adminLIVESTOCK is crucial in supporting the livelihoods of small-scale farmers and the greatest constraint to sustainable livestock production is animal diseases. Diseases are major constraints and animals of poor people are particularly vulnerable to sickness because of the expense, absence or unsuitability of animal-health and production inputs.
For smallholder livestock farmers, the effects of endemic diseases, poor nutrition and other livestock-production constraints are intimately linked.
Research has shown irrefutably that the impact of endemic diseases are mainly felt at farm level, while broader economic impacts can occur with epidemic diseases that restrict trade in livestock and livestock products.
The negative impact of animal diseases on livestock productivity include reduced feed intake, changes in digestion and metabolism, increased morbidity and mortality and decreased rates of reproduction, weight gain and milk production.
This week Farming Matters focuses on a disease that is widespread but is rarely talked about or regarded as deadly by especially small-scale farmers who often lack information and have limited diagnostic data to make disease-control and treatment decisions.
Our focus is on lumpy skin or chirwere chamapundu.
Lumpy skin disease (LSD) is a virus disease in cattle which is characterized by fever, multiple firm, well-defined nodules in the skin, lesions left by erosion on the teats, nose, mouth and pharynx, enlarged lymph nodes and swelling of one of more legs.
It is a livestock sickness with devastating economic effects comparable to that is caused by foot-and-mouth. It causes skin lesions that result in severe and permanent damage to hides.
Lesions can also appear in the animal’s mouth, pharynx and respiratory tract, which affect its ability to eat, causing rapid deterioration and severe emaciation. An outbreak typically culls 10 percent of affected herds, but mortality rates can reach as high as 40 percent.
August and September are the ideal months to prevent your herd against the disease.
Research shows that the disease was first observed in 1929 in Zambia and was initially considered to be the result of poisoning or a hypersensitivity to insect bites. Cases were described in South Africa between 1943 and 1945, and after eight million cattle fell ill to the virus, the disease’s infectious nature was recognized.
Today, incidences of lumpy skin cattle disease are numerous in Zimbabwe, including in Manicaland.
The disease is a major threat to efforts by farmers to rebuild the national heard.
It peaks particularly during the rainy season. The disease affects the skin by causing small lumps that may develop into wounds.
The disease also leads to significant losses in production as a result of emaciation, temporary or permanent loss of milk production, infertility in bulls as well as cows, abortions and permanent damage to the skins.
In severe cases, the disease may affect the respiratory system and may cause death.
Symptoms include fever, discharge from the eyes and nose, skin lesions, edema of the limbs, and swollen lymph nodes.
Affected beasts usually develop some lumps (mapundu) on their skin before dying.
While it has not yet been established by what method the disease is transferred, circumstantial evidence indicates that biting insects play an important role, because the disease occurs more often in the wet summer and autumn months. Another indication that insects could play a role is the inability of isolation and quarantine to prevent spreading of the disease. Although direct animal-to-animal transfer of the disease is ineffective, transfer could occur when sick and healthy animals use the same watering troughs.
Suckling calves can get the disease from drinking contaminated milk.
On the other hand, a calf can be protected up to the age of 6 months if it gets enough colostrums from a cow that has been vaccinated.
Lumpy skin vaccines were available and cost a dollar per dose.
Farmers should seek assistance from the veterinary extension workers deployed in their respective districts.
“Farmers can use penicillin-based antibiotics, but in all cases, of sick animals, they must first consult the veterinary services irrespective of the disease. This is done as a preventive measure against a number of diseases besides lumpy skin. Farmers are advised to vaccinate their cattle as the disease is preventable. This year is a fairly bad year regarding the disease,” said the Makoni district veterinary officer Dr Edwin Kupahwana.
Symptoms
Some animals in a herd seem to have a natural resistance, because only 40 -50 percent of animals show lesions in experimental contagion. After an incubation period of 2-4 weeks the animals develop a fever that could last from 4- days, accompanied by loss of appetite, hyper-salivation and excessive secretion from the nose.
The typical nodules of the skin start to appear about 4-10 days after the onset of the fever reaction and could vary from 5-50mm in diameter, and from a few to hundreds in number.
The nodules are swollen, round, well-defined and firm. They could harden rapidly to rigid nodules that could persist for a year or longer, or they could fall off and leave deep erosions.
In most instances of common skin lesions, the legs are also swollen and the skin could die off and peel. This then leaves open, festering sores on the legs. Mastitis could also occur as a result, with heavy losses because of permanent damage to the tissue of the udder.
Control
Because biting insects most probably play a role in the transfer, cattle could be sprayed with insecticides during the risk period.
A better method is however preventative immunising by means of vaccination. Calves of mothers that have not been vaccinated or cows that have never been exposed to the disease could be vaccinated at any age.
Calves of cows that have been vaccinated should only be vaccinated after 6 months of age.
After that, vaccination should be done annually.
Online Reporter