Intracranial meningioma in two coeval adult cats from the same litter

Case summary In this report we describe the occurrence of intracranial meningioma in two adult cats from the same litter. The location of the meningioma varied: one tumour was at the level of the brainstem, and the other was affecting the temporal and piriform lobes. The cat with the brainstem meningioma was treated with radiotherapy and the littermate had a rostrotentorial craniectomy for tumour removal. Both cats had a histopathological diagnosis of grade I meningioma of a predominantly fibrous subtype. Relevance and novel information Cases of familial meningioma in cats have not previously been described in the veterinary literature. However, familial meningioma is well described in humans and it is possible that cases are underestimated in animals. We discuss the possible genetic background and other causes, as well as challenges we may face in veterinary medicine in identifying these associations.

A novel hypokalaemic polymyopathy and subsequent unrelated nutritional thiamine deficiency in a young Burmese cat

Case summary An 8-month-old female spayed Burmese cat was referred for investigation of reduced appetite, reluctance to walk and jump and amaurosis. On serum biochemistry there was severe hypokalaemia and marked elevation of creatine kinase, suggestive of hypokalaemic polymyopathy. The neurological signs were consistent with thiamine deficiency. The cat was negative for the periodic hypokalaemic polymyopathy (PHP) of Burmese cats, and was ultimately diagnosed with a previously undescribed potassium wasting nephropathy requiring ongoing oral potassium supplementation. The response to treatment was excellent and the cat has remained clinically normal over a 12-month follow-up period. Relevance and novel information PHP in Burmese cats has been well described, but all cases to date have been shown to be secondary to a genetic mutation in WNK4, resulting in potassium wasting into the urine. This is the first case report of another potassium wasting nephropathy in a young Burmese cat, with subsequent development of nutritional thiamine deficiency.

Olivopontocerebellar degeneration associated with 3-hydroxy-3-methylglutaric aciduria in a domestic shorthair cat

Case summary A rescue charity-owned 6-month-old neutered female domestic shorthair cat was presented with progressive tetraparesis, increased extensor muscle tone and signs of spinocerebellar ataxia, including hypermetria. The cat’s male sibling, with similar progressive neurological signs, had been euthanased 2 months previously. An inherited metabolic disorder was suspected. Urine for determination of organic acid concentration was obtained and the cat was prescribed carnitine and taurine supplementation. The cat was euthanased 3 months later following progressive neurological signs, including ataxia, tetraparesis, tendency to fall, bilateral absent menace response and intention tremor. A selective post-mortem examination was obtained, taking samples from the brain, cervical spinal cord, tibial branch of the sciatic nerve, muscle, liver and kidneys. Organic acid analysis results received after euthanasia revealed a marked elevation of 3-hydroxy-3-methylglutaric acid (45 mmol/mol creatine [normal range 0–2]) and isovalerylglycine (27 mmol/mol creatinine [normal range 0–2]). 3-Hydroxy-3-methylglutaric acid was deemed clinically relevant as it is a metabolite of 3-hydroxy-3-methylglutaryl-CoA lyase, the enzyme involved in the final step of leucine degradation. Post-mortem examination revealed diffuse, chronic-active, severe olivoponto-(spino)-cerebellar degeneration. Relevance and novel information This is the first report of 3-hydroxy-3-methylglutaric aciduria in the veterinary literature and the first description of the neuropathology of this disorder in any species. 3-Hydroxy-3-methylglutaric aciduria in humans occurs rarely and is due to a deficiency in 3-hydroxy-3-methylglutaryl-coenzyme A lyase.

Management of severe baclofen toxicosis using hemodialysis in conjunction with mechanical ventilation in a cat with chronic kidney disease

Case summary A 2-year-old castrated male domestic shorthair cat was presented for evaluation of acute and progressive neurologic signs 2–4 h after exposure to baclofen. The suspected ingested dose was 2.1 mg/kg. On admission, the cat was tetraplegic with stuporous mentation, and venous blood gas analysis showed mild hypercapnia (PvCO2 43.4 mmHg) raising concern for hypoventilation. Owing to the acute nature of the ingestion, severity of the clinical signs and reported history of chronic kidney disease, hemodialysis was recommended to remove the toxin. A 5 h hemodialysis session was performed using an intermittent platform without hemoperfusion. At the beginning of hemodialysis, worsening hypoventilation and hypercapnia (PvCO2 88.6 mmHg) required endotracheal intubation and manual ventilation initially, followed by mechanical ventilation. At the end of the dialysis session, the cat was breathing spontaneously and disconnected from the ventilator. The cat was ambulatory and alert 1 h after the end of dialysis. After an additional 12 h of monitoring, the cat had full return of neurologic function and was discharged from hospital. Serum baclofen concentration measured prior to, during and after hemodialysis showed a 77.7% reduction in baclofen levels immediately after hemodialysis. Relevance and novel information This is the first report of baclofen toxicity in a cat successfully treated with hemodialysis and mechanical ventilation simultaneously. Treatment with hemodialysis therapy and mechanical ventilation could be considered in cases of acute baclofen toxicosis to improve outcome and reduce the length of the hospital stay.

Gynaecomastia in a male neutered cat with an adrenal tumour and associated hyperprogesteronism, hypercortisolism and hyperaldosteronism

Case summary A 7-year-old male neutered domestic longhair cat was presented with chronic progressive gynaecomastia, polydipsia, polyphagia, weight loss and poor fur regrowth. Sexualised behavioural changes were not reported and virilisation was not present on physical examination. Pertinent haematology, biochemistry and urinalysis findings at the time of referral included mild hypokalaemia. Left adrenomegaly and mild prostatomegaly were identified on a CT scan. Evaluation of adrenal hormones with a low-dose dexamethasone suppression test, serum progesterone, testosterone, oestradiol, plasma aldosterone, renin, plasma metanephrine and normetanephrine measurement supported a diagnosis of hyperprogesteronism, hyperaldosteronism and hypercortisolism. Adrenalectomy was performed and histopathology was consistent with an adrenocortical tumour. Clinical signs and hormone elevations resolved postoperatively. Relevance and novel information To our knowledge, this is the second report of gynaecomastia secondary to an adrenal tumour in a male neutered cat and the first associated with hyperprogesteronism.

Minimally invasive spinal surgery in a young cat with vertebral hypertrophy

Case summary A 2-year-old neutered female Scottish Fold cat was presented with an 8-week history of progressive back pain, paraparesis and decrease of postural reactions in both pelvic limbs. MRI showed spinal cord compression from both ventral sides, which originated from the T4 vertebral body and pedicle. The lesion compressing the spinal cord had a bone-like density on CT, and endoscopic surgery was performed to excise it. Histopathological examination of the resected tissue showed no evidence of malignancy and the lesion was diagnosed as vertebral hypertrophy. After surgery, the neurological status of the cat gradually improved. The cat was ambulant at the follow-up evaluation 2 weeks after surgery. Six months later, hindlimb paresis had improved considerably, and no recurrence was observed on CT. Relevance and novel information This is the first description of thoracic vertebral canal stenosis due to hypertrophy of a single vertebra in a young cat. Excision of the hypertrophic vertebra by endoscopic surgery is less invasive than open surgery and may give a good prognosis.

Pancreatic candidiasis in a cat

Case summary An 11-year-old female spayed Maine Coon cat was referred for assessment of hyporexia, weight loss, vomiting and diarrhoea. An abdominal ultrasound revealed an enlarged and hypoechoic pancreas containing two large fluid-filled structures. Fine-needle aspiration of the cyst-like structures was performed, and cytology revealed moderate-to-marked predominantly suppurative inflammation with yeast cells. Candida glabrata was cultured from the fluid. The patient was treated with oral itraconazole and the clinical signs resolved, although repeat abdominal ultrasound and cytology revealed persistence of the infected cyst-like structures. The patient remained asymptomatic for 8 months after the discontinuation of antifungal medications, despite the persistence of the pancreatic infection with C glabrata. Relevance and novel information To our knowledge, this is the first report of pancreatic infection with Candida species in a cat, followed by a chronic subclinical infection persisting for at least 8 months after treatment discontinuation.

Acute and severe haemorrhage following pentosan polysulfate injection in a Cornish Rex

Case summary A 14-year-old male castrated Cornish Rex cat was referred for lethargy progressing rapidly to collapse in the hours following a subcutaneous injection of a product containing 100 mg/ml pentosan polysulfate sodium and 168 mg/ml glucosamine. Physical examination revealed the cat to be in hypotensive shock with swelling and interstitial oedema around the cranial thorax and caudal cervical regions without cutaneous haemorrhage. Initial diagnostics revealed a severe anaemia (packed cell volume 11%) which later deteriorated further, necessitating a blood transfusion and aggressive fluid therapy. Post-transfusion, the patient remained dyspnoeic and subsequent diagnostics found evidence of pre-existing cardiomyopathy and congestive heart failure. The cat was euthanased 24 h following presentation due to increasing dyspnoea. Post-mortem findings were of severe subcutaneous and intermuscular haemorrhage over the neck and thorax, among other changes. There were no detectable levels of coumarin anticoagulants in the liver. Relevance and novel information This is the first reported case of acute subcutaneous and intermuscular haemorrhage of this severity suspected to be related to the off-label use of an injectable product containing pentosan polysulfate in a cat. Given the popularity of its use for feline arthritis, there is a need for large-scale clinical trials to evaluate the safety and efficacy of products containing pentosan polysulfate for cats, and any side effects to be reported.

Renal scintigraphy as an early and efficient method for detecting loss of renal function in a cat

Case summary A 6-year-old mixed-breed male cat was evaluated for a routine annual health assessment. No alterations on physical examination were observed other than mild pain on palpation of the right kidney. Complete blood count, serum biochemistry (including symmetric dimethylarginine), urinalysis and urine protein:creatinine ratio were within the reference intervals for the species. Abdominal ultrasonography showed the presence of asymmetric kidneys, decreased corticomedullary definition, presence of a cyst on the left kidney and moderate renal pelvis dilatation on the right kidney. Dynamic renal scintigraphy (technetium [99mTc]-diethylenetriamine pentaacetic acid) revealed a single functioning kidney on the left. Static renal scintigraphy (99mTc-dimercaptosuccinic acid) exhibited renal activity practically restricted to the left kidney (relative uptake was 99% for the left kidney and 1% for the right kidney). Results of renal scintigraphy showed that the left kidney was compensating for the lack of function of the right one. GFR was 2.17 ml/min/kg, which is considered subclinical renal insufficiency and is in accordance with the case, as the cat was asymptomatic and did not present alterations in laboratory parameters. Relevance and novel information Renal scintigraphy was an important tool to determine the loss of renal function in one of the kidneys and mild reduction of global GFR. In this case report, renal scintigraphy proved to be more sensitive in the assessment of renal function than other tests routinely performed.

Ventilatory failure in a cat following radical chest wall resection for feline injection site sarcoma

Case summary A 12-year-old spayed female domestic shorthair cat presented for chest wall resection and radiation therapy following incomplete surgical excision of a feline injection site sarcoma. A CT scan for surgical planning was performed under general anesthesia and showed extensive tumor infiltration of the soft tissues of the right thorax. The cat recovered uneventfully from this anesthetic event. Nineteen days later, the patient was reanesthetized for forequarter amputation plus radical chest wall resection, including ribs 3–8 and all associated soft tissues plus adjacent spinous processes. Postoperatively, the patient developed acute respiratory failure secondary to hypoventilation. The cat was mechanically ventilated for 12 h prior to being successfully weaned from the ventilator. However, the improvement was transient and mechanical ventilation was reinitiated 6 h later owing to respiratory fatigue. On the second day, the cat developed unexplained central nervous system signs and was euthanized. Relevance and novel information To our knowledge, this is the first case report to describe ventilatory failure secondary to radical chest wall resection in a cat. Hypoventilation with subsequent need for mechanical ventilation is a potential complication that should be considered during preoperative planning in patients requiring extensive chest wall resections.