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Mastitis In Ewes and Does

Mastitis is one of the more common health problems affecting sheep and goats. Severe cases can result in death of the ewe, but more often it takes its toll in the form of treatment costs, premature culling, and reduced performance of lambs and kids.

Mastitis is an inflammation of the mammary gland (udder). It can be caused by physical injury or stress or by bacteria which invade the mammary gland. The bacteria which are known to cause mastitis in cows, sheep and goats are Streptococcus sp., Staphylococcus sp., Pasteurella sp., and coliforms, such as E. coli.

Mastitis is usually observed shortly after lambing until the post-weaning period. It can take on several forms. Clinical mastitis (chronic or acute) involves physical changes in the udder. The udder becomes swollen and warm, sometimes painful to the touch.

In severe cases, blood supply to the udder is affected and a blue discoloration may result, hence the name "blue bag." Ewes affected with mastitis become feverish, go off feed and become depressed. They may hold their rear foot up, as if they are lame, and refuse to allow their lambs to nurse.

Ewes with sub-clinical mastitis usually appear quite healthy, but there is a reduction in their milk supply and development of lumps (scar tissue) in their udders, hence the name "hard bag." This is probably the most "serious" form of mastitis to the producer, since it often goes undetected. Keen observation is necessary to pick out these cases and prevent the potential damage.

Ewes which show signs of mastitis should be separated from the rest of the flock and treated with antibiotics. It may be necessary to bottle feed their lambs. Treatment usually involves intramammary infusions of antibiotics and systemic antibiotics. It is helpful to collect milk samples from affected ewes to determine the main bacteria involved and the correct medication to use. Treatment should be continued for several days until the clinical signs have gone away.

The udders of ewes should be examined after weaning and before breeding. Ewes with hard lumps in the udders should be culled, as these ewes will become increasingly poor producers of milk. Ewes that can only nurse one lamb should be culled from the flock. There is some evidence as to a genetic component to mastitis.

Mastitis can be controlled with good management and sanitation. Bedding in drop pens, mixing pens and lambing jugs should be clean and dry. There should be good drainage around the barn and lots. Animals should not be overcrowded. The incidence of mastitis is greater in closely confined flocks.

Preventing respiratory disease in lambs may help to prevent mastitis, as Pasteurella hemolytica, the bacteria that causes baby lamb pneumonia is a major cause of ewe mastitis. Sore mouth is another contributing factor, as lambs with mouth lesions can infect their dams and any other ewe they may nurse. The OPP (ovine progressive pneumonia) virus may be involved in cases where both halves of the udder are affected.

Weaning lambs from ewes whose milk production has not declined sufficiently puts severe stress on the udder; therefore proper management at weaning is also necessary to prevent mastitis. After weaning, it is advisable to restrict the feed and water of ewes for 1 to 2 days to rapidly decrease their milk production.

Some producers will reduce water and all feed 1 to 2 days before weaning. Others will remove grain from the ration 3 to 7 days before weaning. Delaying weaning until after milk production has decreased sufficiently will lessen the occurrence of mastitis.

From Maryland Sheep and Goat website

References and further reading