Case series summary Two cats were presented for further investigation of respiratory signs. One cat had a history of a cough and the other, tachypnoea. In each case, thoracic CT was performed, which revealed a generalised marked reticular pattern in the first cat and focal consolidation of the right caudal lung lobe in the second cat. The first cat was euthanased following completion of the imaging study and a post-mortem examination was performed. The second cat underwent surgical excision of the abnormal lung lobe and survived for 4 years after diagnosis. Histopathology performed on lung tissue removed from each cat was consistent with pulmonary fibrosis.

Relevance and novel information This small case series adds to the existing literature and highlights the heterogeneous clinical course and variable appearance of pulmonary fibrosis on CT of affected cats. These cases provide evidence that pulmonary fibrosis in cats incorporates a wide spectrum of fibrotic lung disease and demonstrates the possibility for prolonged survival following diagnosis where disease is localised and amenable to surgical resection.

Case series summary Following diaphragmatic herniorrhaphy, three cats developed a continuous pneumothorax. All three cats required continuous suction to evacuate air from the thoracic cavity. Despite continuous suction, the pneumothorax persisted for all cats and blood patch pleurodesis (BPP) was performed using blood donor cats. All three cats had resolution of their pneumothorax within 24 h of BPP.

Relevance and novel information This is the first report of BPP used in feline patients. More recently autologous BPP has been reported for use in dogs and humans, with a reportedly high success rate. BPP may allow timely resolution of continuous pneumothorax in cats and provide an alternative treatment option to prolonged medical management or surgical intervention. Allogenic blood from a donor cat may be necessitated in feline BPP when cardiovascular instability is appreciated in these small patients.

Case summary An 8-month-old neutered male domestic shorthair kitten was examined for anorexia, lethargy and palatine ulcers. Systemic lupus erythematosus (SLE) was suspected based on a positive antinuclear antibody (ANA) titer and six manifestations of autoimmunity: fever, paronychia, oral ulcers, proteinuria, thrombocytopenia and leukopenia. Mastocytemia was observed on the blood smear. Although the clinical presentation of this case meets the classification criteria for SLE in humans, tick-borne disease and histopathology evaluation of the oral and cutaneous lesions would have been necessary to support a definite diagnosis of SLE. Baseline ANA titration was performed in two laboratories with conflicting results, which may reflect substrate differences used for the titration, but a false-positive result cannot be excluded. The cat received prednisolone and all clinical and laboratory abnormalities resolved after two months of treatment. Subsequent ANA titers remained positive and were not correlated to the patient’s clinical progression.

Relevance and novel information This report describes new findings associated with a presumptive diagnosis of SLE in a kitten, highlighting that SLE may not be ruled out even in young cats and may be associated with mastocytemia. ANA titration is part of the initial diagnostic work-up of SLE but is a non-specific test and discrepancies can be observed between laboratories. The titration of more specific antibodies such as those used in humans would be helpful to diagnose SLE. ANA titration may not correlate with clinical activity of SLE; hence, the interest of an ANA titer follow-up to establish disease control warrants further investigation.

Case summary Skin tumours are the second-most common form of feline cancer after haematopoietic neoplasms and are often malignant. Cutaneous lymphoma is uncommon in cats and can be classified as epitheliotropic (typically of T-cell origin) or non-epitheliotropic (either of T-cell or B-cell origin). The present study describes a case of multifocal cutaneous non-epitheliotropic B-cell lymphoma. The skin nodules were multiple and variable in size; showed rapid progression; were alopecic and erythematous in appearance and pruritic and ulcerated; and were mostly located on the trunk. Nodule biopsies revealed the presence of uniform medium-to-large round neoplastic cells that infiltrated the dermis and subcutis. The neoplasias were consistent with a round cell cutaneous tumour and did not show evidence of epitheliotropism. Furthermore, immunohistochemical assessments indicated an immunophenotype characterised by round cells with a strong membrane and cytoplasmic positivity for the CD20 antigen, consistent with a lymphocyte of B-cell origin.

Relevance and novel information Cutaneous non-epitheliotropic B-cell lymphoma in cats is rare and was previously reported to appear as single dermal and subcutaneous masses that are variable in size and generally develop in the tarsal region. To our knowledge, this is the first report to describe multifocal cutaneous non-epitheliotropic B-cell lymphoma in a cat.

Case summary A 16-year-old neutered female Korat cat presented with chronic vomiting, mild azotaemia and mild hypercalcaemia. Physical examination revealed bilateral palpable masses on each side of the trachea. Laboratory results were consistent with primary hyperparathyroidism, diagnostic imaging findings with cystic thyroid or parathyroid masses, and fine-needle aspiration cytology with thyroid hyperplasia or adenoma. In order to confirm whether one or two of the masses were the cause of the hyperparathyroidism, cystic fluid was aspirated from both for parathyroid hormone concentration measurement. The concentration was shown to exceed that of the serum manyfold in both samples, confirming both masses to be functional and of parathyroid origin. A total parathyroidectomy and thyroidectomy were performed on the right side, and a subtotal thyroidectomy and a subtotal to total parathyroidectomy on the left, without any major postoperative complications. Histopathology was consistent with bilateral parathyroid carcinoma.

Relevance and novel information To our knowledge, this report is the first to describe a rare case of bilateral parathyroid cystic carcinoma in a cat. It highlights the usefulness of determining parathyroid hormone concentration in the cystic fluid of a suspected neoplastic parathyroid mass preoperatively. It also demonstrates that it may be possible to remove most of the cervical parathyroid and thyroid tissue of a cat without causing any clinically relevant hypocalcaemia or iatrogenic hypothyroidism. However, serum concentrations of ionised calcium, thyroxine and creatinine should be closely monitored in the postoperative period in order to detect and control possible complications.

Case summary A 3-year-old spayed female domestic shorthair indoor cat presented with a 3-week history of pain from the pelvic region. Physical examination revealed pain elicited on palpating the pelvic area and right hip. Radiographs and CT showed an expansile, osteolytic process with intact cortex in the right wing of the ilium. CT revealed a monostotic and soft tissue-attenuating process with clear margins. Preoperative histopathological diagnosis of aneurysmal bone cyst was made from incisional biopsies. The cyst was removed en bloc with limb-sparing partial iliectomy. Histopathology confirmed the diagnosis of aneurysmal bone cyst. Recovery from surgery was uneventful. At re-examination 8 weeks and 8 months postoperatively, the cat was pain free and physical examinations were within normal limits.

Relevance and novel information Feline aneurysmal bone cysts are rare and reported cases are few. To our knowledge, this is the first report describing the CT appearance of a pelvic aneurysmal bone cyst and partial iliectomy with limb preservation in a cat with successful short-term outcome.

Case summary A 6-year-old castrated male domestic shorthair cat presented for lethargy and gastrointestinal signs after possible exposure to Nerium oleander leaves. The cat developed a ventricular arrhythmia that responded positively to the administration of digoxin-specific antibody fragments. Underlying hypertrophic cardiomyopathy was also diagnosed after the development of congestive heart failure. Humane euthanasia was elected owing to a lack of significant response to continued therapy.

Relevance and novel information To our knowledge, this is the first report to describe the use of digoxin-specific antibody fragments in a cat. Nerium oleander toxicosis is associated with significant morbidity and mortality, and digoxin-specific antibody fragments have been used effectively in humans and animals. The development of cardiac necrosis may have contributed to worsening arrhythmias and highlights the importance of early intervention. The use of digoxin-specific antibody fragments for suspected N oleander toxicosis in a cat resulted in a rapid response and appeared to be well tolerated.

Case summary A 5-year-old castrated male domestic shorthair cat was presented for a multidrug-resistant Enterococcus faecium urinary tract infection within its bilateral subcutaneous ureteral bypass systems. After considerable consultation, the cat was treated with oral linezolid (10 mg/kg q12h) for two separate 2-week courses over 5 weeks. Over this time period, the cat became progressively neutropenic and thrombocytopenic, but was otherwise clinically stable. Upon cessation of the linezolid, the bicytopenia resolved within 12 days.

Relevance and novel information The reversible myelosuppression in this case is suspected to be secondary to linezolid administration. While previously reported in people, this effect has not been reported at therapeutic doses in veterinary species. This report demonstrates the potential for adverse drug reaction development in cats treated with prolonged linezolid therapy and highlights the need for extreme caution when utilizing linezolid in patients with renal insufficiency. Linezolid is the only drug currently approved by the Food and Drug Administration to treat vancomycin-resistant enterococci infections in people; however, resistance to this antibiotic appears to be increasing. Multidrug-resistant organisms continue to be a real global public health threat in both human and veterinary medicine. Third-tier antibiotics should only be considered under extreme circumstances and after considerable consultation with a specialist. Please note that the authors of this manuscript followed American Veterinary Medical Association policies on stewardship and International Society for Companion Animal Infectious Diseases guidelines, and do not promote or encourage the use in daily practice.

Case summary A 10-year-old neutered male domestic shorthair cat was diagnosed with renal adenocarcinoma associated with hypertrophic osteopathy. The cat was referred for chronic ambulation difficulties. The physical examination showed a painful thickening of all four limbs, a right cranial abdominal mass and a conjunctival hyperaemia. Radiographic findings were consistent with extensive periosteal new bone formation involving not only the diaphyses of the fore- and hindlimbs, but also of the pelvis, tarsus and carpus. Abdominal ultrasonography and CT revealed a mass within the right kidney and a primary neoplasm was suspected. A ureteronephrectomy of the right kidney was performed and histopathology confirmed the diagnosis of renal adenocarcinoma. Although clinical improvement of the lameness occurred after surgery, no radiographic changes of hypertrophic osteopathy lesions were observed at the 9-month follow-up.

Relevance and novel information Feline cases of hypertrophic osteopathy are rarely reported in the literature and only a few of them were associated with abdominal neoplastic diseases. To our knowledge, this is the first case of renal adenocarcinoma associated with hypertrophic osteopathy in a cat.

Case summary A 15-year-old neutered male domestic shorthair cat presented with a 4-week history of dysphonia and reluctance to chew hard food. Oral examination revealed a mass lesion on the caudal soft palate. Biopsy was performed and histopathology with immunohistochemistry was most consistent with histiocytic sarcoma. CT of the head identified a discrete, left-sided, soft tissue mass lesion cranial to the tonsil with bilaterally symmetrical regional lymph nodes. CT of the thorax was unremarkable. Surgical removal achieved cytoreduction but not complete removal. Adjuvant chemotherapy with lomustine 10 mg (30 mg/m²) was initiated. The patient developed suspected pancreatitis 2–3 weeks postoperatively, so further chemotherapy treatment was discontinued, but supportive treatment with pain relief and appetite stimulants was provided. Three months postoperatively, the patient developed recurrent dysphonia, and oral examination revealed a suspicion of local recurrence. Confirmation of diagnosis (cytopathology or histopathology) was not obtained. Supportive treatment to maintain a good quality of life was continued and the patient was euthanased 6 months after diagnosis owing to progressive disease.

Relevance and novel information Only a few reports have been published describing histiocytic diseases of cats. To our knowledge, this is the first report of a feline histiocytic sarcoma of the oral cavity. Therefore, histiocytic sarcoma should be considered as a differential diagnosis in feline patients with an oral mass, especially if histopathology suggests a pleomorphic and poorly differentiated sarcoma. Immunohistochemistry for the confirmation of cell line origin would be strongly recommended.

Case summary A 7-year-old neutered male Norwegian Forest Cat was presented with decreased appetite and activity, weight loss, fever, neutrophilia and hyperglobulinaemia. A physical examination showed painful stifle joints and enlarged popliteal lymph nodes. Blood examination showed neutrophilia, hyperglobulinaemia and increased serum amyloid A. Urinalysis, thoracic and abdominal radiographs, and abdominal ultrasonography were unremarkable. Synovial fluid from the knee joints had diminished viscosity and revealed neutrophilic inflammation on the smear. There was no evidence of infection in a microbiological culture of the synovial fluid. A diagnosis of idiopathic immune-mediated polyarthritis (IMPA) was made. Prednisolone was initiated at 2 mg/kg q24h PO and tapered with additional immunosuppressants (leflunomide, ciclosporin A and methotrexate); however, prednisolone could not be discontinued. Informed consent was obtained from the owner and mycophenolate mofetil (MMF) at a dosage of 10 mg/kg q12h PO was initiated on day 798. There were no adverse effects of MMF and prednisolone was discontinued on day 1183. Clinical signs resolved and the cat’s general condition remained stable with MMF alone at a dosage of 10 mg/kg q48h PO on day 1600.

Relevance and novel information There is limited information describing feline IMPA and its treatment options other than the use of prednisolone. This is the first report of the successful treatment and long-term follow-up of feline IMPA with MMF. MMF may be a safe and effective option as an additional immunosuppressant in feline IMPA.

Case summary A 6-month-old female Bengal cat was referred for a suspected vegetal foreign body (FB) in the mid-stroma of the right cornea. A small dark linear FB was identified in the dorsal aspect of the cornea, with associated cell infiltrate. Ophthalmic examination was otherwise normal, with no inflammatory reaction of the anterior uvea, and no abnormalities of the lens or fundus. Surgical removal was performed under general anesthesia. The FB, as observed under an optic microscope, was a worker bee stinger without the venom sac. Medical treatment consisted of topical and systemic antibiotics and steroids, and topical administration of atropine. Follow-up was uneventful.

Relevance and novel information Ocular bee stings have been described in humans, with several consequences ranging from mild conjunctivitis to severe lesions affecting the cornea, iris, lens and retina. Most severely affected cases have been observed when the venom sac was found with the stinger, with a likely greater amount of venom being delivered into the ocular structures. The relatively benign presentation of this case was probably due to the lack of the venom sac within the bee sting. To our knowledge, this is the first documented case of a corneal bee sting in a cat.

Case summary A 7-year-old spayed female domestic shorthair cat was presented for persistent anemia of unknown origin. Splenomegaly was diagnosed through physical examination and abdominal radiographs, and an abdominal ultrasound was performed. The ultrasound showed splenomegaly, as well as one discrete mass in the body of the spleen. A splenectomy was performed and histopathology along with immunohistochemistry for CD18 and CD204 confirmed a diagnosis of hemophagocytic histiocytic sarcoma (HS). Two courses of lomustine (CCNU) chemotherapy were used in this cat along with adjuvant oral prednisolone and iron dextran injections, but the cat eventually succumbed to hepatic failure, presumed to be secondary to metastatic disease.

Relevance and novel information The clinical pathology results and ultrasonographic studies performed before and after treatment in this cat provide useful preliminary information about the biologic behavior and response to treatment for this rare cancer. This is also the first reported case where both CD18 and CD204 were strongly positive, confirming hemophagocytic HS in a cat.

Case summary A 7-month-old Siberian cat was presented for investigation of acute onset multifocal neurological deficits. Neurological examination documented dull mental status and an ambulatory left hemiparesis. Serum biochemistry documented marked hyperglobulinaemia. MRI of the brain identified marked leptomeningeal contrast enhancement extending along the brainstem caudally to involve the cranial cervical spinal cord. MRI of the cervical spine further identified a subarachnoid diverticulum that extended from the level of the obex to the C2–C3 vertebrae. Cerebrospinal fluid quantitative RT-PCR was positive for the presence of feline coronavirus. Histopathology revealed pyogranulomatous meningitis and choroid plexitis, uveitis and nephritis.

Relevance and novel information This article describes the first reported case of a subarachnoid diverticulum associated with feline infectious peritonitis.

Case summary An 8-year-old neutered male indoor cat was presented for evaluation of a year-long history of swelling over the bridge of the nose that extended from the subcutaneous tissue of the right upper eyelid to the dorsum of the skull. Intermittent regression of the mass lesion was reported with antibiotic or corticosteroid therapy; however, progressive swelling, malaise and hiding behavior persisted. CT revealed an aggressive osteolytic mass lesion in the right and left nasal cavities and extending into the frontal sinuses. Rhinoscopy using a 2.8 mm rigid telescope revealed somewhat normal-appearing turbinates rostrally and ventrally on the left side, with turbinate destruction on the right. After obtaining a biopsy from the right side of the nasal cavity, thick material filling the entire nasal cavity was visible caudally and was extracted endoscopically from a rostral approach. Surgical biopsy of the dorsal nasal bridge resulted in protrusion of inspissated material from the incision site. Rhinoscopic exploration revealed that the material extended into both frontal sinuses. Following extensive debridement and medical therapy, marked resolution of facial asymmetry was achieved.

Relevance and novel information Facial distortion is often considered suggestive of a neoplastic process; however, it can also be seen with fungal and mycobacterial infections, and, in this case, an inflammatory condition of unknown etiology. In this cat, aggressive intervention and debridement of necrotic debris resulted in substantial bony remodeling of the skull and return to normal activity levels.

Case summary An 8-year-old spayed female domestic shorthair cat was presented for a recheck evaluation of hypertrophic cardiomyopathy and chronic kidney disease. Three years prior to presentation, the patient was diagnosed with obstructive hypertrophic cardiomyopathy and started on atenolol. The left ventricular outflow tract obstruction subsequently resolved. Biochemical analysis a week prior to presentation demonstrated severe azotemia. Transthoracic echocardiograph revealed pericardial effusion, pleural effusion, severe left ventricular concentric hypertrophy, severe left atrial enlargement and continuous left-to-right flow through the interatrial septum near the fossa ovalis. The patient was euthanized owing to poor prognosis, and gross examination at necropsy revealed a valve-incompetent patent foramen ovale secondary to severe left atrial dilation.

Relevance and novel information To our knowledge, this is the first report of an acquired left-to-right shunt through a valve-incompetent foramen ovale in a cat with hypertrophic cardiomyopathy. Severe left atrial dilation was suspected to cause interatrial shunting through the valve-incompetent foramen ovale, and this finding may be relevant to echocardiographic evaluations in other cats.

Case summary A 3-year-old entire female Burmese cat was presented for investigation of intermittent lethargy during gestation followed by persistent hypersalivation and ataxia postpartum. The cat had queened three litters in total, with clinical signs worsening during the most recent lactation period. Mild anaemia (26%), hypoglycaemia (2.4 mmol/l; reference interval [RI] 3.9–8.3 mmol/l) and increased postprandial serum bile acids (74 µmol/l; RI <25 µmol/l) were identified on initial bloodwork. Multiphase contrast-enhanced CT identified a mesentericorenocaval portosystemic shunt; this was attenuated surgically with an ameroid constrictor. Clinical signs resolved after surgery. Follow-up 3 months postoperatively revealed normal pre- and postprandial serum bile acids (2 µmol/l and 3 µmol/l, respectively) with repeat CT identifying evidence of shunt attenuation. The cat continued to be healthy and free of clinical signs 12 months postoperatively.

Relevance and novel information Mesentericorenocaval portosystemic shunt morphology has not been previously reported in the cat and should be considered as a differential diagnosis for cats presenting with peripartum onset of malaise, ptyalism or ataxia.

Case summary A 14-year-old spayed female American Shorthair cat was presented with weight loss and a palpable abdominal mass. Abdominal ultrasound and CT revealed a duodenal mass with suspected perforation and an enlarged jejunal lymph node. Cytological evaluation from a fine-needle aspiration of the abdominal mass displayed many atypical round cells, some with a small amount of light pink material at the cellular edge. The duodenal mass was surgically removed, and was diagnosed as a plasma cell tumour immunohistochemically positive for CD79 alpha, IgA and lambda immunoglobulin light chains. In addition, amyloidosis was detected. PCR to assess the antigen receptor rearrangement of the tumour cells showed a monoclonal rearrangement of the immunoglobulin heavy chain gene. Postoperatively, the cat received chemotherapy with cyclophosphamide and prednisolone. Owing to progressive enlargement of the jejunal lymph node, different chemotherapy protocols were used sequentially, namely chlorambucil, lomustine and L-asparaginase. However, the cat died 96 days after the initial diagnosis. Post-mortem examination confirmed systemic dissemination of tumour cells. The cause of death was considered to be a result of a complication of the tumour itself and associated amyloidosis.

Relevance and novel information This patient was diagnosed with a primary duodenal plasmacytoma, and primary (amyloid light-chain) amyloidosis. In cats, intestinal plasmacytoma is rarely reported and associated amyloidosis is an uncommon feature, when compared with humans. To our knowledge, this is the first clinical report of duodenal plasmacytoma in a cat. The present report shows that feline plasmacytomas should be included in the differential diagnosis of a duodenal mass.

Case summary A 10-year-old castrated male domestic shorthair cat was referred for surgical treatment of a left-sided frontal lobe meningioma diagnosed by CT. Clinically, the cat had generalised tonic–clonic seizures, which reduced in frequency after treatment was started with prednisolone. After definition of the anatomical landmarks of the feline skull, a bilateral transfrontal craniotomy allowed en bloc removal of the meningioma. While postoperative recovery was uneventful, right-sided proprioceptive deficits were still present 6 months after surgery. MRI detected a probable meningoencephalocele herniating through the surgical bone defect in the frontal sinus. Because of the mild neurological deficits and good quality of life, the meningoencephalocele was not treated. Thirty-one months after meningioma removal the cat was alive without further neurological progression.

Relevance and novel information To our knowledge, this is the first report to describe, in detail, the technique of transfrontal craniotomy in cats. Iatrogenic meningoencephalocele is a complication that has not previously been described after meningioma removal in cats, and should be considered as a potential complication after craniotomy.

Case summary A stray female domestic shorthair cat was presented to the emergency service after being hit by a car. The patient was recumbent and vocalizing, with a small wound over the right lateral thorax, and two palpably firm swellings in the right cervical and thoracic soft tissues. The patient was sedated and humanely euthanized to prevent further pain and suffering. Post-mortem whole-body radiographs and subsequent necropsy revealed abdominal wall rupture with herniation of two near-term fetuses within the subcutaneous tissues along the right ventrolateral thoracic wall and neck. Within the abdomen, the right uterine horn was ruptured and a third extra-luminal fetus was identified. The left uterine horn remained intact, containing a fourth fetus.

Relevance and novel information Rupture of the abdominal wall or diaphragm are well-known potential complications of blunt force trauma, such as motor vehicle accidents. While traumatic uterine rupture and diaphragmatic herniation of the gravid uterus have both been reported in the veterinary literature, abdominal wall rupture with subcutaneous fetal herniation is highly uncommon.

Case summary An adult male intact domestic shorthair cat was presented for acute onset of generalised tremors, stupor, horizontal nystagmus, anisocoria and bilateral absence of pupillary light and palpebral reflexes. Response to intravenous (IV) administration of benzodiazepines was minimal; thus, the induction of general anaesthesia with propofol, midazolam and dexmedetomidine was necessary to control clinical signs. Following a clinical suspicion of neurotoxicosis, a low-dose constant rate infusion (CRI) of IV lipid emulsion (ILE) was started. Phenobarbital and a low-dose CRI of ketamine were also used for neuroprotective purposes. Metaldehyde intoxication was confirmed by qualitative faecal toxicological analysis after discharge. Anaesthetic drugs were progressively tapered and stopped after 28 h and extubation was possible after 44 h. The cat was discharged 8 days after admission with a complete recovery of the clinical signs.

Relevance and novel information To the authors’ knowledge, this is the first report to describe a case of metaldehyde toxicosis in a cat treated with intensive supportive care and an additional low-dose CRI of ILE.

Case summary A 3-year-old male neutered domestic shorthair cat presented for further investigation of a swollen left eyelid and a hard, non-painful bony swelling over the left frontal sinus. Physical examination revealed no nasal discharge or airflow through the left nostril. A CT of the head revealed a left frontal sinus obstruction with expansile remodelling and osteolucency. Drainage of the frontal sinus obstruction was alleviated via placement of a temporary polyvinylchloride (PVC) stent that was left in place for 6 weeks. Purulent material removed from the frontal sinus returned a positive culture for Pseudomonas aeruginosa susceptible to marbofloxacin that was continued for 4 weeks, and for an additional 2 weeks after stent removal. A left-sided mucoid nasal discharge returned 3 months after removal of the stent. Repeat CT performed 20 months after surgery found the presence of a gas-filled frontal sinus and partial resolution in the amount of fluid within the mid and rostral nasal cavity. A repeat positive culture for P aeruginosa was also obtained. The exact cause of the chronic unilateral sinonasal obstruction remains unclear, but an underlying chronic rhinitis with secondary obstructive frontal sinusitis or sinus mucocoele with secondary nasal extension was suspected.

Relevance and novel information Chronic rhinosinusitis in cats can be a challenging condition to treat and cure. This case illustrates the partial resolution of chronic unilateral sinonasal obstructive disease in a cat using a temporary PVC stent.

Case summary A 10-year-old Maine Coon cat was presented for acute onset seizures and cerebrothalamic signs. An intracranial mass, suspected to be a meningioma, was diagnosed on MRI and surgically excised. Histopathology appeared consistent with an atypical meningioma. However, following rapid regrowth of the neoplasm, the patient was humanely euthanized 3 months later. On post-mortem histopathology, the neoplasm was diagnosed as a grade III anaplastic gemistocytic astrocytoma.

Relevance and novel information Gemistocytic astrocytomas are rare brain tumors in the feline patient. This case represents the first report of a feline grade III anaplastic gemistocytic astrocytoma in the cerebrum of a cat with surgical excision and recurrence. The challenging nature of ante-mortem diagnosis and the guarded prognosis, despite surgical intervention, are presented in this report.

Case summary A 3-month-old entire female British Shorthair cat presented for further management of thermal burns after falling into a bath of scalding water. On presentation to the primary care clinician the kitten was obtunded, markedly painful and relatively bradycardic, consistent with a state of shock. The haircoat was wet, with erythematous skin and sloughing from the digital pads and anal mucosa. The primary care clinician administered opioid analgesia, sedation, antibiotics and started intravenous (IV) fluid therapy prior to referral. On arrival to the referral hospital the kitten was obtunded with respiratory and cardiovascular stability but was overtly painful and resistant to handling. The kitten required intensive management with IV and regional analgesia, IV broad-spectrum antibiosis, IV fluid therapy, enteral nutrition and wound management, including surgical debridement and topical antibiotic therapy. Septicaemia developed during the hospitalisation. Multidrug-resistant Escherichia coli and Pseudomonas aeruginosa were cultured, and antibiosis was escalated to IV imipenem. Acute respiratory distress syndrome was suspected following the development of dyspnoea. Early enteral nutrition within 24 h of admission was initiated using an oesophageal feeding tube and a veterinary therapeutic liquid diet. Over the ensuing 72 h the kitten started voluntary intake of food alongside oesophageal tube feeds. The kitten experienced continued weight loss despite the provision of nutritional support to meet, and then later exceed, the estimated resting energy requirements. Caloric intake was gradually increased to a total of 438% of the calculated resting energy requirement using the most recent daily body weight, eventually resulting in stabilisation of weight loss and weight gain.

Relevance and novel information There is limited published information on the nutritional management of veterinary patients with thermal burn injury. Hypermetabolic states related to burn injuries are induced and maintained by complex interactions of catecholamines, stress hormones and inflammatory cytokines on proteolysis, lipolysis and glycogenolysis. Secondary infections are common following burn injury and the subsequent proinflammatory state perpetuates hypermetabolism and catabolism. These states present a challenge in both predicting and providing adequate nutrition, particularly in a paediatric septic patient. This subset of patients should be monitored closely during hospitalisation to ensure body weight and condition are maintained (while taking into consideration hydration status), and caloric intake is adjusted accordingly to meet nutritional support goals. Extensive research exists regarding the nutritional requirements and metabolic derangements of people with thermal burns. However, the importance of maintaining body weight and body condition in veterinary burn patients, and the association between nutritional support and reduced morbidity and mortality, has not been investigated and remains to be elucidated.

Case summary A 1-year-old neutered male domestic shorthair cat was presented for polyuria and polydipsia which had progressed since adoption, 7 months previously. On admission, clinical examination did not reveal any remarkable features. Urinalysis showed marked hyposthenuria and calculated plasma osmolality was high, suggesting diabetes insipidus. A positive response to desmopressin administration appeared to confirm pituitary dysfunction. Brain MRI revealed a lesion compatible with a cyst or a neoplasm compressing the pituitary gland. A follow-up MRI performed 9 months later showed that the lesion was stable, which at first argued in favour of a congenital pituitary cyst. Intranasal administration of desmopressin was then used to achieve a long-term clinical response.

Relevance and novel information Central diabetes insipidus (CDI) is a rare cause of polyuria and polydipsia in cats, resulting from inadequate or impaired secretion of antidiuretic hormone from the posterior pituitary gland. Recognised causes include head trauma, central nervous system (CNS) neoplasia, idiopathic CDI and congenital pituitary cysts. Apart from one cat with CNS lymphoma, the few previously reported feline cases have described CDI in young cats with a previous history of trauma, but brain imaging has rarely been performed to look for underlying anatomical abnormalities. This report describes the first case of CDI in a cat with a confirmed congenital pituitary cyst and, as in previous cases, demonstrates successful treatment with desmopressin.