Ruminants can be infected by several parasites of the skin (external parasites) which feed on the animal's skin and blood. The parasites cause disease, loss of weight, and can lead to death of the animal. The parasites can also carry other infections and spread diseases from one animal to another. Some of these diseases can kill.
All animals and man can be hosts to parasites which live on the skin.
These parasites look like insects. Mites are very small and cannot be seen without a microscope.
Lice (singular is louse) are big enough for you to see. Man can be infected with the head louse. Cattle, buffalo, sheep and goats can be infected with different lice which attack the body, legs or tail region. Lice live and lay their eggs on the skin amongst the hair or wool.
Ticks are bigger than lice and can be as big as a fingernail. Young ticks have 6 legs while adults have 8 legs. All ticks feed on the blood of the host and then drop off onto the pasture. They lay their eggs on the ground. Some ticks live on one host while others may live on two or three different animals throughout their lives.
Problems caused by external parasites
Mites cause mange. They infect the head, legs, body or tail region causing the skin to become crusted and cause loss of hair and wool. The infected area itches and the animal scratches. The host does not feed well. The infections cause loss of valuable wool in sheep and damage hides of cattle and goats.
Sometimes young animals become infected with a skin disease called ringworm. Ringworm causes circular, whitish patches on the skin which do not itch.
Animals can have both mange and ringworm and large areas of skin may be affected.
Lice also cause irritation of the skin and the animal scratches, rub and bite the infected areas. The host loses, or does not gain weight, and looks in poor condition.
Both lice and mites can pass from one animal to another.
Biting and scratching are the first signs of infection. If you examine the animal you will be able to tell if the skin problem is caused by lice or mites, if lice are on the animal you will find them in its coat, if you do not see any the animal probably has mange caused by mites.
Ticks are very important parasites. They bite the host and suck its blood and when full drop off onto the pasture where they can live for many months without feeding again. Animals can be poisoned or paralysed by the bites of some ticks. Ticks also spread diseases, tick-borne diseases, which can cause death of the host. Ticks cause the loss of meat, wool, milk and leather.
Treatment and Control
Mites and lice are controlled by washing the infected area, spraying or dipping the animal with a suitable treatment.
All of the flock or herd must be treated to ensure control. Some animals can be infected but show little or no sign of infection and the parasites will spread from them to other animals if they are not treated too.
If an animal has only a few ticks these can be carefully pulled off making sure the mouth parts of the tick are removed.
Rubbing ticks with a cloth soaked in kerosene (paraffin) will make them drop off the host.
Large numbers of ticks are treated using sprays and dips. It will be necessary to treat all of the herd or flock.
Moving animals to different pastures and resting the contaminated pasture for a length of time can help to control the ticks.
Cutting the bushes and ploughing the affected area can help to control ticks.
Large numbers of ticks can be found around water holes and animal shelters.
Mix common salt and few camphor in castor oil or neem oil and apply over the affected area.
Whole plant extract of ghaner (Lantana camara) should be diluted with the urine of cattle and apply externally.
Boil 250 gm of tobacco in 2 litres of water and add 5 litres of water and sprayed over the body of 10-20 animals.
If mange or ticks are a problem in your community's livestock you should talk to your local veterinarian about it. He will advise you on the best treatment and control to use in your area. He may ask you to collect some ticks or take scrapings of skin from animals with mange so the parasite can be identified. This will help him to decide which treatment you should use.