Mastitis is the term for a bacterial infection in the udder. It is a common problem in sheep and goats, especially those that are intensively or semi-intensively managed. Heavy milking females and those nursing multiple offspring are most commonly affected.
Two bacterial species (Staphylococci) are responsible for causing most of the cases of mastitis in sheep and goats. Soremouth can be another cause, as nursing lambs/kids transfer infection to the teats. Poor milking technique and hygiene can be the reason for mastitis in dairy females.
OPP (ovine progressive pneumonia) and CAE (caprine arthritic encephalitis) are viral diseases that can cause a similar disease condition. In the case of OPP and CAE, the udder is usually firm and shapely, but it produces little to no milk. If both halves of the udder are affected, it is often OPP or CAE. If only one half is affected, it is usually mastitis.
There are two forms of mastitis: clinical and sub-clinical. Sub-clinical may be difficult to identify. However, it causes significant economic loss, as affected females produce less milk, sometimes not enough for all their offspring to do well. Elevated somatic cell counts (SCC) affect marketability of milk.
While most producers make a diagnosis based on observation of clinical signs, mastitis, especially sub-clinical, can be diagnosed with a micro-biologic culture of the milk. A milk culture can also identify the causative organism and appropriate course of treatment.
Providing good nutrition and a clean environment, especially during birthing and lactation, are the keys to preventing mastitis. Rations should be balanced to ensure that the nutrient requirements of females are being met, but not exceeded. Both underfeeding and overfeeding have been implicated as causes of mastitis. Proper management at weaning (drying off) is also important. Good udder conformation will help to reduce the incidence of mastitis. Females with pendulous, low hanging udders should be culled.
Mastitis is usually treated with antibiotics and anti-inflammatory drugs. The sooner treatment is initiated, the more likely it will be successful. No treatment protocols are FDA-approved for treating mastitis in sheep and goats; therefore, producers need to work with their veterinarians on developing and implementing treatment plans.
While a ewe or doe is being treated for mastitis, it is often necessary to bottle or tube-feed her offspring. In some cases, the lambs/kids will have to be removed for artificial rearing. Females which suffer permanent damage to their udders should not be kept for breeding.
Females that only produce milk on one side of their udder should not be retained. Females with lumpy udders should be culled. Mastitis is often a confounding problem that worsens each year. When culling a female that you have treated for mastitis, be sure the drugs have cleared her system before taking her to market or slaughtering her for meat.