Dear daktari, I am a regular reader of your articles in Smart Harvest. With the rains currently pounding the nation what diseases should farmers be wary of?
George Njoroge, Naivasha
Dear George, Thank you so much for the compliments and a good question. Most disease and condition outbreaks follow or depend on certain weather changes like what is happening now with above-average rains in most parts of the country.
Many studies have been done on the effect of climate change on animal health, with many pointing to an increase in disease prevalence. This is attributed to a widening of disease vector habitats and subsequently an increase in their populations. Climate change is also resulting in the emergence and re-emergence of animal diseases. Diseases long forgotten are coming back.
A change in weather patterns creates a suitable habitat for an increase in disease vector populations. This can easily result in a specific disease outbreak. Similarly, a change in the vegetation or pastures due to rains has the potential to cause several digestive system conditions. A change in weather conditions by itself could also cause diseases, for example, of the respiratory system. Harsh weather conditions stress animals, and in this state, they are prone to a myriad of diseases. Livestock can be swept away by the raging waters so as we plan for the evacuation of people, we should also be mindful of animal welfare.
Here are some of the diseases that farmers need to watch out for as the skies continue to yield.
Rift Valley Fever
This is a deadly viral human and animal disease spread by mosquitoes between animals and contact with or eating livestock products from infected animals. Rift Valley Fever often follows above-average rains that result in pooling and stagnation of waters. These water masses create favourable conditions for the multiplication of mosquitoes that spread the disease in naïve stocks. The disease is zoonotic and is characterised by stormy abortions in small stocks, especially sheep and deaths in young animals. If you observe these abortions, urgently contact your veterinary doctor and do not touch the aborted fetuses with bare hands. Fortunately, this disease can be prevented through strategic vaccination. Do not attempt to vaccinate during outbreaks, though.
Diarrhoea or scours
Expect lots of diarrhoea with the rains, especially for animals grazing out in the open fields. Consumption of lush pasture can result in diarrhoea in young lambs and kids. A scouring lamb or kid loses large amounts of fluids and electrolytes, and if this is not corrected, it can easily end in death. Sheep that have diarrhoea are more prone to flystrike (blowflies or maggots). Docking or cutting of the tail can help prevent flystrike.
Stomach and intestinal worms
Warm moist conditions are favourable for the multiplication of gastrointestinal worms. An infestation will also cause diarrhoea. Control of gastrointestinal parasites is best achieved through rotational grazing if you have a large piece of land. This helps to break the cycle of transmission. Strategic and/or selective deworming of affected animals with effective anthelmintics is the other strategy. But this should be guided by a veterinary doctor for efficiency.
[Dr. Othieno is a veterinary surgeon and currently the head of communications at the Food and Agriculture Organization of the United Nations (FAO) Kenya. The views expressed here are not necessarily those of FAO but his own]
