Case summary An 11-year-old male castrated domestic shorthair cat presented with increased respiratory effort, pleural effusion, lymphadenopathy, lethargy and decreased appetite with weight loss. A diagnosis of T-zone lymphoma was made from histopathology of an extirpated popliteal lymph node that had a marked paracortical expansion of small lymphocytes and prominent high endothelial venule proliferation. T-cell receptor gamma (TRG) molecular clonality PCR yielded a clonal rearrangement and immunohistochemistry demonstrated that the neoplastic lymphocytes expressed CD3 and did not express CD20. The cat was initially treated with two doses of intravenous vincristine and oral prednisolone followed by oral chlorambucil. The pleural effusion, lymphadenopathy, lymphocytosis, abdominal organomegaly and lethargy resolved, and the cat’s appetite and body weight returned to normal. At the time of manuscript submission, the cat continued to do well, more than 24 months after presentation.

Relevance and novel information T-zone lymphoma is a common indolent lymphoma in dogs, but it has only been histopathologically described in one cat before this report. This is the first report to describe the clinical presentation, clinicopathologic findings and outcome for a cat with T-zone lymphoma.

Case summary An 8-year-old female spayed Russian Blue cat presented for acute progressive dyspnoea. The patient had pleural effusion and was diagnosed with chylothorax. A multiphase contrast-enhanced CT scan of thoracic and abdominal cavities was performed to facilitate diagnosis and surgical planning. Incidentally, a large lobulated, elongated, cystic and encapsulated peritoneal mass was found. Contrast pooled within the peritoneal mass during lymphography, suggesting lymphatic origin. The patient was eventually euthanased as a result of recurrence of chylothorax. Necropsy revealed multiple irregular, thin-walled pockets of chylous fluid pooling within the mesentery. Histopathology of the affected mesentery was compatible with a diagnosis of lymphatic malformation.

Relevance and novel information To the authors’ knowledge, this is the first case describing a feline presentation of mesenteric lymphatic malformation. This is also the first case reporting the presentation of chylothorax for a veterinary patient with mesenteric lymphatic malformation.

Case summary An unowned, entire male domestic shorthair cat was surrendered to a rescue centre. On physical examination, poor body condition (score 3/9) and pigmented mass lesions on the lateral aspects of the upper gingivae were noted. The oral lesions were identified as haematomas only after examination under sedation. A diagnosis of probable primary immune thrombocytopenia (pITP) was made based on profound thrombocytopenia, rapid response to glucocorticoid therapy and the absence of identified triggers for secondary immune thrombocytopenia. The patient was treated with glucocorticoids and remained in remission 18 months from diagnosis.

Relevance and novel information pITP is infrequently reported in cats and oral haematomas have not previously been documented as a presenting clinical sign. This case report serves to raise awareness of feline ITP and highlights the availability of evidence-based diagnostic and therapeutic guidelines that were published after the case was treated. While pITP can be refractory to treatment and can be associated with treatment-related morbidity, this case report demonstrates that an acceptable outcome can be achieved, albeit with a requirement for long-term treatment and regular monitoring.

Case summary A 6-year-old female spayed domestic shorthair cat was presented for abdominal distension and weight loss. Abdominal radiographs and ultrasound revealed two cranial abdominal masses and another mass adjacent to the jejunum. Cytologic features of the cranial abdominal masses were consistent with exocrine pancreatic tissue. Four months later, a repeat abdominal ultrasound revealed progressive enlargement of the abdominal masses and medial iliac lymphadenopathy. On exploratory laparotomy, two abdominal masses were associated with the pancreas and incorporated large blood vessels supplying the liver, pancreas and spleen. The masses were non-resectable and incisional biopsies were obtained. The histologic features were diagnostic for a hyalinizing subtype of exocrine pancreatic adenocarcinoma. Chemotherapy was not pursued. Over 28 months after the initial detection of abdominal masses, the cat was still alive and reportedly doing well.

Relevance and novel information To the authors’ knowledge, this is the first report of a hyalinizing subtype of pancreatic adenocarcinoma in a cat. This subtype is considered to behave less aggressively in dogs, and this case may support that a similar, more indolent behavior may be seen in cats.

Case summary A 4-year-old male castrated domestic shorthair cat presented with a 3-month history of coughing and progressive dyspnea. The cat was diagnosed with idiopathic chylothorax after serum biochemistry, thoracocentesis, cytology of pleural effusion, echocardiography and thoracic imaging were performed. After failure to respond to medical management with repeated thoracocenteses, the oral administration of rutin and a low-fat diet, the cat underwent staged interventions consisting of CT lymphangiogram, subtotal pericardiectomy and pleural access port (PAP) placement, followed by thoracic duct ligation (TDL) and cisterna chyli ablation (CCA) 2 months later. The cat made a clinical recovery based on resolution of chylous pleural effusion 1 month after TDL and CCA, and the PAP was removed 1 month later. The cat remained free of clinical signs 3 years postoperatively.

Relevance and novel information This is the first report documenting the use of a PAP for the management of feline chylothorax to disease resolution. Employing this device enabled frequent, low morbidity drainage of the pleural effusion as an alternative to repeated thoracocenteses and facilitated staging the interventions throughout management of idiopathic chylothorax in a cat. PAPs can be used successfully in the management of chylous pleural effusion in cats.

Case summary A 4-year-old male castrated Ragdoll cat presented for generalised seizures. The cat displayed hyporexia, lethargy and hiding behaviour 24–48 h before presentation. The cat had a chronic history of daily vomiting and tachypnoea for 12 months. Severe hypoglycaemia was noted at 1.8 mmol/l (reference interval 4.11–8.84) on initial presentation. The hypoglycaemia persisted despite multiple glucose boluses, resulting in the cat being treated with a glucose and glucagon continuous rate infusion. The cat underwent extensive diagnostic evaluation during hospitalisation, consisting of serial venous blood gas assessment, haematology and biochemistry analysis, urinalysis, serum insulin assay, resting cortisol, adrenocorticotropic hormone (ACTH) stimulation test, abdominal and thoracic imaging, and airway culture. A resting cortisol level of <14 nmol/l was obtained on day 2 of hospitalisation with a follow-up ACTH-stimulation test reporting a baseline cortisol of <28 nmol/l and a 1 h post-ACTH cortisol of 7 nmol/l, supporting a diagnosis of hypoadrenocorticism. The cat was successfully treated with glucocorticoid therapy and discharged home 8 days after initial presentation.

Relevance and novel informationThere are limited cases of feline hypoadrenocorticism present in the literature, most of which describe cats with both glucocorticoid and mineralocorticoid deficiency. Only two previous case reports of feline atypical hypoadrenocorticism exist. Only one of these case reports describes hypoglycaemia with signs of neuroglycopaenia on initial presentation. To the author’s knowledge, this is the first successfully treated case of atypical hypoadrenocorticism presenting with hypoglycaemic seizures in a cat, demonstrating successful long-term management.

Case summary A 6-year-old male castrated Maine Coon cat was presented with a 3-day history of lethargy, hyporexia and weight loss. Abdominal ultrasonography demonstrated a double intestinal intussusception with the colon intussuscepting a thickened ileal segment, which was in turn intussuscepting the jejunum. A jejunal prolapse through the anus occurred 3 days later as a complication of the double intussusception, at which time the cat underwent surgery. Manual reduction of part of the intussusception was achieved, while the remaining 30 cm, including of the ileocaecocolic junction, was resected followed by functional end-to-end anastomosis. The cat recovered uneventfully without any reported long-term gastrointestinal complications.

Relevance and novel informationDouble intussusception is rare in cats. To the best of the authors’ knowledge, this is the first case to describe ultrasonographic features of double intussusception in a cat.

Case summary A 4-month-old Maine Coon kitten was presented for the surgical correction of pectus excavatum (PE). Originally presenting with progressive respiratory distress, the cat underwent video-assisted thoracoscopic surgery (VATS) for stabilisation using a locking compression plate. Postoperative complications included two separate episodes of infection, which ultimately resolved after implant removal. The cat showed gradual improvement and exhibited no clinical signs related to PE at the 12-month follow-up.

Relevance and novel information The VATS approach may provide a useful technique to help reduce intraoperative risk during PE correction in cats.

Case summary In cats, polyuria (PU) and polydipsia (PD) are defined as a urine specific gravity (USG) consistently <1.035 and water consumption >100 ml/kg/day. A 2-year-old castrated male domestic shorthair cat with PU/PD was brought to our hospital. Diagnostic tests for PU/PD included physical examination, blood analyses (complete blood count, serum chemistry profile, electrolytes, ionised calcium, symmetric dimethylarginine and thyroxine concentration), thoracic radiography, abdominal ultrasound examination, urinalysis, urine cortisol:creatinine ratio, urine protein:creatinine ratio and urine culture. A modified water deprivation test resulted in a USG >1.036 and cranial MRI did not identify any abnormalities. Therefore, the cat was administered desmopressin, which failed to decrease water consumption or increase the USG above the untreated level; thus, primary PD was confirmed.

Relevance and novel information This rare case of feline primary PD is the first reported that did not identify evidence of structural pathology of the pituitary gland.

Case summary A 2-year-old female spayed domestic shorthair cat with a 1-week history of lethargy and dysorexia was presented to a veterinary teaching hospital. Physical examination identified severe left nephromegaly, hyperthermia and abdominal pain. Abdominal ultrasound revealed a left ureteral dilation due to obstruction by a ureterolith, associated with marked subcapsular effusion. Urinalysis showed alkaline urine with crystals of struvite. Culture of urine from the renal pelvis and the urinary bladder was positive for Staphylococcus pseudintermedius. An infected struvite ureterolith due to the presence of urease-producing bacteria was suspected. The ureterolith was removed via ureterotomy and a temporary ureteral stent was positioned in an antegrade fashion. Results of infrared spectroscopy showed pure struvite urolithiasis. The stent was removed via cystoscopy 35 days after surgery. The cat was still doing well at the 6-month follow-up.

Relevance and novel information To the best of the authors’ knowledge, this is the first case of a struvite ureterolith due to ureolytic pyelonephritis in a cat.

Objectives The objective of this study was to retrospectively assess the pathogens associated with feline ocular and respiratory diseases in routine diagnostic samples submitted to Georgia Veterinary Diagnostic Laboratories. Furthermore, pathogens detected by the respiratory PCR panel in the upper vs lower respiratory tract were compared (specimen separation at pharynx).

Methods Test records from feline ocular and respiratory PCR panels were collected from 2012 to 2022. While the ocular panel targets feline herpesvirus-1 (FHV), feline calicivirus (FCV) and Chlamydia felis, the respiratory panel covers FHV, FCV, C felis, Mycoplasma species, Bordetella bronchiseptica and influenza A virus.

Results In total, 120 and 453 submissions were made for the ocular and respiratory panels, with positivity rates of 49.2% (59/120) and 69.3% (314/453), respectively. Based on the available signalment, cats aged younger than 3 years made up 59.3% (32/54) and 47.3% (130/275) of positive cases, respectively. The top two findings by ocular and respiratory panels were single detection of FCV (28.8%, 17/59), FHV (25.4%, 15/59) and Mycoplasma species (36.9%, 116/314), co-detection of FCV + Mycoplasma species (20.4%, 64/314), respectively. The most common detection from samples of upper vs lower respiratory tract was Mycoplasma species (39.6%, 97/245) and FCV + Mycoplasma species (25%, 10/40).

Relevance and novel information FCV and FHV were the most frequent detections by the ocular panel, with Mycoplasma species and FCV + Mycoplasma species being the most frequent detections by the respiratory panel. Incorporating FCV and FHV in the vaccination regimen could help reduce the cases of feline ocular and respiratory diseases, especially for cats aged younger than 3 years. Veterinarians should consider Mycoplasma species when dealing with feline respiratory infections.

Case summary A 7-year-old female spayed domestic shorthair cat was presented to our hospital with a 2-day history of anorexia, dyspnoea and lethargy. Blood tests revealed mild anaemia (packed cell volume [PCV] 22.4%) and the biochemistry panel was unremarkable. Thoracic radiographs and echocardiography showed the presence of pericardial effusion with cardiac tamponade as well as pleural effusion. During the initial attempt at pericardiocentesis, a small sample was obtained, sufficient only for fluid analysis and cytology. Subsequently, the pericardial effusion immediately resolved, presumably owing to the drainage of pericardial fluid into the pleural space. Thoracocentesis was then performed, yielding 50 ml of fluid. The analysis of the fluid was consistent with a protein-rich transudate associated with macrophagic-neutrophilic inflammation in both sampled areas. PCR was positive for Bartonella henselae in the pleural/pericardial fluid pool and peripheral blood. Bacterial culture was negative and feline coronavirus real-time PCR was negative. The patient was treated with marbofloxacin 5 mg/kg PO q24h for 5 weeks. No clinical signs were reported at this time; however, blood B henselae PCR remained positive. Treatment was changed to doxycycline at 5 mg/kg PO q12h for 6 weeks. The cat remained subclinical throughout the treatment, and a blood PCR after 6 weeks yielded negative results.

Relevance and novel information To the best of the authors’ knowledge, the present clinical findings related to B henselae infection in a cat without concurrent heart failure have not been previously documented. This clinical case highlights the need to include Bartonella species as a differential diagnosis in cats with protein-rich transudate effusions associated with neutrophilic-macrophagic inflammation and fever.

Case summary A 2-year-old female spayed domestic shorthair cat was presented for evaluation of severe thickening of the proximal duodenum identified on abdominal ultrasound after a 1-year history of vomiting. At surgery, a proximal duodenal mass encompassed the areas of the major and minor duodenal papillae. A gastrojejunostomy was performed to bypass the proximal duodenum and maintain the integrity of the major duodenal papilla. Histopathology revealed changes consistent with feline eosinophilic sclerosing fibroplasia. The cat was treated with prednisolone and survived for 2.5 years. It was euthanized for bronchopneumonia.

Relevance and novel information This case report describes a surgical approach for cats with lesions involving the pylorus and proximal duodenum. Gastrojejunostomy provided a therapeutic option that preserved exocrine pancreatic and biliary secretion in this cat.

Case summary A 5-year-old female spayed domestic shorthair cat presented for sudden onset vision loss 3 days after a dental procedure. Bilateral blindness was confirmed on ocular examination, with fundoscopy revealing segmental wedge-shaped areas of retinal oedema and partial non-rhegmatogenous retinal detachments. An initial differential diagnosis included angioinvasive pulmonary carcinoma, based on previously reported fundoscopy images of this condition; however, general physical examination, blood pressure and chest radiographs were all normal. Four weeks after initial presentation, fundoscopy revealed the resolution of the retinal detachments; however, bilateral segmental chorioretinal necrosis was present. The cat regained some vision and remained well 13 months after the initial presentation. Considering the clinical findings, the onset of blindness after a lengthy dental procedure and improvement of vision over time, a diagnosis of pulmonary carcinoma was unlikely and instead a diagnosis of chorioretinal ischaemia secondary to maxillary artery blood flow restriction is proposed.

Relevance and novel information Maxillary artery blood flow restriction has been well documented with varying degrees of jaw opening in cats. Presumed central blindness as a result of this blood flow restriction has also been documented. However, to the authors’ knowledge, vision loss due to retinal changes, documented by fundoscopic images and their progression over time following suspected chorioretinal ischaemia after a dental procedure, have not previously been reported. We propose that temporary occlusion of the maxillary artery can result in segmental chorioretinal necrosis and associated blindness in cats. This finding further supports the recommendation to minimise prolonged jaw opening during surgical procedures in cats.

Case summary A 12-year-old male castrated domestic shorthair cat exhibited right Horner’s syndrome, right facial nerve paresis, difficulty swallowing, coughing, gait abnormalities and weight loss. Despite prior unspecific treatment by a primary care veterinarian with cortisone and antibiotics, the cat’s condition worsened, culminating in tetraparesis and right hemispasms. Imaging studies, including CT and MRI, identified a mass extending from the carotid body into the neurocranium, causing displacement of adjacent brain structures and meningeal contrast uptake. Histopathology confirmed a malignant B-cell lymphoma. Differential diagnoses are explored, with a particular focus on carotid body tumours, which originate from the chief cells of the carotid body. These neoplasias are rare in non-human primates, dogs, cats and horses, possibly influenced by genetic predisposition and environmental factors such as hypoxia.

Relevance and novel information Carotid body tumours are rare in cats, as they are in other animal species. Although lymphomas are the most common feline neoplasms, to our knowledge, no previous case of a B-cell lymphoma in the carotid body has been described in the feline species to date. This case underscores the importance of considering rare and common neoplastic entities in feline patients with atypical clinical presentations and locations. Thereby highlighting the diagnostic challenges in veterinary oncology.

Case summary This report describes a case of gastric mucormycosis in a young Ragdoll cat with a 5-day history of vomiting. Physical examination detected mild dehydration and tenderness was elicited on abdominal palpation. The results of blood work-up and radiographic study were unremarkable; however, abdominal ultrasonographic examination revealed multiple hyperechoic neoformations at the level of the pyloric antrum, which were confirmed on endoscopic examination. Non-septate hyphae of irregular diameter with a branched appearance were observed on cytology, and histological examination revealed severe diffuse necrotising and granulomatous gastritis with the presence of intralesional fungal hyphae indicative of mucormycosis, which was confirmed by PCR tests. Antifungal therapy with ketoconazole in addition to supportive treatment temporarily improved the clinical condition. Lethargy, fever and abdominal effusion developed in the following days. Cytological examination of abdominal fluid was compatible with septic peritonitis and, given the severity of the condition, euthanasia was opted by the owners. Post-mortem examination confirmed septic peritonitis resulting from perforation of the gastric wall at one of the neoformations of the pyloric antrum.

Relevance and novel information To the authors’ knowledge, this is the first reported case of gastric mucormycosis in a cat. Previous literature includes a case of mucormycosis in a Persian cat affecting only the duodenum. In both the Persian cat and the cat described here, gastrointestinal mucormycosis disease progressed rapidly and was fatal.

Case summary A 9-year-old male castrated domestic shorthair cat from northern California was evaluated for a 12-month history of dermal and subcutaneous dermatitis in the inguinal region. Histopathologic examination of a biopsy revealed severe, chronic, multifocal to coalescing pyogranulomatous dermatitis and panniculitis, accompanied by ulceration and central necrosis. Aerobic bacterial culture of lesions yielded mycobacterial growth. Empiric antimicrobial therapy was initiated with doxycycline and marbofloxacin pending culture and susceptibility. Culture of a biopsy followed by rpoB gene sequencing at a mycobacterial reference laboratory yielded Mycobacterium porcinum after 6 weeks. Ten months after initial antimicrobial administration, the lesions resolved.

Relevance and novel information To date, in cats, M porcinum panniculitis has been reported from Ohio, Massachusetts and British Columbia in North America; two additional cases were reported from southeastern Australia. In humans, M porcinum infections have been reported from several states in the USA, predominantly in the Midwest and coastal south, but not from the west. This report extends the known spatial distribution of M porcinum to the western USA and strengthens its association with panniculitis in cats. It also demonstrates the need for prolonged incubation for diagnosis of some rapidly growing mycobacteria infections using culture.

Case summary Toxoplasma gondii is a globally distributed apicomplexan protozoan infecting all warm-blooded animals. Cats are the definitive host, susceptible to clinical disease. In Spain, studies have shown the widespread presence of Toxoplasma IgG antibodies in cats but there are no published data on clinical toxoplasmosis in cats from Spain. We describe a case of fatal disseminated toxoplasmosis in a 7-year-old outdoor domestic shorthair cat. The cat, an active hunter, was presented with a 1-week history of malaise and acute deterioration over 24 h. Fever, tachypnoea and abdominal discomfort were detected on physical examination. No evidence of immunosuppressive disease or previous treatment could be found. A moderate increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was found on serum biochemistry. Radiography revealed hepatomegaly and a small patchy pulmonary alveolar pattern in the caudal lung lobes. In 48 h, the AST and ALT levels were severely increased and the cat’s respiratory signs worsened. Parenteral clindamycin administration (25 mg/kg IV q12h) and supportive treatment could not prevent progression to death. Cytology from the liver and lungs revealed organisms morphologically consistent with T gondii. Indirect immunofluorescence antibody test Toxoplasma titres were 1:100 IgM and 1:100 IgG. PCR performed on scraped material from glass cytology slides was positive for T gondii in both lung and liver aspirates.

Relevant and novel information To the authors’ knowledge, this is the first case of fatal disseminated toxoplasmosis in a cat described in Spain, confirmed by PCR. Fine-needle aspirates from the liver could assist in the diagnosis of fatal disseminated toxoplasmosis when liver enzymes are increased.

Case summary A 13-year-old male castrated domestic shorthair cat presented with a 2-month history of progressive lameness, poor appetite and constipation. Physical examination revealed palpable lesions in muscles of several extremities. Ultrasound examination confirmed the presence of round lesions with a hypo- or anechoic centre within the muscles. These lesions were characterised by an anechoic, occasionally trabeculated, central area surrounded by a hyperechoic band with heterogeneous echotexture. In total, seven lesions affecting six appendicular muscles were detected in different evolution stages, as suggested by their sizes and ultrasonographic features. Fine-needle aspiration of the muscle lesions revealed nests and isolated pleomorphic large neoplastic cells consistent with a carcinoma (vs sarcoma) and one mass was surgically removed. The histological and immunohistochemical studies confirmed a diagnosis of metastatic urothelial carcinoma. Although this neoplasia typically originates from the urothelium of the urinary bladder or renal pelvis, the primary tumour could not be detected in repeated abdominal ultrasound examinations. The cat was euthanased and further evaluations were declined by the author.

Relevance and novel information Urothelial carcinoma is a rare and highly aggressive neoplasia in the cat. While metastasis to regional lymph nodes and lungs are common in cats and dogs, to the authors’ knowledge, there have been no reports of metastasis to multiple appendicular muscles in cats. This clinical presentation should be considered in the differential diagnoses of multiple nodular or cystic lesions affecting long muscles in cats.