Increased Vaginal Prolapses in Lame Ewes
During the spring of 2020 I was called to a farm that showed an increased rate of fatal vaginal prolapses pre-lambing. Out of 800 ewes, 50 had prolapsed and 15 had subsequently died. On examination of the flock, 25% were found to be lame. On questioning the farmer, the warm, wet spring had caused major issues with water build up within the building with numerous days where the rain had caused the bedding to become saturated.
The whole flock had been vaccinated with Footvax the previous spring but it was felt that the build up of water had caused ideal conditions for dichelobacter nodosus and fusobacterium necrophorum, the primary and secondary bacterial causes of footrot, to grow and proliferate. This had then caused the ewes to lay down more and eat the straw in front of them, rather than go to the feed troughs to eat the balanced diet that was available to them. This then increased rumen fill which combined with heavy pregnancy increased intra-abdominal pressure and subsequently caused the vaginal prolapses.
The ewes are always blood sampled three weeks prior to lambing in order to ascertain energy and protein status pre-lambing, a key indicator of predisposition to vaginal prolapse and twin lamb disease. This was found to be satisfactory at the time, but the bloods were taken prior to the rapid increase in lameness. It was agreed that in subsequent years the flock was to be vaccinated twice yearly, between March and May and between October and December, to increase the flock’s resistance to footrot.