Farmer's Weekly (South Africa)
Dealing with lumpy skin disease
Lumpy skin disease is a notifiable disease. This means the state veterinarian must be informed if you suspect your cattle are infected with it, as specific control measures must be implemented.
Lumpy skin disease (LSD) is a viral disease of cattle characterised by nodules on the skin. The virus is normally spread by biting insects, so the disease usually occurs during the wet summer and autumn months, when there are large numbers of stable flies, mosquitoes and ticks. Any cattle breed can be affected.
LSD can also be spread via the saliva of infected animals at communal drinking troughs.
The disease causes emaciation (loss of body condition because of an unwillingness to eat); temporary or permanent loss of milk production; lowered or complete loss of fertility in bulls and cows; and abortion. Up to 45% of a herd can become infected and the mortality rate can reach 10%.
SYMPTOMS AND DIAGNOSIS
Signs of LSD include one or more of the following:
• Skin nodules and ulcers. These occur anywhere on the skin and in the mouth and range from 0,5cm to 5cm in diameter.
• Swollen legs with sores on them.
• Enlarged lymph nodes.
• Pneumonia/coughing due to infection of the respiratory tract and lungs. • Infertile cows and bulls.
• Mastitis, which lowers milk production.
• Fever, emaciation and excessive salivation.
The most obvious sign of LSD is nodules on the skin and in the mouth. If you farm long-haired cattle, feel for the nodules on the skin, or wet the hair so that you can see the nodules more easily.
Diagnosis can only be confirmed by a laboratory, however, because other diseases can cause similar symptoms. If you suspect LSD in your herd, you must inform the state veterinarian so that the disease can be confirmed and controlled.
PREVENTION
To prevent your cattle becoming infected with LSD, you need to vaccinate all of them every year. The vaccine contains a weakened version of the virus; when it is administered, the animal develops protective antibodies and can fight the disease if it ever becomes infected.
The correct vaccine to use against LSD is the attenuated Neethling strain vaccine.
To ensure optimal protection, vaccinate the animals before the summer rain. Animals that have had the disease and have recovered are immune and do not have to be vaccinated.
There is also no need to vaccinate calves under six months old that were born to vaccinated cows. However, they should be vaccinated as soon as they reach six months, and every year thereafter.
Swelling may develop at the site where the vaccine is given, and milk production may decrease temporarily, but both these problems will disappear within a few weeks.
Read the instructions on the vaccine label. If you have any questions or need help with vaccination, contact your state vet or animal health technician.
• Source: Thomas, L. 2002. ‘Lumpyskin disease: a disease of socio-economic importance’. Department of Agriculture, Forestry and Fisheries. Retrieved from nda.agric.za/docs/Infopaks/Lumpyskin.pdf.