Every week, Food For Mzansi readers have free access to a veterinarian. You simply need to email your animal health questions to firstname.lastname@example.org and we’ll get an expert to help you. Remember to include pictures that could assist the vet in making the right diagnosis.
Malcolm Goliath from Gauteng writes: Help! I’ve got the weirdest nodules growing on my cattle – some as big as 5 cm. It’s all over the show. Some cows have it on the nose and udder, but I’ve also seen the exact nodules in the mouth.
You’re dealing with lumpy-skin disease (LSD), which can affect all cattle breeds in Mzansi. It is a viral disease of cattle, typically characterised by nodules or lumps on the skin. It usually occurs during the wet summer and autumn months when biting insects, like biting flies and mosquitoes, are in abundance.
LSD is a notifiable disease, which means that any suspected or confirmed case must be reported to the responsible state veterinarian. According to a government information brochure, up to 45% of your herd can become affected and the death rate may reach 10%.
The disease causes production losses: pregnant cattle may abort, marked reduction in milk yield, pneumonia, infertility, permanent damage to skin and emaciation (loss of body condition). There is a loss in income because of lower production (deaths, milk and meat, abortions, lowered breeding potential and damage to valuable hides), and the costs of drugs to treat sick animals.
Although cattle of all ages can get the disease, vaccinated cattle are less likely to get LSD and may have less severe symptoms. Also, cattle which have had the disease and survived, cannot be infected again. Calves are protected against the disease while drinking their mother’s milk before six months.
How do cattle become infected?
- Biting flies play the most important role in spreading the virus.
- Infections increase when there are more flies.
- Calves can be infected by drinking milk from a cow which has the disease.
- The disease can also spread through the saliva of infected animals when they use the same drinking trough. It can also be spread by man when injecting infected animals when using one needle to inject different animals.
What are the signs of lumpy-skin disease in cattle?
Skin nodules and ulcers can vary from a few to several thousand. The size ranges from 0,5 to 5 cm. They literally occur anywhere on the skin, including the nose, udder and vulva in cows, the scrotum in bulls, as well as in the mouth (the gums).
Legs may become swollen and the animal does not want to move. Enlarged lymph nodes are visible as well as pneumonia or coughing. This is as a result of infection of the respiratory tract.
There may also be a discharge from the nose and eyes. Other symptoms include infertility, mastitis which lowers milk production, fever, emaciation and salivation.
How can LSD be diagnosed?
- A basic diagnosis can be made by the presence of the typical lesions on the skin and in the mouth.
- In long-haired animals you should feel for the nodules on the skin, or you can wet the hair so that you can see the nodules more easily.
- A definite diagnosis can only be confirmed by a veterinarian by taking blood samples or samples of the skin nodules to a laboratory where they can identify the virus (this has to be done because there are other diseases which cause similar signs in cattle and therefore require different methods of control and treatment).
- If you suspect LSD in your herd, you must inform the state veterinarian.
How can you prevent lumpy-skin disease in your herd?
Prevention is the cheapest and best method of control of the disease. If your animals are vaccinated, you will suffer limited or no production or financial losses as a result of the ill effects of this disease. There are several vaccines available on the market against LSD. When a vaccine is administered the vaccinated animal develops protective anti-bodies (made by white blood cells).
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