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If you are concerned that your goats may need drenching now, but are unsure, please go to the Drench Decision Guide for your region.
A WormTest or worm egg count is generally the most accurate means to determine the burden of worms carried by an individual goat or groups of similar goats, however there are other ways to assess whether goats have worms and what level of worms exist.
Unfortunately, most are lagging indicators and rely on signs of significant production loss from worms having already occurred.
When the costs of drench, labour, testing and production loss are weighed up, the most profitable option for worm control is always to implement an integrated control program that includes grazing management, good nutrition, breeding for worm resistance and regular monitoring with worm egg counts to ensure that drenching occurs at the right time and before signs become obvious.
The other methods of identifying if goats may be suffering from worms include the following:
Mucous membranes are the moist areas of ‘internal skin’, such as inside the mouth (gums), nasal cavity, eyelids and vagina.
Where these do not have dark pigment, they can be used to observe the richness of colour from the blood. Normal healthy goats have dark pink to red mucous membranes. Goats suffering from anaemia, which can occur with barber’s pole worm (Haemonchus contortus) and liver fluke, will have paler membranes; in severe cases they can be almost white. Liver fluke may also cause jaundice, which will cause a yellow colour in the membranes.
Other roundworms do not cause anaemia, however liver fluke do. There are other causes of anaemia such as cobalt or copper deficiency. A WormTest will help when diagnosing the cause of anaemia.
Checking the colour of the inside of the lower inner eyelid has been standardized into a test for worms in South Africa, called the FAMACHA test. It uses a special card with different shades of pink and red and a standard method for comparing the eye mucous membrane colour. It is widely used in goats in South Africa and in the U.S.A. Goat farmers must receive training in this system before they can purchase these laminated coloured cards.
Goats are yarded and every individual is tested and recorded each 1–2 weeks during the worm season. This may not be practical if goat herds are very large, but is very useful in smaller goat herds. The FAMACHA© card allows goats to be given a score from 1 (red mucous membranes) to 5 (white mucous membranes). Goats are less likely than sheep to be scored as a 1. Only those goats with high scores (5, 4 or sometimes 3) are drenched for Haemonchus contortus worms.
By only drenching goats with high FAMACHA© scores (a higher worm burden) and not drenching goats with low scores of 1 or 2, worm larvae derived from goats not exposed to drench will be left to develop on the pastures and drench resistance development will be delayed.
By recording the FAMACHA© scores, it is also possible to cull goats that are less resilient to Haemonchus contortus worm burdens and require more frequent drenching.
Also called the “bike” or “dog” test, walking the goat herd over 100 metres and seeing whether some are lagging (a tail in the herd), or whether some collapse, is a very crude indicator of exercise intolerance in goats affected by a worm infection. If lagging or collapse are evident—and it is due to worms, and not some other cause—goats are already suffering from production loss that has generally warranted earlier drenching. If a few goats do lag or collapse when being mustered, individuals can be treated for worms, but the herd should also be sampled for a WormTest to see if drenching should be done now. In many herds, if the tail is collapsing on exercise, then deaths due to worms are highly likely as well, resulting in an animal welfare issue.
Scour worms cause a loss of appetite resulting in weight loss. This can be seen by loss of body weight and also by a reduction in condition score.
Regular weighing or condition scoring of animals either on a herd basis or as individuals can show when these start to decline. However, weight loss often results from other causes, in particular, a decline in pasture quality, quantity or both. Early lactation can also cause weight and condition loss.
Condition scoring of goats is slightly different between dairy goats and fibre/meat goat breeds. This is best demonstrated by these videos:
A WormTest is more accurate, less labour-intensive, and a less stressful (to the goats) method to monitor the worm burden of a goat herd; however, observed weight loss can be a useful trigger to carry out a WormTest.
Worms cause a variety of signs, however all of these signs can occur with other diseases. Refer to our signs of worms page to see a full list. Also, when goats have poor nutrition or another illness, they are more likely to pick up high worm burdens.
When any of these signs are apparent, a WormTest of the herd may be appropriate. If only a small number of goats are showing signs it may be useful to treat these individually while awaiting your WormTest results. If more than 2% of the herd are showing signs, it may be appropriate to drench the whole herd. The Drench Decision Guide for your region will provide a recommendation on whether to drench or to test.