Feline Uterine Prolapse

Introduction

This case involved a young cat who presented to WVS Thailand with a prolapsed uterus after giving birth. She was dehydrated and hypothermic on presentation and the clinical exam found a necrotic and congested uterus. She was stabilised and an emergency ovariohysterectomy was performed.

Figure 1 - Depressed demeanour on presentation at the clinic

History

A one-year-old, 3.4-kg cat was presented to WVS Thailand clinic with a protrusion of a mass through the vulva. The cat had delivered one live kitten 48 hours before the consultation.

Clinical Signs

Physical examination showed she was depressed, hypothermic at 36.1C, 7% dehydrated and her mucous membranes were pale.

The mass protruding from the vulva was a dark red colour and swollen with areas of necrosis (Figure 2).

Figure 2 - Prolapsed uterus. Note the darkened and crusted necrotic areas

Differential diagnoses

Differential diagnoses included:

• Vaginal and/or uterine prolapse
• Vaginal hyperplasia
• Vaginal tumour
• Uterine torsion

Diagnostic tests

With further examination and palpation of the protruding mass, a uterine prolapse was diagnosed. The exposed uterus was congested, oedematous and necrotic.

Blood was taken which revealed:

• Anaemia (haematocrit: 15.8% [Range: 30-45%], haemoglobin 4.6 g/dL [Range: 9.8-15.4 g/dL])
• Elevated BUN (blood urea nitrogen) (86.3 mg/dL [Range: 19-24])

Treatment

The treatment chosen was an ovariohysterectomy (OVH) and it was decided to carry this procedure out urgently, due to her deteriorating condition. Due to the degree of oedema and necrosis of the uterine tissue, it was non viable and replacement of the uterus would not have been possible. The owner was in agreement and did not want her to reproduce again.

Before surgery, the uterus was reduced as much as possible using sugar and a cold compress. The sugar absorbs water from the mucosal surface, thereby shrinking the tissue.

The patient was premedicated with:

• 4 mg/kg Tiletamine-Zolazepam (Zoletil®)
• 1 mg/kg xylazine

This was given by intramuscular injection into the lumbar muscles. A 24G cephalic catheter was placed and she received the following IV:

• 20 mg/kg cefazolin (a cephalosporin antibiotic)
• saline fluids throughout the procedure at a rate of 10 ml/kg/hr.

In addition, 0.2 mg/kg tramadol was given by subcutaneous injection for analgesia.

The cat was positioned in dorsal recumbency for surgery. The contaminated, prolapsed uterus was irrigated with saline solution to clean the tissue as much as possible. A ventral midline laparotomy was performed. The prolapsed organ was reduced manually and retracted into the abdominal cavity. Abdominal ovariohysterectomy was performed, then the abdomen was closed using absorbable suture material (PGA 2/0,3/0).

Post-op medication was provided:

• Cephalexin 25mg/kg BID, by mouth, for 7 days to continue antibiotic therapy
• Ferric plus-K, 1/4 of a tablet once per day by mouth for 7 days (an iron and vitamin supplement to help resolve the anaemia)

Figure 3 - The surgically removed uterus with the Left (L) and Right (R) horns indicated

Prognosis

The prognosis following treatment for a uterine prolapse is guarded depending on the timing of veterinary intervention, and the severity of secondary complications. Survival following successful manual reduction of uterine prolapse is common, but infertility, dystocia and relapse may occur. Prognosis is more favourable following surgical removal of the uterus.

Discussion

Uterine prolapse in cats is relatively rare. The condition usually occurs during, or within, 48 hours of parturition. It results from prolonged straining during parturition or with forceful foetal expulsion during a dystocia. The uterus inverts through the cervix and then exteriorises through the vulva. It can involve the uterine body as well as one or both of the horns.

Uterine prolapse can be treated medically or surgically. It should be managed as an emergency because of the risk of uterine rupture and haemorrhage, even with immediate attempts to reduce the oedema. It is important to give fluids if the animal is in shock or has suffered haemorrhage or dehydration.

The animal should be assessed initially for the following factors, which will inform your treatment plan:

• level of oedema, contamination and damage to the protruding uterine tissue.
• presence of other foetuses in the uterus
• signs of shock or haemorrhage (including whether uterine and ovarian vessels may have ruptured).
• position of other abdominal organs, and whether they may be included in the prolapse

Medical Treatment

Medical treatment has a much lower success rate, and is only recommended if a uterine prolapse is caught very quickly. It is only appropriate if the organ has a viable blood supply, doesn't have excessive oedema, contamination or damage to the mucosa and there are no additional foetuses remaining in the uterus.

It must be noted that recurrence of uterine prolapse is likely if the queen becomes pregnant again, in particular with the stretching of the ovarian pedicles and broad ligament which will have occurred due to the prolapse.

The cat should also be assessed for signs of shock which could indicate a rupture of the internal blood vessels supplying the uterus, indicating that surgery is essential.

Palpation (and, if available, ultrasonography or radiography) should be used to assess the position of the other organs, in particular the urinary bladder and intestines which may become trapped in the prolapse. It is also important to ensure that there are no remaining foetuses.

Gentle manual reduction can be used if the uterus is small enough to be reduced back through the vulva and cervix. If the uterus is enlarged, cold compresses and sugar solutions can be used attempted to reduce the size before manual reduction.

To reduce the uterus, start at the edges nearest the vulva and gently evert the uterus back to its usual position. It is imperative not to use force, as this risks damaging and possibly even tearing the uterine tissue.

It will be necessary to convert treatment from medical to surgical if the uterus becomes damaged during reduction, or if it is not possible to fully reduce the uterus. Partial reduction will lead to continued straining and uterine necrosis.

Analgesia and/or anti-inflammatory medication should be provided to reduce the pain and inflammation associated with this procedure. Appropriate antibiotics should also be considered depending on degree of contamination and/or damage to the uterus.

Surgical Treatment

OVH is a curative surgical treatment option.

• It is important to check that none of the associated blood vessels have been torn during the prolapse, in particular those of the ovarian pedicle and broad ligament. Damage should be addressed surgically.
• This procedure should definitely be performed if the uterine tissue is devitalised or irreducible, or if the broad ligament vessels have ruptured.

If the uterus is still healthy with an intact blood supply, hysteropexy can be considered to reduce the likelihood of prolapse recurring.

In this case OVH was performed because the uterine tissue was oedematous and necrotic.

After surgery urination should be monitored because swelling and pain may cause urethral obstruction.

Key Points

• Uterine prolapse should be treated as an emergency.
• Initial assessment must include evaluating the level of tissue damage, the chance of haemorrhage, and presence of any remaining foetuses.
• Surgical ovariohysterectomy generally carries a higher chance of successful treatment and better prognosis.

References

1. Deroy, C., Bismuth, C., & Carozzo, C. (2015). Management of a complete uterine prolapse in a cat. Journal of Feline Medicine and Surgery Open Reports, 1(1), 2055116915579681.
2. Forseberg C. L., (2010). Abnormality in Canine Pregnancy, Parturition, and The Periparturient period. In S. J. Ettinger, E. C. Feldman (eds.), Small Animal Internal Medicine. St. Louis: Saunders Elsevier.
3. MacPhail C. M., (2013). Surgery of the Reproductive and Genital Systems. In T. W. Fossum (ed.), Small Animal Surgery. (4th edn.) (pp.826-827). St. Louis: Elsevier Mosby.
4. Özyurtlu, N., & Kaya, D. (2005). Unilateral uterine prolapse in a cat. Turkish Journal of Veterinary and Animal Sciences, 29(3), 941-943.
5. Sabuncu, A., Dal, G. E., ENGİNLER, S. Ö., Karacam, E., TOYDEMİR, T. S. F., & Ucmak, M. (2017). Feline unilateral uterine prolapse: a description of two cases. İstanbul Üniversitesi Veteriner Fakültesi Dergisi, 43(1), 67-70.
6. Ucmak, Z. G., Ucmak, M., Cetin, A. C., & TEK, Ç. (2018). Uterine prolapse in a pregnant cat. Turkish Journal of Veterinary and Animal Sciences, 42(5), 500-502.
7. Bigliardi E, Di Ianni F, Parmigiani E, Cantoni AM, Bresciani C. Complete uterine prolapse without uterine mucosal eversion in a queen. J Small Anim Pract. 2014 Apr;55(4):235-7. doi: 10.1111/jsap.12190.

About the author

Dr Julaluk Jaiboon (aka "Luk").