An increased tick burden after the recent rain that fell over a short period in Limpopo, Mpumalanga and northern KwaZulu-Natal means livestock farmers must be on their guard for diseases transmitted by ticks and other biting insects, says Dr Roelf van Rooyen, a veterinarian from Limpopo.
Heartwater, redwater and gallsickness pose the most significant risk to cattle herds in these provinces, and he says farmers should discuss with their veterinarians how to protect their herds.
“Lumpy skin disease also tends to occur more frequently in rainy years,” says Van Rooyen. He advises farmers to vaccinate preventatively, but like all veterinarians he is concerned about vaccine availability. He urges farmers to inquire about availability as soon as possible to begin preventative vaccination.
Three-day stiffness disease is another viral disease transmitted by midges that can thrive in wet weather. Here, it’s essential to vaccinate breeding bulls in time, although the same issues around vaccine availability apply.
Van Rooyen says although three-day stiffness disease isn’t necessarily fatal for cattle, it has catastrophic consequences for herds if breeding bulls “won’t do their work” because they’re sick.
“With the exceptionally wet weather, Rift Valley fever also hangs like a sword over farmers’ heads,” warns Van Rooyen. He advises farmers in Limpopo and Mpumalanga not to start vaccinating against it immediately. “Over the years, we’ve seen the disease first breaks out in KwaZulu-Natal and the Free State. Therefore, farmers in Limpopo and Mpumalanga should first monitor if it breaks out in Natal or the Free State, which would be the sign to start vaccinating against it.”
Feedlots and stables
Footrot becomes a considerable risk when soil is so saturated that water pools stand for days. In extensive farming operations, cattle can be moved to drier camps, but the risk must be managed more aggressively in feedlots and dairies.
Van Rooyen says some of the feedlots in Limpopo now look like swimming pools. Farmers must carefully monitor their animals’ hooves and treat them with copper sulphate or other available remedies against footrot at the first signs of infection.
Although pneumonia is more prevalent in winter, it is also a risk in wet weather, especially in feedlots, and he says farmers should consider vaccinating their animals against this preventatively.
Regarding sheep and horses, Van Rooyen warns farmers to be especially careful of the virus transmitted by midges that causes horse sickness and the closely related virus that causes bluetongue in sheep.
In both cases, he says farmers who can get vaccines should vaccinate now. There are alternative measures to help prevent outbreaks where vaccines are not available.
“Move horses to higher-lying areas where midges don’t occur. Otherwise, get horses in the stable early in the evening, as early as five in the afternoon, and spray midge-repelling agents, available at most cooperatives, on the horses’ coats. They must be in the stable during the cooler early morning hours.”
The same applies to sheep. Van Rooyen recommends farmers keep their sheep in a kraal in the evening when it’s cooler and the midges become more active.
