Diseases in free-ranging red deer introduced to Patagonia: implications for native ungulates

FLUCK, WT; SMITH-FLUECK, JM

Huilo Huilo

Congreso; 7th International Deer Biology Congress; 2010

The red deer (Cervus elaphus) invasion in Patagonia has been continuing for nearly a century. Red deerare found in all habitats between 34-55°S, occupying >51,000 km², and reaching densities of 100deer/km² in ecotones and 40-50 deer/km² in steppes. Their distribution, movement patterns and densityraise concerns over their potential epidemiological role (e.g. Foot and mouth disease, brucellosis,tuberculosis). Adult females collected by rifle and radiocollared deer that died naturally werenecropsied in the field to determine gross pathology, and whole specimens were also examined in anational pathology laboratory. No ectoparasites were found (n = 73). Fasciola hepatica wasencountered at prevalences of 9-50% (n = 108). Taenia ovis krabbei was identified, and Cysticerustenuicollis was found at a prevalence of 8% (n = 12). Ostertagia sp., Bunostomun sp., and Dictyocaulussp. had a prevalence of 75%, 25% and 13%, respectively. Testing for Foot and mouth disease wasnegative (n=41). A suspect case of tuberculosis had substantial parietal pleural adhesions,granulomatous mediastinal lymph nodes, nodules covering the costal pleura and liver, lesions in theintestinal tract including lymph nodes covering the rumen. Antler damage was found on 73% of shedantlers, with 36% having major breaks of tines and main beam, possibly indicating mineral imbalances.One male not only had broken tips and tines, but both entire antlers, including pedicles with portions offrontal, parietal and occipital bones, were broken off the skull, causing his death. Regarding nativehuemul (Hippocamelus bisulcus), several gastrointestinal parasites found at low prevalence in Chile arecommon in livestock and considered commensals in ruminants. Sympatry of huemul with livestock iscommonplace, whereas with red deer it occurs in <2% of known populations. In one area of sympatry,per huemul there were 1.2 red deer, but 25.2 livestock, making livestock the determiningepidemiological factor. Considering that red deer have been coexisting with livestock for >100 years inArgentina, both red deer and livestock play epidemiological roles for shared diseases. Research,conservation and management efforts should be directed towards livestock herd health programs orrestriction of free livestock movements, particularly if diseases are shown to impact on recruitment ofthreatened natives. Livestock, being routinely researched and inspected at slaughtering time canprovide a proxy for diseases afflicting co-existing ungulates.