OSU Sheep Team

Clif Little, Ag/NR Agent, Guernsey County

(Originally Published in Sheep Team Newsletter June 2004)

Wet weather may contribute to fly infestations on livestock. Young lambs and sheep are particularly vulnerable. Wet soiled wool, wounds and dying tissue attract blow and bottle flies in the spring. Young animals may become infested very quickly. Flies usually deposit eggs on wet navels or around the rear end of the animal. Infected animals appear lethargic, walk with a limp, tail twitch, and generally appear depressed. If not treated immediately maggots may enter animals through the rectum, vagina or navel area.

Examine animals frequently this time of year. Closely inspect animals which are soiled or exhibit the clinical signs mentioned above. If maggots are found, look the animal over closely for spreading populations. In addition to the locations above, maggots can often be found between the hooves and in the flank region. Shearing and crutching helps to control outbreaks on mature animals. It may be necessary to clip wool to determine the extent of the infestation, remove the maggots and spray on a wound healing dressing such as screw worm spray. Fly larvae that have entered the body of animals can be encouraged to leave by coating the area where they entered with petroleum jelly. Once the wound is treated and larvae killed, there are many products approved for sheep containing Permethrin which will kill flies and provide some residual protection. Severe infestations may require antibiotic treatment, contact your veterinarian for assistance.