Anti-parasite remedies should be changed every two years to prevent resistance from forming.
In young lambs internal parasites such as milk tapeworm (Moniezia expansa) can prove problematic, while adults can fall victim to wireworm (Haemonchus contortus).
The wireworms are bloodsuckers that can cause death due to anaemia from severe internal blood loss. Animals that carry heavy worm loads can furthermore develop immunity disorders, making them helpless to opportunistic diseases.
If animals are left untreated for lengthy periods they can become ‘reservoirs’ for parasites, and will keep on reinfecting animals that are healthy on communal rangelands.
Parasite-infested animals become unproductive and give birth to weak offspring; they also struggle to feed their young. Low-quality wool may be produced by wool sheep.
Although some animals can develop some immunity against parasites and diseases and remain functional, others are continually affected. These animals should be culled.
Symptoms of worm infestation
- A swelling that develops under the lower jaw called bottle jaw;
- A condition where the abdomen appears swollen, known as Ascites;
- Coughing and laboured breathing;
- Diarrhoea, that is often mixed with blood;
- A swollen belly on a thin body, in lambs. This may be a sign of serious milk tapeworm infestation;
- A pale or white, instead of pink, inner eyelid. This can be a sign of anaemia.
Management protocols farmers should consider introducing
- Request proof of the health status of the animals, when buying new livestock;
- Hold animal health workshops that include signs of parasite infestation, where farmers are educated what to look for when buying new livestock.
- A quarantine area should be created where all new animals can be placed on arrival. Experts must then inspect the new animals for signs of parasites, both external and internal, and they must administer a mandatory vaccination booster injection, dip the animals, and dose them suitably.
- Sickly animals must be treated with antibiotics and monitored for recovery.
- If animals are quarantined for 10 days or so, worm loads will rather be expelled into this area than into the rangelands. You must change the quarantine area every two months and keep all animals off the old quarantine area for 30 days; this will allow parasites that are in the area to die off.
- Collect fresh dung from at least three sheep owned by five owners. Each sample should be kept in a separate packet. Samples should then be sent to the state vet for a faecal egg test; that will indicate the specific type of parasites and the levels of infection that are being dealt with. Once you know this, obtain a drench dose or even an injectable remedy. Only treat sheep that show signs of infection in a community. Treat all livestock if more than three in every 10 sheep (about 30%) show signs of infection.
- Treat all animals for internal and external parasites at the change of the seasons or when outbreaks become clearly visible. Then again, don’t dose animals too often (monthly is too much), as it can create parasite resistance and even toxicity problems.
- Young lambs should be vaccinated with a broad-spectrum vaccination (obtain advice on the best brands) at about six weeks of age, then deworm them.
- To prevent resistance from forming, change anti-parasite remedies every two years
Treat all the village animals at the same time by using the same injectable treatments or doses. If even a few animals are left untreated, reinfection will be rapid, and dosing will need to be undertaken more often.
Source: Farmer’s Weekly