Syd Sydney":285itcen said:
Lucky Penny see if you can contact Ontario Agriculture.They have a web site and you should be able to find out who your rep for your area is.This may have to wait until Monday though.Your rep should know the area of all the outbreaks and be able to tell you if it can be carried on by transition.Sorry that's all I can tell you I am not familiar with "black leg" myself.I am sure there are a few other people that can help perhaps Bez knows and will respond since he is familiar with cattle and a lot of Canada.
>Syd
All I know is Black Leg can live in the soil for many years.
Never seen it or experienced it.
OMAFRA may be able to help - but your veterinarian is your fastest and best source of information.
One thing to note - Black Leg is common throughout North America and it is possible to transport the disease by moving dirt from one area to another.
Here is some info for you.
-------------------------------------
Blackleg is a disease of cattle, and less frequently of sheep, caused by the soil-borne bacterium, Clostridium chauvei. The disease develops rapidly in affected animals and often deaths occur before the owner has noticed any sickness in the herd.
Distribution
Blackleg occurs on all continents, although there are some local areas in various countries which are not affected. Most parts of Alberta are affected, but new outbreaks are found almost yearly in areas where the disease has not previously been reported. For this reason, livestock owners should not assume they will not have blackleg losses simply because they never have before. Because the causative bacteria are soil-borne, the disease may be introduced to new areas in several ways, including windstorms, water-ways and wild animals.
Signs
Blackleg commonly occurs in the warmer months of the year in young animals on pasture. Calves and yearlings are most often affected. Often no symptoms are observed; the animals are found dead on the pasture with no previous signs of illness. At other times, one or more of the young calves show signs of illness by a high fever, lack of appetite, depression, lameness, and swellings that appear in the muscles on various parts of the body. Sometimes the leg muscles are involved, or the muscles in the region of the back, hip, flank, chest or shoulder. In the latter stage of the disease, these swellings spread and become quite mushy, producing a characteristic crackling sound when pressed with the hand. This sound is due to the gas under the skin which is produced by the growing bacteria.
Postmortem changes
Putrefaction occurs rapidly in the carcass of an animal infected with blackleg and results in a typical bloated appearance of the carcass soon after death. The legs are extended stiffly and a frothy, bloody discharge is often apparent at the anus and the nostrils. The skin over the swelling is usually normal but in the centre it may have undergone dry gangrene. When cut open and examined, the swellings are usually found to contain discolored serum and gas. When affected muscles are cut open, they are usually found swollen and either black or darker in color than normal, with gas present. It is unwise to cut open a swelling unless necessary for a diagnosis, as this increases the contamination of the soil.
Diagnosis
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 is often difficult to make an exact diagnosis in the field because of the similarity of the signs of blackleg to certain other diseases. Lead, mercury and arsenic poisoning and bloat, as well as some of the plant poisons, can be confused with blackleg.
Although certain features of the disease are characteristic, a positive diagnosis requires laboratory confirmation. Contact your local veterinarian about submitting specimens for laboratory analysis. The laboratory will need a portion of the affected muscle tissue placed in a clean glass jar or plastic bag and packed so that it will not break or leak, and sent, packed in ice, to the laboratory as soon as possible after the death of the animal.
Treatment
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.
Control and prevention
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 that the so-called mixed bacterin be used. This contains the killed bacteria of both diseases, (Clostridium chauvei and Clostridium septicum). A second injection of the bacterin 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 revaccinated annually until they reach three years of age. Routine vaccination procedures will vary with the type of livestock operation involved.
In case of an outbreak of blackleg in a herd, it is advisable to vaccinate or revaccinate, as the case may be, all of the animals with a recommended dose of the bacterin. As with other vaccines, there is a period of about two weeks following vaccination in which the animals have not built up a strong resistance to the disease. Losses may continue during this period, so it may be advisable to move the herd to another pasture after losses from blackleg occur and vaccination is carried out.
The bacterins used for vaccination against blackleg and malignant edema are perishable products and deteriorate rapidly if they are not stored properly. The manufacturer's directions regarding storage and handlng should be rigidly followed in order to assure that the vaccine is at it's highest potency. After the vaccination has been completed, any partially used vaccine containers should be discarded and not retained for later use.
Sanitation
The bacteria that cause blackleg are capable of living in the soil. They have the capacity to form spores which can protect the organism from the effects of weather, and hence soil can remain infected for many years. Carcasses
of animals affected by the disease are the chief source of soil infection. They harbor the germs in large numbers and liberate them from both artificial and natural body openings into the surrounding soil. For this reason, every dead animal should be promptly burned or buried. The surface of the ground may be treated by burning it over with a heavy layer of straw, used oil, etc.