Yersiniosis in cattle
09 Sep 2022
Cases of mud scours – or yersiniosis - are being seen across the North Coast with the current conditions being ideal for the bacteria responsible for the infection.
Yersiniosis is a type of infection often seen in winter and early spring in cattle grazing wet, waterlogged or recently flooded pastures. Yersiniosis can cause severe diarrhoea and death in cattle.
Cattle aged between 9 months and 4 years are most frequently affected. Bos indicus cattle seem to be more susceptible than British breeds.
Often several cases are seen over a short period on properties when conditions are favourable for the bacteria.
Flood Mud Scours is caused by the bacteria Yersinia psuedotuberculosis. The bacteria can be carried by a range of animals including cattle, rodents and birds. Animals shedding the bacteria in their faeces contaminate pastures and the bacteria can survive for long periods and multiply in water at low temperatures.
Animals that are stressed from concurrent low nutrition or parasite burdens are more likely to be affected by Yersiniosis.
Occasionally animals will be found dead without showing prior clinical signs, however more frequently cattle will become depressed, go off feed and develop a profuse, watery, foul diarrhoea. Affected cattle become dehydrated and often lie down and may die after a few days.
A post-mortem examination reveals swelling of the intestinal lining, and watery gut contents. The diagnosis can be confirmed by submitting faecal samples to the laboratory and culturing the bacteria.
Early treatment with an appropriate antibiotic will save many animals, however when treatment is delayed it is much less successful. Antibiotics are restricted substances and as such must be prescribed by a veterinarian. Withholding periods for meat and milk will apply.
Isolation of affected animals from the rest of the mob is recommended. Frequent observation of cattle grazing high risk paddocks is recommended to enable early treatment.
For further information contact your local LLS district veterinarian or private veterinary practitioner.