Lice
Lice infestation in cattle
Damalinia bovis (cattle hair coat)
In cattle sucking and biting lice play the most significant role as "harmful winter guests" because they find particularly good breeding conditions in the thick winter coat of the cattle. In pigs the hog louse occurs throughout the year.
The irritations caused by the parasites lead to restlessness in the herd and to a deterioration of feed conversion which after treatment improve immediately.
Damalinia bovis
A single treatment of cattle in the late autumn controls lice infestation throughout the winter and prevents economic losses. In pig farming it is important to treat sows with an acaricide before transfer to the farrowing pen, above all to prevent infestation of the piglets.
Lice infestation in sheep
Sheep keds
Apart from mange, the principal pests in sheep are a mallophage species and the sheep ked.
Damalinia ovis (also Bovicola) is a 1.5-1.7 mm long biting louse which lives in the wool close to the skin and causes considerable irritation by great activity.
The sheep bite and rub themselves, thus causing damage to the wool. The patchy wool loss and the thickening of the inflamed skin suggest mange.
Fleece damage caused by biting lice
The differential diagnosis can be performed by demonstration of the biting lice which occur in large numbers on the margins of the bald patches. From the deposited eggs larvae hatch within 7-12 days and the life cycle from egg to egg of the next generation takes approx. 3-4 weeks.
The sheep ked possesses no wings and is a blood-sucking stationary parasite. Females live up to 4 months and produce 12-15 larvae by viviparity. The larvae pupate on their first day of life for 19-36 days depending on the temperature; 3-4 days after hatching the female is ready for mating and can produce her first larva on the 14th day of life. As the sheep ked sucks blood on the same spot for a prolonged time, an infestation leads not only to irritations with its consequences, but also to direct skin damage.
A single thorough treatment in the autumn, preferably in a plunge dip, controls the pests for the next 12 months, provided that massive new infestations, for example by buying-in lice-infested stock, are prevented.