Naturally occurring parasitic bronchitis in red deer: effect of vaccination using live bovine lungworm vaccine.

Fifteen red deer calves were put to pasture in two groups, at the same set stocking rates, one group of 10 and one of five, in separate but adjoining enclosures likely to be carrying infective stage larvae of dictyocaulus naturally parasitising the red deer of Scotland. The group of 10 had been vaccinated with a live, bovine lungworm oral vaccine; the group of five had not. Results did not indicate any advantage to the vaccinated deer in weight gain or general health but they excreted fewer dictyocaulus larvae. The findings, although based on only a few animals, support the conclusion that vaccination of red deer would not give them increased protection against the establishment of naturally occurring dictyocaulus infection although it would enhance the suppression of larval production.