VAGINAL prolapse remains a problem that even the best sheep farmers experience and in the run-up to lambing can be frustrating and difficult to control.
This can be a major welfare concern if steps are not quickly taken to minimise the strain on affected ewes. It also causes considerable pain, which may persist for days if not correctly treated.
Here, the National Animal Disease Information Service (NADIS) gives advice on coping with the problem in sheep.

Vaginal prolapse:

  • It occurs during the last month of pregnancy
  • Typically affects around 1% of pregnant sheep
  • The prevalence varies from zero to 15%
  • Recurrence is common during the next pregnancy.

Many factors have been implicated in the cause of vaginal prolapse. These centre around excessive body condition (body condition score 4 and above on a scale of 1 to 5).
Other causes include the ewe carrying triplets (or more than twins) and the feeding of high fibre diets, particularly those containing root crops.
Limited exercise in housed ewes can also be a feature and lameness, which can lead to prolonged periods of sternal recumbency.
Some sheep with short-docked tails can also succumb and those straining to walk on steep fields will be prone too.

Costs associated with vaginal prolapse include:

  • Time spent catching ewe and treatment costs
  • Veterinary assistance may be required to replace prolapse
  • Abortion of lambs
  • Assisted lambing is not uncommon after a prolapse
  • Veterinary attendance if caesarean operation needed for difficult lambing 
  • Death of the actual ewe 

Clinical signs

  • Ewes may show many behavioural signs consistent with labour 
  • Isolation from the remainder of the flock
  • Failure to come forward for feeding
  • Long periods in lateral recumbency, with repeated, short duration, forceful abdominal contractions and associated vocalisation
  • Pain.

Diagnosis is simple upon close examination and early treatment is essential as the duration of prolapse directly affects the degree of contamination with faeces, bedding material and soil. 
It also has an effect on the friability of the vaginal mucosa and the eventual lambing process.
Some early mild prolapse cases respond well to the use of harnesses and retainers. 
The method described here refers to the more complicated cases, often either where the vaginal prolapse cannot be returned to its normal position or harnesses and retainers have not worked. 

Veterinary treatment of difficult vaginal prolapse cases includes:

  • Caudal anaesthesia allows replacement of the vaginal prolapse
  • Emptying the urinary bladder can then be readily achieved in the standing ewe. 
  • Prolapse is cleaned in warm water containing surgical scrub solution.
  • An analgesic drug is administered intravenously 
  • A long acting antibiotic such as oxytetracycline is administered, or three to five days’ penicillin treatment is started

Methods of retention after replacement of vaginal prolapse include:

  • The use of a Buhner suture
  • Plastic retention devices
  • Harnesses or trusses
  • All ewes with retention sutures for vaginal prolapse must be clearly identified
  • Permanent ewe identification is essential to ensure culling before the next breeding season commences

The Buhner suture:

  • A 5mm nylon tape is placed by the veterinary practitioner in the subcutaneous tissue around the vulva 2cm from the labia and tightened to allow an opening of approximately 1.5cm diameter
  • The modified Buhner suture can easily be untied to allow examination of the posterior reproductive tract for signs of first stage labour
  • Sutures which penetrate the vaginal mucosa, such as single interrupted or mattress sutures, must however be avoided because they cause considerable discomfort and resultant straining
  • Single interrupted and mattress sutures prevent ready manual examination for impending parturition
  • The Buhner suture should be untied well before the expected lambing date – impending lambing can be estimated from the ewe’s keel mark; a slackening of the ligaments around the ewe’s tail head; and/or development and filling of the udder and accumulation of colostrum in the teats
  • Signs of first stage labour include separation from the remainder of the group, a lack of appetite, frequent getting up and lying down, sniffing at the ground, and abdominal straining, then foetal membranes are present at the vulva
  • Complications as a consequence of vaginal prolapse include abortion, incomplete cervical dilation (ring womb); and the death of lambs, causing death of the ewe

There are no specific prevention measures, however, the following have been recommended:

  • Avoid over-conditioned ewes
  • Do not feed root crops to pregnant sheep during late pregnancy
  • Ensure sufficient exercise during late pregnancy
  • Treat lameness promptly