Case summary This report describes a cat with initial respiratory signs prior to developing fulminant feline infectious peritonitis (FIP) after adoption from an animal shelter. Histologic examination of the tissues revealed typical lesions associated with FIP in the lung, liver, large intestine and small intestine. Histologic examination of the nasal cavity revealed pyogranulomatous rhinitis. Immunohistochemistry with monoclonal antibody FIPV3-70 targeting FIP antigen in macrophages confirmed FIP and molecular analysis identified a spike protein mutation (R793S) consistent with the presence of an FIP virus. Pathological changes, immunolabeling and molecular analysis provide evidence that respiratory infection by feline coronavirus is part of the spectrum of FIP-associated disease.

Relevance and novel information This report highlights nasal pathology associated with FIP through a combination of histopathology, immunohistochemistry and molecular characterization of the virus. Our work supports a little-appreciated role of the respiratory tract in FIP.

Case summary A 1.5-year-old male neutered Persian cat was referred for acute deterioration of chronic left head tilt and ataxia. A lateral intraventricular cystic lesion, closely associated with the left choroid plexus, was identified on MRI. The intralesional signal intensity and cytological analysis of the fluid revealed a liquid similar to cerebrospinal fluid. After trepanation, an endoscopic-assisted fenestration and aspiration of the cyst were performed to temporally relieve the high intracranial pressure while waiting for surgical cystoperitoneal shunt placement. Three weeks after surgery, clinical relapse and recurrence of the lesion were noted on the pre-cystoperitoneal shunting MRI. During anaesthesia, the cat arrested. Cardiac resuscitation was successfully performed and cystoperitoneal shunting was postponed. Global brain ischaemia was then suspected, based on major forebrain clinical signs and MRI abnormalities. During a 6-month recovery period, a further three fine-needle CT-guided aspirations of the lesion were required, owing to clinical recurrence and increased cyst size. Cystoperitoneal shunting was eventually performed, allowing persistent reduction of the lesion and long-term improvement of the cat’s neurological status.

Relevance and novel information This is the first report of a symptomatic lateral intraventricular cystic lesion in a cat. A left lateral intraventricular choroid plexus cyst was suspected based on the MRI features. Our case suggests that endoscopic fenestration and CT-guided aspiration are not adequate treatments for long-term management. Cystoperitoneal shunting may be a safe procedure, allowing significant and stable reduction of the cystic lesion, associated with improvement in the cat’s neurological status by preventing high intracranial pressure.

Case summary Primary pancreatic adenocarcinoma is an uncommon neoplasm seen in cats and often has a poor prognosis. We report a case of an 8-year-old male neutered domestic shorthair cat weighing 5.8 kg diagnosed with pancreatic adenocarcinoma treated with surgical resection and toceranib phosphate, which had a progression-free interval of 1148 days and survived for more than 1436 days. The treatment was well tolerated; however, the cat developed generalised coat hypopigmentation.

Relevance and novel information To our knowledge, the cat in our report has the longest progression-free interval and survival time post-surgical resection of pancreatic carcinoma treated with toceranib. Hypopigmentation as a side effect of toceranib has been reported in dogs, but this is the first case reported in cats.

Case summary A 13-year-old female domestic longhair cat was presented for further investigation of chronic sneezing combined with a right-sided nasal discharge. A CT scan of the head revealed a locally invasive, aggressive right nasal mass radiographically consistent with a malignant neoplastic process. Histopathology on rhinoscopically guided biopsies revealed an unusual pathology consistent with fibro-osseous hyperplasia/dysplasia. Surgical treatment via a ventral rhinotomy and curettage was performed, and the diagnosis confirmed by repeat histopathology. The cat’s clinical signs significantly improved postoperatively.

Relevance and novel information This case report describes an unusual feline nasal pathology. To our knowledge, there are no previous reports of a non-neoplastic, non-inflammatory expansile feline nasal tumour. Also described are the CT and histological appearance of the mass, and the difficulties encountered obtaining the definitive diagnosis. Information regarding the prognosis following surgical removal of proliferative fibro-osseous lesions in cats is poor, especially from the nasal cavity where clean margins may well be impossible to obtain. In this case, surgical resection improved clinical signs and the cat remains well at 15 months post-procedure.

Case summary A 4-year-old cat involved in a road traffic accident presented with paraparesis, which was worse on the right-hand side. Neurolocalisation was to the T3–L3 spinal cord segments. Survey radiographs showed rib fractures but no definitive diagnosis for the paraparesis. CT revealed fracture of the dorsal rim and a T9 rib subluxation through the intervertebral foramen at T8–T9. This caused a contusive spinal injury. Treatment consisted of rest and analgesia. The cat recovered well, with the owner reporting no abnormalities 5 months following the injury.

Relevance and novel information Road traffic accidents are a common cause of injury in the cat population, with a significant number having thoracic injuries. These include rib injures such as fractures. This is the first reported case of a traumatic rib subluxation causing a contusive injury in the spinal cord of any species. Previously reported rib subluxations have been seen in humans with spinal deformities. Conservative management in this case was sufficient.

Case summary A 4-month-old male entire domestic shorthair cat presented for sudden onset of right thoracic monoparesis following a fall; within 18 h, the clinical signs progressed to non-ambulatory right hemiplegia with absent sensation in the distal right thoracic limb and left hemiparesis. MRI revealed changes consistent with a C6–C7 acute non-compressive nucleus pulposus extrusion with suspected secondary C5–C7 spinal cord haemorrhage. Rehabilitation exercises were started immediately after the diagnosis of acute spinal cord trauma. Sensation in the right thoracic limb improved and, with the help of a splint applied to that limb, the cat was ambulatory on all four limbs. Unfortunately, clinical signs started to progress over the course of 10 days. The cat developed progressive discomfort on manipulation of the right elbow and carpus, and a hyperflexion of the right carpus. Radiographs revealed no skeletal abnormalities. Muscle contractures were suspected. Under general anaesthesia the triceps and flexor muscles of the carpus and digits were injected with a total of 100 U of botulinum toxin type A (BTX-A). No complications were associated with the procedure and 24 h after the injection the carpal hyperflexion resolved.

Relevance and novel information The use of BTX-A to treat muscle contractures in human medicine is an established and increasingly used technique. For example, in subacute stroke patients with a non-functional arm, BTX-A forearm injection appears to prevent disabling finger stiffness, likely by minimising the development of contractures. Here, we demonstrate that intramuscular BTX-A is an effective treatment for acquired muscle contractures in a cat.

Case summary A 15-year-old male neutered domestic longhair cat was referred for investigation of a pancreatic nodule. Fine-needle aspiration of the nodule was performed on two occasions, 2 weeks apart, and cytology revealed pyogranulomatous inflammation and moderately dysplastic exocrine pancreatic epithelium, suspicious for neoplasia. Thoracic radiographs were unremarkable and a partial pancreatectomy was performed. On histopathology, the nodule was diagnosed as a moderately differentiated pancreatic adenocarcinoma. Two weeks after surgery, a firm subcutaneous nodule was detected on the left ventrolateral abdomen. Cytology of the nodule was suggestive of pancreatic carcinoma and needle tract seeding was suspected. With palliative treatment, the cat lived a further 136 days.

Relevance and novel information To our knowledge, this represents the first report of suspected transabdominal needle tract seeding of pancreatic carcinoma following fine-needle aspiration in veterinary medicine. Veterinarians should consider this when discussing risks of pancreatic fine-needle aspiration with owners and should attempt to minimise the number of needle aspirations where possible.

Case summary A 9-year-old cat was presented with a right globe lesion of 6 months’ duration. A large pink elevated mass covering two-thirds of the right cornea was detected. The corneal mass was surgically removed by superficial keratectomy and diagnosed by histopathology as a squamous cell carcinoma (SCC). The surgical procedure led to a relatively transparent cornea, but recurrence was likely. To avoid relapse, 1 month after surgery three cycles of mitomycin C 0.04% eye drops were applied q8h for 15 days on/15 days off. No local or systemic side effects were seen, and no recurrence was detected after 1 year of follow-up. Topical mitomycin C was successfully used as adjuvant local chemotherapy agent and prevented relapses owing to its cytostatic effect.

Relevance and novel information SCCs are relatively common in feline patients, especially in the non-pigmented extremities of the nose, ears and eyelids, but with the cornea being a rare location. They rarely metastasise and they seldom relapse locally after surgical excision. Surgical-free margins of 2 cm are advisable to prevent relapses. Corneal tumours are rare, as the cornea is avascular; corneal transparency is essential to assure clear vision. In corneal SCC this margin is impossible to achieve without enucleation. In the present report, surgical removal of the neoplasm was combined with topical administration of the anticancer drug mitomycin C and a good prognosis was obtained. This combined treatment may be an appropriate therapeutic option for feline corneal SCC.

Case summary A 3-year-old neutered male domestic shorthair cat developed pancytopenia 6 months after starting phenobarbital for treatment of recurrent seizures. The cat was switched from phenobarbital to levetiracetam and complete resolution of the pancytopenia was documented within 10 weeks, consistent with phenobarbital-induced pancytopenia.

Relevance and novel information While phenobarbital is frequently used as the first-line treatment for seizures in cats, phenobarbital-induced feline pancytopenia has not been documented in the veterinary literature before. Based on this case, regular monitoring of the complete blood count in cats receiving long-term phenobarbital treatment should be considered. In cases of persistent or severe haematological abnormalities, further investigations are required and treatment discontinuation may be needed in the absence of other causes of pancytopenia.

Case summary A 3-year and 8-month-old male entire European domestic shorthair cat was presented with a history of recurrent rectal prolapse, straining and pain when defaecating. Previous non-surgical and surgical treatments had not provided a satisfactory result. Rectal prolapse had recurred within 2 weeks of treatment. Upon clinical examination, an intraluminal mass could be palpated rectally. A CT scan examination revealed the mass was of a cystic nature and the cyst was surgically excised via a transanal approach. On histological evaluation, the cyst walls consisted of three of the layers of normal rectum: mucosa, muscularis of the mucosa and submucosa. These findings led to the definite diagnosis of rectal duplication.

Relevance and novel information Enteric duplication is among the differential diagnoses for straining and rectal prolapse in cats. This condition has previously been discussed in the veterinary literature, with a single case report describing a rectal duplication in a cat. In that particular case, the authors described a perineal surgical approach. Here we present a novel approach whereby the duplicated material was excised transanally in order to limit intra- and postoperative morbidity. The clinical outcome was excellent in our case, with complete resolution of clinical signs and no recurrence 18 months after surgery.

Case summary A 9-year-old male neutered Maine Coon cat presented with a 6-month history of polyphagia and one recent episode of tremors and weakness. Blood work revealed profound hypoglycemia and results of a paired insulin glucose test were consistent with an insulinoma. Abdominal ultrasound revealed a solitary pancreatic mass, and results of a fine-needle aspirate (FNA) gave further support for the location of the neuroendocrine tumor. After unsuccessful medical management of the hypoglycemia, the mass was surgically removed. Immunohistochemistry confirmed that it was an insulinoma. At the time of writing, the patient had been in clinical remission for 9 months.

Relevance and novel information Feline insulinomas are rare and there is very little information on their behavior, clinical course and histologic characteristics. This is the first reported case of an insulinoma in a Maine Coon cat and the first to describe results of an ultrasound-guided FNA of the mass. In addition, the progression of disease, histopathology and immunohistochemistry results add to the currently minimal database for feline insulinomas.

Case summary An 11-year-old spayed female cat presented with a 6-month history of a progressive nodular skin disease with concurrent, ocular lesions, intermittent vomiting, halitosis and weight loss. The cat had received different topical treatments without success prior to referral to the Dermatology Department of Faculty of Veterinary Medicine, Ghent University. Several fine-needle aspirations of the lesions showed a vast number of macrophages with intra-cytoplasmic inclusions compatible with Cryptococcus species. Histopathological examination revealed pyogranulomatous inflammation with capsulated yeast. Periodic acid–Schiff stain was positive. Latex cryptococcal antigen agglutination test on serum was positive with a titre of >1/524,288. PCR and fungal culture identified Cryptococcus neoformans. The cat was treated with itraconazole 10 mg/kg PO q24h. After 10 months of therapy, there was a complete resolution of the lesions except for a small nodule on the ventral aspect of the tongue.

Relevance and novel information As far as we are aware, this is the first feline case reported of cutaneous nodular cryptococcosis without nasal involvement in Belgium. Oral itraconazole therapy was well tolerated and appeared to give a good result and prognosis.

Case summary A 5-year-old domestic shorthair neutered female cat was presented for a wound in the region of the subcutaneous ureteral bypass shunting port with externalisation of the device, 2 years after its initial positioning. The cat had had positive urine bacterial cultures over the previous year and a half without any clinical signs of urinary tract infection. Bacterial cultures of urine and the wound revealed the same bacteria, suggesting a complication caused by infected urine from the implanted system. The wound was successfully treated with surgery and at the time of writing, 3 months later, the cat is healthy with no evidence of recurrence.

Relevance and novel information To our knowledge, this is the first report of a subcutaneous ureteral bypass shunting port extrusion as a long-term major complication of the bacterial infection of the device.

Case summary A 15-week-old kitten presented with a 1-month history of intermittent generalised tremors and abdominal distension. Hypocalcaemia associated with increased 1,25-vitamin D₃ was consistent with vitamin D₃-dependent rickets type II. The bone appearance on CT scan was most consistent with the changes typically seen with nutritional secondary hyperparathyroidism and less typical of the changes seen with rickets. Our patient had a positive response to high vitamin D₃ therapy as it remained normocalcaemic 16 months after diagnosis, supporting the diagnosis of rickets.

Relevance and novel information This case report is an unusual and interesting presentation of rickets in a kitten. Despite the characteristic vitamin D₃ disturbance for rickets type II, the atypical radiographic changes have not been previously reported. In the literature, a positive response to treatment is not commonly seen or follow-up is short. Our case responded well to treatment and was followed for 16 months from the time of diagnosis. This emphasises that the pathophysiology of the condition is not well understood, and that different types of vitamin D₃-dependent rickets type II may exist. Although the genetic defects responsible for some cases of rickets type I have been identified, this has still not been determined for rickets type II.

Case summary The present study describes the case of a feline meningioma that was detected using 5-aminolaevulinic acid hydrochloride (5-ALA)-induced protoporphyrin IX (PpIX) fluorescence at surgery. An extra-axial mass in the temporoparietal region was observed by MRI. Following craniectomy and durotomy, photodynamic detection (PDD) was performed for detection of the tumour. Intratumour PpIX was detected using fluorescence spectrum evaluation and high-performance liquid chromatography. PDD revealed bright fluorescence of PpIX induced by 5-ALA, facilitating fluorescence-guided resection of the tumour tissue. Postoperative examination demonstrated an intratumour PpIX protein concentration of 16.8 nmol/g, and based on histopathological findings we diagnosed the mass as meningioma.

Relevance and novel information PDD using 5-ALA has been used to identify the surgical margins during resection of primary human brain tumours. Recently, we have reported post-mortem PDD using 5-ALA for a canine glioblastoma. To our knowledge, this technique has not been previously used for the detection and resection of feline brain tumours. Our findings suggest that PDD using 5-ALA is useful for intraoperative fluorescence-guided resection of malignant meningioma in cats.

Case summary A castrated male domestic shorthair cat from a wooded area in Missouri had recovered from typical severe cytauxzoonosis at 4 years of age, after intensive in-hospital supportive care and administration of atovaquone and azithromycin. At 11 years of age, the same cat again experienced an acute febrile illness compatible with cytauxzoonosis. Intraerythrocytic piroplasms typical of Cytauxzoon felis were identified by cytology. The owners opted for euthanasia but allowed collection of splenic and hepatic tissue for histopathologic examination. Schizont-laden macrophages were identified in both tissue specimens, confirming active cytauxzoonosis at the time of the cat’s death.

Relevance and novel information Although cats that have recovered from cytauxzoonosis can harbor red blood cell piroplasms for many years without apparent clinical illness, repeat illness owing to either disease recrudescence or repeat infection has never been documented. In fact, recovered cats have been thought to be resistant to reinfection and subsequent illness. This report describes a cat that had recovered from documented cytauxzoonosis 7 years previously and then developed a subsequent clinical illness typical of cytauxzoonosis, which was accompanied not only by intraerythrocytic piroplasms, but also by schizont-laden tissue macrophages pathognomonic of clinical cytauxzoonosis.

Case summary A 2-year-old female neutered domestic shorthair cat presented with an 18-month history of intermittent lameness on all four limbs. The cat was markedly lame on all four limbs. There was alternation between toe-walking on the forelimbs with a hunched posture and using the dorsal aspect of the carpi to walk on. The cat would hiss repeatedly when walking and would lie down tentatively, appearing happier and less painful when lying. When not lying, the cat preferred to sit back on the hindlimbs and non-weightbear on the forelimbs (the so-called kangaroo stance). Physical examination detected pain on palpation of the calcaneus bone and Achilles tendon bilaterally, and general resentment to handling. Investigations revealed an elevated creatine kinase, a positive Toxoplasma gondii IgG titre, toxic neutrophilic inflammation within the Achilles tendon bursae, electromyography and nerve conduction velocity studies consistent with a diffuse muscular disease, and histopathology of the muscle consistent with a chronic and diffuse myopathy. Arthrocentesis samples and an antinuclear antibodies titre were normal. Prior treatment with meloxicam had been ineffective. A 6-week course of clindamycin was prescribed; an improvement was seen within 3 days and clinical resolution at 3 months. The cat remained clinically normal after 20 months.

Relevance and novel information To our knowledge, there have been no previously published reports of histopathologically confirmed myopathy as a result of T gondii in cats. This report suggests toxoplasmosis should be considered as a differential diagnosis in cats with myopathies or lameness in the absence of other causes.

Case summary A case of nasal adenocarcinoma as a suspected secondary malignant neoplasm following definitive radiation therapy and multiagent chemotherapy for nasal lymphoma is described. An 11-year-old spayed female domestic shorthair cat was presented for a 3-week history of progressive facial swelling located over the nasal planum and extending to the medial canthus of the right eye. The cat was previously diagnosed with nasal lymphoma and treated with chemotherapy and definitive radiation 2.5 years prior. Although a definitive diagnosis could not be obtained via cytology, recurrent lymphoma was suspected based on the cat’s history and recurrent clinical signs. A lymphoma-directed chemotherapy protocol was attempted, but no clinical response was achieved. The cat was euthanased owing to progressive clinical signs and a diagnosis of nasal adenocarcinoma was made on necropsy examination. Both the original diagnosis of nasal lymphoma and the secondary diagnosis of nasal adenocarcinoma were confirmed with immunohistochemistry.

Relevance and novel information Secondary malignant neoplasm following radiation therapy is infrequently reported in the veterinary literature. In the few reports that exist, most have described sarcoma development in the dog following radiation therapy. In the present report, we describe a cat with a suspected radiation-induced nasal adenocarcinoma that developed 2.5 years after definitive radiation treatment for nasal lymphoma.

Case summary A 9-year-old neutered male domestic shorthair cat was referred for assessment of a chronic non-weightbearing left forelimb lameness that had an acute onset following a suspected cat bite to the distal limb 4 weeks previously. There was minimal improvement following conservative management. On examination there was discomfort on palpation of the left palmar metacarpal region. An orthopaedic examination performed under sedation identified a moderate effusion of the left fourth metacarpophalangeal joint. A CT scan was performed, which identified fragmentation of the medial palmar sesamoid of the fourth digit (sesamoid V). Arthrocentesis of the fourth metacarpophalangeal joint identified septic inflammation. Surgical removal of the fragmented palmar sesamoid was performed and was submitted for histopathology and bacteriology analysis. Postoperative CT confirmed the removal of all fragments. Pasteurella species were isolated from the sesamoid fragments. Histopathology revealed osteomyelitis, neutrophilic inflammation and multifocal necrosis, with evidence of fibrosis present. The cat was re-examined 3 months postoperatively, at which point there was no evidence of lameness and orthopaedic examination of the limb was unremarkable.

Relevance and novel information To our knowledge, this is the first reported case of fragmentation of a palmar sesamoid in a cat. This case study describes the diagnosis and the successful management of a cat with fragmentation of a palmar sesamoid, following an altercation with another cat.

Case summary A 17-year-old neutered male European Shorthair cat was presented owing to an inability to jump and respiratory stridor. The owner did not report any other clinical signs. On physical examination, the main findings were plantigrade stance, broad facial features and inspiratory stridor. Neurological examination revealed posterior paraparesis, hypotonia and right hindlimb muscle atrophy. Laboratory findings were unremarkable and glycaemia was normal. Serum insulin-like growth factor 1 concentration was elevated (>1000 ng/ml). A total body CT scan showed an enlarged pituitary gland, thickening of the nasal turbinates and an L7–S1 right foraminal stenosis. Electrodiagnostic testing confirmed the presence of a neuropathy affecting both sciatic nerves. The cat was treated with gabapentin only and was still alive and euglycaemic 16 months after the diagnosis.

Relevance and novel information This case describes for the first time sciatic neuropathy, an occasional complication of acromegaly in people, as a possible clinical presentation in acromegalic cats without concurrent diabetes mellitus.

Case summary A 12-year-old female neutered indoor–outdoor domestic longhair cat presented with frequent sneezing and a nodular, suppurative lesion on its dorsal nose. Histopathological examination revealed a fungal granuloma. PCR and sequencing of the ribosomal internal transcribed spacers (ITS) regions (ITS-F and ITS-R) confirmed an infection with a Sporothrix species. Further sequencing of the beta-tubulin and calmodulin genes confirmed Sporothrix humicola, which lies within the Sporothrix pallida complex. The cat had concurrent diabetes mellitus, which responded to insulin therapy and diet. Oral itraconazole at 10 mg/kg PO q24h resulted in resolution of the lesions after 12 months. Treatment was well tolerated.

Relevance and novel information This is the first report of sporotrichosis in a cat in the UK and only the fifth worldwide involving the S pallida complex. Clinicians, pathologists and microbiologists need to be aware of the potential of Sporothrix infections in the UK and the ability of S pallida complex to cause opportunistic infections. Molecular techniques can achieve rapid and accurate identification of rare fungal organisms. A precise diagnosis with molecular testing can provide information regarding prognosis, treatment and zoonotic implications.

Case summary A 3-year-old male neutered domestic shorthair cat was presented with a 1-week progressive and rapidly deteriorating history of lethargy and abnormal behaviour. Neurolocalisation indicated multifocal intracranial lesions (right oculomotor nerve, brainstem [obtundation, non-ambulatory tetraparesis, vestibular dysfunction and intermittent decerebrate rigidity] and possibly the thalamus [left-sided pleurothotonus]), or more likely a single brainstem lesion with mass effect. MRI of the brain demonstrated a brainstem abscess causing severe dorsal displacement particularly affecting the pons and the medulla oblongata causing cerebellar vermis herniation through the foramen magnum. CT-guided free-hand technique drainage of the brain abscess was performed and broad spectrum antibiotics were started based on sensitivity results. The cat recovered uneventfully from anaesthesia displaying marked improvement immediately after the procedure. Antibiotics were continued for 8 months; repeat imaging prior to withdrawal found complete resolution of the brainstem abscess.

Relevance and novel information Free-hand CT-guided drainage of a brainstem abscess is not without risk; however, in this case it led to significant clinical improvement and stabilisation likely owing to reduced intracranial pressure. It also provided a diagnostic sample that allowed successful medical treatment planning and outcome. To our knowledge, this is the first report describing the successful management of a brainstem abscess by CT-guided drainage in the veterinary literature. It suggests that stereotactic drainage followed by medical therapy can be considered a successful therapeutic alternative to brain surgery or medical treatment alone, providing an emergency treatment in cases of acute brainstem dysfunction.

Case summary A 6-year-old neutered female European Shorthair cat was referred for chronic, moderately pruritic, alopecic and exfoliative dermatosis that was unresponsive to antiparasitic, antibiotic or steroidal anti-inflammatory drugs. The cat presented with truncular alopecia and numerous whitish adherent scales covering the whole body. Differential diagnoses included sebaceous adenitis, dermatophytosis, demodicosis, exfoliative dermatitis associated or not with thymoma, drug reaction, feline immunodeficiency virus- or feline leukaemia virus-associated dermatoses, epitheliotropic T-cell lymphoma, and Malassezia yeasts and/or bacterial overgrowth. Blood tests were within normal limits and the retrovirus tests were negative. Skin scrapings, fungal culture, coat brushing and skin cytology were negative for parasitic or microbial elements. Radiographs showed no signs of a thymic mass. Histological examination of skin biopsies revealed marked orthokeratotic hyperkeratosis, lymphocytic (CD3⁺) interface dermatitis and mural folliculitis with absence of sebaceous glands and occasional apoptotic cells in different epidermal layers. Clinical and histological findings were consistent with non-thymoma-associated exfoliative dermatitis syndrome. Ciclosporin A (7 mg/kg) was administered once daily. A dramatic improvement was observed after 3 weeks. Ciclosporin A intake was then progressively spaced out as the clinical signs diminished. Skin biopsies revealed resolution of hyperkeratosis, disappearance of the inflammatory infiltrate and recovery of the sebaceous glands.

Relevance and novel information T-cell infiltration with signs of epidermal cytotoxicity, in the absence of infectious agents or neoplastic process, suggests an immune-mediated process, and ciclosporin A, a calcineurin inhibitor, would be the drug of choice. This is the first report showing resolution of both the clinical and histological signs of non-thymoma-associated exfoliative dermatitis.

Case summary A 1-year-old spayed female domestic shorthair cat presented for evaluation of a non-weight bearing right pelvic limb lameness after falling from a 4 m height. On orthopedic examination there was substantial swelling and pain on manipulation of the right pes. Radiographs were obtained under sedation, and these revealed dorsoproximal luxations of the third, fourth and fifth metatarsophalangeal joints, and lateral rotation of the second digit. Closed manual reduction under sedation was unsuccessful and open reduction under general anesthesia was therefore performed. Combined transarticular pinning and external skeletal fixation were performed to maintain reduction of the third and fourth digits. Marked postoperative swelling of the distal pes and internal rotation of the third and fourth digits were noted within 24 h of surgery. Three weeks postoperatively, the cat had a persistent weight bearing right pelvic limb lameness and minor pin tract inflammation. All implants were removed and the limb was splinted for 1 week. Internal rotation and pin tract inflammation had resolved at the time of splint removal, and the lameness resolved within 6 weeks of surgery. The cat was not lame, but radiographs revealed mild-to-moderate degenerative osteoarthrosis when the cat was evaluated 6 months after surgery.

Relevance and novel information There are limited reports describing metatarsophalangeal luxations in cats. Although several surgical techniques have been advocated, specific outcomes in clinical cases have not been reported. This report describes the clinical application and outcome of combined transarticular pinning and external skeletal fixation for the management of multiple metatarsophalangeal luxations in a cat.

Case summary A 5-year-old spayed female domestic shorthair cat was referred for severe anaemia. Findings on initial work-up were consistent with a diagnosis of idiopathic immune-mediated haemolytic anaemia. A combination of prednisolone and mycophenolate mofetil (MMF) was instituted. On revisit approximately 2 months later, red blood cell parameters were normal, but the plasma was described as icteric, prompting further investigation. Concurrent hepatopathy and pancreatitis were diagnosed, suspected as being adverse reactions to MMF, as has been reported with use of the drug in humans. Resolution of serum biochemistry abnormalities took approximately 2 months, following discontinuing MMF. At the time of writing, the cat remained clinically well 1 year after initial presentation.

Relevance and novel information With increasing use of MMF as an immunosuppressive agent in cats, clinicians should be aware of both common and potentially rare adverse effects, such as those described herein. In addition, suitable monitoring tools need to be in place to facilitate early detection and appropriate management.

Case summary A 3-year-old neutered male indoor British Shorthair cat was referred for a 2-week history of intermittent right forelimb lameness. Radiographic examination showed a diaphyseal monostotic, expansile, fusiform, lytic lesion in the right ulna. CT further defined the lesion and also demonstrated ipsilateral pulmonary consolidation. Histology was conclusive of osteomyelitis, and microbiology and fluorescence in situ hybridisation analysis (FISH) were negative on aerobic and anaerobic bacterial culture, as well as fungal culture. Clinical and radiographic improvement was seen after anti-inflammatory treatment and a short initial period of antibiosis.

Relevance and novel information This is an unusual monostotic diaphyseal cortical location for osteomyelitis in cats and, moreover, may represent a rare case of sterile osteomyelitis. To our knowledge, non-traumatic osteomyelitis in this location in cats has not been reported in the veterinary literature.

Case series summary The aim of this case series was to describe the clinical presentation, imaging findings and histopathology of three cats with limited dorsal myeloschisis (LDM). The history, examination and MRI sequences were reviewed in three cases presented to a single referral hospital. The surgery report and histopathology were described in two cases. All cats were young (10 weeks old, 5 months old, 4 years old), presenting with varying degrees of progressive paraparesis. All had a midline skin defect overlying the spinal column that was either sunken or saccular, containing fluid thought to be cerebrospinal fluid. MRI sequences demonstrated tissue extending from the dura through an overlying bifid spinous process and attached to the dermis, with associated spinal cord tethering, atrophy and syringomyelia. Lesions were located at L2–L3, T8–T9 and L4. Histopathology described a fibroneural stalk with a glio-ependymal lining, surrounded by glial nests and nerve fibres. The youngest and most severely affected was euthanased, while the other two underwent surgery. Both regained independent ambulation with persistent paraparesis; however, one required ongoing management of urinary incontinence.

Relevance and novel information LDM is a primary neural tube defect that may result in neurological deficits, including bladder dysfunction, and is characterised by a fibroneural stalk between the dermis and the spinal cord. Distinct MRI features, such as a visible intrathecal tract, dorsally tethered cord and syringomyelia, help distinguish this condition from the clinically similar dermoid sinus. The presence of progressive neurological signs, with a palpable midline defect overlying the affected spinal cord segment, may raise suspicion for this clinical entity in veterinary patients.