Deworming goats and sheep
published:
Saturday | April 26, 2008
Dr Graham Brown in his veterinary laboratory.
Worms are the number one health problem affecting small ruminants, especially in tropical climates. Sheep and goats are more susceptible to these parasites due to their grazing behaviour and poor immunity. Most farmers rely heavily on anti-parasitic drugs (anthelmintics) to control these parasites. Unfortunately, drug resistance has become an increasing problem.
The parasite that is most problematic for goats is Haemonchus contortus, also called 'barber pole' worm. This worm feeds on blood and lives in the abomasum (stomach).
The signs associated with this worm are anaemia, characterised by pale or white gums and inner eyelids, and 'bottle jaw' - an accumulation of fluid under the jaw. Diarrhoea (scours) does not usually occur with barber pole infestation.
Other parasites of concern include the brown stomach worm (Ostertagia circumcinta) which causes diarrhoea and weight loss, tapeworms, lungworms, liver flukes and occidian.
Recommendations for deworming your goats
1. Consult with your veterinarian.
2. Dose, using the heaviest animal as a guide.
3. Under-dosing results in resistant worms.
4. Oral drenching is the recommended method of treatment and the drug should be placed over the back of the tongue.
5. Fasting animals for up to 24 hours before drenching may improve efficacy (do not restrict water).
6. Drugs should NOT be rotated after each use. Use for at least one year or until it is no longer effective.
7. Do not deworm your goats frequently (for example, more than three times per year).
8. Always deworm newly purchased goats.
9. Deworm two to four weeks before kidding/lambing.
10. Goats require higher dosage. (one and a half to two times higher than for sheep or cattle. In the case of levamisole the dose is one and a half times).
11. Do not treat every animal in your herd at once, since approximately 20 per cent are responsible for pasture contamination.
FAMACHA
This technique uses a colour eye-chart depicting degrees of anaemia to determine the need for anthelmintic treatment. It only works for 'barber pole' worms.
It was developed for sheep, but works with goats with slight modifications. The FAMACHA technique reduces the number of animals treated because only animals showing physical signs of infestation are dewormed.
Some uses and advantages of FAMACHA
1. A significant drop in the frequency of deworming, reducing the amount of money spent on drugs.
2. Because fewer animals are treated, the development of worm resistance will be slowed.
3. Inspecting the eyes is quick.
4. If examined regularly, animals can be treated before the signs and effect of anaemia become too severe.
5. Individual animals that repeatedly fail to cope with worms, in spite of the control programme, can be identified and culled.
6. Build-up of infected larvae on the pasture can be detected early by the sudden increase in the number of anaemic animals.
- Adapted from FAMACHA Training Course, University of Maryland, USA.
