STREPTOTRICOSIS

This is a chronic exudative dermatitis characterized by scab formation. The disease is caused by Dermatophylus congolensis. Horses, cattle, sheep and goats are commonly affected. It has been reported in pig, donkey, cat and dog. Bovine streptotricosis is of great economic importance in Nigeria because it destroys hide and skin. West African muturu and Ndama cattle are resistant to the disease.
Transmission
The organism is found on skin epidermis. It appears to be necessary for the skin to be broken before infection can occur. The skin may be damaged by ticks, biting flies or mechanically by barb wires.
Clinical features
In some animals, the lesions are found on the back, extremities like necks and face and others generalized all over the body. The commonest site of infection in goat seems to be the face, ears and inguinal region. In affected site, exudation and scab formation caused the hair to stand erect and become matted together to form paint brush lesions. These are so called because they resemble the hairs of the wet paint brush. The lesions increased in size and thick variable scabs are formed. Affected animals are emaciated and limp if the feet are affected. Death may occur eventually.
Diagnosis
This is based on the appearance of cutaneous scabs on endemic areas. Confirmation of diagnosis is by making a smear from scab which has been emulsified in water for some hours. The smear is stained by Gram’s procedure, Leishmann or Giemsa and examined for the presence of branching filaments and coccoid cells.
Fluorescent antibody technique is the most effective diagnostic method.
Establishment of experimental lesions in rabbits by skin scarification in the presence of suspension of lesion or culture the organism and rub it on scarified area.
Treatment
It is treated by removal of scabs and application of antibacterial substances like antibiotic cream/powder.
Give high doses of penicillin and streptomycin parenterally. This treatment is repeated after 2 weeks. This treatment is effective if it is given early in the disease.
Give long acting antibiotics.
Immunization
There is no available effective vaccine at the moment.
Control
It is necessary to eliminate those factors that predispose to the diseases like ticks (spray the animal), biting insects (insecticide).
Animals should be dipped regularly to rid them of ticks.
Sheep should not be sheared in wet hot weather.
All affected animals should be culled for meat or isolated and treated.
Increased herd resistance by selective breeding from resistant animals.