7 January 2000

Licensed products can beat dermatitis

CONTAGIOUS ovine digital dermatitis can be successfully treated with products licensed for use in sheep, and horn regrows quickly after treatment.

That is the experience of Glos vet Chris Watson of the Wood Vet Group, after the treatment of a severe CODD outbreak in 100 lambs running with a 300-ewe flock.

Handling facilities and staff problems meant only a single treatment was possible, he reports in a letter to the Vet Record.

Lambs were treated using oxytetracyline aerosol spray on the affected area and a single injection of the long-acting antibiotic tilmicosin. The spray is licensed for foot conditions and the injectible antibiotic for pneumonia treatment with activity against spirochetes, the same species of organism causing CODD.

The level of lameness fell rapidly after treatment, he says. After only a few days new horn started to grow, and four weeks later the whole claw had a good covering of horn. But this horn was not the normal thickness and shape; it was smaller and more rounded in appearance (see pic).

"It was strange that the whole claw was covered in horn growing from basal layers rather than the slower process of growing down from the coronary band at the side of the foot," says Mr Watson. But it is possible horn would grow from the coronary band later and a horn wall would be established.

"There is concern about using unlicensed products for treating CODD, but these licensed products worked well." However, tilmicosin doses must be accurate, it can only be used in lambs over 15kg and there is a 42-day withdrawal period, he warns. &#42