Veterinary Medicine - August 2008 - (Page 422d)

From the expert 1. Why talk about heartworm disease out West? In 2002 and 2005, the AHS conducted surveys of clinics throughout the United States on the prevalence of canine heartworm disease. Western clinics that responded to surveys in both years reported a substantial increase in heartworm positive cases in 2005 from 2002. Nevada’s cases almost doubled and Washington’s almost tripled. Utah’s case increased by about 20%, California’s by 8%, and Oregon’s increased by 5%.a Overall, the reported heartworm-positive cases in the West are comparatively low; however, what’s crucial is the rate at which the numbers are increasing. ring for quite some time. As heartworm-positive dogs continually move into low endemic areas, the infection rate in untreated domestic dogs and the wild canid population is expected to increase. And once heartworms are established in the local wildlife reservoirs, eradication is virtually impossible. This has been best demonstrated by looking at prevalence of heartworn in wild canids over the past several years. One study detected pockets of heartworm infection as high as 91% in northern California coyotes.4 Tom Nelson, DVM a Companion Animal Parasite Council Board Member and the past President for the American Heartworm Society (AHS), explains why some practitioners in the West are taking a closer look at heartworm disease. 4. How aware are veterinarians of the existence of heartworm disease within the West? Many practicing veterinarians started their careers when there were few, if any, reports of heartworm disease out West. Because of this, I think some western veterinarians don’t view it as a potential threat to or as an established issue in their areas I heard an internal medicine expert say that Los Angeles did not have many cases of heartworm disease, and most cases diagnosed were in dogs that have moved from a more endemic area. However, the L.A. County West Vector Control District website states that Aedes sierrensis are common in L.A. County, which indicates that heartworm disease can be locally transmitted. Historically, heartworm disease in the United States was found in the Southeast. Now it’s spread across the country, including areas that aren’t testing for it or recommending use of heartworm preventives. If testing and preventive use in those areas doesn’t increase, the incidence of heartworm disease will reach a critical mass. References * 1. Scoles GA, Dickson SL, New foci of canine heartworm associated introductions of new vector species: Aedes sierrrensis in Utah, in Proceedings. Heartworm Symposium 1995;25-35. 2. Mar Vista Animal Medical Center. “The heartworm situation in L.A.” Available at: www.marvistavet.net/html/body_the_ heartworm_situation_in_la.html. Accessed July 23, 2008. 3. Davis County Mosquito Abatement. “Western treehole mosquito.” Available at: www.davismosquito.org/mosquitoes/ mosquitoes.keyhtm#treehole. Accessed July 23, 2008. 4. Sacks BN. Increasing prevalence of canine heartworm in coyotes from California. J Wildl Dis 1998;34:386-389. 2. How is the arid West a suitable environment for heartworms? People create a suitable environment as they change it. Salt Lake City went from almost no incidence of heartworm disease to having a problem when the city planted trees to improve the urban environment. Over time, knotholes developed, which created a breeding ground for the Aedes sierrensis. A common misconception is that all mosquitoes need a lot of standing water to breed, but the Aedes sierrensis needs only a knothole filled with water for a breeding ground.1-3 If our society and environment were static, heartworms would only be in the southeast— but they’re not. Mosquitoes migrate and transform an area that was not endemic for heartworms to an endemic area—it just takes a little bit of time. Aedes sierrensis can be found throughout California, Oregon, Washington, Idaho, Nevada, and Utah. 3. How has the relocation of heartworm-positive animals from Hurricane Katrina affected the West? Initially, some veterinarians believed the relocation would create an increase in the incidence of heartworm disease in the West. But, what it has done is increased the awareness of heartworm disease in the West while possibly speeding up a process that has been occura Data on file with the American Heartworm Society. © 2008 Merial Limited, Duluth, GA. All rights reserved. To view this publication online, visit www.advanstarvhc.com/c47. Cover image Getty Images. HGD08SPOTLIGHTW Sponsored by http://www.marvislavet.net/html/body_the_heartworm_situation_in_la.html http://www.marvislavet.net/html/body_the_heartworm_situation_in_la.html http://www.davismosquito.org/mosquitoes/mosquitoes.keyhtm#treehole http://www.davismosquito.org/mosquitoes/mosquitoes.keyhtm#treehole http://www.advanstarvhc.com/c47

Table of Contents Feed for the Digital Edition of Veterinary Medicine - August 2008

Veterinary Medicine - August 2008 Contents Editors' Note Leading Off ClinQuiz Idea Exchange Practical Matters Diagnosing and Treating Canine Copper-Associated Hepatopathies Canine and Feline Demodicosis CE Form Advertiser Index Product Preview Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - August 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.