Black Leg Disease in Cattle

Black leg disease is one of the most dangerous animal deceases and a leading cause of fatalities among young cattle.  The black leg disease is caused by anaerobic bacteria which is found in the soil around areas where animals are raise in herds. The disease is comparable to other clostridial diseases such as malignant edema and botulism. The spores of the anaerobic bacteria which causes black leg disease can remain dormant in the grazing grounds in the soil for several years, waiting to infect their victims. Some of the areas in which cattle contract the black leg disease include grazing grounds which have had excavations or floods which expose the dormant spores to the surface e for the cattle to ingest. Cattle also contract the disease through wound openings through which the spores inter the body. Although cattle cannot infect other cattle, herds of young cuttle get infected at the same time or between different days since they feed on the similar grounds before the farmer can realize the disease and take action.

How Cattle Contract the Black Leg Disease

Injury is one of the most common environmental factors which expose cattle to the black leg disease. When cattle sustain serious injuries, the blood and oxygen reduce and this develops an environment which activates the dormant black leg spores (Tagesu et al., 2019). Injured cattle can also contract the black leg disease during transportation, improper injections and interactions with rough pastures in open grounds.

Eating contaminated food is also another common means through which cattle contract the black leg disease. When farmers fail to verify the levels of contamination in their animal feed or provide animal with food that has been exposed rain or other natural conditions, they expose them, to the chauvoei spores which cause infection in muscle tissue (Tagesu et al., 2019). Animals may also inject infected grass and other animal feed in the feeding grounds where dormant pores have spread out to crops and other forms of ferriage.

Excavation is also another factor which exposes the black disease spores and causes infection in cattle. Excavation machinery exposes the spores which have been lying dormant on the ground. Wet seasons such as winter and during large storms are also other periods in which black leg disease infects majority animals since the spores are carried by flood waters into farms or forced onto the ground by the water and melting ice. Improper disposal of carcases also causes the spread of the C. Chauvoei over long distances and this increases infection cases.

How the Disease Affects Cattle

After Animals ingests bacterial spores while grazing, the spores enter the intestine and later move to the skeletal muscle through the bloodstream and remain there for extended periods. When infected animals encounter events such as injuries or other muscle bruises, the oxygen concentration around the wound lowers and this condition allows spore to germinate (Abreu et al., 2018). After the germination of the spores around the infected areas, the spores multiply and this condition created a toxin which causes muscle haemorrhage and necrosis.

Young cattle between 6 and 12 months are the majority victims of the black leg disease since they feed the most during the 6-mobnth periods and this exposes them to the risk of ingesting contaminated animal feed (Nicholson et al., 2019). In most cases, animals die because the disease does not have immediate clinical signs in the first 12-48 hours; this gives cattle owners a limited period to take action and save animals.

Intramuscular gas bubbles are also common in infected animals, the bubbles are visible in different areas of the skeletal muscle. During testing, areas with visible infection float in formalin and this is one of the most common procedures for animals which have succumbed to black disease (Nicholson et al., 2019). Affected cattle have parallel necrotizing myocarditis and fibrinous pericarditis. The skeletal muscle around the infected areas had a foul smell which most doctors have compared to rancid butter.

Infected animals also experience fever during the first few hours when the bacteria start affecting the muscles; the fever later subsides as the disease enters into more serious stages. Lameness is the next stage of infection after fever; cattle show signs of lameness in infected legs and this is another sign farmers should look out for when determining infected animals. Infected animals also show signs of reduced appetite while others my completely stop eating. The disease also causes animals to lie down and show sings of inability to get up when trying to move to the shelter.

Treatment

black leg disease in untreatable and fatal in most cases among cattle; the disease is among the most dreaded health conditions among cattle and the main cause of fatalities among other animal which contract the disease (Idrees et al., 2019). Some of the instances in which the disease can be treated and animals saved is when cattle owners realize the infection early and administer insulin; the treatment dos not guarantee full recovery since most treated animals still develop permanent lameness and deformity.

Prevention

Vaccines are the most effective prevention methods for the black leg disease; since there are no effective means of treating infected animal, vaccines can be used to prevent healthy cattle from contracting the disease. 6-8 months is the recommended age in which calves should get vaccinated to prevent them from contracting the disease. The period is recommended since young calves below 6 months receive antibodies which provide protection before, they can receive their first vaccines.

Doctors recommend that farmers should prevent against the deadly disease by initiating a regular vaccination protocol wit semi annual and annual booster until the young cattle attains 2 years. The vaccines which are currently available are a bit expensive, but researches have proven that the vaccines are completely effective since 100% of vaccinated cattle have not contracted the disease within the first two years. The black leg vaccines stimulate unique vaccines to reduce the negative effects of black leg spores which may enter the cattle’s body or become active at any time in the animal’s life.

The vaccines are also effective since they safeguard young calves after birth from contracting the diseases as the consume antibodies from their mother’s milk. Studies indicated that after young cattle get vaccinated for the first time, their serological response increases at 30 days after the injection and the serum igG levels that fight against the disease increases significantly in vaccinate calves (Jerram, 2019). Other studies indicate that cattle should get vaccinated for a period of 4 months after birth to ensure that they receive full protection from the black leg disease.

Control

One of the methods through which farmers and researches can control the spread of the black leg decease is through regular testing of sand and animal grazing grounds to determine whether there are dormant pores hiding in the ground. The method should mostly be used by farmers who have experienced an outbreak of the disease to prevent other outbreaks from occurring. Cattel owners should contact professional to test their soil and recommend the right methods for dealing with dormant spores when the results turn positive.

Avoiding grazing and using alternative forms of feeding is also another control method that could be used to minimize the spread of the black leg disease and the fatality levels. Farmers should keep young cattle in secure and clean cattle sheds and prevent them from getting into contact with anther cattle which had been herding in open grounds; this move could reduce the number of infections among young calves since they are the most vulnerable (Jerram, 2019). The calves should also be fed with processed animal feed which cannot harbour inactive black leg spores and clean water which has not come into contact with the ground. Although the prevention moves are not effective enough to stop the disease, it could save young calves and help them get through to the ages in which they are less susceptible to the disease.

Cattle leg disease is one of the diseases that have been killing cattle for a long period, it is a condition that has particularly dangerous for young cattle. Cattle ingest the spores when grazing in open grounds, feeding on contaminated animal feed or getting infected through injured muscle. Injection of insulin is the most common means of treating animals, but most animals still end up getting permanently paralyzed. Vaccination is the only prevention method, with doctors recommending that cattle should reive their vaccines since they are 4 months old for full protection against black leg decease.

References

Abreu, C. C., Blanchard, P. C., Adaska, J. M., Moeller, R. B., Anderson, M., Navarro, M. A., … & Uzal, F. A. (2018). Pathology of blackleg in cattle in California, 1991–2015. Journal of Veterinary Diagnostic Investigation, 30(6), 894-901.

Idrees, M. A., Younus, M., Farooqi, S. H., & Khan, A. U. (2018). Blackleg in cattle: Current understanding and future research perspectives-A review. Microbial pathogenesis, 120, 176-180.

Jerram, L. (2019). Clostridial disease in cattle. Livestock, 24(6), 274-279.

Nicholson, P., Furrer, J., Hässig, M., Strauss, C., Heller, M., Braga-Lagache, S., & Frey, J. (2019). Production of neutralizing antibodies against the secreted Clostridium chauvoei toxin A (CctA) upon blackleg vaccination. Anaerobe, 56, 78-87.

Tagesu, T., Abdisa, T., Hasen, R., Regea, G., & Tadesse, G. (2019). Review on blackleg in cattle. J. Dairy Vet. Sci, 9.