Experimental infections with Dictyocaulus viviparus in vaccinated and unvaccinated red deer

Abstract

Four of eight red deer calves which had been artificially reared and were lungworm free were vaccinated with bovine lungworm oral vaccine when eight weeks old; the other four were not vaccinated. Three of each category were challenged daily with 500 Dictyocaulus viviparus infective stage larvae per kg liveweight for 17 days when six months old while one in each category was left as an unchallenged control. The effects of challenge were monitored and all challenged deer and one control were killed for post mortem assessment. Challenge with D viviparus was associated with reduced food intakes and weight gains but vaccinated calves were less affected than unvaccinated ones. The reaction of the alveolar tissue of red deer lung to D viviparus was mild in vaccinated and unvaccinated animals and differed from that of bovine lung in that alveolar epithelialisation was limited and hyaline membrane formation and interstitial emphysema were not seen. The disease was most evident in and around airways and was less in vaccinated calves. It was concluded that young red deer are tolerant to D viviparus but will readily acquire infection.

Epidemiology and pathogenesis ofMycobacferium bowisinfection of red deer (Cervus elaphus) in New Zealand

“…In deer, lymphoid tissue is well recognised to form in peribronchiolar, interlobular and subpleural sites in response to infection with Dictyocaulus spp. (Corrigal et al, 1982;Munro and Hunter, 1985). Careful macroscopic examination should be able to differentiate small grey homogeneous nodules into those due to tuberculosis and those with a lymphoid follicular appearance.…”

Viral, parasitic and prion diseases of farmed deer and bison

“…Diagnosis in the live animal depends upon examination of faecal samples using the Baermann technique and the finding of larvae (26). More specific (and expensive) diagnosis of the actual species of Dictyocaulus may not be warranted for routine herd management purposes.…”

“…The principal method practised to control this parasite is a combination of good stockmanship and the strategic use of anthelmintics (26,37,53,90,96). If there is sufficient land available, it may be possible to rotate animals through paddocks at intervals great enough to ensure that any larvae that have been passed onto pasture are no longer infective by the time the animals return.…”

“…Trials with the bovine irradiated lungworm vaccine were carried out in a small number of red deer and showed that vaccination had a limited positive effect upon feed intake and weight change, but the use of this product has not become established (26).…”

“…The specific taxonomic name of the Dictyocaulus affecting various deer species or bison has not been fully established. Cross-infection trials have shown that the cattle parasite can infect red deer and wapiti, and instances of infection of a wapiti and red deer calves with the cattle strain has been reported (26,109). Cattle should therefore be considered as a potential source for infection of these deer species.…”