Mastitis in sheep from my view point is poorly understood. In acute mastitis treatment targets salvaging the ewe and seldom if ever is the infected portion of udder remain functional. Sub acute mastitis as to wether it exists and shows up following years is anybody’s guess. Then you have the OPP people that believe based on a blood test that the majority of the adult ewes are positive to that all hard bag is OPP. Far from it, you can create hard bag by feeding to high a level of protein and I strongly suspect many hard bag ewes had subacute infection in previous lactation. In some instances they have been assembled as culls and resold into the market place as breeding ewes. First time lambing ewes that have been fed to hard will deposit fat in udder and will never milk well. Good luck taking over weight fat bred ewe lambs out of a feed lot and trying to make ewes out of them.
Prevention is a challenge but there are some considerations that have value. Be aware that assembled sheep may be some one else’s culls. Don’t overfeed ewe lambs that are to be kept for breeding. Pull ewe lambs off full feed when they reach eighty pounds. Don’t over feed high quality alfalfa hay prior to lambing. Generally a half pound of corn or equivalent along with medium quality hay is sufficient prior to lambing. Beware of feeding a 16% concentrate if protein level in roughage is adequate. Maintain good husbandry conditions. The most heavy milking ewes will be the most vulnerable. Don’t strip out after weaning.
Symptoms of acute mastitis include off feed, depression, swelling and hardness of udder and unilateral lameness. Generally a foul smelling reddish secretion from teat. Udder may feel cool, normal or warm. Crepitation would indicate gangrene.
Treatment targets salvaging the ewe and many of these ewes will be heavy milkers and if you can get them through clinical symptoms they still may be able to raise twins. Lambs may need to be tubed in the interim. I like to use Nuflor 6cc per 100# body wt. subq, repeat in 48 hrs. Penicillin at the rate of 10cc per 100# body wt subq daily. Five cc Dexamethasone once. LA 200 may be substituted at 5cc per 100# subq for Nuflor. Mastitis tubes are useless. If gangrene develops may want to open infected teat so it can drain. With gangrene the affected portion will slough. Not many develop gangrene but one should be aware of the process when it happens. If ewe is retained for breeding next year the affected portion will be non functional.