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BILATERAL PERINEAL IN THREE CATS: CASE STUDIES

Author : KATHRYN PRATSCHKE, LAURA MARTIN

Categories : Vets

Date : May 5, 2014

KATHRYN PRATSCHKE and LAURA MARTIN present case studies that detail the problems surrounding this condition, explaining diagnostic approaches and surgical techniques carried out

Summary

Two males and one female with bilateral perineal were treated; all were neutered. Two cases had a history of , one had chronic and all had recurrent anal sac impaction. All cases were treated surgically with bilateral internal obturator muscle flap transposition, plus incisional colopexy in the two with concurrent rectal prolapse. All had full thickness intestinal biopsies and mesenteric lymph node biopsies.

Histological diagnosis was suggestive of inflammatory bowel disease, and two cases had positive cultures for known intestinal pathogens. Postoperative outcome was good or excellent with follow- up at least six months after surgery.

Key words perineal hernia, cat, anal sac, internal obturator muscle flap transposition, colopexy

PERINEAL hernia is caused by a failure of the pelvic diaphragm muscles resulting in loss of support to the colorectal junction and . It is a common condition in male entire and is generally considered a disease of middle-aged and older individuals.

1 / 11 It is much less commonly documented in the cat where it seems to occur mostly in neutered animals and typically develops as a secondary problem, rather than a primary one. However, numbers reported in the literature are too small to draw any firm conclusions about relationships between specific primary conditions and perineal hernia (Ashton, 1976; Benitah and et al, 2004; Johnston and Gourley, 1980; Galanty, 2005; Pratschke, 2002; Rashbaum, 1965; Risselada et al, 2003; Vnuk et al, 2005; Welches et al, 1992). Bilateral herniation is apparently more common than unilateral (Welches et al, 1992). The following cases describe perineal herniation linked with concurrent anal sac/rectal disease and potential inflammatory bowel disease (IBD) in three cats.

Case 1

A four-year-old, male, neutered Burmese cat was referred with a two-year history of recurrent rectal prolapse. Medical treatment with laxatives and placement of purse string sutures had been attempted. Over the two-year period, the prolapse became progressively larger, with the most recent episode resulting in five centimetres of rectum being prolapsed. The cat was also receiving treatment with prednisolone for feline asthma and had been tentatively diagnosed with IBD in the past.

On presentation, the cat was bright and alert with routine clinical parameters within normal limits other than a slightly low body condition score (BCS) of 3/9. Abdominal palpation revealed faecal balls within the colon and mild discomfort. No rectal prolapse was present at this time. Haematology and biochemistry were unremarkable, except for a mildly increased urea (11.6mmol/L; reference range [RR] 2.7-9.2mmol/L) and alanine transaminase (ALT; 45 U/L; RR

Surgical correction of the perineal hernias, combined with colopexy for the recurrent rectal prolapse, was recommended. The owners were also advised the previous diagnosis of IBD should be confirmed and accurately characterised with full thickness intestinal biopsy samples. At surgery, the liver appeared grossly paler than normal, with a mottled appearance, so a hepatic biopsy was taken in addition to jejunal and mesenteric lymph node. An incisional colopexy was performed as described in the literature (Figure 1) (Popovitch et al, 1994).

Bilateral perineal herniorrhaphy was then performed with the internal obturator elevation technique (Figures 2 and 3; Bellenger and Canfield, 2003). The overall surgery time was 150 minutes. Perioperative analgesia was provided with a constant rate infusion of fentanyl (0.1µg/ kg/min to 0.3µg/kg/min; Martindale) and buprenorphine IM (0.02mg/kg every six hours, Vetergesic; Alstoe). Prophylactic antibacterial therapy was provided with cefuroxime IV (20mg/kg, Zinacef; GlaxoSmithKline). Postoperatively, the cat received oral amoxicillin- clavulanate tablets (17mg/ kg every 12 hours, Synulox; Pfizer) for seven days, meloxicam (0.05mg/kg every 24 hours, Metacam; Boehringer), ranitidine for two days (2.5mg/kg every 12 hours, Zantac; GlaxoSmithKline) and lactulose (2ml every 12 hours; Sandoz). Prednisolone was stopped temporarily while on treatment with NSAIDs. The cat recovered well from surgery, with no early signs of recurrent prolapse and was discharged five days after surgery.

2 / 11 Histopathology of the samples taken during surgery showed vacuolar hepatopathy of the liver, a likely consequence of glycogen accumulation due to the prednisolone medication for feline asthma. The jejunal biopsy showed mild chronic enteritis, consistent with mild inflammatory disease previously diagnosed. The mesenteric lymph node showed lymphoid hyperplasia, consistent with a reactive node.

During a follow-up telephone interview seven months after surgery, the owner reported excellent results, stating the cat had a changed life, a good regular appetite and no apparent difficulty or tenesmus when defaecating. There had been no recurrence of the rectal prolapse since surgery.

Case 2

A 13-year-old female, neutered domestic shorthair (DSH) was referred with a one-month history of constipation. The straining was so severe that vomiting had occurred and the cat had become distressed and lethargic. Weight loss had occurred despite a good appetite. Medical treatment had been attempted with laxatives and , which helped transiently.

On presentation, the cat was bright and alert with routine parameters within normal limits other than a high BCS of 7/9. Abdominal palpation revealed impacted faeces in the colon and discomfort. Haematology identified a leukocytosis (22.7 × 109/L; RR 5.5-15.5 × 109/L) with neutrophilia (20.88 × 109/L; RR 2.5-12.5 × 109/L). Viral testing was negative for FeLV and FIV, and the coronavirus titre was zero. Ultrasonography showed a prominent spleen with slightly hypoechoic parenchyma, but an ultrasound-guided aspirate showed no significant abnormalities. The ileocolic lymph nodes were prominent and reactive, and the surrounding mesentery hyperechoic. Radiography showed a diffuse interstitial pattern in the lungs, likely due to obesity. Abdominal radiography was unremarkable. Rectal palpation under sedation diagnosed bilateral perineal hernias and bilateral anal sac impactions.

A standard midline exploratory coeliotomy was performed, which identified a chain of enlarged ileocolic lymph nodes. Two were removed for histopathology, one of which was abscessed. A swab of the abscessed node was also taken for bacteriology. Incisional full thickness biopsies were taken of the colon and jejunum and a liver biopsy was collected. Bilateral perineal herniorrhaphy was then performed as described in case one (Bellenger and Canfield, 2003). The total surgery time was 135 minutes.

The cat received an epidural prior to surgery, containing both morphine (0.1mg/ kg; Martindale) and bupivacaine (2.5mg/kg; Astra- Zeneca). Amoxicillin-clavulanic acid (20mg/kg, Augmentin; GlaxoSmithKline) was given IV for perioperative antibacterial therapy, followed by oral amoxicillin- clavulanic acid (12.5mg/kg every 12 hours, Synulox; Pfizer) for seven days. Analgesia was provided postoperatively with buprenorphine (0.01mg/kg every six hours, Vetergesic; Alstoe) and meloxicam (0.05mg/kg every 24 hours, Metacam; Boehringer). In addition, ranitidine was provided for five days (2mg/kg every 12 hours, Zantac; GlaxoSmithKline) and lactulose (2ml every 12 hours;

3 / 11 Sandoz). The cat was discharged two days after surgery with no early complications and owners were advised on dietary management with IBD.

Histopathology identified cholangiohepatitis with a lymphoplasmacytic infiltrate, neutrophilic and lymphoplasmacytic colitis and lymphoplasmacytic enteritis. Lymphoid hyperplasia, in addition to severe necrotising and pyogranulomatous lymphadenitis, were also diagnosed. A pure growth of Streptococcus canis was cultured from the abscessed node, which was sensitive to the antibiotics already dispensed.

At routine check-up, two weeks after the surgery, the cat was making very good progress. Motions were being passed without any difficulty daily, with no recurrent pain or tenesmus. At telephone interview six months after surgery, the owner reported continued improvement. There was still minimal tenesmus when defaecating, but this was much improved compared to before surgery.

Case 3

A three-year-old male, neutered DSH was referred with a three-month history of rectal prolapse. A purse string suture had previously been placed, but the condition recurred. Apart from occasional anal sac impactions, the cat had no other history of gastrointestinal problems.

On presentation, the cat was bright and alert with routine clinical parameters within normal limits and no abnormalities on abdominal palpation. There was a small area of everted rectal mucosa in the left dorsal quadrant of the anus. The tissue was pink and looked healthy, although the owners noted it bled occasionally. Routine haematology was unremarkable, but serum biochemistry revealed mild elevations in ALT levels (62U/L; RR

Perineal hernia repair, combined with colopexy, was recommended, but in light of the mild elevations in urea and creatinine, it was recommended the procedures be separated into two surgeries rather than having one longer anaesthetic episode. At surgery, a subjective assessment was made that the small and large intestinal walls were thinner and more flaccid than normal, with overall poor motility throughout the . Full thickness biopsies were taken from the jejunum and the colon, as well as the mesenteric lymph nodes. Incisional colopexy was then performed using a standard technique and surgery lasted 50 minutes (Popovitch et al, 1994). Perioperative analgesia was provided with a constant rate infusion of remifentanil (0.2µg/kg/min, Ultiva; GlaxoSmithKline) plus methadone (0.2mg/kg every four hours for four doses; Martindale) followed by buprenorphine (0.01mg/kg every six hours, Vetergesic; Alstoe). IV fluid therapy with isotonic crystalloids was continued overnight at 4ml/kg due to the raised renal parameters. Amoxicillin-clavulanic acid (20mg/kg every eight hours, Augmentin; GlaxoSmith- Kline) was used for perioperative antibacterial therapy.

Two days after the initial surgery, bilateral perineal herniorrhaphy was performed, as described previously, with a surgery time of 60 minutes (Bellenger and Canfield, 2003). The cat received an

4 / 11 epidural with bupivacaine (0.5mg/kg; AstraZeneca) preoperatively. Biochemistry taken before anaesthesia showed the urea levels had returned to within normal limits (8mmol/L; RR 2.7mmol/L to 9.2mmol/L), but the creatinine levels had increased further (204µmol/L; RR 91µmol/L to 180µmol/L), again suggestive of renal insufficiency. IV fluid therapy was administered at 10ml/kg/ hr during surgery, maintained at 4ml/kg/hr overnight and urine output was monitored. Perioperative analgesia and antibacterial therapy were the same as for the first operation with postoperative buprenorphine (0.01mg/kg every six hours, Vetergesic; Alstoe) and metronidazole (10mg/ kg every 12 hours, Flagyl solution; Winthrop). The day after surgery, the creatinine level had fallen slightly (180µmol/L; RR 91µmol/L to 180µmol/L), but urea was slightly raised further (8.5mmol/L; RR 2.7mmol/L to 9.2mmol/L) and management for renal insufficiency was continued. Repeat bloods two days later confirmed both and urea (7.2mmol/L; RR 2.7mmol/L to 9.2mmol/L) and creatinine (157µmol/L; RR 91µmol/L to 180µmol/L) were within normal limits again. There was still a small portion of protruding rectal mucosa present, but the cat was passing faeces without difficulty at this stage and was discharged four days after the second surgery. The owners were advised to ensure adequate fibre intake in the diet to promote intestinal motility and stool formation.

Histopathology showed a neutrophilic, chronic-active, diffuse colitis and enteritis. The sample from the jejunum was significantly more severe than the colonic sample. Neurons were present in expected numbers within the intestinal samples and the architecture was normal. The mesenteric lymph node showed evidence of active lymphoid hyperplasia. Bacteriology from this node identified a non-haemolytic Escherichia coli. There was no evidence of nematode eggs, cryptosporidium oocysts or faecal protozoa on faecal examination.

At telephone interview 12 months after surgery, the owner reported good improvement. The cat still had occasional tenesmus and a small persistent area of mucosal prolapse, but the condition had improved markedly in terms of severity since the surgery and the owners felt it was now readily manageable.

Discussion

Perineal hernia is an uncommon condition in the cat. It is most often seen in neutered animals as in the three cases reported here and has most commonly been reported as a secondary condition. Bilateral herniation has been more commonly reported in cats, as was the situation in all three cases reported here (Bellenger and Canfield, 2003; Fossum, 2002; Welches et al, 1992). It is tempting to speculate the more private nature of cats’ toilet habits compared to dogs makes it less likely a problem will be noticed until the condition is more advanced and the clinical signs are more obvious.

Potential causes of perineal herniation in cats have been reported to include previous perineal urethrostomy surgery, , perineal masses, chronic fibrosing colitis, trauma and cutaneous asthenia (Bellenger and Canfield, 2003; Benitah et al, 2014; Johnson and Gourley, 1980, Welches et al, 1992). Two of the cases reported here had a history of rectal prolapse, all three had recurrent

5 / 11 anal sac impaction and one had chronic constipation in addition to which all three had histopathology results that were suggestive of a component of underlying IBD. Anecdotally, recurrent anal sac impaction is often seen with perineal hernia in the , presumably due to loss of normal muscle contractions at the rectocutaneous junction, compromising expression of anal sac contents. It seems reasonable to assume a similar phenomenon exists in cats with perineal hernia. Once recurrent anal sac impaction is present it will then contribute to perineal and rectal irritation, and could potentially become a perpetuating factor. The finding of rectal prolapse in two of the cats supports previous reports of its occurrence alongside perineal hernia (Welches et al, 1992). In dogs, it is mainly reported as a postoperative complication occurring because of straining due to pain, from sutures placed within the rectal lumen or from nerve damage during surgery (Bellenger and Canfield, 2003; Matthiesen, 1989). The cases seen in this study, however, support the theory that rectal prolapse may be an important predisposing cause for perineal hernia development in cats. All three cases had histopathology results suggestive of IBD, and two cases had positive cultures for intestinal pathogens (S canis and E coli) from mesenteric lymph node biopsies. It could be theorised the inflammatory intestinal disease in these cats may have affected normal gastrointestinal contractility, transit times and peristalsis, thereby contributing to tenesmus and rectal prolapse and thus further progression to perineal hernia.

Medical management is of limited value as a sole method in the treatment of perineal hernias due to the progressive nature of the condition and as quality of life can become affected by its presence. Longterm use is contraindicated, as life-threatening visceral entrapment and strangulation can occur (Fossum, 2002). It has its main use in mild hernias and those with minimal clinical signs, hence surgery is generally the preferred treatment choice, with success rates of 73 per cent reported in cats (Welches et al, 1992). The internal obturator muscle flap transposition technique (IOFT) was used in all three cases here and aids to fill the ventral defect in the perineal diaphragm, which can prove difficult with other techniques (Bellenger and Canfield, 2003; Hardie et al, 1983). The procedure follows that for the dog and has been described in previous reports of perineal hernia repair in cats. Our findings provide further evidence the technique is an effective way of managing the condition in cats and that bilateral one-stage repair can be safely performed (Benitah, 2004; Galanty, 2005; Welches et al, 1992).

The traditional anatomic repair, similar to the technique described in dogs, has also been used in the past, but there are important species differences to note. Cats have no sacrotuberous ligament and the muscles of the are much less substantial than in the dog, meaning this technique is likely to be less satisfactory in the cat. As it is already associated with a significantly higher recurrence rate in dogs than IOFT, it cannot be recommended for routine use in cats in bilateral, chronic or large hernias (Bellenger and Canfield, 2003; Martin et al, 1974; Vnuk et al, 2008). There has been one report documenting the use of a semitendinosus muscle flap technique in a cat with a trauma-induced perineal hernia, with the semitendinosus muscle being transected at the mid- belly and rotated ventrally beneath the anus to fill the defect. The right semitendinosus muscle was used to repair a left-sided traumatic hernia with a good outcome reported (Chambers and Rawlings, 1991; Vnuk et al, 2005).

6 / 11 Overall, perineal hernia is an uncommon, but potentially important, and very possibly under- diagnosed, condition in cats that can have a significant adverse effect on the quality of life. Although it does have some similarities in presentation to dogs, it should be noted it may present quite differently and we suggest cats presenting with tenesmus and constipation all warrant further investigation to rule out perineal hernia - and also that rectal examination should be utilised more frequently in cats with this type of presentation. Based on our cases, clinicians should consider perineal hernia may be associated with rectal prolapse, anal sac impaction and IBD in cats, but good outcomes are possible with the appropriate diagnostic and surgical approach.

References

Ashton D G (1976). Perineal hernia in the cat - a description of two cases, Journal of Small Animal Practice 17(7): 473-477. Bellenger C R and Canfield R B (2003). Perineal Hernia. In Slatter Textbook of Small Animal Surgery (3rd edn), W B Saunders, Philadelphia pp 487-488. Benitah N, Matousek J L, Barnes R F et al (2004). Diaphragmatic and perineal hernias associated with cutaneous asthenia in a cat, Journal of the American Veterinary Medicine Association 224(5): 706-709. Chambers J N and Rawlings C A (1991). Applications of a semitendinosus muscle flap in two dogs, Journal of the American Veterinary Medicine Association 199: 84-86. Fossum T W (2002). Surgery of the digestive system in Small Animal Surgery (2nd edn), Mosby, St Louis pp 433-437. Galanty M (2005). Perineal hernia in 3 cats, Polish Journal of Veterinary Science 8: 165-168. Hardie E M, Kolata R J, Earley T D et al (1983). Evaluation of internal obturator muscle transposition in treatment of perineal hernia in dogs, Veterinary Surgery 12: 69-72. Johnson M S and Gourley I M (1980). Perineal hernia in a cat: a possible complication of perineal urethrostomy, Veterinary Medicine Small Animal Clinician 75: 241-243. Martin W D, Fletcher T F and Bradley W E (1974). Perineal musculature in the cat, Anatomical Record 180: 3-14. Matthiesen D T (1989). Diagnosis and management of complications occurring after perineal herniorrhaphy in dogs, Compendium of Continuing Education for the Practicing Veterinarian 11: 797-822. Popovitch C A, Holt D and Bright R (1994). Colopexy as a treatment for rectal prolapse in dogs and cats: a retrospective study of 14 cases, Veterinary Surgery 23: 570-581. Pratschke K (2002). Management of hernias and ruptures in small animals, In Practice 24: 570-581. Rashbaum R A (1965). Perineal hernia in a cat, Journal of the American Veterinary Medicine Association 147: 514-515. Risselada M, Kramer M and Van De Velde B et al (2003). Retroflexion of the associated with a perineal hernia in a female cat, Journal of Small Animal Practice 44: 508-510.

7 / 11 Vnuk D, Babic´ T, Stejskal M et al (2005). Application of a semitendinosus muscle flap in the treatment of perineal hernia in a cat, Veterinary Record 156: 182-184. Vnuk D, Lipar M, Maticic D et al (2008). Comparison of standard perineal herniorrhaphy and transposition of the internal obturator muscle for perineal hernia repair in the dog, Veterinary Archives 78: 197-207. Welches C D, Scavelli T D, Aronsohn M G et al (1992). Perineal hernia in the cat: A retrospective study of 40 cases, Journal of the American Animal Hospital Association 28: 431-438.

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Figure 1. Incisional colopexy. B = bladder, C= colon, S =

9 / 11 Figures 2 (left) and 3. Internal obturator muscle flap elevation. A = anus, IOMF = internal obturator muscle flap.

Figures 2 (left) and 3. Internal obturator muscle flap elevation. A = anus, IOMF = internal obturator muscle flap.

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