Scottish farmers are being warned about the rise in the incidence of blackleg in cattle following several cases of the disease being diagnosed.
Thurso Disease Surveillance Centre has confirmed a number of cases in the Caithness area following unexpected deaths.
Scotland’s Rural College vets are advising farmers to investigate the unexpected death of any cattle and consult their vet about the need to vaccinate youngstock when out on pasture. Blackleg is fatal, but can be easily prevented by vaccination.
The increase in cases of the disease, caused by the bacterium Clostridium chauvoei in soil, can lead to substantial losses. Cattle between six and 24 months old are particularly susceptible to blackleg. Affected animals are often found dead, although occasionally they may be lame and have a swollen upper limb before they die.
The bacterium that causes the disease can survive in soil for several years as highly-resistant spores, tough enough to withstand environmental challenges such as frost. Once in the animal’s body, the spores are activated. The bacteria then multiply, producing lethal toxins that spread throughout the body and cause rapid death of infected animals.
It is not unusual to see outbreaks of blackleg during the warmer months. Most bacteria prefer warmth and at this time of year youngstock are out to grass. Any disturbance of soil in grazing areas could expose clostridial spores and is considered to be a potent trigger factor.