Case series summary Three domestic shorthair cats from California presented to veterinary ophthalmologists with immature cataracts. Other presenting clinical signs included corneal edema, anisocoria, anterior uveitis, elevated intraocular pressure, blepharospasm and/or lethargy. All patients were immunocompromised due to concurrent diseases and/or immunomodulatory drugs. Diagnostics included serial comprehensive ophthalmic examinations with tonometry, ocular ultrasound, electroretinogram and testing for other causes of feline uveitis. Testing for Encephalitozoon cuniculi included serology, histopathology and/or PCR of aqueous humor, lens material or paraffin-embedded whole eye. Treatments included antiparasitic medication, anti-inflammatory medication and supportive care in all three cases. Surgical treatment included enucleation (one case), bilateral phacoemulsification and unilateral intraocular lens placement (one case) and bilateral phacoemulsification with bilateral endolaser ciliary body ablation and bilateral intraocular lens implantation (one case). Both cats for which serologic testing for E cuniculi was performed were positive (1:64–1:4096). In all cats, diagnosis of intraocular E cuniculi was based on at least one of the following: lens histopathology or PCR of aqueous humor, lens material or paraffin-embedded ocular tissue. The clinical visual outcome was best in the patient undergoing phacoemulsification at the earliest stage of the cataract.

Relevance and novel information Encephalitozoon cuniculi should be considered as a differential cause of cataracts and uveitis in cats in California, the rest of the USA and likely worldwide.

Case summary A 7-month-old domestic shorthair cat was presented for evaluation of stunted growth, recurrent hypoglycaemia during the first months of its life and altered mentation. Complete blood count and biochemistry were unremarkable, except for mildly elevated serum creatinine concentration (despite low muscle mass) and concurrent isosthenuria. Hyposomatotropism was diagnosed based on persistent low circulating insulin-like growth factor 1 concentrations and a lack of response of circulating growth hormone (GH) concentration after the administration of GH-releasing hormone. Other endocrinopathies such as hypothyroidism and hypoadrenocorticism were excluded. MRI of the brain revealed a fluid-filled empty sella tursica, consistent with a pituitary cyst and atrophy/hypoplasia of the pituitary. Echocardiography was unremarkable at the time of diagnosis of hyposomatotropism. Three months later, ovariohysterectomy revealed immature ovaries, raising the suspicion of luteinising and follicle-stimulating hormone deficiency. At 1 year of age, the cat developed congestive heart failure secondarily to dilated cardiomyopathy (DCM) with severely reduced left ventricular systolic function and died a few days later. Pathology showed atrophy of the adenohypophysis, epithelial delineation of the pituitary cysts, mild cardiomegaly, multifocal fibrosis of the left ventricle and a mild, multifocal, chronic epicarditis.

Relevance and novel information GH deficiency is a very rare endocrinopathy in cats. This is the first case to describe the development of DCM with concurrent hyposomatotropism, which has previously been reported in human medicine. Other notable abnormalities that could be related to GH deficiency are juvenile self-limiting hypoglycaemia, behavioural changes and possible nephropathy.

Case summary An 11-year-old male neutered domestic shorthair cat was presented with a 4-week history of an intermittent cough and dyspnoea. A pleural effusion was identified, which was confirmed as chyle. Echocardiography and CT revealed a 16 mm mass cranial to the heart, which was invading the cranial vena cava. Because of the location of the mass, it was assumed that chylothorax had developed as a result of direct disruption of the thoracic duct by the tumour or secondarily to central venous hypertension. An exploratory thoracotomy was performed, and the mass, which originated within the wall of the cranial vena cava, was excised with narrow gross margins. Histopathology and immunohistochemistry were consistent with a chemodectoma with residual tumour cells at the surgical margin. Given the residual microscopic disease, adjuvant treatment with toceranib phosphate was initiated. The cat remained well for the duration of treatment and was euthanased 31 months after diagnosis when CT identified recurrent pleural effusion, a heart base mass with cranial vena cava and azygos vein invasion.

Relevance and novel information Chemodectomas are rare in cats, with only 13 cases reported in the literature to date, and all were located in either the aortic or carotid body. The reported survival with partial resection and/or subtotal pericardiectomy was 13–19 months. Treatment of feline chemodectomas with toceranib phosphate has not been previously reported. To our knowledge, this is the first description of the surgical management of a feline vena cava chemodectoma, combined with adjuvant toceranib phosphate, resulting in a prolonged survival.

Case summary A 7-year-old male neutered domestic shorthair cat was presented with a 3-month history of dyspnea when exercising and increased respiratory noise when purring. Initial radiographs identified a suspected laryngeal mass. Point-of-care ultrasound found a fluid-filled structure on the larynx, which was drained percutaneously. The cat initially recovered well but, due to recurrence of clinical signs, a CT scan was performed, which confirmed the presence of a laryngeal cyst that was subsequently surgically resected. Histopathological analysis was consistent with a suspected thyroglossal cyst.

Relevance and novel information This is only the second report of a laryngeal cyst in the cat. While malignant laryngeal disease may be more prevalent in the cat, benign differentials should be considered as treatment could be curative, as was observed in this case.

Case summary An 8.75-year-old male neutered Burmese cat was referred for treatment of pyothorax. The cat was responsive, cardiovascularly stable and tachypnoeic (40 breaths/min) on arrival. Medical management of pyothorax was initiated, bilateral thoracic drains were placed and thoracic lavage using aliquots of saline 0.9% was performed every 4 h. Regional analgesia was provided using 1 mg/kg of intrapleural bupivacaine divided equally between the left and right hemithoraxes every 6 h. On the second day of hospitalisation, the cat developed hypersalivation, mydriasis and tonic–clonic seizure activity 25 mins after accidental intrapleural administration of a 10 mg/kg bupivacaine overdose. Cardiovascular compromise was also noted; the cat became bradycardic (120 beats/min) and blood pressure decreased to 110 mmHg. Clinical signs resolved after administration of intravenous lipid emulsion (ILE) as an intravenous (IV) bolus (1.5 ml/kg over 5 mins), followed by a continuous rate infusion (0.25 ml/kg/min over 25 mins). Local anaesthetic intrapleural anaesthesia was discontinued. There was recrudescence of clinical signs 10 h post-overdose and repeat ILE 20% infusion was required. The cat was discharged with no ongoing complications.

Relevance and novel information Treatment of IV local anaesthetic systemic toxicity with ILE has been reported in cats. To our knowledge, this is the first reported case of intrapleural bupivacaine overdose with initial response and resolution of clinical signs followed by recrudescence and subsequent successful treatment using ILE.

Case summary A 7-year-old female neutered domestic shorthair cat was presented with weight loss, abdominal distension, lethargy, pyrexia and hyporexia. Haematology and biochemistry were unremarkable. Abdominal ultrasound revealed a cystic mass within the left cranial abdominal quadrant, adjacent to the pancreas, stomach and spleen. CT revealed a 10.5 cm, rounded, well-encapsulated, hypodense mass arising from the left pancreatic lobe. The remaining organs of the abdominal and thoracic cavity were unremarkable. A partial left lobe pancreatectomy and splenic lymph node removal were performed. Histopathology of the pancreatic mass reported a proliferating population of neoplastic spindle cells most consistent with a preliminary diagnosis of soft tissue sarcoma. Immunohistochemistry characteristics, together with the morphological findings, were consistent with a diagnosis of leiomyosarcoma. The patient recovered without any concerns after receiving routine postoperative care. Clinical examination and abdominal ultrasound 5 months postoperatively revealed no abnormalities.

Relevance and novel information To our knowledge, this is the first report of pancreatic leiomyosarcoma in a cat. Pancreatic leiomyosarcoma should be considered as one of the possible differential diagnoses for cats presenting with a pancreatic mass.

Case summary A 6-week-old entire female domestic shorthair cat was presented for evaluation of a soft bulge and a palpable skull defect on the forehead, present since adoption a few days earlier. The neurological examination revealed an absent menace response bilaterally and apparent blindness, localising the lesion to the occipital cortex. The main differential diagnoses were meningocoele (MC) and meningoencephalocoele (MEC). Surgical repair was proposed once the cat reached adult size. Meanwhile, the cat developed seizures and was treated with anticonvulsant therapy. At 6 months of age, CT confirmed a frontoparietal MEC with associated porencephaly. Based on a three-dimensional printed skull mould, a polysulfone implant was created. The meninges were dissected from the skin, a durectomy was performed and samples of the protruding brain were obtained. Part of the cerebrospinal fluid was drained until the size of the protruding brain decreased enough to be included below the implant that was anchored on top of the skull with cerclages. Histopathology confirmed the diagnosis of MEC. Three years and 7 months later, the cat had partially recovered vision but continued to seize monthly despite antiepileptic drugs.

Relevance and novel information MC/MEC is a relatively uncommon disease reported in companion animals, and only four cases of surgical management have been described, and did not use a polysulfone tailor-made implant. In human medicine, surgical intervention is the treatment of choice. This case highlights a new implant option for surgical correction of MEC with good long-term result and no complications after 3 years and 7 months.

Case summary A 7-month-old intact female Maine Coon presented with a 2-week history of vomiting. A peritoneopericardial diaphragmatic hernia (PPDH) and a mass arising from the cardia, protruding into the gastric lumen, were diagnosed using a combination of ultrasound and CT. An exploratory gastrotomy revealed a circumferential, irregular, ulcerated mass involving the submucosal layer of the cardia. This mass was excised by partial-thickness resection of the gastro-oesophageal wall. The PPDH was corrected and a gastrostomy feeding tube was placed under the same anaesthetic. Histopathologically, the most characteristic feature of this mass was a submucosal fibroplasia associated with marked ulceration and granulation tissue. No infectious or neoplastic cells were identified. The affected region of the gastric wall appeared narrowly excised. Resolution of clinical signs was achieved until the cat was lost to follow-up 12 months postoperatively.

Relevance and novel information This is the first report of the surgical management of an oesophagogastric mass in a cat with a concurrent PPDH and no other underlying disease. A benign fibrous mass should be considered as a differential diagnosis of an oesophagogastric mass in feline patients with PPDH. While medical and surgical options are debated for the management of PPDH, symptomatic patients with a concurrent oesophagogastric mass are legitimate candidates for surgical herniorrhaphy to prevent further complications. Based on this case, prognosis can be considered good if surgical resection is complete.

Case summary A 7-month-old female neutered Bengal cat was referred to the Queen Mother Hospital for Animals following unknown trauma. Clinical and radiographic examination revealed a grade IIIB open, comminuted, mid-diaphyseal fracture of the left tibia and fibula, and grade IIIB open mid-diaphyseal fractures of the left metatarsals II–V. The fractures were stabilised with tibial and metatarsal external skeletal fixators. The open wounds were initially debrided surgically using conventional dressings, resulting in a small amount of circumferential granulation tissue formation by 10 days postoperatively. Following this 10-day period of conventional wound management, negative pressure wound therapy (NPWT) was applied over the external skeletal fixators and wounds. After 8 days of NPWT complete granulation tissue coverage was achieved in the tibial wound, and only small areas of two metatarsals remained exposed. The tibial wound was left to heal by second intention; a free meshed skin graft was applied to the pedal wound. Twenty weeks postoperatively, all wounds had completely healed and revision surgery with internal fixation was performed to treat a non-union of the tibia. Thirty weeks after the initial surgery, radiographic union of the tibia and metatarsals II–IV was confirmed.

Relevance and novel information This is the first report of NPWT application over external fixation for the management of wounds associated with open fractures in veterinary medicine. This case was presented to introduce a novel, well-tolerated and simple technique for the management of tissue loss over an open fracture immobilised with external fixation.

Case summary A 9-year-old spayed female domestic shorthair cat was presented to a referral hospital for management of recurring non-healing ulcerations and a subcutaneous mass on the ventral abdomen. Prior treatment included antibiotics (cefovecin followed by clindamycin), wound cleaning and surgical debulking, but the ulcerations and mass recurred 1 month after surgical removal. At this point, the cat was started on doxycycline and pradofloxacin and referred for further work-up. The culture of skin biopsy specimens obtained at the time of referral revealed a population of bacterial colonies with two distinctly different phenotypes. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene sequencing identified both colonies as Mycobacterium goodii. A diagnosis of a cutaneous infection of rapidly growing mycobacteria was made, and treatment with oral pradofloxacin and doxycycline was initiated. The ulcerations resolved within 4 months, and the subcutaneous mass gradually decreased in size until it was no longer palpable, even 4 months after the cessation of antibiotics.

Relevance and novel information This is the second reported feline cutaneous M goodii infection in North America. The organism was not visualized on histopathology but was successfully cultured from tissue obtained by skin punch biopsy. A phenotypic switching phenomenon affecting the susceptibility results was suspected, possibly explaining the presence of phenotypically different but genetically identical strains. This case highlights the importance of submitting aseptically obtained tissue, fluid or fine-needle aspirates for culture and species identification, as well as histopathology, when infection with higher bacteria, such as rapidly growing mycobacteria, is suspected.

Case summary A 9-month-old male neutered domestic shorthair cat presented 2 weeks after castration with a 48 h history of acute-onset lateral recumbency and severe hindlimb rigidity. Physical examination findings included hyperthermia, tachypnoea, hindlimb rigidity and a healed orchidectomy site. Neurological examination of the head and forelimbs was normal; however, there was a spastic, non-ambulatory paraparesis of the hindlimbs, which was more severe on the left. Abnormal findings included mildly elevated serum creatine kinase levels and on electromyography there was bilateral pathological spontaneous activity of the biceps femoris muscles. A tentative diagnosis of tetanus was made based on clinical presentation. Treatment was initiated with tetanus antitoxin, diazepam, metronidazole, buprenorphine and physiotherapy of the hindlimbs. There was an improvement over the following 20 days. Twenty-five days later the cat presented with acute, painful, non-weightbearing lameness of the left hindlimb. Physical examination was suggestive of craniodorsal coxofemoral joint luxation, which was confirmed radiographically. This was treated with analgesia and rest. A marked clinical improvement was observed at the 3-month follow-up.

Relevance and novel information To our knowledge, there have been no previously published reports of spontaneous coxofemoral joint luxation as a complication of hindlimb localised tetanus infection in cats. This report suggests that coxofemoral luxation should be considered as a possible complication in young cats with hindlimb localised tetanus.

Case series summary In this report we describe the origin of protein loss and development of acute kidney injury after ibuprofen intoxication in two cats. Two 13-month-old neutered male domestic shorthair siblings were presented with acute kidney injury (AKI) and severe glomerular proteinuria following witnessed ibuprofen intoxication 3 days prior. Both cats presented with severe azotaemia (creatinine >900 µmol/l [>10 mg/dl]) and severe proteinuria (urine protein:creatinine [UPC] >20, normal <0.5). Urine protein electrophoresis upon presentation revealed mainly albumin and primary glomerular protein losses. The proteinuria and azotaemia resolved completely within 5 days of hospital treatment (8 days after ingestion). Urine protein electrophoresis, once the azotaemia and proteinuria resolved (UPC 0.11; normal <0.5), had a similar pattern to the one from admission. Both cats made a full recovery with supportive care.

Relevance and novel information This is the first clinical report of AKI with nephrotic-range protein losses following ibuprofen intoxication in cats. We propose that this finding is due to idiosyncratic glomerular injury, as described in humans.

Case series summary Three cats affected by unilateral temporomandibular joint ankylosis underwent segmental mandibulectomy, while one cat with bilateral ankylosis underwent right temporomandibular joint gap arthroplasty and left segmental mandibulectomy. Minimal intraoperative complications were linked to the segmental mandibulectomies in the cases reported. All cats recovered their ability to open the mouth, and the vertical range of motion was unaltered during the postoperative period. Mandibular drift and dental malocclusion were the main postoperative complications related to the segmental mandibulectomies.

Relevance and novel information Surgical excision of ankylotic tissue at the temporomandibular joint region may be technically challenging and associated with severe iatrogenic trauma of surrounding tissues. The results of this case series suggest that middle or caudal segmental mandibulectomy is a safe, feasible and effective surgical procedure to treat unilateral temporomandibular ankylosis in cats and could be considered as an alternative surgical technique to surgical excision of ankylotic tissue at the temporomandibular joint.

Case summary An indoor-only 6-year-old spayed female domestic cat was evaluated for a history of stertorous respiration. Skull radiographs revealed increased soft tissue density within the caudal aspect of the left nasal cavity. CT and rhinoscopy revealed a mass lesion in the choana, plus a smaller lesion, nearly completely occluding flow through the nasal passages. Rhinoscopy was used to collect a biopsy specimen from a fleshy, tan–yellow mass visualized in the caudal nasopharynx. Histopathology was diagnostic for Cryptococcus species infection and systemic antifungal therapy with fluconazole was initiated. Following a series of discordant results, serum samples were submitted to a veterinary diagnostic laboratory that utilized a cryptococcal antigen latex agglutination system with pretreatment of serum with pronase. Twenty-three months after the initial diagnosis, the cat’s serum cryptococcal antigen titer declined to 1:5 and the cat has responded well to continuing treatment.

Relevance and novel information This case illustrates challenges associated with discordant test results for cryptococcal antigen among laboratories. Discordancies may be due to differences in assay design, or the underlying disease state itself, or whether serum is pre-treated with pronase; with some tests relying on the training and experience of the operator if the cryptococcal antigen detection test requires a subjective interpretation. It also resolves some confusion in the literature related to the assay types available and terminology used to describe them, and emphasizes the importance of considering cryptococcosis as an important differential for cats with upper respiratory signs, without nasal discharge, even if the cat is kept exclusively indoors.

Case summary An 18-month-old castrated male domestic shorthair cat was presented with a 2-month history of collapse and severe weakness, particularly affecting the pelvic limbs. A biceps femoris muscle biopsy revealed excessive variability in myofibre size, mild necrosis, minimal centronucleation and scattered 10 µm intracytoplasmic oval inclusions. The inclusions appeared amphophilic with haematoxylin and eosin, blue with Gomori trichrome and unstained with nicotinamide adenine dinucleotide dehydrogenase tetrazolium reductase staining. ATPase staining revealed a normal mosaic pattern and atrophy of both type 1 and 2 myofibres. The pathological diagnosis was a myopathy with inclusions. In contrast to previous feline myofibre inclusions previously reported in the literature, inclusions were not identified after immunohistochemistry using anti-desmin, tubulin, spectrin, laminin, LAMP and LC3 antibodies. After supportive care and corticosteroid treatment, clinical improvement was noted and the cat was discharged 10 days after initial presentation. Clinical and neurological re-examinations were performed at 1, 3, 6 and 9 months after discharge. Owner contact at both 10 and 30 months post-discharge confirmed that persistent muscular weakness was present.

Relevance and novel information This case report describes a novel and slowly progressive feline myopathy associated with oval amphophilic inclusions unreactive to immunostaining, which have not been previously reported in feline myopathies.

Case summary An 8-year-old neutered female domestic shorthair cat was referred with complaints of lethargy, anorexia, fever, tachypnoea and a pulmonary mass on thoracic radiography. Whole-body CT revealed the presence of a nodular lesion in the right caudal lobe of the lung. Fine-needle aspiration of the lung mass yielded purulent fluid and cytology showed a large number of mildly to moderately degenerated neutrophils with numerous cocci and bacilli, leading to the diagnosis of a lung abscess. Empirical administration of doxycycline and orbifloxacin was initiated on the day of referral. Bacterial culture and antibiotic susceptibility tests using the collected fluid sample detected two types of bacteria, which were susceptible to both antibiotics. The clinical signs of the cat improved after the initiation of treatment, and the antibiotics were discontinued 28 days later, after the lung lesions disappeared. No recurrence of lung abscess was observed until 588 days after the discontinuation of treatment.

Relevance and novel information Only one case of a lung abscess has been previously reported in cats. Furthermore, while surgical resection is the most common treatment for lung abscesses in the field of veterinary medicine, this is the first report of successful treatment with antibiotic administration alone.

Case summary A 2-year-old female spayed domestic shorthair cat was presented with a history of collapse, possible hypodipsia/adipsia, severe dehydration and hypernatremia. MRI of the brain revealed a failure of separation of the cerebral hemispheres as characterized by an absence of the rostral part of the corpus callosum, fornix and septum pellucidum and the presence of a single fused lateral ventricle. A diagnosis of hypodipsic/adipsic hypernatremia with lobar holoprosencephaly was made. Dietary management of the cat’s condition was attempted by increasing oral water intake, but the cat’s hypernatremia and azotemia persisted. Plasma arginine vasopressin (AVP) analysis revealed a low concentration of circulating AVP (2.3 pg/ml), prompting therapy with oral desmopressin in addition to the dietary management. This combined therapy decreased water consumption of the cat from 200 ml/day (85 ml/kg/day) to 100 ml/day (30 ml/kg/day), normalized plasma sodium concentration and resolved the azotemia.

Relevance and novel information To our knowledge, this is the second case report of an MRI diagnosis of lobar holoprosencephaly with hypodipsic/adipsic hypernatremia in a cat and the first case report of the successful management of this condition using oral desmopressin. This case report emphasizes that holoprosencephaly should be suspected in cats presented with hypodipsic/adipsic hypernatremia and highlights the utility of MRI in establishing the diagnosis. Measurements of plasma osmolality and AVP concentration corroborate the pathophysiology and support the use of oral desmopressin in addition to dietary management to resolve the hypernatremia.

Case summary A 4-month-old female domestic shorthair kitten was presented for a congenital cleft palate causing nasal discharge and sneezing episodes. CT revealed a palatal bone defect involving 20% of the palatal area. Surgical correction of both the hard and soft palate defects was performed using the overlapping and medially positioned flap techniques, respectively. Complete healing of the wound and full resolution of the clinical signs occurred within a 1-month period. At 2 months postoperatively, two punctiform oronasal fistulae were observed rostrally without associated clinical signs. Control CT, performed 6 months postoperatively, revealed a 50% enlargement of the palatal bone defect. At 12 months postoperatively, the cat was still in good general condition without any clinical signs.

Relevance and novel information To the best of our knowledge, this is the first report to describe the treatment of a congenital cleft palate in a kitten using the overlapping flap technique with a successful medium-term clinical outcome, despite the formation of two oronasal fistulae. This suggests that, as in dogs, full restoration of oronasal compartmentation is not mandatory to achieve functional outcome. The increase of the palatal bone defect over time may play a role in late oronasal fistulae formation and should be considered for surgical planning.

Case summary A 15-week-old male British Shorthair cat was presented for peracute paralysis immediately after microchip implantation. Neurological examination revealed a non-ambulatory tetraparesis and left thoracic limb plegia localised to C1–C5 spinal cord segments. CT of the cervical spine showed a diagonally orientated metallic foreign body (microchip transponder, 10 mm in length) within the vertebral canal at the level of C1–C2, resulting in a penetrating spinal cord injury. Based on concerns about further iatrogenic spinal cord injury through surgery, medical management was chosen. Despite the severe clinical signs, the kitten returned to ambulation within 6 days of the injury, with controlled urination and defecation. Continuous neurological improvement was seen for up to 6 weeks after the injury at which point a mild-to-moderate ambulatory tetraparesis and ataxia remained, with an overall good quality of life. Follow-up CT at the age of 13 months revealed a relative cranial displacement and rotation of the microchip towards the foramen magnum, while the cat’s neurological status was unchanged.

Relevance and novel information This case demonstrated a cervical penetrating spinal cord injury in a growing cat caused by a microchip, which was successfully managed with medical treatment, suggesting that this might be an option for patients at risk of severe surgery-related complications or where owners reject surgery.

Case series summary Gradual attenuation of an extrahepatic portosystemic shunt using cellophane banding was achieved with a laparoscopic technique in two cats. The portosystemic shunts were treated via a right or left lateral laparoscopic approach. Ultrasonography or CT angiography were used to verify the results of surgery. The success of the procedure was confirmed by normalisation of serum bile acid concentrations and clinical signs at the final re-evaluation.

Relevance and novel information The aim of this case series was to determine the feasibility and outcome of laparoscopy for portosystemic shunt attenuation in two cats. Laparoscopic portosystemic shunt attenuation appeared to be a feasible, safe and effective procedure in cats.

Case summary A 10-year-old male neutered domestic shorthair cat from Quilmes (Province of Buenos Aires, Argentina) presented at the Infectious Diseases and Parasitology Unit with a hyperpigmented nodule of 5 cm diameter on the nasal plane with a small ulceration of more than 1 year’s evolution. A scaly and hyperpigmented alopecic lesion of 3 cm in diameter was found on the lower edge of the tail. The patient was under immunosuppressive therapy with corticosteroids for lymphoplasmacytic duodenitis. Samples of the lesion present on the nasal plane were taken under a surgical procedure. In the wet mount preparations, pigmented irregular hyphae were observed. They developed dark colonies when cultured on Sabouraud medium. On micromorphology, structures compatible with Phialophora species were identified. PCR and sequencing of ITS (ITS1-5.8S-ITS2) confirmed Phialophora americana as the etiologic agent. A therapeutic scheme that included a combination of itraconazole oral solution (1.5 mg/kg PO q12h) with terbinafine (30 mg/kg PO q24h) was indicated for a period of 10 months. The patient died of complications resulting from its underlying disease.

Relevance and novel information As far as the authors are aware, this is the first study to report P americana as an etiologic agent of phaeohyphomycosis in cats. In this case study, the species was identified using molecular tests.

Case summary A female neutered domestic longhair cat, aged 1 year and 5 months, presented with lymphadenomegaly and anaemia following therapy with phenobarbital for idiopathic epilepsy. Physical examination revealed pale pink mucous membranes and peripheral lymphadenomegaly. Haematology showed a regenerative anaemia (haematocrit 19.3%, reticulocyte count 118.08 ×10⁹/l), and saline agglutination was positive. Infectious disease screening was negative and lymph node cytology was consistent with reactive lymphoid hyperplasia. A diagnosis of phenobarbital-induced reactive lymphoid hyperplasia and immune-mediated anaemia was suspected. Complete resolution of the lymphadenomegaly and anaemia was documented within 4 weeks of phenobarbital discontinuation.

Relevance and novel informationThere are limited case reports of phenobarbital-induced haematological changes and lymphadenomegaly; however, the combination has not previously been reported in cats and is similar to the rare but significant syndrome in humans known as ‘anticonvulsant hypersensitivity syndrome’. Anticonvulsant hypersensitivities should be considered as a potentially serious, yet reversible, sequela to phenobarbital treatment that may be mistaken for more severe illness such as neoplasia.

Case summary A 5-year-old domestic shorthair cat was evaluated for weight loss and poor coat condition due to an inability to open its mouth (trismus) following head trauma 2 months previously. Contrast CT, electromyography and temporal muscle biopsy identified findings consistent with muscle atrophy, denervation and degeneration. Conservative treatment failed to improve the trismus so a rostral mandibulectomy was performed. Following surgery, the patient resumed normal grooming behaviour and was able to eat soft food unaided. The cat re-presented 5 months postoperatively at which time its body condition had improved; however, episodes of sneezing had been noted. An oronasal fistula was diagnosed and treated successfully with a silicon nasal septum button. Follow-up at 30 months reported an excellent outcome.

Relevance and novel information Management of trismus with rostral mandibulectomy may be associated with a good return to function, including prehension and ingestion of food, and restoration of normal grooming activity. Rostral mandibulectomy could be considered for animals with trismus for other aetiologies such as masticatory myositis where other management options are not available.

Case summary An 11-year-old female domestic shorthair cat was presented with cutaneous mast cell tumours (MCTs) localised at the right temporal region, the left buccal region and on the third digit of the right thoracic limb. Staging was negative and locoregional lymph nodes appeared normal, based on clinical findings. During surgery, real-time indocyanine green (ICG)-based lymphography was performed to detect the cutaneous draining pattern of all the primary MCTs. ICG was injected intracutaneously in four quadrants around each tumour, and a clear lymphogram was visible shortly after injection. Using near-infrared lymphography (NIR-L) for guidance, all lymphadenectomies were performed in 12 mins or less, with a maximal incision length of 3.5 cm. The smallest resected node was 0.9 cm in diameter. All MCTs were classified as low-grade cutaneous MCT. All four ICG-positive lymph nodes were considered premetastatic or metastatic. The only ICG-negative resected node was also negative for tumour cells. No complications related to NIR-L were recorded.

Relevance and novel information This is the first description of NIR-L in a cat with MCT. Application was straightforward and ICG enrichment only occurred in the metastatic nodes, suggesting correct identification of lymphatic draining patterns. Of note, as previously described in dogs, we did detect nodal metastasis, despite low-grade primary tumours. The clinical relevance should be evaluated in future studies.

Case summary A 5-year-old male neutered cat weighing 3.56 kg presented owing to the development of two masses over the dorsal cervical and cranial thoracic areas, as well as weight loss, inappetence and vomiting. Diagnostic tests revealed a grossly lipaemic sample with hypercholesterolaemia (440 mg/dl; reference interval [RI] 90.0–205.0), hypercalcaemia (>16.0 mg/dl [RI 8.0–11.8]) and urine specific gravity 1.022 (RI ⩾1.035). When re-presented 9 months later, fasted blood analyses revealed elevated ionised calcium (1.87 mmol/l [RI 1.11–1.38]), persistently elevated total calcium, normal phosphate and persistent minimally concentrated urine with calcium oxalate dihydrate crystals. Ultrasound-guided fine-needle aspiration of the masses produced blood-tinged purulent fluid with negative culture results. Excisional biopsies of both masses were undertaken, and histopathology was consistent with cutaneous xanthoma. No organisms were identified with special staining, and deep-tissue culture did not grow bacteria or fungi. Postoperatively, repeat fasted biochemical analysis revealed persistent hypercholesterolaemia with normal triglycerides, and normalisation of ionised and total calcium levels. Based on these findings, a diagnosis of cutaneous xanthoma causing hypercalcaemia due to primary dyslipidaemia was made. The cat was reported to be significantly improved in comfort and energy levels postoperatively and a transition to a fat-restricted diet was instituted. Eight months after xanthoma removal no recurrence was reported.

Relevance and novel information To our knowledge, this is the first report of cutaneous xanthoma and associated granulomatous inflammation causing hypercalcaemia due to dyslipidaemia in a cat. Familial hypercholesterolaemia is an example of a primary condition that could cause dyslipidaemia in cats, and further studies are warranted to better describe the genetic characteristics. Xanthoma formation and the resultant granulomatous inflammation should be considered in cases of hypercalcaemia.

Case summary A 7-year-old male domestic shorthair cat was presented with a non-pruritic erythematous crusted nasal hypotrichosis along with bilateral ceruminous otitis externa. The cat was diagnosed with diabetes mellitus and was positive for feline immunodeficiency virus (FIV). Deep skin scraping, trichograms from lesional skin and ear canal parasitological examination were positive for Demodex cati. A 250 mg (55.5 mg/kg) fluralaner spot-on for medium-sized cats (Bravecto; MSD) was applied to the base of the cat’s head. Re-examinations were carried out on the fourth, sixth and eighth weeks after therapy. On the fourth week, the ceruminous otitis had resolved completely and the nasal lesions were markedly improved. One dead adult D cati was found in deep skin scrapings while other tests from the skin and both ear canals were negative. On the second re-examination only a mild hypotrichosis persisted on the nasal region and all parasitological examinations were negative. Eight weeks after the initial examination, the skin lesions had almost clinically resolved. On the 12th week, fluralaner spot-on was repeated. No recurrence was noted at the 6-month follow-up.

Relevance and novel information The use of isoxazolines has been reported for only a few demodectic cats but was described to be safe and effective. This is the first report to evaluate the efficacy of a single spot-on fluralaner for the treatment of localised dermatitis and otodemodicosis due to D cati, and suggests it as an effective, safe and practical treatment.

Case summary A 4-year-old domestic shorthair cat presented to North Downs Specialist Referrals for treatment of a 7 mm melanoma of the nasal planum. Two treatments of electrochemotherapy using intravenous bleomycin as a chemotherapeutic agent were administered. The tumour was no longer visible after treatment. At the 292-day follow-up there was no recurrence at the site and the patient was clinically well.

Relevance and novel information There are few data concerning the outcomes of cats with non-ocular feline melanomas and there are currently minimal descriptions in the literature of electrochemotherapy as a treatment option. The available data suggest that nasal melanoma may have a worse prognosis, and that melanomas are locally invasive and have a high propensity for metastasis. The current most effective means for local control is surgery with wide margins. Given the location in this case, this would have required nasal planectomy, while electrochemotherapy provided an effective and possibly more attractive alternative.

Case summary A 4-year-old castrated male domestic shorthair cat with a continuous cough was brought to a private veterinary clinic for detailed examination. Radiography of the thoracic cavity revealed a severe radiopaque region in the caudal lobe of the right lung. At 108 days after the initial visit, CT showed a mass of 27 × 23 × 18 mm in the caudal lobe of the right lung. At that time, no abnormalities in other organs except for the lung were detected on CT and peripheral blood and blood biochemistry tests. The mass in the caudal lobe of the right lung was resected by lobectomy; it had a white surface and was firm. Histopathologically, the mass was non-encapsulated, showing an unclear boundary with surrounding tissues. The mass comprised large, round or polygonal neoplastic cells arranged in a diffuse pattern. Immunohistochemically, neoplastic cells were diffusely positive for CD20, feline leukaemia virus (FeLV) p27 and FeLV glycoprotein 70 but negative for CD3, CD204 and E-cadherin. Based on these findings, diffuse large B-cell lymphoma associated with FeLV infection was diagnosed. Although the cat showed no clinical signs of gastrointestinal or respiratory injury, a routine ultrasonography revealed thickening in the jejunum wall 196 days after lobectomy, and subsequent fine-needle aspiration examination confirmed high-grade lymphoma.

Relevance and novel information This is the first report of primary pulmonary diffuse large B-cell lymphoma associated with FeLV infection in a young cat.

Case series summary Two Japanese domestic cats with GM2 gangliosidosis variant 0, diagnosed at different times, are included in this case series. Both cats were diagnosed by genetic analysis and had the HEXB:c.667C>T pathogenic genetic variant, which have been previously reported in Japanese domestic cats with GM2 gangliosidosis variant 0. Clinical signs and the identification of vacuolation in circulating lymphocytes were consistent with those in previous reports of feline GM2 gangliosidosis variant 0. Radiography showed that both cases had similar skeletal radiographic manifestations, which has not been previously reported in Japanese domestic cats with GM2 gangliosidosis variant 0. Radiographic findings included abnormally shaped vertebral bodies, obscure or irregular endplates (both of which were seen especially in the cervical and thoracic vertebrae), generalised osteopenia and new bone proliferation around articular facets.

Relevance and novel information To the best of our knowledge, this is the first report to present the skeletal radiographic abnormalities of Japanese domestic cats with GM2 gangliosidosis variant 0 caused by the HEXB:c.667C>T pathogenic genetic variant. Furthermore, together with a report published in 2015 on the radiographic findings of feline GM2 gangliosidosis variant 0 caused by another pathogenic genetic variant, this report suggests that these findings may be indicators of feline GM2 gangliosidosis variant 0. The easily obtained radiographic findings described in this report may be useful as a finding suggestive of feline GM2 gangliosidosis variant 0, in addition to the cytological finding of the vacuolated cells. The report emphasises the utility of radiography for diagnosis of cases with suspected progressive neurodegenerative diseases.

Case series summary This case series describes three shelter-housed cats concurrently diagnosed with feline infectious peritonitis (FIP). The cats were from a cohort of seven surrendered from the site of a house fire. The three cats presented with mild upper respiratory signs. Within 10 days they clinically declined: progressive signs included pyrexia, icterus, lethargy, anorexia and cavitary effusions. Necropsy followed by histopathology and immunohistochemistry confirmed a diagnosis of FIP in all three. Molecular analysis of the causative feline coronavirus (FCoV) revealed varied amino acid alterations in the spike gene both between cats and between sample types in individual cats. A fourth cat from the cohort remained healthy in the shelter but succumbed to FIP 6 weeks post-adoption.

Relevance and novel information This case series places FCoV genetic sequences in the context of clinical signs in a small shelter outbreak. Each of the three cats concurrently developed a slightly different clinical presentation. PCR amplification and genetic sequencing revealed that two cats shared an S1/S2 cleavage site mutation (R790S) previously described to be associated with the development of FIP; one of the cats had an additional S1/S2 cleavage site mutation (R793S). The third cat had a single, identical S1/S2 point mutation (R790G) unique from the other two cats; the R790G mutation has not been previously reported. This case series provides interesting data on point mutations associated with the development of FIP and provides support for a ‘circulating virulent–avirulent theory’ of FIP pathogenesis in a small shelter outbreak.

Objectives This study was aimed at detecting feline autosomal dominant polycystic kidney disease in a population of Persian and Persian-related breeds by a molecular method in Iran.

Methods Buccal swab samples were collected from 47 cats and examined with a touchdown PCR method. Additionally, partial sequencing was performed in two cats with bilateral renal cysts.

Results Twenty-two cats (46.8%) were diagnosed as heterozygous for this mutation. Sequence analysis of two cats showed C to A point mutation in the PKD1 gene, as in previous studies.

Conclusions and relevance Prevalence of this disease is high in Iran, highlighting the need for molecular screening tests before including cats in breeding programmes.