Dictyocaulus infection in farmed red deer (Cervus elaphus)
Corrigall, W.; Easton, J.F.; Hamilton, W.J.
Veterinary Record 106(15): 335-339
1980
ISSN/ISBN: 0042-4900 PMID: 6445622 Document Number: 168246
At Glensaugh deer farm in north-east Scotland, 3 groups of 20 red deer calves born in June or July 1975 were monitored for Dictyocaulus infection. Group A were captured from the wild and hand-reared until put out in September; the others were home-bred and kept with their mothers until September (group B) or January, 1976 (group C). 10 calves from group A were given one or 2 doses (one month apart) of Dictol (D. viviparus vaccine), and 10 from each of the other 2 groups received only one dose. Dictyocaulus larvae were found in the faeces of group A from early December, of group B from the end of November and of group C from mid-January. Up to May (1976) 44%, 63% and 61% respectively became larval excretors. Of the 5 calves given the full course of Dictol (2 doses), 2 died of foxglove poisoning. One had no D. viviparus in its respiratory tract but the other had 30 adults. 11 of 24 calves given a single dose of vaccine and 15 of 30 unvaccinated calves excreted larvae. 2 calves, one in group B and one in group C, were clinically affected severely enough to need treatment. Mean daily weight gains by the 3 groups were 0.07, 0.07 and 0.06 kg, respectively (in the clinical cases it was 0.03 kg). Experimentally, it proved difficult to produce clinical lungworm infection in well fed and housed red deer, even in those given high larval doses. 3-month-old calves weighing about 28 kg showed little effect, other than excretion of larvae, from a single dose of 530 larvae/kg (total 15 000 larvae). Vaccination with Dictol was effective in penned deer, judging by the lower larval excretion and smaller adult lungworm burdens in the vaccinated animals. Moreover, the vaccinates achieved greater weight gains. 2 deer aged 13 months and 2 aged 20 months (all housed since a few days old) did not excrete larvae or show clinical signs after dosing with 180 and 420 larvae/kg, respectively. This suggests an age-related immunity.