The Famacha (FAffa MAlan CHArt) system was developed in South Africa by Drs Francois Malan, Gareth Bath and Jan van Wyk after the emergence of drug-resistant worms. It involves studying the colour of the mucous membranes of the eye in sheep or goats. Anaemia is assessed using a chart (see Table 1) to assess the severity of parasitic infection. Appropriate deworming measures can then be taken.
A bright red colour indicates that the animal has few or no worms, or can tolerate worms. If the membranes are very pale, the animal is anaemic, and there is a high parasite load. The sheer number of worms in the sheep’s gut drain the animal’s blood. Untreated, animals with this degree of infestation will die.
The Famacha system contains five eye scores (1 to 5), which have been correlated with packed cell volumes (the percentage of blood made up of red blood cells). Animals in categories 1 or 2 (red or red-pink) do not require treatment; animals in categories 4 and 5 (pink-white and white) do. Those in category 3 may or may not require treatment. Mature sheep in category 3 will probably not need treatment, while category 3 lambs should be treated.
The frequency of examination depends on the season and the weather pattern. More frequent examinations are usually necessary in July, August and September – the peak worm season. Checking the eyes is a quick task and can be added to other management practices. The Famacha system slows down drug resistance, as only the selected animals are treated.
It should not be used in isolation, but incorporated into a worm control programme that includes pasture rest, good nutrition, multi-species grazing, alternative forages, zero grazing and strategic deworming. Instruction on how to use the system is needed and farmers should consult their vet before implementing it.
For further information, visit www.scsrpc.org.