Dispersive Deer and their Role at the Wildlife-Livestock Interface
Transmission of disease between wildlife and livestock is a concern addressed by wildlife managers, livestock producers and veterinarians trying to protect their respective populations and maintain food safety. Ongoing concern has been expressed by both entities in the ability of wildlife and livestock to impede population health programs by transmitting and reintroducing parasites and disease among naïve or previously uninfected populations. A researcher at the University Of Calgary Faculty Of Veterinary Medicine hopes to address this issue in relation to one of the most prominent disease problems within the Alberta sheep industry in the last decade.
Dr. John Gilleard of the UCVM hopes to investigate the role wild deer play in spreading the gastro-intestinal parasite Haemonchus contortus between sheep farms within Alberta. Producers of past and present have placed great reliance on the use of drugs like ivermectins and benzimidazoles to protect their herds from the said parasite. H. contortus has shown resistance to these critical treatment options and so introduction of a parasite with such abilities would deem primary treatment options useless. The project is funded by the Alberta Livestock and Meat Agency which has since been dissolved by the Alberta Provincial Government (full story). The project’s current stage largely relies on collection of wild deer feces and so expertise of Dr. Susan Kutz and Collin Letain of the UCVM and CWHC Alberta have been crucial in the collection of samples.
To date, a total of 229 samples of both mule deer and white-tailed deer ranging in sex and age have been collected throughout the province of Alberta. Most samples have come from deer within the central prairie parkland region between Calgary & Edmonton but additional samples have been collected within Waterton Lakes National Park, Sheep River Provincial Park and the foothills region of Alberta. Of the 229 fecal samples, only 19.7% have tested positive in low numbers for strongyle eggs, a group of gastro-intestinal nematodes which are indistinguishable based egg appearance alone. Samples containing these eggs are further cultured within the feces to develop them into third stage larvae (L3’s) required to identify if the strongyle nematodes are indeed H. contortus proven to be detrimental to the health of domestic sheep. The study is now at the stage where we have harvested L3 larvae from 11.4% of the 229 fecal samples collected. These will be the first sample set to be run through DNA analyses to determine if the parasites in deer are H. contortus. If the target parasite is found, information including prevalence of H. contortus among other parasites in deer will be used to gather information on gastro-intestinal parasite diversity in wild deer. Further objectives include comparing parasite burdens between deer in contact with sheep to those that are not and investigating the occurrence of drug resistance in H. contortus in wild deer and their possible transmission to sheep flocks. Further significance of this project can help to determine what parasites are in our wild Alberta deer herds and create baseline information on the status of deer populations.