Parasites wreak havoc on herds and can even lead to animals succumbing. The well-known, award-winning veterinarian, Dr Faffa Malan has developed the Famacha system (FAffa MAlan CHArt) in collaboration with Prof Gareth Bath, convenor of the Small Stock Health Advisory Body (SSHAB) and Dr Jan van Wyk to help farmers examine their animals for parasites on-farm.
Wireworm infestation is frequently encountered in sheep and goats, especially in the summer rainfall regions. Wireworms are bloodsucking parasites that cause anaemia. Pale mucous membranes and bottle jaw are clinical symptoms of wireworm infestation. The mucous membranes of a healthy animal are red, but wireworm causes the membranes to become paler, turning pink and then white, after which the animal generally succumbs.
This parasite poses a problem as there is no anthelmintic that is 100% effective in controlling wireworm. As a result, specific anthelmintic-resistant wireworm strains have developed. Resistance is a growing and rapidly expanding threat.
Live with the problem
Dr Malan, or Doc Faffa, as he is generally known, and Prof Bath, believe it is better to live with the problem rather than treating animals in such a way that the parasite gradually becomes a far more serious issue, despite treatment.
Prof Bath says the biggest problem is that producers misuse dewormers. “Many farms are stuck with the problem of resistance against many groups of anthelmintics. This threatens the sustainability of sheep and goat farming, because you cannot rely on medication alone to control parasites,” he says.
He explains that most sheep and goats can endure the discomfort caused by worm infestation and that only a handful of animals in the flock will get seriously ill.
The Famacha answer
Doc Faffa identified this problem years ago and came up with the Famacha system, which is named after him.
This system compares the colour of sheep and goats’ eyelids to the colours on a chart to measure their levels of anaemia (internal parasite infestation). Only heavily infested animals are treated. It keeps anthelmintic resistance to a minimum and identifies animals with natural parasite resistance.
Doc Faffa says it is unnecessary to dose the entire herd every time. “First of all, you are encouraging the selection of resistant parasites and secondly, it is an expensive process for the producer. Research has also indicated that the ability of sheep and goats to prevent, suppress or resist parasitic infestations, is hereditary. Animals can thus be bred with inherent parasitic resistance.”
According to him, examining your sheep on a regular basis is the only real answer. “The easiest way to treat wireworm is to examine your sheep regularly and to treat only those animals that cannot cope with the wireworm infestation. The Famacha examination is very effective in this regard.”
Dr Malan, Prof Bath and Dr Van Wyk initially tested and implemented the Famacha system in South Africa. It has been tested in other countries since 1990 where it has proven to be equally successful.
Dr Malan explains that wireworm causes anaemia. Normally, this condition would have to be tested in a laboratory, but the Famacha system allows the producer to determine the degree of infestation on-farm.
“Blood consists of plasma (a clear liquid) and red blood cells. The ratio between the red blood cells and the plasma determines whether the animal is healthy or sick. Too many or too few red blood cells are indicative of disease. This ratio is usually measured in a laboratory, but with practise it can be determined fairly accurately by looking at the colour of the animal’s eye mucosa.
“Wireworms are bloodsuckers and heavy parasitic infestation leads to a low red blood cell to plasma ratio. This leads to the eye mucosa being paler than it should be. By examining the mucous membranes, anaemic animals can be identified and treated,” he says.
Advantages of the method
Prof Bath says this method of examination offers many benefits. According to him, it not only saves on medication costs, but it helps sheep and goats build up natural resistance to infestation and prevents parasites from becoming resistant to treatment. “This way, sheep with clinical signs of wireworm are identified timeously and can be treated with an effective agent before the symptoms get out of hand. Such animals should be culled.”
According to Dr Malan, it is easy to notice instances in which animals have been treated with ineffective medication, as there are fewer sheep to keep an eye on. When an effective dewormer is used, pale eye mucosa will show signs of improvement within seven to ten days, provided the animal’s protein intake and body condition are up to standard.
In his experience, sheep that are treated only when it is absolutely necessary, are stronger and better able to withstand the effects of wireworm. “It is easy to spot the problem when you examine your sheep regularly. Consequently, it is easier to identify camps or kraals where these parasites occur.”
Dr Bath agrees and says the method is also very cost effective, which is another great advantage. Inspecting the animals’ eyes can be done at the same time as vaccinating or weighing. According to him, up to 500 sheep can easily be examined in an hour.
According to Dr Malan, there is no silver bullet that will solve all disease problems and preventative action should always be taken. “Only wireworm infestation can be thoroughly examined with the Famacha system. Although several other bloodsucking parasites have been successfully identified using this process, the test is only certified for wireworm management. It has not yet been tested thoroughly for other parasites.”
He emphasises that the Famacha examination method complements good parasite control and must not be used as a single parasite control method. “Although wireworm is the main cause of anaemia, other causes such as liver fluke, external parasites, blood parasites, infections and even nutritional deficiencies, may lead to confusion.
“On the other hand, there are conditions that cause the eye membranes of animals to appear more red. These conditions include: dusty or hot, dry conditions that irritate the eyes; driving animals across long distances without rest; fever; infectious eye diseases; and diseases associated with poor circulation.”
The five-point plan
Dr Malan and Prof Bath have drawn up a five-point examination plan that producers can use to combat most parasites on the farm. Step one involves the Famacha method. The other four checks in the plan include:
- The nasal area: The nose can be checked as this will easily indicate whether the animal has any nasal infestations. The nose will show a watery discharge, which inhibits the animal’s sense of smell and has a negative effect on weight gain. Other diseases and parasites that may be identified with this examination are lungworm, pneumonia, bluetongue and orf.
- Body condition score: To determine the body condition score, the animal’s loin must be measured. Emaciated animals in particular are likely to be infested with parasites such as brown stomach worm, bankrupt worm, long-necked bankrupt worm, nodule worm and pear-shaped stomach fluke.
- Faecal examination: Examining a sheep or goat’s hind area may indicate whether the animal is infected with parasites. Clean buttocks are a sign of good animal health. However, if there are faeces sticking to the wool and soiling the animal’s hind legs, it is a clear indication of diarrhoea, which is often caused by parasites. Diseases or parasites that can cause diarrhoea are brown stomach worm, bankrupt worm, long-necked bankrupt worm, nodule worm, whipworm, pear-shaped stomach fluke, cryptosporidiosis and coccidiosis.
- Bottle jaw: Bottle jaw is a common clinical sign of wireworm and liver fluke infestation. These parasites can cause weight loss and mortalities and have an impact on the animal’s immunity and fertility.
It is very important to quarantine animals that are bought in, after which the five-point plan and faecal egg counts can be used to prevent resistant parasites from entering the herd. – Koos du Pisanie, Stockfarm
For more information, contact Prof Gareth Bath on 082 802 2526 or firstname.lastname@example.org, or Dr Faffa Malan on 082 908 8666 or email@example.com