Case summary A 1-year-old domestic shorthair queen with five neonates was referred for umbilical cord entwinement in three kittens 24 h after parturition. The owner noticed the kittens were stuck to each other 3 h before admission. Despite a conservative treatment approach, prolonged ischaemia led to dry gangrenous changes in one of the kitten’s metatarsi.

Relevance and novel information This and other neonatal complications in cats are rarely reported. Primiparity is a known factor contributing to postpartum complications. Furthermore, inexperienced owners require more assistance in mitigating these challenges. Therefore, further research and collaboration among breeders, owners and veterinary professionals are imperative in order to accurately determine the prevalence of this condition in kittens and develop effective strategies to address it.

Case series summary This case report describes the history and presentation of two cats with presumed gabapentin-induced myoclonus. Although this phenomenon is well documented in people, there are no previous reports in cats. Both cats in the current report had International Renal Interest Society (IRIS) stage 2 chronic kidney disease, a history of seizures (one generalized, one focal), and received gabapentin before veterinary hospital visits to alleviate anxiety (doses in the range of 11.8–16.4 mg/kg). While in the hospital, both cats were noted to have intermittent short jerks of the head that were different from the seizure activity previously noted by their owners at home. These cases appear to be the first published reports of this potential adverse effect of gabapentin in cats and risk factors in the present cases mirror those described in people.

Relevance and novel information Clinicians should be aware of the potential for this phenomenon in cats receiving recommended doses of gabapentin, and future studies should focus on the role of chronic kidney disease and other neurologic conditions as risk factors for development of this condition.

Case summary A 2-year-old female intact domestic shorthair cat was referred to the neurology service at the Foster Hospital for Small Animals as a result of lifelong weakness, seizure-like episodes after excitement, muscle spasms, stiffness of the limbs and shortness of breath. A diagnosis of myotonia congenita (MC) was made based on compatible history, clinical signs and electromyography findings, and excluding other causes of muscle weakness using muscle biopsy, baseline bloodwork and echocardiography. Initial treatment with procainamide had overall low efficacy. The cat was then switched to carbamazepine, which provided long-term improvement in clinical signs at a dosage of 7.4 mg/kg PO q12h with no observed clinical side effects.

Relevance and novel information To date, there is only a single case report describing the successful treatment of MC in cats, and no report describing the use of carbamazepine to treat this condition in this species. This anti-convulsant medication was shown to be anecdotally effective in the case reported. Further research is needed to categorize the metabolism, pharmacokinetics, tolerance, dose range and efficacy of carbamazepine in cats with and without MC.

Case summary Acute hepatitis and liver damage are rare adverse effects of clopidogrel in humans. In veterinary medicine, clopidogrel is mainly prescribed in the treatment of feline patients with cardiomyopathies. Little is known regarding the safety and adverse effects of clopidogrel in this group of patients. The limited number of studies scarcely report adverse effects. In this case report, a 6-year-old male castrated crossbred cat with the hypertrophic cardiomyopathy phenotype had signs of acute hepatitis after 5 weeks of clopidogrel treatment.

Relevance and novel information Evaluation of the case and review of the literature indicate that acute hepatitis might be a potential adverse effect of clopidogrel in feline patients. Therefore, hepatotoxicity should be taken into consideration when a feline patient shows clinical deterioration after the use of clopidogrel.

Case series summary Described are three cats diagnosed with rhinosinusitis secondary to Mycobacterium bouchedurhonense, Aspergillus species and Alternaria species, respectively. Medical records were retrospectively reviewed to identify cats with decreased nasal airflow and mucopurulent discharge that failed to improve on antibiotic therapy of 3 months or longer duration. Surgical debridement was followed by nasal packing using 5% povidone-iodine saturated umbilical tape, which was replaced at 24 h postoperatively. At 48 h postoperatively, the rhinotomy site was closed. Systemic therapy continued in the postoperative period. All cases were minimally responsive to previous medical management. History, signalment, clinical signs, diagnostic findings, treatment, and short- and long-term outcomes were retrieved. All cats were middle-aged with outdoor access and had clinical signs that commenced during the summer months. CT revealed turbinate destruction and soft tissue densities within the nasal passages. The otic apparatuses and calvaria were intact in all cats before surgery. A repeat CT examination revealed an improvement of the proliferative tissue identified in preoperative imaging in all cases. All cats achieved successful interruption of nasal discharge and restoration of nasal airflow with follow-up times of up to 16 months postoperatively.

Relevance and novel information To the authors’ knowledge, this is the first report of the use of intranasal povidone-iodine packing in cats for the management of infectious rhinosinusitis. Surgical debridement and intranasal packing in addition to systemic therapy were successful in restoring nasal airflow and resolving nasal discharge in all cats with long-term follow-up.

Case summary An 8-month-old male neutered domestic shorthair cat presented for acute vomiting. Abdominal ultrasound examination revealed a jejunal foreign body, which was removed via enterotomy. Preoperatively, the patient was hypoglycaemic and, intraoperatively, a dopamine infusion was required to maintain a mean arterial pressure >60 mmHg. Despite glucose supplementation, the cat remained severely hypoglycaemic on recovery. Within 24 h postoperatively, despite euglycaemia and normalisation of the cardiovascular status, the patient developed progressive polyuria (up to 14 ml/kg/h). This was associated with neurological signs suggestive of diffuse brain disease, and absence of azotaemia or signs of overhydration. During the first 4 days of hospitalisation, any attempts to decrease intravenous fluid therapy were associated with hypotension, weight loss and clinical dehydration. Urine specific gravity (USG) during this time was in the range of 1.005–1.010 and failed to increase during fluid challenges. A presumptive diagnosis of central diabetes insipidus was made, and desmopressin (1 µg/cat SC) was administered on day 5 of hospitalisation. Consequently, the cat’s urinary output decreased and his weight increased within 4 h. The patient required a total of four doses of desmopressin during hospitalisation, but no further doses since discharge. Urinary output on discharge was 3 ml/kg/h. Three months later, the cat’s neurological signs and polyuria had completely resolved, and the USG was >1.050.

Relevance and novel information In this case, a presumptive diagnosis of central diabetes insipidus was supported by clinical progression, neurological signs and the response to desmopressin. To our knowledge, this is the first report of reversible diabetes insipidus after diffuse brain injury secondary to hypotension and hypoglycaemia.

Case summary A 10-year-old castrated male crossbreed Birman cat was presented for respiratory difficulties, nasal discharge, dysphagia and wheezing. An obstructive nasopharyngeal mass invading the caudoventral nasal cavity and the left sphenoid sinus was observed on a CT scan. Surgical treatment via a ventral rhinotomy and curettage was performed. Histopathology revealed an adenocarcinoma with tubulotrabecular architecture. The cat’s clinical signs significantly improved postoperatively. After 10 months, a recurrence was documented and a second surgical procedure was performed that allowed the patient to live an additional 6 months without clinical signs and an overall survival time of 19 months after first presentation.

Relevance and novel information This case report describes a nasopharyngeal adenocarcinoma treated by ventral rhinotomy in a cat. To our knowledge, there is only one other report describing this surgery on a nasal adenocarcinoma in a cat. The tomodensitometric, endoscopic and unusual histological appearance of the mass are reported. The prognosis after surgical removal of nasal adenocarcinomas in cats is only sparsely documented. This case demonstrates that ventral rhinotomy might be considered if first-line treatment is declined.

Case summary Two 18-day-old domestic shorthair kittens presented with dyspnoea, mild cyanosis, heart murmur, lung pattern, abnormal crawling and a marked dorsoventral flattening of the thorax. Deformity of the thoracic wall without pectus excavatum was diagnosed. Cardboard corsets tailored to each kitten were applied. This gave immediate respiratory relief, easing distress and pain. After 10 days, clinical and radiographic monitoring revealed normalisation of the shape of the chest wall with an improvement in general condition. At 6 months of age, clinical examination showed normal growth and development of both kittens, with a normal thoracic profile and shape also seen on radiographs.

Relevance and novel information Data about flat-chested kitten syndrome and its aetiopathogenesis, treatment and outcome are scarce, but there is significant experience among breeders that is shared through online communities. High mortality rates are reported. The use of a cardboard splint appears to be novel in the published literature; in this case report, it proved to be a rapid and easy solution. For this reason, cardboard splints could be considered as a first approach for the clinical management of flat-chested kitten syndrome.

Case series summary Medical records of two kittens diagnosed with type I phimosis were reviewed. Clinical signs on presentation, investigations, description of the surgical technique, and short- and long-term follow-up were reported. Type I phimosis was diagnosed in both kittens based on the clinical, radiographic and surgical exploration findings. Modified circumferential preputioplasty using 4 and 6 mm Keyes biopsy punches was performed by the same surgeon in each case. The biopsy punch was centred over the existing narrowed preputial orifice and rotated clockwise and anticlockwise to obtain a sharp circumferential cut through the skin and submucosa of predictable diameter. The underlying mucosa was resected with micro curved scissors and mucocutaneous apposition was achieved with simple interrupted sutures placed circumferentially. Minor protrusion of the tip of the penis was recorded in the short-term follow-up (2 weeks) but resolved on the long-term follow-up (10 and 72 months). No evidence of urinary tract infection, strictures or clinical signs associated with phimosis were recorded at long-term follow-up.

Relevance and novel information This short case series describes the surgical correction of type I phimosis by circumferential preputioplasty implemented using a Keyes biopsy punch in two kittens. The technique described in this case series can be considered alongside other reported surgical techniques, and appears to provide a reliable, rapid and accurate removal of preputial skin in the two reported cases.

Case summary Persistent and progressive weakness secondary to hypokalaemia, that is, hypokalaemic polymyopathy, is one of the most common clinical signs of primary hyperaldosteronism (PHA). Herein, we report a case of PHA with infraspinatus muscle necrosis. A 5-year-old castrated male domestic shorthair cat presented with a history of polyuria and polydipsia, decreased activity, staggering gait, difficulty in jumping and inward rotation of both forelimbs. Blood examination revealed hypokalaemia, increased serum creatinine kinase activity and high serum aldosterone concentration. Abdominal ultrasonography and CT revealed an enlarged right adrenal gland. Post-contrast thoracic CT showed peripheral contrast enhancement and a non-enhanced centre in the bilateral infraspinatus muscles. From the day of initial presentation, the cat was started on oral potassium replacement therapy. On day 17, the right adrenal gland was surgically resected and the left infraspinatus muscle was biopsied. Histopathological examination confirmed the presence of an adrenocortical adenoma in the right adrenal gland and necrosis of the muscle fibres in the left infraspinatus muscle. On day 29, all clinical signs had disappeared, and the serum potassium concentration, creatinine kinase activity and aldosterone concentration had normalised. On day 57, atrophy of the bilateral infraspinatus muscles was noted, but there was no evidence of any posture or gait abnormalities.

Relevance and novel information To the authors’ knowledge, this is the first report of possible infraspinatus muscle necrosis in a cat with PHA. It is also possible that the infrinatus muscle necrosis with hypokalaemic polymyopathy secondary to PHA was caused by compartment syndrome in the cat described here.

Case series summary A 12-year-old castrated male domestic shorthair cat was referred for investigation of lethargy, hindlimb weakness with plantigrade stance and ventroflexion of the neck. The cat was fed a balanced diet and had received methylprednisolone acetate at a dose of 20 mg intramuscularly every 6 months for 6 years. On blood work, severe hypokalaemia and marked elevation of muscle enzymes were noticeable. The findings were suggestive of hypokalaemic myopathy. Urine fractional excretion of potassium (FE_k) was moderately high (9.04%), and serum aldosterone was below the reference interval. An adrenocorticotropic hormone (ACTH) stimulation test was compatible with adrenal suppression. Upon hospitalisation, the patient was given intravenous (IV) Ringer lactate solution supplemented with potassium chloride and oral potassium citrate. The serum potassium concentration normalised by the fifth day of hospitalisation; therefore, IV potassium supplementation was suspended. The cat was discharged with oral potassium and the dose was gradually reduced over time. After 4 months, the cat was clinically normal; the serum potassium concentration remained within the normal range and the adrenal glands showed some response to ACTH stimulation. Potassium supplementation was therefore discontinued. One month later, the serum potassium concentration was still within normal limits and at the time of writing (7 months after presentation), no clinical signs had reoccurred.

Relevance and novel information This report describes a case of hypokalaemic myopathy associated with iatrogenic hypercorticism in a cat. This condition was successfully treated with supplementation of potassium and a complete clinical remission was achieved within 4 months.

Case summary An 11-year-old castrated male domestic shorthair cat presented with chronic regurgitation and weight loss. Despite a 2-month history of weight loss, regurgitation intensified over 4 weeks, occurring with every food intake, even on a semi-liquid diet. Physical examination revealed thinness and dehydration, and a focal oval mass was noted in the middle mediastinum on thoracic radiography. Oesophagoscopy identified a 6 cm neoformation almost completely obstructing the oesophageal lumen. Biopsies were taken and histopathology, positivity to melanoma triple cocktail and PNL-2 by immunohistochemistry led to the diagnosis of melanocytic neoplasm. Palliative debulking with argon plasma coagulation (APC) was performed, significantly improving the cat’s quality of life for 2 months. The cat survived for 107 days after diagnosis.

Relevance and novel information This case report describes the first report of melanocytic neoplasia originating from the oesophageal mucosa in a cat. In cats, melanomas outside the eyes are exceedingly rare and oesophageal neoplasms are exceptionally rare in veterinary medicine, particularly melanomas. The diagnosis relied on positive immunohistochemistry markers aligning with previous research. Treatment with APC emerged as a novel, potentially palliative approach, successfully alleviating regurgitation for 3 months. This underscores APC’s potential in feline oesophageal neoplasia palliative care, which deserves further investigation in a broader feline cohort to confirm its efficacy. Overall, this report provides valuable insights into the diagnosis and treatment of oesophageal melanoma in cats.

Case summary A 7-year-old male castrated domestic shorthair cat was presented for treatment of a bilateral sacroiliac luxation (SIL). CT was performed and the data were extracted in a stereolithography (STL) file, after which a 3D-printed drill guide (3DPDG) was devised, using computer-aided design (CAD) software, and printed. Using an open surgical approach, the guide was used as an aid for drilling the sacrum. The ilial wings were drilled free-hand later and a transiliosacral pin (TP) was inserted to realign and stabilise the SIL. The cat exhibited an early return to normal limb function and a CT scan performed at the postoperative follow-up showed early signs of bone remodelling at the sacroiliac joint.

Relevance and novel information To the authors’ knowledge, this is the first report using a 3DPDG for implant placement in the feline sacrum without intraoperative imaging.

Case series summary Two cats were referred to a veterinary teaching hospital with a cotton tip applicator (CTA) tracheobronchial foreign body (FB) after induction of anesthesia for an elective dental cleaning. In both cases, a lidocaine-saturated CTA, utilized to desensitize the larynx before endotracheal (ET) intubation, broke when introduced into the oropharynx and was subsequently aspirated into the tracheobronchial tree. Both CTAs were successfully removed bronchoscopically, and the cats survived with no short- or long-term complications noted.

Relevance and novel information Utilizing a lidocaine-saturated CTA to facilitate ET intubation in cats is not well described, and information on the relative risks and benefits of this specific method for laryngeal desensitization is lacking. This retrospective case series is the first to describe a complication of this technique and successful treatment. These cases highlight the risk inherent to using a CTA to desensitize the feline larynx.

Case summary A 6-year-old female spayed domestic shorthair cat was presented with a 7-month history of a subcutaneous mass on the dorsal nasal surface. A CT examination revealed the presence of a nasal dermoid sinus cyst with a nasal bone defect. The cyst was excised and an autologous fascia lata graft was used for reconstruction. The dorsal nasal bone was reconstituted and no compromise of respiratory function was reported in the long-term outcome. No short-term complications were observed at the 2-week follow-up. No long-term complications or recurrence were observed at the 2- and 12-month follow-ups. Fascia lata grafting appears to be an effective method for repairing a nasal bone defect after surgical excision of a nasal dermoid sinus cyst in cats. It is inexpensive and the tissue is easily harvested and provides good functional and cosmetic results.

Relevance and novel information To the authors’ knowledge, this is the first report that evaluates the effectiveness of repairing a nasal bone defect after dermoid sinus cyst excision in a cat using an autologous fascia lata graft.

Case summary An 8-year-old male neutered domestic shorthair cat was presented with an acute onset of left thoracic limb lameness and a firm swelling on the lateral aspect of the left distal antebrachium. A CT scan of the left thoracic limb revealed an expansile osteolytic cystic bone lesion centred at the distal left ulnar metaphysis. Cytology from fine-needle aspiration was not consistent with neoplasia. The CT features and the cytology results were suggestive of a bone cyst. A distal partial ulnectomy with ulnar styloid process excision was performed as the biopsy method and as the treatment approach. Histopathology results were consistent with an aneurysmal bone cyst (ABC). Carpal instability was not detected after distal partial ulnectomy; therefore, a stabilisation method was not required. Limb function was excellent after surgery, with no lameness and no recurrence detected by the owner at 2, 6 and 24 weeks postoperatively. The veterinary examination at 12 weeks postoperatively confirmed the owner’s outcome assessment.

Relevance and novel information To the authors’ knowledge, this is the first report describing a distal partial ulnectomy with ulnar styloid process excision in a cat. Despite disrupting the short ulnar collateral ligament, this technique provided excellent short-term limb function with no need for carpal joint stabilisation. This technique allowed for the complete excision of a distal ulnar ABC and avoided cyst debridement, which could be associated with haemorrhage, recurrence and malignant transformation. Distal partial ulnectomy should be considered for distal ulnar bone lesions in cats.

Case summary A 6-year-old castrated male domestic shorthair cat was evaluated for recurrent pleural effusion, atrial fibrillation and suspected congestive heart failure. During thoracocentesis, the fenestrated over-the-needle catheter became fractured and a catheter fragment remained in the patient’s left pleural space. Later in the course of treatment, the patient acutely decompensated and was euthanized. There were no immediately observed complications associated with the retained catheter fragment.

Relevance and novel information To the authors’ knowledge, there are no reports of over-the-needle catheter fractures with retained pleural catheter fragments in veterinary medicine. Similar cases in humans have been successfully managed with and without removal of catheter fragments. In veterinary medicine, the decision to attempt removal of a catheter fragment must consider both the likelihood of related morbidity and the patient’s ability to tolerate an invasive procedure.

Case summary A 4-year-old cat was presented with acute onset of lateralised neurological central nervous system (CNS) signs and seizures. Haematological and serum biochemical parameters were within normal limits. Imaging diagnostics revealed severe CT and MRI abnormalities of the right brain, similar to Dyke-Davidoff-Masson syndrome (DDMS) in human medicine. This syndrome includes cerebral hemiatrophy with compensatory calvarial hyperostosis and ventriculomegaly. Such changes have previously been reported only once in a single feline case of approximately the same age. In humans, DDMS is described as an embryonic and perinatal developmental disturbance or an acquired injury in early childhood.

Relevance and novel information This case report shows that without further imaging diagnostics, congenital disorders can be overlooked in some rare cases of adult cats with later onset of their first clinical signs.

Case summary An 11-year-old neutered male Turkish Angora cat was referred for obstructive feline lower urinary tract disease (FLUTD). On physical examination, the penis was curved at the tip and had a smaller than normal urethral opening proximal to the end, consistent with singular glandular hypospadias with a dorsal penile curvature. Because of its recurrent obstructive FLUTD history and inability to catheterise the urethra, a preputial urethrostomy (PRU) was performed. The PRU resolved the clinical signs with no clinical recurrence and no short- or long-term complications.

Relevance and novel information To the authors’ knowledge, this is the first description of singular glandular hypospadias in a cat. In addition, this is the first time feline hypospadias has been reported to occur with obstructive FLUTD and to be treated by preputial urethrostomy.

Case summary A 2-year-old spayed female domestic shorthair cat presented with tetraparesis after being involved in a road traffic accident. Survey spine radiographs revealed a C2–C3 cervical subluxation, which was confirmed by a CT scan. Surgical stabilisation was performed using screws and polymethyl methacrylate (PMMA) via a ventral approach. A postoperative CT scan demonstrated correct implant positioning and good reduction of the subluxation. After surgery, the cat rapidly recovered to a neurologically normal status.

Relevance and novel information Trauma-induced cervical subluxation is an uncommon occurrence in cats but should be considered in the differential diagnosis. This report describes the surgical management of a C2–C3 cervical subluxation in a cat using screws and PMMA. This is the first case report of a surgically treated subaxial cervical subluxation in a cat.

Case summary A 5.5-year-old male neutered domestic shorthair cat was presented with a 2-year history of progressive chronic kidney disease. Abdominal ultrasonography revealed bilateral chronic renal degeneration, nephrolithiasis, cortical hyperechogenicity and infarction. Left orthotopic renal transplantation was performed using the Synovis vascular coupling system for end-to-end anastomosis of the renal arteries and veins. Two months after transplantation, renal values were elevated, and abdominal ultrasonography revealed hydronephrosis and hydroureter of the transplanted kidney. Fluoroscopic antegrade pyelography identified a proximal ureteral stricture. Proximal neoureterocystostomy was performed and renal values normalized postoperatively. The cat was re-evaluated for acute stranguria and severe azotemia 12 months later. Contrast-enhanced CT revealed severe hydronephrosis of the transplanted kidney, obstruction of the proximal ureter and adhesions to the urinary bladder. Upon exploration, retroperitoneal fibrosis was found covering the transplanted kidney. Given the clinical situation, a subcutaneous ureteral bypass device (SUB) was placed. Clinicopathologic analyses, trough cyclosporine levels, aerobic urine cultures and ultrasonographic evaluations of the transplanted kidney were monitored every 1–3 months. Patency of the SUB was reassessed every 3–6 months. At 15 months after placement, the SUB occluded due to kinking of the cystostomy catheter and was replaced. At 28 months after SUB placement, renal function and clinical status deteriorated, and the cat was euthanized.

Relevance and novel information To the authors’ knowledge, this is the first report of a SUB device being used for management of ureteral obstruction in a transplanted kidney in a cat.

Case summary A 2-year-old domestic longhair crossbred female cat was referred for a second opinion on a non-healing surgical wound after left eye enucleation. In addition to the left orbital lesion, ulcerative granular masses protruding from the left nostril and on the base of the left ear were noted. A diagnosis of cryptococcosis was established using histopathological examination and a latex cryptococcal antigen agglutination test. The cat was successfully treated with itraconazole.

Relevance and novel information Cryptococcosis, commonly reported in Australia, western Canada and the western USA, is rarely reported in companion animals in Europe. This marks the first report of cryptococcosis in cats in Bosnia and Herzegovina, emphasising the need to raise awareness within the veterinary community, both local and regional, about this disease.

Case summary A 6-month-old male entire domestic shorthair cat presented for presumptive Toxoplasma myopathy that was non-responsive to antiprotozoal therapy. Clinical features included marked macroglossia, dysphagia, regurgitation, truncal muscle hypertrophy, pelvic limb gait abnormalities and megaoesophagus. Relevant diagnostics included serial creatine kinase activity, cardiac troponin I, fluoroscopic swallow study and routine muscle histopathology. Ultimately, post-mortem histopathology with immunostaining demonstrated markedly decreased or absent staining for the rod and carboxy terminus of dystrophin, confirming a dystrophin-deficient muscular dystrophy (MD). The misdiagnosis of toxoplasmosis was based on an increased IgG titre and muscle histopathology submitted to a local laboratory. Treatment for megaoesophagus included vertical feeding of wet food only, sildenafil and omeprazole. Dysphagia and regurgitation improved moderately. Presumptive hyperaesthesia and muscle pain were managed with anti-inflammatory doses of prednisolone. The patient was ultimately euthanased as a result of progressive MD signs and uraemia at 2 years of age.

Relevance and novel information This case report highlights the collective clinical features of MD, as they could be considered pathognomonic for this rare condition and must be differentiated from other myopathies via specific immunostaining of muscle biopsies. This is crucial to obtain a correct and early diagnosis, allowing instigation of potentially valuable treatments. Megaoesophagus is an inconsistent feature in feline MD in addition to the more commonly observed oropharyngeal dysphagia. Management with a canned diet, sildenafil, omeprazole and upright feeding was beneficial with moderate improvement in the frequency of regurgitation. Prednisolone was thought to minimise the presumptive myalgia.

Case summary A 9-year-old male castrated domestic shorthair cat was presented with a 2-week history of acute, progressive left pelvic limb lameness. Gait evaluation revealed a grade 3/5 left pelvic limb lameness with no apparent orthopedic cause for the lameness based on orthopedic examination or radiographs. The neurological examination was otherwise normal. MRI revealed a left-sided L6–7 far lateral intervertebral disc extrusion with possible secondary neuritis of the L6 spinal nerve. A left-sided L6–7 foraminotomy was performed to remove the extruded disc material and provide additional space for the significantly enlarged nerve root. An L6–7 fenestration was also performed. The patient made an excellent recovery with near-complete resolution of lameness at 26 days postoperatively.

Relevance and novel informati This case report contributes to the growing body of literature on lateral intervertebral disc extrusion as an etiological factor in pelvic limb lameness in cats, particularly when neurological deficits are absent. Furthermore, the case report highlights the diagnostic utility of cross-sectional advanced imaging for cats with lameness for which an orthopedic or radiographic cause cannot be identified. Finally, this case underscores the efficacy of surgical intervention as a treatment option for cats with lumbar far lateral intervertebral disc extrusions that do not improve with medical management alone. This finding could have implications for future surgical approaches in cats with similar findings.

Case summary A 4-year-old female neutered Scottish Fold shorthair cat was presented for further investigation of circling towards the right. MRI of the brain revealed an extensive, right-sided temporal muscle lesion with associated frontotemporal bone osteolysis, intracranial, extra-axial extension along the calvarial convexity with severe pachy- and leptomeningeal thickening and contrast enhancement, and an intra-axial space-occupying lesion in the right piriform lobe. The regional lymph nodes were moderately enlarged. Cytology of the right parotid lymph node and the temporal muscle was performed and histiocytic sarcoma (HS) was diagnosed. The owners elected euthanasia.

Relevance and novel information HS of the central nervous system (CNS) is a very rare neoplastic condition in cats. Although a few case reports mention MRI, to our knowledge, the characterisation of MRI features of feline CNS HS have not been investigated in detail. Therefore, the aim of this case report was to describe the MRI characteristics in a feline HS involving not only the CNS, but also the fronto-temporal bone, temporal muscle and the regional lymph nodes. In particular, aggressive neoplastic bone invasion was a novel finding.

Case summary An 11-year-old male neutered cat was referred to The Ohio State University’s Veterinary Teaching Hospital after being diagnosed with pleural effusion by a referral veterinarian. After thoracocentesis, analysis of the effusion was consistent with chyle. Echocardiography, radiographs and bloodwork were used to diagnose hypertrophic cardiomyopathy phenotype and left-sided congestive heart failure, suspected to be secondary to uncontrolled hyperthyroidism. While initiating medical therapy, repeated thoracocenteses were required. A severe pneumothorax developed, necessitating placement of bilateral thoracostomy tubes. A thoracic CT scan did not reveal a cause for the pneumothorax; therefore, it was suspected to have occurred secondarily to an iatrogenic laceration of the parenchyma during thoracocentesis. An autologous blood patch pleurodesis was considered contraindicated so instead the cat was administered a blood patch using blood from a canine blood donor. The cat’s respiratory status remained stable without additional intervention. At 30 h after blood patch pleurodesis, the thoracostomy tubes were removed and thoracic radiographs revealed near resolution of the pleural effusion and pneumothorax. The cat remained subclinical and was discharged from the hospital 48 h after the blood patch pleurodesis. Upon follow-up at 4 and 8 weeks after discharge, the cat was alive and had no complications or adverse reactions from the blood patch pleurodesis.

Relevance and novel information This case documents the first report of a xeno-blood patch pleurodesis performed in a cat using blood from a canine donor. The cat had a successful discharge from the hospital with no adverse reactions from the xeno-blood patch pleurodesis.

Case series summary Two cats, aged 13.5 and 14 years, presented with duodenal masses ultimately diagnosed as Brunner’s gland (BG) adenomas. In the first cat, the lesion was a firm, pale tan, proximal duodenal polyp adjacent to the major duodenal papilla that was composed histologically of a well demarcated, expansile mass of well-differentiated BGs separated by fibrovascular septa and few adipocytes. This patient was euthanized for otitis-related vestibular signs, and the clinical significance of the duodenal polyp is unknown. The second cat presented with a 6-month history of vomiting. This cat had a mural duodenal mass in the region of the major duodenal papilla of approximately 2 cm, which was histologically composed of a dense population of variably ectatic BGs expanding the submucosa and lamina propria. This patient’s mass was non-resectable, but the vomiting resolved after palliative gastroenterostomy loop surgery to allow ingesta to flow past the mass. The patient survived 35 months after the procedure.

Relevance and novel information BG adenoma is a rare, typically benign tumor in humans with non-specific clinical manifestations and no clear etiopathogenesis. This lesion, and the related condition BG hyperplasia, has been documented rarely in animals (one dog, two horses, and in mice and rats). This is the first description of the lesion in the cat. The comparative pathology, differential diagnoses and possible significance of these lesions are discussed.

Case summary A 10-year-old neutered female domestic shorthair cat was presented to our hospital with a 2-day history of anorexia, vomiting and lethargy. The biochemistry panel revealed increased hepatic enzyme activity and serum amyloid A concentration. Haematological values were within reference intervals. An abdominal ultrasound identified a hyperechoic spindle-shaped structure within the common bile duct and a suspected secondary subobstruction, associated with signs of intra- and extrahepatic biliary tract inflammation. During hospitalisation, the cat developed severe and sustained ionised hypercalcaemia. Exploratory surgery was elected as a result of the lack of clinical improvement, despite supportive treatment and suspected retrograde migration of the spindle-shaped structure. Two grass awns were extracted at the junction of an extrahepatic duct and the common bile duct via choledochotomy using intraoperative ultrasound guidance. A stent was then placed in the bile duct to prevent subsequent bile leakage. Histopathology of the liver revealed a moderate neutrophilic and lymphoplasmacytic inflammation with rare bacterial colonies. Escherichia coli was cultured from a bile sample. No specific cause of hypercalcaemia was identified. The cat recovered uneventfully from surgery. Hepatic enzyme activities and hypercalcaemia progressively decreased within a few weeks after surgery and remained within the reference intervals without treatment. Therefore, hypercalcaemia was suspected to be secondary to a foreign body-related granulomatous reaction.

Relevance and novel information To our knowledge, only one other feline case report of biliary tract obstruction secondary to a biliary foreign body has been described in the literature. This is also the first case reporting the use of intraoperative ultrasound to localise a vegetal foreign body within the biliary tract of a cat. This case is also unique because of the onset of hypercalcaemia suspected to be secondary to a foreign body-related granulomatous reaction.

Case summary An 8-month-old spayed female cat presented with a 7-week history of progressive dyspnoea, dysphagia and regurgitation. Plain radiography revealed megaoesophagus with a large, rounded, soft tissue opacity laryngeal mass. Endoscopic examination revealed a fluid-filled lesion, which was lanced and drained completely. As a result of recurrence of the mass and infection 2 days later, the mass was surgically excised. The mass was diagnosed as a laryngomucocele based on clinical and histopathological findings. Clinical signs resolved immediately after removal of the mass, the megaoesophagus resolved a couple of days postoperatively and no relapse was noted over the following 3 years.

Relevance and novel information To the author’s knowledge, this is the first case of laryngomucocele described in a cat. This cause should be included in the differential diagnosis of respiratory obstruction and acquired megaoesophagus in cats. This report demonstrates that megaoesophagus resulting from a respiratory obstruction resolves spontaneously after removal of the obstruction; therefore, respiratory tract assessment should be recommended in cats with signs of megaoesophagus because the prognosis could be good compared with other causes of megaoesophagus.

Case summary A female kitten with two ectopic supernumerary pelvic limbs arising from the umbilicus was born in our clinic. Five weeks after the kitten’s birth, she showed an acute deterioration in condition, with clinical signs of an ileus in the intestines entering the supernumerary body part. We then performed a surgical separation of the supernumerary limbs and intestines. Based on clinical findings and radiography, the kitten was classified as a case of parasitic twinning-omphalopagus or a subtype of asymmetrical caudal duplication, rather than a case of polymelia. Parasitic twinning and caudal duplication are rare congenital malformations in many animal species and in humans, which can often have a poor outcome. Almost 1 year after the separation, the cat appeared to be living a normal life without complications.

Relevance and novel information A good outcome is rare in parasitic twinning because many of these animals present with other concurrent health issues, such as congenital heart malformation or cleft palate, or they are stillborn. However, this pathological entity is scarce in small animal medicine, and there is no documented survival rate. To our knowledge, this is the first officially documented case of parasitic twinning-omphalopagus in a cat in the past decade.