Exploratory Laparotomy - Donkey

Indications for Exploratory Laparotomy

Uterus distended with pus exteriorised ready for surgical removal. (Image courtesy of The Donkey Sanctuary)

Drainage of pus intra-operatively. (Image courtesy of The Donkey Sanctuary)

Uterine tumour removed via ovariohysterectomy. (Image courtesy of The Donkey Sanctuary)

Massive cystic ovary that ruptured causing death by haemorrhage. (Image courtesy of The Donkey Sanctuary)

Cystic ovaries removed post-mortem. (Image courtesy of The Donkey Sanctuary)

Exploratory laparotomy may be required in the donkey, as in the horse, for emergency or elective purposes, such as surgical colic, caesareans, and uro-genital surgery.

As discussed, colic in the donkey, especially impaction colic, may present with more subtle clinical signs than in a horse. However, acute signs of pain with nasogastric reflux and distended viscera are occasionally seen, and may indicate prompt surgical intervention. It is important to make an assessment of triglyceride levels and pancreatic enzymes as speedily as possible, as concurrent hyperlipaemia and/or pancreatitis will reduce the prognosis even if recognised and treated. Pancreatitis can present with signs of peracute pain in the anterior abdomen, which may be exacerbated by external ballotment behind the ventral sternum. In addition, peritoneal tap samples may show high levels of neutrophils, amylase and lipase.

The examination of the donkey with suspected surgical colic may be hampered due to the small size of the patient. A rectal examination is nearly always possible even if sedation is required. If this is truly impossible, ultrasound examination of the abdomen externally should be performed to assess viscera size, position and motility.

A peritoneal tap provides useful information; however most UK donkeys carry considerable fat deposits above the linea alba. If ultrasound is available, the depth of the peritoneal fat may be measured and an appropriate needle or (more safely) a teat cannula used.

In aged donkeys, a good assessment of dental disorders and possible chronic hoof disease should be made before surgery is contemplated. Our records show that internal neoplasia is also a significant complicating factor in geriatric donkeys. This should be taken into account and discussed with the donkey owner, especially if there has been a history of progressive weight loss, or unexplained changes in haematological/biochemical parameters. Despite all the warnings, donkeys have been successfully operated on for correctable surgical lesions, for example, small intestine strangulation and large colon displacements.

Surgical correction of urogenital problems has been used at The Donkey Sanctuary for the following conditions: caesarean section, ovariohysterectomy for pyometra, ovary removal, bladder stone removal, and cryptorchidism. The approach required will depend on the surgery to be performed.

We have used

• flank laparatomy for unilateral ovarian removal
• paramedian approach for cryptorchidism
• ventral abdominal approach for colic and caesarean operations

Pyometra has been recognised in a number of our donkeys. Most donkey pregnancies are unplanned and unmonitored, which may lead to a higher incidence of endometritis. This, combined with cervical lacerations, can cause accumulation of pus in the uterus. In some cases the only presenting sign is low grade pain, manifesting as dullness. On rectal examination, a distended uterus can be felt.

Medical attempts to resolve the pyometra should be made using uterine drainage and prostaglandin mediated cervical relaxation. If this fails, surgical removal of the uterus may be attempted (Thiemann and Makhambeni, 2006). The donkey cervix may be predisposed to the development of pyometra, as it is longer than the cervix in the horse mare and protrudes into the vagina (Vendrammi et al 1998; Pugh, 2002). This makes drainage of the uterus difficult. There is also a reference in the literature to removal of a uterine tumour in a donkey mare (Bonfig and Ingenhorst, 1992).

Ovarian removal has been indicated for cases showing pain associated with grossly enlarged ovaries due to cysts, haematoma and abscesses. In female donkeys presenting with signs of abdominal pain, a rectal examination is indicated to assess the condition of the ovaries. Ultrasound per rectum and via the flank is required to fully evaluate the ovary. We have encountered ovaries up to 20 cm in diameter due to abnormalities. In some cases external flank drainage of the ovary may be useful to temporarily alleviate the discomfort. We use two operators for this procedure, one with the arm per rectum to stabilize the ovary against the abdominal wall and one to aspirate the cyst externally.

The indications for, and treatment of, bladder stones and cryptorchidism are similar to those in the horse.

Caesarean section

The indications are as for the horse (e.g. foetal oversize, dystocia) and, in most cases, a ventral midline approach is used as in the horse. Many donkeys are poorly supervised around foaling and may be presented for dystocia in a state of endotoxic shock. In a paper by Bourassi and Kay (2006), the results of standing left flank approach to caesarean section under sedation and local anaesthesia is presented. Although the sample size was small, the authors comment that the technique may provide a safe, low cost and viable alternative to conventional mid-line laparotomy. In addition, the same authors suggest that donkeys carrying hinny foals may be more susceptible to dystocia due to poorer regulation of foetal growth.

References

• Thiemann, A. (2008) Surgery In Svendsen, E.D., Duncan, J. and Hadrill, D. (2008) The Professional Handbook of the Donkey, 4th edition, Whittet Books, Chapter 16

• Bonfig, H., Ingenhorst, I. (1992). ‘Surgical removal of a pedunculated uterine tumour in a donkey mare’. Tierarztl Prax 20(1). pp 65-68.
• Pugh, D.G. (2002). ‘Donkey reproduction’. AAEP proceedings 48. pp 113-114
• Thiemann, A.K., Makhambeni, M.M.S. (2006). ‘Five cases of ovariohysterectomy in the donkey’. 'Proceedings of the 9th congress of the W.E.V.A. pp 487-489.
• Vendrammi, O.M., Guintard, C. , Moreau, J., and Taintuner, D. (1989). ‘Cervix conformation: a first anatomical approach in Baudet de Poitou jenny asses’. Animal Science 66. pp 741-744.
• Abd El-Karim, R.(1995). ‘Two cases of rectal prolapse in the donkey’.Equine Veterinary Education 7 (1). pp 12-14.
• Bell, N.J., Thomas, S. (2001). ‘Use of sterile maggots to treat panniculitis in an aged donkey’. Veterinary Record 149. pp 768-770.
• Bouayad, H., Rifai, S., Kay, R.S., Knottenbelt, D.C., and Smith, M. (2006). ‘Bifid tongue and Mandibular cleft in three mule foals’. Proceedings of the 9th Congress of the W.E.V.A. pp 334-346.
• Bourassi, M., Kay, G. (2006). ‘Dystocia in donkeys carrying mule foals in Morocco: an evaluation of 32 cases’. Proceedings of the 9th Congress of the W.E.V.A.
• Farmand, M., Stohler, T. (1990). ‘The median cleft of the lower lip and mandible and its surgical correction in a donkey’. Equine Veterinary Journal 22 (4). pp 298-301.
• Kay, G. (2005). ‘Sialolithiasis in donkeys’. In: Veterinary care of donkeys. Matthews, N.S., and Taylor, T.S. (eds). International Veterinary Information Service. www.pubmedcentral.nih.gov/articlerenderfcgi?articl=14449901
• Misk, N.A., Nigam, M.V. (1984). ‘Sialolith in a Donkey’. Equine Practice 6(4). pp 49-50.
• Thiemann, A.K. (2003). ‘Treatment of a deep injection abscess using sterile maggots in a donkey’. World Wide Wounds website. November 2003 (www.worldwidewounds.com)

SURGERY - DONKEY