Blackleg

Time to Vaccinate for Blackleg

Once again, as weaning time is here, disease problems begin to surface. We have had several reports of Blackleg in calves this fall with moderate calf losses.

Blackleg is a common cattle disease, caused by a soil borne bacterium, Clostridium Chauvei. One of the challenges of the disease is that it occurs very rapidly with little or no warning until losses start to occur. Animals die with little or no warning.

Blackleg occurs in all areas of Manitoba, and new outbreaks are reported every year. Just because Blackleg has not occurred in an area does not mean producers should relax. As Blackleg is a soil borne disease, it can be spread in many ways including wind, water, wild animals, etc.

Symptoms

Blackleg is common in the warmer months of the year, usually affecting young cattle on pasture. Calves and yearlings are most commonly affected, with animals often found dead with little or no prior symptoms. Cattle may show signs of the disease by a high fever, lack of appetite, lameness or swellings on muscle. In the later stages of the disease, swellings spread and produce a crackling sound when pressed with the hand. When blackleg is suspected, contact your local veterinarian for accurate diagnosis.

Prevention of Blackleg

As it is nearly impossible to prevent contact with the disease, a vaccination is a must.   It is generally recommended to vaccine all young cattle between 1 and 3 months of age.  Upon weaning, a regular vaccination program should be administered including a booster shot 4-6 weeks after the first vaccination to ensure good protection from the disease.  Annual revaccination of replacement animals up to 2 years of age should be done.

In the case of an outbreak in a herd, it is advisable to vaccinate or revaccinate all of the animals for the disease.  Adequate protection from the disease takes about 2 weeks after the initial vaccination.  Consult your local veterinarian to detail a program.  Blackleg vaccine is commonly marketed with products to protect against clostridial diarrhea diseases for a combined benefit.

Dispose of Blackleg-Afflicted Animal Properly

Blackleg bacteria can live in the soil, thus carcasses of affected animals, which are full of the bacteria which causes blackleg should be promptly burned or buried to prevent further spread of the disease.

Prepared by Melinda German and Dr. Terry Whiting, Manitoba Agriculture, Food and Rural Initiatives.

For More Information contact your Local Specialist or MAFRI GO Teams Office or Centre.