By Gary Sliworsky
Ag rep, Emo
Last week was the first of a two-part article on blackleg—a disease of cattle, and less frequently of sheep, caused by a soil-borne bacterium.
This week’s article continues by looking at the diagnosis, treatment and control, and prevention of the disease.
Livestock owners should familiarize themselves with the signs of this dangerous and costly disease so that cases are not ignored or passed off as bloat.
A veterinarian should be called to make an accurate diagnosis as soon as possible. A wrong diagnosis, or no diagnosis, could be serious and expensive because more animals may become infected and result in heavy losses in the herd.
It often is difficult to make an exact diagnosis in the field because of the similarity of the signs of blackleg to certain other diseases.
If cases are noted in the early stages of infection, they may respond to immediate treatment with penicillin or other antibiotics in large doses.
It is essential, of course, that an accurate diagnosis be made in order that the correct treatment is given.
In recovered cases, the animal may be stiff in the leg, shoulder, etc. due to shrinking or thickening of the muscles.
Because it is practically impossible to prevent animals from coming into contact with the disease, the chief control method for blackleg lies in building up resistance in the animals by use of a bacterin or vaccine.
The recommended procedure for vaccination is to inoculate all young cattle between one and three months of age with a bacterin.
Because blackleg and malignant edema are so similar, and often may both be present in an outbreak, it is recommended the so-called mixed bacterin be used. This contains the killed bacteria of both diseases.
A second injection of the bacteria should be given when an animal reaches six months of age.
To be on the safe side, and to ensure as permanent immunity as possible where the disease has occurred before, all the cattle should be re-vaccinated annually until they reach three years of age.
Routine vaccination procedures will vary with the type of livestock operation involved.
Dates to remember
•July 27–Soil and crop tour (starts at 11 a.m. from the Emo research station); and
•July 27–Emo research station open house, 7 p.m.