Veterinary session

Over the last ten years, the red deer, fallow deer, roe deer and mouflon population has shown an almost continuous increase. Wild ruminants can often be seen in the closer vicinity of cattle and sheep kept in pastures or fenced areas on the edges of forests.

In sheep, goat and cattle livestock pasteurellosis, caused by Mannheimia haemolytica and Bibersteinia trehalosi is a common disease with significant economic damage. The question arises whether cervids can be a reservoir of these bacteria, thus maintaining the pasteurellosis of our animals. We have not found any literature stating that these pathogens would also be present in the wild ruminants occurring in our country, or whether they can cause disease and economic losses. Although we became aware about one previous pasteurellosis case in roe deer in the Veterinary Diagnostic Directorate, National Food Chain Safety Office (NÉBIH ÁDI).

In the framework of passive sampling, we reviewed the strain collection in Budapest and monitored its new cases. Here we found one case each of roe deer, mouflon, and Indian antelope, which was the subject of our investigation. As part of active sampling, we collected a total of 87 nasal swab samples, mainly from the Zselic area, originating from 45 hunted and 14 bred, living red deer, 4 hunted fallow deer and 22 hunted roe deer. From Győr and Nyíregyháza zoos, we also received one sample each from fallow deer and barbary sheep. No symptoms of respiratory disease were observed in the animals included in the sampling.

Bacteria were cultured from the nasal swab samples and species-specific PCR tests were performed. The serotype of the strains isolated in NÉBIH ÁDI was determined using the passive haemagglutination method. From the swab samples we collected, the cultureeculture ended with negative results in all cases, the PCR test was positive for M. haemolytica in the case of one roe deer. Among the strains we got from NÉBIH ÁDI, 2 B. trehalosi (serotypes T4 and T3) and one M. haemolytica (non-typeable) from wild living animals were found.

In this thesis, we publish for the first time the presence and pathological role of M. haemolytica and B. trehalosi in roe deer, mouflon and Indian antelope species. Based on our tests, however, we believe that only a very small proportion of wild ruminants carry these pathogens in Hungary, nonetheless sporadic pathological cases may occur. Looking at our results, we conclude that the ruminants in our forests have no particular role in the maintenance of pasteurellosis, but a more comprehensive picture will only be obtained after further studies.