P. E. Holt

Successful Surgical Treatment of a Cat with Primary Aldosteronism

A 5-year-old cat was presented with a history of episodic weakness and cervical ventroflexion. Screening blood tests revealed moderate hypokalaemia, mild hypernatraemia, and grossly elevated creatine kinase (CK) levels. On clinical examination, a large mass was palpable adjacent to the left kidney. Ultrasonographic examination confirmed this mass to be an enlarged left adrenal gland, a finding which in association with the history and laboratory data was suggestive of primary aldosteronism (Corm’s syndrome) due to unilateral adrenal neoplasia. The diagnosis was confirmed by demonstrating a markedly elevated circulating aldosterone concentration. The cat was initially treated supportively and then underwent unilateral adrenalectomy. Histopathology of the adrenal gland confirmed the presence of an adrenocortical adenoma. Post-operatively the cat recovered well and had no known further problems (follow-up period currently 20 months). This is the first published case of successful surgical treatment of aldosteronism in the cat. Primary aldosteronism was first described in humans by Corm in 1955 and is consequently known as ‘Corm’s syndrome’. In humans, the disease occurs as a result of uncontrolled overproduction of aldosterone by the zona glomerulosa of the adrenal gland, usually due to either unilateral neoplasia (adenoma or, rarely, adeno-

Vacuum-assisted wound closure following urine-induced skin and thigh muscle necrosis in a cat

Vacuum-assisted closure (VAC) is a relatively new technique for wound management in dogs and cats. It was successfully used in this cat to treat severe urine-induced skin and thigh muscle necrosis, resulting from a traumatic urethral rupture. No complications were encountered with application of the VAC technique and production of a healthy granulation bed, suitable for wound reconstruction, was achieved after only five days of VAC treatment. The marked wound contraction (40.3%) obtained after eight days of treatment, was sufficient to allow closure of the defect using a simple, rotational subdermal plexus flap. This was a safe, effective and efficient treatment for a challenging wound in a difficult anatomical location.

Urethral sphincter mechanism incompetence in male dogs: a retrospective analysis of 54 cases

Incompetence of the urethral sphincter mechanism is uncommon in male dogs. This paper reviews 54 cases. As in the bitch, the condition can occur either as a congenital or as an acquired condition, in which neutering may play a part; larger breeds appear to be at greater risk. Incontinence is more likely to occur when the intra-abdominal pressure might be expected to increase, for example when the dog is recumbent. In comparison with the bitch, the condition appears less likely to respond to medical therapy and its pathophysiology is poorly understood.

Treatment and long-term follow-up of extrahepatic biliary obstruction with bilirubin cholelithiasis in a Somali cat with pyruvate kinase deficiency.

A 2-year-old female neutered Somali cat was presented with vomiting and acute onset jaundice 1 year after diagnosis of pyruvate kinase (PK) deficiency. Diagnostic investigations revealed a moderate regenerative haemolytic anaemia, severe hyperbilirubinaemia and elevated liver enzymes. Ultrasonography revealed marked distension of the gall bladder and common bile duct (CBD), consistent with extrahepatic biliary obstruction (EHBO). At cholecystotomy, the gall bladder contained purulent material, and two obstructive choleliths were removed from the CBD by choledochotomy. The cat recovered from surgery uneventfully, and serum liver enzymes and bilirubin normalised within 10 days. Postoperative treatment consisted of cephalexin, metronidazole and ursodeoxycholic acid (UDCA). Bacterial culture of the gall bladder contents yielded a pure growth of an Actinomyces species. Cholelith analysis revealed that they consisted of 100% bilirubin. Antibiotic treatment was stopped 4 weeks after surgery but UDCA was continued indefinitely. The cat remains clinically well with no recurrence of cholelithiasis 20 months after initial presentation. This is the first report of successful treatment and long-term follow-up of a cat with EHBO due to bilirubin cholelithiasis in association with PK deficiency-induced chronic haemolysis.

The efficacy of chlorhexidine gluconate in canine skin preparation – practice survey and clinical trials

OBJECTIVES To determine the use in practice and efficacy of different concentrations of chlorhexidine gluconate for canine pre-operative skin preparation. METHODS Questionnaires were used to establish which antiseptics and techniques were used for patients undergoing elective neutering. In a clinical study, five different concentrations of chlorhexidine gluconate - 0 per cent (tap water, as a control) 1, 2, 3 and 4 per cent - were tested on 50 dogs undergoing elective ovariohysterectomies and orchidectomies. RESULTS A variety of preparation practices occurred but only 21 per cent of the veterinary nurses surveyed were aware of the concentration and contact time they used whilst preparing animals. The clinical study revealed there was a significant difference (P<0.001) between the different concentrations used. All concentrations of chlorhexidine were significantly more effective than the control tap water. There was a tendency towards increasing efficacy as concentration increased from 1 to 4 per cent but this was not statistically significant. CLINICAL SIGNIFICANCE The lack of significant differences in efficacy between the different concentrations of chlorhexidine gluconate means that current practices may be adequate, although if the chlorhexidine gluconate concentrations and contact times used are unknown, they may be lower than those tested here and, possibly, ineffective, especially if contact times are short.

Efficacy of Adhesive Incise Drapes in Preventing Bacterial Contamination of Clean Canine Surgical Wounds

OBJECTIVE To investigate the efficacy of adhesive incise drapes in reducing bacterial contamination of clean canine surgical wounds. STUDY DESIGN Randomized clinical trial. ANIMALS Dogs (n=100) having elective ovariohysterectomy or stifle surgery. METHODS Dogs were randomly assigned to 1 of 2 groups: drape or no drape. Swabs obtained from the inner edge of the surgical wound at the beginning (swab 1) and end (swab 2) of surgery were submitted for microbial culture. Number of colony forming units was counted for all positive cultures and change in bacterial counts between swabs 1 and 2 was calculated. Percentage adhesive drape adherence at the end of surgery was calculated from a digital photograph of the surgical site. duration of surgery/anesthesia and the anesthetic induction agent used were recorded. RESULTS There was a significant increase in bacterial counts between swabs 1 and 2 (P=.001). Wound contamination was 14% (6 drape; 8 no drape; P=0.78) with Staphylococcus spp. most commonly isolated. Median percentage drape adherence at the end of surgery was 89.3% (0-100%). Duration of anesthesia was significantly related to wound contamination (P=.013), but duration of surgery and anesthesia induction agent were not. CONCLUSIONS Adhesive incise drapes did not reduce wound contamination of clean canine surgical wounds. CLINICAL RELEVANCE Use of adhesive incise drapes in clean surgical procedures is of questionable benefit in dogs.

Recovery characteristics following maintenance of anaesthesia with sevoflurane or isoflurane in dogs premedicated with acepromazine

A standard anaesthetic protocol was used to anaesthetise 40 dogs for intravenous urography and a retrograde urethrogram or vaginourethrogram. The dogs were allocated by blocked randomisation to receive either isoflurane or sevoflurane for maintenance of anaesthesia after they had been premedicated with acepromazine and pethidine, and anaesthesia induced with propofol. An observer who was unaware of which agent had been used assessed ataxia 30 and 60 minutes after discontinuation of administration of the anaesthetic and assigned an overall recovery score. No complications occurred during anaesthesia of either group of dogs. The scores for ataxia were significantly lower after 60 minutes than after 30 minutes, but there was no significant difference between the groups. The quality of recovery was significantly better in the dogs that received sevoflurane than in those that received isoflurane, but the recovery times were similar.

Breed predisposition to ureteral ectopia in bitches in the UK

Beagle Bedlington terrier Border collie Border terrier* Briard* Bulldog* Cairn terrier Cocker spaniel Corgi (breed not specified) Crossbreed Dalmatian English springer spaniel Golden retriever* Griffon* Irish setter Irish wolfhound Jack Russell terriert Labrador retriever* Lakeland terrier Miniature poodle Munsterlander Old English sheepdog Rottweiller Rough collie Shetland sheepdog Siberian husky Skye terrier* Staffordshire bull terrier Wire-haired fox terrier Yorkshire terrier Total (all breeds and crosses) Breed predisposition to ureteral ectopia in bitches in the UK

Acquired immune-mediated myasthenia gravis in a cat associated with a cystic thymus

Abstract Acquired myasthenia gravis was diagnosed in a five‐year‐old domestic shorthair, neutered, female cat with generalised muscle weakness, tremors, dysphagia and alterations in voice. Radiographs indicated the presence of a mass in the anterior thorax. A response to edrophonium chloride, and raised levels of anti‐acetylcholine receptor antibodies in the serum, confirmed the diagnosis and indicated an immune‐mediated aetiology. Clinical remission occurred following thymectomy and the use of immunosuppressive corticosteroids. This is the first fully‐documented case of acquired feline myasthenia gravis associated with the presence of a thymic abnormality in the United Kingdom. The clinical features, laboratory findings and response to treatment are compared with those reported previously in cats and other species.

Liver size, bodyweight, and tolerance to acute complete occlusion of congenital extrahepatic portosystemic shunts in dogs

OBJECTIVE To investigate the relationship between preoperative liver size, bodyweight, and tolerance to shunt occlusion in dogs with congenital extrahepatic portosystemic shunt(s) (CPSS). STUDY DESIGN Longitudinal cohort study. ANIMALS Dogs with CPSS (n=35). METHODS Ultrasonography was used to measure preoperative maximum transverse dimension of the liver (TS) of each dog. Intraoperative portal pressures were measured, before and after CPSS occlusion, via a jejunal vein catheter. Tolerance to shunt occlusion was judged on gross visceral observations, and on changes in portal pressure, central venous and mean arterial pressures. RESULTS TS was significantly related to bodyweight (P<.05). Mean ratios for TS/bodyweight were calculated for dogs tolerant and intolerant of acute complete shunt occlusion. Dogs tolerant to occlusion had significantly higher TS/bodyweight ratios than dogs intolerant to occlusion (P=.025). Dogs with a TS/bodyweight ratio of >7 were more likely to tolerate CPSS occlusion than dogs with a TS/bodyweight ratio of <5 (P=.036). A model was generated to predict portal pressure rise after shunt occlusion, based on liver dimensions and bodyweight (R=0.668). Intestinal oxygenation did not correlate significantly with tolerance to CPSS occlusion (P=.29). CONCLUSION In dogs with CPSS, liver size (relative to bodyweight) is significantly greater (P=.025) in dogs that are tolerant of full ligation than intolerant of occlusion. CLINICAL RELEVANCE Preoperative measurement of bodyweight and liver size help indicate the likelihood of tolerance to acute complete occlusion of CPSS in dogs.