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- Bont legged ticks are a familiar sight in South Africa, often leaving a trail of disease and complications in its wake.
- Sweating sickness is not very common as not all bont legged ticks have the ability or toxin to cause it.
- Within four days of being bitten affected calves can present with a high fever, suppressed appetite, and lethargy.
- No medicine is available to remove the toxin from the animal’s body; the animal itself must do this.
- As a preventive measure it is best to dip cattle regularly if they are farmed in areas that are home to bont legged ticks.
Bont legged ticks are a familiar sight in South Africa, often leaving a trail of disease and complications in its wake. One of these is sweating sickness. The presence of these ticks was confirmed in all nine provinces in 2023, with the Free State, North West and Limpopo reporting the most cases of sweating sickness, and KwaZulu-Natal not far behind.
Sweating sickness is not very common as not all bont legged ticks have the ability or toxin to cause it. However, a single tick can cause serious damage. Young calves in particular are susceptible to infection.
According to Dr Danie Odendaal of Veterinarian Network, sweating sickness is transmitted by the female bont legged tick of the species Hyalomma truncatum. Her saliva contains a toxin that causes the skin and mucous membranes of the host to become inflamed, including internal organs such as the respiratory tract and intestines. The inflamed skin forms lesions and a discharge is visible – this discharge eventually dries and forms a crust.
Read more about Protect your livestock from two-host ticks.
Signs of disease
Within four days of being bitten affected calves can present with a high fever, suppressed appetite, and lethargy. They will have watery eyes and a nasal discharge.
The mucous membranes of especially the nose and eyes turn red, animals will salivate more and have sores in the mouth. The eyelids can stick together. The skin under the ears, shoulders, and between the hind and front legs usually becomes warm and then moist and sticky – these symptoms may spread to the rest of the body. The hair of the calf’s coat becomes loose and can be pulled out easily. The skin under the coat is red and painful. In some cases, the tips of the animal’s ears and tail can dry out and fall off.
Animals with sweating sickness become emaciated and dehydrated. They also tend to seek shade. Some 20 to 30% of animals with the disease can die suddenly. The hair coat of recovering calves will fall out, but it will eventually grow back.
Read more about Voorkom sweetsiekte deur deeglike bosluisinspeksies.
Treatment options
No medicine is available to remove the toxin from the animal’s body; the animal itself must do this. Dr Odendaal’s advice is to get rid of the ticks and provide supportive treatment such as shade and quality nutrition until the toxins have been eliminated. Only secondary infections are treated with antibiotics to prevent bacteria from infecting wounds – these antibiotics have no effect on the toxin. The secret is to identify the disease timeously and act immediately.
The local herd veterinarian will assist in treating symptoms. More good advice is to dip animals to get rid of ticks. Drench the animal’s entire body, including the tip of its tail. Ticks can remain hidden on the tail switch and continue their path of destruction.
In addition to the switch being clean, it is also important to give the areas above the hooves a good look to make sure there are no ticks. The number of treatments will depend on the severity of the case and response to treatment. Get the basics right – plenty of shade, water and feed are the most important. Calves with mouth ulcers can be bottle-fed.
Prevention is essential
As a preventive measure it is best to dip cattle regularly if they are farmed in areas that are home to bont legged ticks. Perform weekly inspections and treat especially the tail switches of cattle. If one case of sweating sickness is identified in a herd, preventive treatment and inspections should be stepped up to contain its spread. – Koos du Pisanie, Stockfarm
For more information, contact Dr Danie Odendaal at 082 454 0532.
