Case summary A 14-year 3-month-old spayed female mixed-breed cat presented with jaundice, anaemia and thrombocytopenia. Haemophagocytic syndrome associated with lymphoma was suspected after cytological examination of the spleen. Despite treatment with prednisolone, L-asparaginase and nimustine, the cat died 176 days after the initial presentation. Necropsy revealed splenomegaly and hepatomegaly, without lymphadenopathy. Histopathologically, neoplastic lymphoid cells infiltrated the hepatic sinusoid and splenic sinus. The neoplastic lymphoid cells showed marked hepatocytotropism and contained erythrocytes, which was also confirmed by electron microscopy. Immunohistochemically, neoplastic lymphoid cells were positive for CD3, TIA1 (GMP-17) and granzyme B, and negative for CD8, CD20, CD56, CD57, CD79a and Iba1. Based on these findings, the cat was diagnosed with hepatosplenic T-cell lymphoma (HS-TCL) with hepatocytotropism.

Relevance and novel information This case shows cytotoxic immunophenotype of HS-TCL in a cat, which has not been demonstrated before. Severe hepatocytotropism and haemophagocytosis of the neoplastic cells were likely to be associated with jaundice and anaemia, respectively, and the poor outcome of the present case.

Case summary A 7-year-old neutered male Siamese cat was referred for investigation of weight loss and hypercalcaemia (3.3 mmol/l; reference interval 2–3 mmol/l). Haematology, serum biochemistry, thoracic imaging, bronchoalveolar lavage (BAL), Ziehl–Neelsen staining of the BAL fluid and interferon gamma release assay (IGRA) were compatible with pneumonia caused by the less pathogenic member of the Mycobacterium tuberculosis complex, that is, M microti (the ‘vole bacillus’), which is common in cats in the UK. Treatment with azithromycin, rifampicin and marbofloxacin was given for 2 months, followed by 4 months of azithromycin and marbofloxacin. Treatment recommendations for tuberculous pneumonia have since changed. The cat remained asymptomatic for 1 year but went on to develop M microti pneumonia on five other occasions, and was treated for 6–12 months on each occasion. The patient’s clinical signs, hypercalcaemia and radiographic/CT pulmonary pathology always resolved completely, and the IGRA became negative, before antimycobacterial treatment was stopped. This suggests cure followed by reinfection owing to avid hunting behaviour. Alternatively, this could represent recrudescence of dormant disease. This case has previously been included in a study that described a series of cases of feline tuberculosis.

Relevance and novel informationThis case shows that M microti infection in cats can present as recurrent episodes of pneumonia, even after prolonged treatment courses.

Case summary This paper presents two cases of acute postoperative upper airway obstruction following ventral bulla osteotomy (VBO) in cats. The first cat underwent a unilateral left-sided VBO for a suspected inflammatory polyp. The second cat underwent a single-session bilateral VBO procedure for bilateral otitis media. In the first case, immediate re-intubation and a gradual lightening of the anaesthetic plane resolved the clinical signs; in the second case, the patient deteriorated and went into acute cardiorespiratory arrest and received cardiopulmonary resuscitation. Both patients recovered well and were discharged home 3 days after surgery. Both cases were reported to show no further clinical signs on postoperative follow-up 3 weeks and 4 months after surgery, respectively.

Relevance and novel information Upper airway obstruction should be regarded as a potential complication of VBO in cats.

Case summaryAn 8-year-old neutered female domestic longhair cat was presented for investigation of a 48 h history of lethargy and pelvic limb ataxia. MRI of the spinal cord and vertebral column (C1 to sacrum) and brain was unremarkable. Lumbar cerebrospinal fluid analysis revealed pleocytosis and increased protein concentration. Thoracic radiographs and abdominal ultrasound were unremarkable. Anti-inflammatory doses of prednisolone were administered. Clinical deterioration occurred over the following 2 days, with the development of lower motor neuron deficits in both thoracic limbs. On repetition of the MRI, bilateral enlargement, T2-weighted hyperintensity, and marked contrast enhancement of the C7, C8 and T1 nerve roots, spinal nerves and brachial plexuses were observed. Infectious disease testing was negative. An immune-mediated inflammatory process was suspected and immunosuppressive doses of prednisolone were commenced. The clinical signs improved transiently, but marked deterioration occurred after 2 weeks. The patient was euthanased and a post-mortem examination was performed. A lymphocytic inflammatory infiltrate was detected in the C7, C8 and T1 nerve roots and dorsal root ganglia, and neoplastic plasma cells were identified in multiple organs. A diagnosis of non-cutaneous extramedullary plasmacytoma with multiorgan involvement and paraneoplastic ganglioradiculoneuritis was reached.

Relevance and novel information Paraneoplastic ganglioradiculoneuritis in association with a plasma cell neoplasia has not been previously reported in the cat and should be considered as a differential diagnosis for cats with clinical or imaging evidence of an inflammatory process affecting the nerve roots, spinal nerves or brachial plexuses.

Case summary A 7-month-old intact female Maine Coon cat was presented with a 2-month history of regurgitations. Contrast radiographic and endoscopic examinations revealed a diffuse megaoesophagus secondary to a severe lower oesophageal stricture. An epiphrenic diverticulum was noted. Endoscopic balloon dilation was unsuccessful. Gastrotomy was thus performed in order to incise the oesophageal wall radially along the stricture site, and then to dilate the stricture. A diameter of 20 mm was reached. With the aim of preventing stricture recurrence, submucosal injections of triamcinolone acetonide were performed. An 18 Fr oesophagogastric feeding tube was placed and a left gastropexy was performed in order to exert some traction on the gastroesophageal junction, with the aim of reducing the oesophageal diverticulum. Twelve months postoperatively, clinical signs had completely resolved and follow-up radiographs revealed marked improvement of the oesophageal dilatation.

Relevance and novel information Lower oesophageal strictures should be considered when evaluating regurgitations or megaoesophagus in a kitten. Surgical mucosal radial incision is a therapeutic option in cases of lower oesophageal stricture refractory to balloon dilation, and can lead to a marked improvement of clinical signs and of the oesophagus diameter leading to clinical success.

Case summary This case report documents the clinical appearance, diagnosis and novel treatment of a central Texas cat with cutaneous leishmaniosis. The cat presented with a linear erosion on the right pinnal margin, an ulcerated exophytic nodule on the right hock and a swelling in the right nostril. Cytological and histopathological findings were consistent with leishmaniosis. PCR confirmed the presence of Leishmania mexicana, a species endemic to Texas. An epidemiological investigation was conducted by trapping sandflies from the cat’s environment. Sandflies collected were identified as Lutzomyia species, known vectors of Leishmania species. Given the lack of validated medical therapies for L mexicana in cats, treatments typically prescribed for canine leishmaniosis were administered. Allopurinol achieved clinical success but was discontinued due to suspected drug-related neutropenia. Topical imiquimod also improved lesional skin but was not sustainable due to application difficulty. Oral administration of artemisinin resulted in significant clinical improvement of cutaneous lesions without reported adverse events. Nearly 8 months after the initiation of artemisinin therapy, the cat remained systemically healthy with stable lesions.

Relevance and novel information This case report demonstrates endemic feline leishmaniosis in central Texas and provides the clinician with alternative therapeutic options for medical management.

Case summaryA 7-year-old neutered female domestic longhair cat was presented for further investigation of suspected hepatobiliary disease. Increases in serum 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester lipase and hepatobiliary enzymes, with concurrent hypoalbuminaemia, were documented on blood biochemistry. Abdominal ultrasonography findings were consistent with acute pancreatitis with multiple pancreatoliths visualised within the pancreatic duct. Treatment for suspected triaditis was initiated with a hydrolysed protein diet, amoxicillin–clavulanate, hepatoprotectants and buprenorphine. Fifty-three days later, the patient presented with hypercalcaemia and obstructive pancreatolithiasis, and was euthanased. Post-mortem examination revealed severe chronic active pancreatitis with moderate chronic lymphocytic, plasmacytic cholangiohepatitis and mild chronic lymphocytic–plasmacytic duodenal enteritis (triaditis). Multiple calcium carbonate pancreatoliths present within the pancreatic ducts had resulted in pancreatic duct obstruction.

Relevance and novel information Pancreatolithiasis is a very rare condition in cats, with only five reports to date. In human medicine, pancreatolithiasis is often a sequala to chronic pancreatitis, seen in up to 50–90% of patients. However, in cats the aetiology of pancreatolithiasis, and indeed chronic pancreatitis, is poorly understood. This report describes a case of obstructive pancreatolithiasis in a cat with histopathological confirmation of triaditis and is the first report of hypercalcaemia in a cat with obstructive pancreatolithiasis. This further adds to the evidence base that pancreatolithiasis may have a similar pathogenesis to humans and can develop secondarily to chronic pancreatitis in cats.

Case summary A rescued stray cat with an unknown history was examined for non-ambulatory paraparesis in the hindlimbs. Survey radiographs revealed typical findings of hypervitaminosis A, characterised by vertebral exostoses and extensive osteophytes, mainly in the cervicothoracic spine. CT findings were consistent with the radiographic findings, and CT-based volume rendering and virtual endoscopy into the vertebral canal were created for three-dimensional visualisation of the lesion. MRI revealed a focal and mild dilation of the central canal of the spinal cord. Although the clinical diagnosis of hypervitaminosis A is based on an unusual dietary history and characteristic radiographic findings, the history of this cat was unknown and serum concentrations of vitamin A were unremarkable, when measured >1 month after rescue. However, other possible differential diagnoses were thought to be unlikely and clinical signs never worsened, and thus, hypervitaminosis A was presumed.

Relevance and novel information To our knowledge, this is the first report to present the CT and MRI characteristics of a cat with suspected hypervitaminosis A.

Case summaryA 13-year-old neutered female domestic shorthair rescue cat presented asymptomatically with raised hepatic enzymes following a routine pre-anaesthetic blood test. Cholangitis was suspected, and supportive treatment with 2 weeks of amoxicillin–clavulanic acid and 4 weeks of ursodeoxycholic acid and S-adenosylmethionine was trialled, with no improvement in biochemistry parameters. Clinicopathological investigations also revealed a markedly raised total bilirubin and abnormal bile acid stimulation test. Abdominal ultrasonography revealed pathological changes in the gallbladder, hepatomegaly with increased echogenicity and markedly thickened common bile duct walls. An exploratory laparotomy was performed revealing a grossly abnormal gallbladder with a small rupture at the dorsal fundus, which was managed via cholecystectomy. Pancreatic and hepatic biopsies were collected concurrently. Histopathology from the submitted samples revealed a gallbladder adenoma, chronic neutrophilic cholangitis and nodular hyperplasia of the pancreas. Culture of the gallbladder bile was negative but may be attributable to the initial treatment with antibiosis. At the time of writing, 5 months postoperatively, the cat had recovered well and remained asymptomatic and clinically healthy, but hepatic enzymes and bilirubin were only mildly reduced from the preoperative levels, despite the cat remaining clinically normal.

Relevance and novel information To our knowledge, this is the first case of a gallbladder adenoma confirmed histopathologically in a feline patient. Our findings suggest that although gallbladder neoplasia is rare in cats, this benign tumour should be considered a differential diagnosis.

Case summary A 4-month-old cat was presented with acute paraplegia after the referring veterinarian performed a subcutaneous injection (cefovecin and dexamethasone) in the caudodorsal thoracic area, during which the cat suddenly became uncooperative. A complete neurological examination performed 1 day after the injection revealed paraplegia without deep pain perception and reduced segmental spinal reflexes in the pelvic limbs. Findings were consistent with either an L4–S3 myelopathy or a T3–L3 myelopathy with subsequent spinal shock. MRI showed swelling of the spinal cord from T1 to L1 with heterogeneous T2-weighted intramedullary hyperintensity and no contrast enhancement. A centrally located intraspinal signal void was visible in T2*-weighted images. These changes were compatible with a suspected traumatic intraspinal injection. Despite intensive supportive care over 4 days, neurological status did not improve and the cat was euthanased. Gross pathology findings revealed severe intramedullary haemorrhage and myelomalacia in the T10–L1 spinal cord segments. Histopathology of the spinal cord after haematoxylin and eosin staining revealed a severe intramedullary space-occupying haemorrhage with focal malacia. A trajectory-like, optically empty cavity containing some eosinophilic droplets at the edges was detected. Although no further evidence of trauma was noted in the surrounding structures, the spinal cord changes were compatible with a perforating trauma.

Relevance and novel information To our knowledge, this is the first report of thoracic intraspinal injection causing myelomalacia defined by an ante-mortem MRI and confirmed post mortem by histopathology. The traumatic myelopathy appeared to be most compatible with an intraspinal injection causing vascular rupture.

Case summary This report describes a cat with a rare form of histoplasmosis: invasive rhinitis with adnexal involvement, mimicking disease more commonly caused by cryptococcosis or aspergillosis. This case is especially noteworthy as it was from an area where histoplasmosis is not enzootic.

Relevance and novel information Invasive fungal rhinitis causes significant morbidity in cats. Diagnostic investigation of more common pathogens includes detection of fungal antigen (Cryptococcus) or antifungal antibodies (Aspergillus). This case demonstrates that histoplasmosis can present as chronic nasal disease in cats. Histoplasma antigen testing provides a non-invasive diagnostic option. Moreover, this case serves as a reminder that histoplasmosis can affect cats anywhere, even in non-enzootic areas.

Case summary A 9-year-old neutered male domestic shorthair cat was presented for evaluation of severe hemodynamic collapse and suspected lower urinary tract disease. On admission, severe metabolic acidosis, hyperkalemia and azotemia, and electrocardiographic findings consistent with cardiotoxicity were identified. The diagnosis of uroabdomen was made based on abdominal fluid to plasma concentration ratios of creatinine and potassium. A central line catheter was placed percutaneously into the abdomen for peritoneal drainage and used for peritoneal dialysis as a bridge to surgery. Retrograde contrast cystography confirmed rupture of the urinary bladder. Point-of-care ultrasound of the chest postoperatively revealed the presence of mild pleural effusion. Echocardiography was then performed showing no evidence of cardiac disease. Pleural fluid analysis revealed a transudate with a creatinine ratio of 2.38 ([Creatinine]_{pleural fluid}/[Creatinine]_plasma), consistent with the diagnosis of urothorax. The cat recovered uneventfully from surgery and was monitored for signs of respiratory distress during the rest of its stay in hospital. The cat was discharged 4 days later and the pleural effusion resolved without further medical intervention.

Relevance and novel information There is limited information on the causes of urothorax and uroabdomen management of feline patients. Pleural effusion is a complication observed in critically ill cats secondary to fluid overload, underlying cardiomyopathy, primary thoracic pathology or a combination of these. To our knowledge, this is the first report of urothorax in a cat secondary to non-traumatic uroabdomen. Careful monitoring of respiratory signs consistent with pleural space disease is recommended in cases of uroabdomen.

Case summary A 9-month-old intact female domestic mediumhair cat presented with a 5-month history of obtundation, lethargy, hypernatremia (181 mmol/l; reference interval [RI] 151–158 mmol/l), hyperchloremia (142 mmol/l; RI 117–126 mmol/l), azotemia (blood urea nitrogen 51 mg/dl; RI 18–33 mg/dl), creatinine 3.0 mg/dl (RI 1.1–2.2 mg/dl), hyperphosphatemia (8.3 mg/dl; RI 3.2–6.3 mg/dl) and total hypercalcemia (11.4 mg/dl; RI 9–10.9 mg/dl), with concurrent polyuria with adipsia. Neurologic evaluation revealed proprioceptive deficits, and this finding paired with a history of focal seizure-like activity despite improving sodium concentrations suggested a cerebrothalamic lesion. For this reason, and historical and biochemical findings consistent with adipsic diabetes insipidus (DI), MRI of the brain was performed, which revealed a lesion of the hypophyseal fossa consistent with a pituitary cyst. Given the patient’s age and the timeline of clinical signs, a congenital pituitary cyst was strongly suspected. The patient was managed initially with intravenous fluids to correct the hypernatremia, then managed for more than 4 years with topical ocular desmopressin acetate administration and free water administered through a feeding tube. This cat’s clinical diagnosis included a congenital pituitary cyst with subsequent central DI and primary adipsia.

Relevance and novel information The clinical presentations of primary adipsia or central DI are both rare in cats. This is the first report to describe these conditions occurring in a cat owing to a congenital pituitary cyst and describes successful long-term management of this condition.

Case summary A 10-week-old intact male domestic shorthair kitten presented for an acute onset of lethargy, vomiting and anorexia. An abdominal mass effect was palpable on presentation. Blood work, abdominal radiographs and point-of-care abdominal ultrasound showed severe anemia, decreased serosal detail and abdominal effusion, respectively. Based on the concern for an abdominal organ torsion or ruptured mass, an emergency abdominal exploratory surgery was performed. Torsion of the entire caudate liver lobe was discovered with a secondary hemoabdomen, and a liver lobectomy was performed. The kitten was stabilized and discharged 3 days after surgery. At the recheck examination, 15 days postoperatively, the patient was reported to be doing well.

Relevance and novel information Liver lobe torsion is a rare condition previously reported in six other cats; however, this is the first peer-reviewed report in a kitten successfully treated with surgery with no identifiable underlying cause.

Case summary A 5-year-old neutered male domestic longhair cat was presented for the investigation of a cranial abdominal mass following a 1-month history of inappetence and lethargy. Abdominal ultrasound revealed a large cavitated mass confluent with the mesenteric aspect of the descending duodenum. At surgery, the mass was found to involve the pylorus, proximal duodenum and pancreas, and was non-resectable. Histopathological examination of surgical biopsies revealed a non-neoplastic process involving eosinophils and fibroplasia.

Relevance and novel information This case report describes an uncommon feline gastrointestinal pathology with an unusual appearance that may provide an additional differential diagnosis other than neoplasia or abdominal abscess when confronted with a cavitated abdominal mass in cats.

Case summary A 16-year-old neutered female British Shorthair cat presented with a 5-year history of swelling lateral to the left mandible that intermittently discharged viscous, clear fluid from a small defect in the skin. CT, ultrasonography, physical characteristics and cytology of the fluid were suggestive of sialocoele. CT showed a large, cavitary, fluid-filled mass lateral to the left mandible. A ventral approach was used to resect the left mandibular, sublingual and molar salivary glands and sialocoele. Histopathology of the molar and mandibular and sublingual glands showed chronic active sialoadenitis with more severe changes in the molar gland. There were no signs of recurrence of the sialocoele 12 months after surgery.

Relevance and novel information This is the first report of a cranial cervical sialocoele potentially involving the molar salivary gland in a cat. Resection of the mandibular, sublingual and molar salivary glands should be considered in cats that present with a cranial cervical sialocoele.

Case summary An 11-year-old neutered female domestic shorthair cat presented to our hospital with a 5-day history of vomiting, lethargy, anorexia and hyperbilirubinaemia, despite intravenous fluid therapy, gastroprotectants and antibiotic treatment. An abdominal ultrasound revealed a markedly distended common bile duct (diameter 6.2 mm). The cystic duct and intrahepatic bile ducts were also dilated. A linear structure formed by two parallel hyperechoic lines was identified in the common bile duct and could be traced to the duodenal papilla. The cat underwent laparotomy for surgical decompression of the biliary tree. A tubular, brown-coloured structure was retrieved from the common bile duct. Histological examination was consistent with a degenerate helminth. The cat recovered uneventfully from the surgery and its demeanour and appetite improved rapidly over the following days. Liver and gallbladder wall histopathology was consistent with bacterial cholangitis and cholecystitis. Escherichia coli was cultured from both bile and liver parenchyma.

Relevance and novel information To our knowledge, this is the first reported case of extrahepatic biliary duct obstruction caused by a helminth in a cat in the UK. We hypothesised that the obstruction had been caused by the aberrant migration of an intestinal nematode that became lodged in the duodenal papilla. Ultrasound allowed prompt diagnosis and guided the treatment decision.

Case summary This case report describes a 9-year-old neutered male cat with a functional adrenal tumor showing aggression toward other cats in the household, excessive meowing and urine spraying. The diagnosis was made based on the clinical signs, an enlarged right adrenal gland on ultrasound, penile spines and elevated sex hormones on an adrenocorticotropic hormone stimulation test. The cat was submitted to celiotomy and adrenalectomy. Histopathological examination confirmed the adrenocortical adenoma. Three months after surgery the penile spines disappeared and urine spraying, as well as excessive meowing, had greatly decreased; however, aggressive behavior took much longer to stop and required behavior therapy.

Relevance and novel information Functional adrenal tumors producing only sex hormones and behavioral changes are uncommon. The cat reported herein started showing behavioral changes before spines appeared on the penis, and structural alterations in the adrenal gland at the abdominal ultrasonography were detected. Considering all the possible implications resulting from severe behavior problems such as cat–cat aggression, from a permanent separation of the cats to relinquishment, a detailed investigation of underlying medical mechanisms in these animals is crucial from the start. Examinations may need to be repeated later in the course.

Case summaryA 12-year-old spayed female domestic shorthair cat was presented to a referral hospital for chronic intermittent hyporexia and weight loss. An abdominal ultrasound was performed, which revealed a mid-jejunal mass and mesenteric lymphadenomegaly. Surgical resection and placement of an oesophagostomy tube (O-tube) was performed. Upon recovery the cat exhibited signs of Horner syndrome, which resolved over the span of 2 weeks. Subsequently, the cat developed signs of unilateral Pourfour du Petit syndrome in the left eye at day 20 and unilateral Horner syndrome at day 25 ipsilateral to the O-tube insertion site. The O-tube was removed 32 days postoperatively, and Horner syndrome resolved 24 h later. Follow-up examination 15 months later did not show any recurrence of ocular signs.

Relevance and novel information To our knowledge, this represents the first report of alternating ipsilateral Horner and Pourfour du Petit syndrome in a single patient that underwent placement of an O-tube. Neurological complications after O-tube placement are uncommon, with only a single previously published report of a cat developing Horner syndrome after O-tube placement. Veterinarians should consider potential ocular and neurological complications after O-tube placement and monitor for such signs postoperatively.

Case summary A 10-year-old spayed female Russian Blue cat was presented with a 3-month history of excessive otic discharge and scratching, only involving the right ear. Other than a moderate amount of ceruminous exudate present within the right ear on video-otoscopic examination, there were no other cutaneous abnormalities. The cat was deemed to be otherwise in good health based on physical examination and several laboratory profiles. A diagnosis of otodemodicosis was determined due to the presence of a large number of Demodex cati mites retrieved from cerumen. Treatment consisted only of monthly topical application of sarolaner/selamectin to the nape of the neck with a marked reduction in mite counts and otic pruritus after a single dose. Complete resolution was achieved after a total of four doses.

Relevance and novel information This is the first report to describe the resolution of mite infestation owing to D cati after treatment with a sarolaner-containing spot-on product. In addition, to the best of the author’s knowledge, this is the first report of any isoxazoline product used in the successful treatment of demodicosis affecting the ear canal. In general, there is a lack of reports describing safe and effective treatments for feline otodemodicosis. Topically applied sarolaner/selamectin resulted in resolution of mites while avoiding any potential ototoxic events from medications applied directly into the ear, and provided a treatment that was easier to apply than oral or injectable macrocyclic lactones.

Case summary A 13-year-old neutered female domestic shorthair cat was presented for further investigation of a right-sided cervical mass. Oral cavity examination revealed a unilateral, right tonsillar mass. Following a contrast-enhanced CT scan of head, thorax and abdomen, which showed no clear evidence of distant metastasis, cytology of the cervical mass was consistent with a metastatic retropharyngeal lymph node, and the patient underwent tonsillectomy and lymphadenectomy. The tumour was histopathologically confirmed to be a well-differentiated squamous cell carcinoma with lymph node metastasis, and sequential chemotherapy treatments with carboplatin were administered. The cat underwent a second surgery to treat local recurrence and chemotherapy was continued. Subsequently, multiple lymphadenectomies to remove additional metastatic lymph nodes were performed, followed by adjuvant treatment with doxorubicin. Restaging procedures, performed every 3-6 months did not document any local recurrence nor any local or distant metastasis. The patient was euthanased after developing neoplastic pleural effusion 965 days following tonsillectomy.

Relevance and novel information Tonsillar tumours are rare in cats, but clinical presentation can be similar to that in dogs. Treatment with surgery and chemotherapy, and more importantly multiple lymphadenectomies, may delay the onset of distant metastasis and it should be considered in similar cases to possibly prolong survival.