Mastitis in Sows

Mastitis can be important in swine-raising units. Peracute mastitis can affect sows and gilts and is most commonly associated with coliform (Escherichia coli, Enterobacter aerogenes, and Klebsiella) infections. It is most common at or just after parturition, and affected sows have a moderate to severe toxemia. The sow’s temperature may increase to 107°F (42°C) or may be subnormal. The affected glands are swollen, purple, and have a watery secretion. Sow mortality is high, and the piglets will die unless fostered or fed artificially. Milk production of recovered sows may be impaired in the next lactation. The treatment of peracute coliform mastitis in sows is similar to that in cows. Ampicillin, dihydrostreptomycin, or oxytetracycline administered systemically have been used. Treatment of lactating sows requires consideration of withholding periods, because affected sows are often culled after weaning.

Subacute mastitis may occur in older sows and lead to induration of one or more glands, impairing the sow’s ability to nurse a large litter. This form of mastitis is more likely to be associated with infection by streptococci or staphylococci. Granulomatous lesions in the mammae of sows have been associated with Actinobacillus lignieresii, Actinomyces bovis, and Staphylococcus aureus infections. Fusobacterium necrophorum and Trueperella (formerly Arcanobacterium) pyogenes also have been incriminated in sow mastitis. A thorough examination and culture of the mammary glands of the sow are important to diagnose any of the above peracute and subacute types of mastitis. (Also see Postpartum Dysgalactia Syndrome and Mastitis in Sows.)

The control of mastitis in sows has not been extensively investigated, but isolating sows in adequately disinfected pens before, during, and for an adequate period after farrowing should help prevent the severe losses associated with coliform mastitis.