0), underscoring the correlation between dog importation and heartworm prevalence in Colorado over the given period.
Animal welfare organizations have long been transferring large numbers of dogs between states to foster adoption and mitigate euthanasia rates among the homeless dog population. However, according to the study, only about one-third of these organizations carry out heartworm screening or offer treatment and preventive measures before transportation. Historically, the prevalence of heartworm in rescue dogs and those from animal shelters, especially after natural disasters, has been ranging from 14.6% to 48.8%.
The Comprehensive Analysis: 2013-2017 Data and the Colorado Dog Importation Scene
This extensive study used data sourced from the Companion Animal Parasite Council (CAPC) interactive heartworm prevalence maps and the Colorado Department of Agriculture Pet Animal Care Facilities Program (PACFA) to analyze the relationship between dog importation and the changing heartworm prevalence in Colorado from 2013 to 2017.
The statistics are quite revealing: from 2014 to 2017, over 114,000 dogs were imported to Colorado via more than 130 animal shelters and rescue organizations. This number represented roughly 9.5% of the estimated total 2017 Colorado dog population, which stood at approximately 1.2 million. The majority of these imported dogs came from states with higher heartworm prevalence rates, with New Mexico accounting for just over 30% of the relocations. Texas and Oklahoma combined amounted to 49% of the total.
The Risk Factor: Relevance to Local Transmission
Veterinary experts and animal welfare advocates are raising the alarm about the potentially heightened risk of local heartworm transmission due to the movement of dogs from highly endemic areas to regions with historically lower prevalence rates. Heartworm disease is transmitted through mosquito bites and is a grave threat to canine health, potentially leading to severe lung disease, heart failure, and other organ damage.
The study’s implications are far-reaching, suggesting that animal welfare organizations—and veterinarians alike—must elevate their efforts in heartworm testing and preventive initiatives both before and after the relocation of dogs, particularly from high-risk states. The silent nature of heartworm infection, with its 6-month pre-patent period, warrants repeated testing to ensure early detection and treatment.
Acting on the Findings: Recommendations for Animal Welfare and Veterinary Practices
The authors of the study, Jason J. Drake and Rudolph S. Parrish of Elanco Animal Health, advocate for increased vigilance and ongoing preventive strategies in order to mitigate this growing public animal health issue. Their recommendations include:
1. Enhanced testing protocols for animal welfare organizations that transport dogs between states.
2. Regular and repeated testing for heartworm by veterinarians, especially in areas witnessing an influx of imported dogs.
3. Strengthening preventive measures by following guidelines recommended by organizations such as the American Heartworm Society and Companion Animal Parasite Council.
4. Raised awareness among pet owners regarding the risks and signs of heartworm disease, highlighting the importance of preventive care.
5. Inter-organizational cooperation to establish standards for the interstate transport of rescue and shelter dogs.
In the face of these challenges, other studies referenced within this research, such as those conducted by Levy JK et al., 2007 (DOI: 10.2460/javma.231.2.218), Tzipory N et al., 2010 (DOI: 10.1016/j.vetpar.2010.03.016), and others, have consistently exhibited the critical need for enforceable policies and collaborative strategies to combat the spread of heartworm disease.
As communities in Colorado and beyond navigate the complexities of canine importation and adoption, it becomes clear that rigorous and proactive health protocols are the linchpin in securing the welfare of these companion animals. The veterinary profession, in concert with animal caregivers and welfare groups, must remain vigilant and responsive to the evolving landscape of pet health threats such as heartworm disease.
References
1. Drake, J. J., & Parrish, R. S. (2019). Dog importation and changes in heartworm prevalence in Colorado 2013-2017. Parasites & Vectors, 12(1), 207. DOI: 10.1186/s13071-019-3473-0
2. Levy, J. K., Edinboro, C. H., Glotfelty, C. S., Dingman, P. A., West, A. L., Kirkland-Cady, K. D. (2007). Seroprevalence of Dirofilaria immitis, feline leukemia virus, and feline immunodeficiency virus infection among dogs and cats exported from the 2005 Gulf Coast hurricane disaster area. JAVMA, 231(2), 218–225. DOI: 10.2460/javma.231.2.218
3. Tzipory, N., Crawford, P. C., Levy, J. K. (2010). Prevalence of Dirofilaria immitis, Ehrlichia canis, and Borrelia burgdorferi in pet dogs, racing greyhounds, and shelter dogs in Florida. Veterinary Parasitology, 171(1-2), 136–139. DOI: 10.1016/j.vetpar.2010.03.016
4. Barrett, A. W., & Little, S. E. (2016). Vector-borne infections in tornado-displaced and owner-relinquished dogs in Oklahoma, USA. Vector Borne Zoonotic Dis, 16(7), 428–430. DOI: 10.1089/vbz.2015.1923
5. Donnett, U., Hubbard, K., Woodruff, K., Varela-Stokes, A. (2018). Prevalence of canine heartworm infection in Mississippi animal shelters. Veterinary Parasitology, 259, 68–73. DOI: 10.1016/j.vetpar.2018.07.007
With stakes as high as the health and wellness of our beloved pets, the commitment to comprehensive testing, informed decision-making regarding animal transport, and rigorous preventive care becomes not just a recommendation, but a requisite course of action.