A clean environment is important from weaning to at least 10 days post mating. In the first 2 or 3 days post weaning the mammary gland is full of milk creating pressure which may predispose to mastitis. Contamination of the teat end with faeces and urine greatly increases this risk. The housing should be washed and dried between each batch of sows weaned. If this is not possible, it should be done at least once a month. If the sows are confined individually, the rear of the pens are best slatted to allow urine to drain away. Faeces should be removed daily. The rear gates in stalls should have a 100mm gap above the floor so that faeces are squeezed out behind the sow and not allowed to build up and cause heavy bacterial contamination of the vulva. If solid floors are used they should have a fall of at least 1:20 in the last 450mm behind the sow to allow for good drainage. Alternately the pen should be well bedded with straw daily. In loose housing the pens should be well drained and a deep bed of fresh clean straw used daily.

The vagina of the sow is susceptible to ascending infection in the immediate post weaning period and for 2 to 4 days post oestrus.