Address parasite infections among sheep, goats

Small stock producers in Namibia are faced with significant livestock health challenges, mostly associated with parasite infestations.

According to Agribank’s technical advisor for livestock and rangeland, Erastus Ngaruka, parasites can be classified into two main categories: internal and external parasites.

Their prevalence is seasonal or depends on the prevailing environmental conditions.

For example, internal parasites include types of tapeworms, roundworms and flukes, whereas external parasites are ticks, lice, fleas, mites and flies.

“The prevalence of these parasites is seasonal, where some prevail in winter and some prefer the summer months for their survival.”

In addition, parasites are host-specific, and their survival or completion of their life cycle is dependent on the availability of a host animal.

Control measures

Other predisposing factors to parasite infestation are related to poor management of kraals and the absence of or an inappropriate parasite control schedule, amongst others.

Parasite infestation results in huge production and economic losses for small stock farmers in the country,” Ngaruka warned.

“Moreover, the control measures are cumbersome for some farmers who may not understand or have limited knowledge of the types of parasites, their life cycles, seasonality, symptoms and remedial actions to follow.”

Parasite infestation can be detected by marked symptoms or changes in animal condition and behaviour, as well as through closer inspection of their presence on the body.

Some of the parasite activities on an animal include blood sucking, feasting on skin, hair and pre-digested feed in the rumen.

The most observed symptoms, depending on the type of parasite, include anaemia, diarrhoea, bottle jaw, runny nose, hair loss, and emaciation, among others,” Ngaruka said.

Furthermore, the effects of internal parasites can be organ-specific. For example, the liver fluke affects the liver, and the lungworm affects the lungs.

Be prepared

Ngaruka said the two distinct seasons for Namibian farmers to focus on livestock management programmes are winter and summer, as both present varying challenges when it comes to parasite control.

For example, during the summer months, there is a high prevalence of flukes, mosquitoes, ticks and flies, whereas during the winter months, a high prevalence of tapeworms, mites and fleas is observed.

However, the unhatched eggs of some parasites can be carried over between seasons.

Ngaruka noted several cases of goat and sheep losses have been reported, especially after good rains, and most post-mortems reveal liver damage, thus indicating liver fluke infestation in many kraals.

Liver fluke is an internal parasite characterised by a life cycle that depends on a snail. Snails prefer moist environments, leaving the parasite on the vegetation around standing water. This is how animals grazing around standing water are infested.

One of the external symptoms of liver fluke infestation is bottle jaw, a fluid-filled swelling below the jaw.

He said other internal parasites to look out for are lungworms and nasal worms, both of which cause distress in the animal’s respiratory system.

Lung worm infestation symptoms include runny nose, coughing and difficulty breathing, whereas nasal worm infestation commonly shows signs of runny nose and sneezing.

Select remedies

Ngaruka said there are many remedies that farmers can choose from to control internal and external parasites, and this choice should be based on the potency of the remedy against the targeted parasites.

“These remedies are administered orally to directly control internal parasites, while others are administered topically to control external parasites.”

There are injectable solutions that can control both internal and external parasites at once.

“The first and cheapest line of defence against parasites and diseases in small stock is to maintain a clean kraal environment. Secondly, farmers need to regularly observe their animals’ condition and behaviour.”

Ngaruka said one of the approaches that any farmer should follow is to conduct basic post-mortem examinations on an animal that is slaughtered at the farm, even for home consumption.

This presents an opportunity to study or inspect the animal body and the condition of the visceral organs for abnormalities that may be prevalent in the flock.

Lastly, always consult local veterinarians, experienced farmers, or livestock experts for advice.