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An 18-month-old, female spayed, Australian Mist cat presented with a 24 h history of muscle tremors and inappetence progressing to collapse with generalised muscle fasciculations. The cat was diagnosed with a hypochloraemic metabolic alkalosis due to a duodenal foreign body found to be a trichobezoar at coeliotomy. The cat made a complete recovery after enterotomy to remove the trichobezoar, with cessation of neuromuscular clinical signs and normalisation of its electrolyte and acid–base imbalances.
Relevance and novel information
Muscle fasciculations and tremors in cats can be caused by intoxications, metabolic derangements, encephalomyelitis, feline hyperaesthesia syndrome and cerebellar diseases. The presenting clinical signs of severe muscle fasciculations and tremors have not previously been reported in association with an intestinal obstruction in the cat.
A 10-month-old, male castrated, domestic shorthair cat was presented with fast-progressing ataxia of the pelvic limbs. MRI and CT were performed, revealing a bony proliferation at T11, with mass effect and laterodorsal compression of the spinal cord. After hemilaminectomy and the removal of the bony mass, the cat recovered uneventfully. At the 1 year follow-up, the cat did not show any neurological deficits or signs of recurrence.
Relevance and novel information
Solitary osteochondroma as a cause of neurological deficits in the pelvic limb has been described in dogs and humans, but, to the best of our knowledge, there are no reported feline cases described in the literature, in which CT and MRI were performed in combination with the successful removal of the lesion and an excellent outcome for the patient.
A 16-year-old, castrated male, feline immunodeficiency virus (FIV)-positive, domestic shorthair cat developed multiple skin lesions. Most of these were Bowenoid carcinoma in situ and contained DNA sequences consistent with Felis catus papillomavirus type 2. Two additional lesions that developed in the skin and subcutaneous tissues between the digital and carpal pads on the left forelimb and right hindlimb were shown by cytology, histology and culture to be caused by Prototheca wickerhamii. These lesions failed to improve in response to systemic therapy treatment with itraconazole, but excision by sharp en bloc resection with follow-up oral itraconazole therapy proved curative for one lesion, although the other lesion recurred, necessitating a second surgery.
Relevance and novel information
This is only the second reported case of feline protothecosis from Australia and the first case that has been cultured and identified to the species level. Also of great interest was the presence of multiple papillomavirus-associated neoplastic lesions, which may have afforded a portal of entry for the algal pathogen and the cat’s positive FIV status; the latter might have impacted on both viral and algal pathogenesis by effects on immunocompetence.
A 10-year-old, castrated male domestic shorthair cat presented with a 2–3 month history of weight loss, lethargy and coughing. Thoracic radiographs revealed a soft tissue opacity overlying the dorsal trachea from the first rib to second rib and the ventral aspect of the trachea extending from the second rib to approximately the fourth rib. CT confirmed a mass involving the dorsal, right lateral and ventral aspects of the trachea narrowing the lumen and extending from vertebra C7 through T4. Bronchoscopy revealed a partially circumferential irregular and multilobulated tracheal mass, which was biopsied. The histopathological diagnosis was tracheal adenocarcinoma. The cat was treated with a definitive course of external beam radiation therapy (RT; 3 Gy × 18), cytotoxic chemotherapy, a tyrosine kinase inhibitor and palliative RT. The cat remained asymptomatic for 2 months and the mass remained stable radiographically for 11 months after RT.
Relevance and novel information
With multimodal treatment the cat had a survival time of 755 days. Initial treatment included definitive RT, carboplatin and piroxicam, followed by toceranib phosphate and palliative RT when the mass recurred. This case report describes the first documented use of non-surgical treatment and long-term outcome of tracheal adenocarcinoma in a cat. This case report is an indication that prolonged survival can be achieved with multimodal therapy.
This case series describes eight cases of invasive tracheal neoplasia that were recognized between the years 1989 and 2014 from a single tertiary referral hospital. This is a disproportionately high number of cases compared with the total number of reports in the current literature.
Relevance and novel information
Invasive tracheal neoplasia is uncommonly diagnosed in domestic cats. Feline tracheal tumors mimic other upper respiratory diseases making diagnosis challenging. Prognosis is guarded to grave, with most cats surviving less than 1 month after beginning treatment. Severe respiratory distress in cats often warrants humane euthanasia. Appropriate clinical suspicion and awareness can expedite diagnoses leading to prolonged survival rates with appropriate treatments. This case series represents the largest number of feline tracheal tumors reported and also describes the first unique histological presentation of what the authors believe to be a poorly differentiated tracheal carcinoma.
The aim of this retrospective case series was to describe seven cases where cats with primary lung tumours were presented because of metastases to extra-pulmonary sites (‘feline lung–digit syndrome’). Specifically, we wanted to emphasise less typical case descriptions where tumour emboli resulted in lesions developing in the musculature (including the muscles of the head), skin or distal aorta.
Relevance and novel information
The cases are presented to increase clinical awareness of this entity in feline practice, especially when characteristic combinations of clinical signs are present. When clinicians have a high index of suspicion for these presentations, radiology (thorax and digits) or ultrasound (distal aorta), combined with collection of fine needle aspirate specimens for cytology, are usually sufficient to secure a definitive diagnosis. Novel information in this series includes CT and MRI findings from some cases. Typically, needle aspiration or biopsy targeting the skin, digits and lesions in musculature is far easier compared with sampling the primary tumour site in the lungs. The differential diagnosis and investigation of multiple digital lesions is also considered.
A 14-year-old female spayed cat was referred for recurrent otitis externa and unusual proliferative lesions in both ear canals. The affected pinnae and external ear canals were covered with large reddish-to-dark-brown verrucous and necrotic tissue. Friable material and exudates occluded both ear canals. Proliferative lesions developed in both ears 2–3 weeks before referral. The histopathological diagnosis from two biopsies obtained from the friable materials with endoscopic biopsy forceps was proliferative and necrotising otitis externa (PNOE). Treatment was initiated with once-daily application of a potent topical glucocorticoid (mometasone furoate) to both ears. Although the auricle and vertical ear canals responded well, no improvement was seen in the horizontal part of the ear canal after 9 weeks. Therefore, oral triamcinolone (0.9 mg/kg q24h) was added for 1 week, and was then tapered (q48h) for 3 weeks. Most lesions resolved, and after a further 2 weeks of prednisolone (2 mg/kg q48h) there was complete resolution. No recurrence was observed during a 2 year follow-up period.
Relevance and novel information
PNOE commonly occurs in kittens, but it can develop in older cats. To our knowledge, the PNOE in this case is the oldest age of onset reported. This condition is rare and was only described recently, and therapeutic options appear limited. According to previously published reports, steroid therapy is ineffective, and tacrolimus is the only treatment known to achieve resolution. However, oral and topical glucocorticoids were beneficial in this case.
A 9-year-old male neutered domestic shorthair cat presented with anorexia. Ultrasonography showed an irregularly shaped hypoechoic mass in the cranial pole of the right kidney. Ultrasound-guided fine-needle aspiration of the renal mass was performed. Cytology revealed moderate cellularity smears composed of epithelial cell clusters, which consisted of an exclusive population of oncocytic cells seen in sheets and papillary clusters along with abundant single cells. A moderate-to-abundant amount of densely stained granular cytoplasm with round nuclei and indistinct nucleoli was seen. The cytological diagnosis was renal oncocytic neoplasm. CT and surgical resection revealed a firm tan mass in the right kidney. A final diagnosis of renal oncocytoma was made on the basis of histology, immunohistochemical staining profile (positive for cytokeratin, and negative for chromogranin A, neuron-specific enolase and vimentin) of neoplastic cells, together with the electronic microscopy results.
Relevance and novel information
We believe that this is the first report of the cytological features of feline renal oncocytoma.
A 13-year-old domestic shorthair cat presented for evaluation of pain and difficulty ambulating. Orthopedic examination and CT facilitated a diagnosis of bilateral elbow synovial osteochondromatosis with medial humeral epicondylitis and concurrent osteoarthritis. Right humeroradial subluxation was evident on CT images, but no instability was evident preoperatively. Surgical treatment was elected, including external neurolysis of the ulnar nerve, removal of the areas of mineralization within the flexor carpi ulnaris muscle and medial arthrotomy to remove intra-articular mineralized bodies. Following closure, instability of the right elbow was noted with humeroradial subluxation necessitating placement of circumferential suture prostheses to provide satisfactory stability. Reassessment was performed 2, 6, 12, 24 and 40 weeks postoperatively and revealed maintenance of elbow stability and substantial improvement in mobility and comfort.
Relevance and novel information
While humeroradial subluxation has been reported in association with medial humeral epicondylitis on post-mortem examination, associated clinically significant instability has not been documented previously. Surgeons should be aware of the potential for this complication and check elbow stability following surgery. Despite this complication, a favorable medium-term outcome was achieved for this cat.
This report describes a rare case of crossed fused renal ectopia (CFRE) in a cat. A mature intact male Persian cat presented with bloody nasal discharge and ascites. Diagnostic studies revealed an ectopic left kidney fused with an orthotopic right kidney and a concurrent feline infectious peritonitis (FIP) infection. The FIP was responsible for clinical signs in this cat, while clinical signs associated with CFRE were not obvious. Despite receiving intensive treatment, the cat died. A post-mortem examination was not performed because the owners declined approval.
Relevance and novel information
To the best of our knowledge, this is the first report of L-shaped CFRE in a cat. In addition, this report describes the CT features of L-shaped CFRE in a cat.
A 6-month-old cat was successfully treated for bilateral quadriceps contracture. Conventional treatments including surgery, dynamic flexion apparatus and physical therapy along with analgesics and non-steroidal anti-inflammatory drugs resulted in temporary clinical improvement that was relapsing. The initiation of supplementary corticosteroid treatment with prednisolone coincided with an immediate and sustained clinical improvement and long-term resolution.
Relevance and novel information
Successful treatment of bilateral quadriceps contracture has not previously been reported in a cat. Quadriceps contracture remains a challenging condition to treat with some cases unresponsive to therapy. Systemic prednisolone treatment appeared to be of benefit in the management of this case and may have a role in some cats where muscle contracture appears relapsing in nature. Further prospective investigations in cats with muscle contracture, including muscle biopsies of affected cats, are warranted.
A case of acquired acute obstructive hydrocephalus that developed as a complication of an ischaemic infarct in the vascular territory of the rostral cerebellar artery is described in an adult domestic shorthair cat. The clinical findings, diagnostic investigations, treatment and prognosis are reported. MRI findings are described in detail.
Relevance and novel information
This is the first report of obstructive hydrocephalus as a complication of an ischaemic infarct in the region of the rostral cerebellar artery in a cat. MRI findings are described in detail with regard to the recognition of the early signs of obstructive hydrocephalus. A brief review of the literature is included, as this complication has been frequently reported in humans.
A 17-year-old female neutered domestic shorthair cat presented for several days of reduced faecal volume and a rectal prolapse. Physical examination revealed a 2 cm rectal prolapse, hepatomegaly and a low body condition score of 3/9. Haematology and biochemistry revealed a mild non-regenerative anaemia (haematocrit 24.5%; reference interval [RI] 30.3–52.3%), a mild mature neutrophilia (16.21 × 109/l; RI 1.48–10.29 × 109/l) and a mild increase in alanine aminotransferase activity (222 IU/l; RI 12–130 IU/l). Abdominal radiographs identified hepatomegaly. The rectal prolapse was reduced under general anaesthesia. Abdominal ultrasound identified a caecocolic intussusception and a large hepatic mass. Thoracic radiographs were unremarkable. Hepatic fine-needle aspirate cytology revealed well-differentiated hepatocytes. A typhlectomy was performed and the quadrate liver lobe, with mass, was resected. Gross examination of the caecum identified a focal polyp; histopathology showed moderate plasmacytic–lymphocytic typhlitis and reactive mucosal-associated lymphoid tissue. The hepatic mass was diagnosed as a well-differentiated hepatocellular carcinoma. Six weeks postoperatively the cat had gained 0.5 kg, had an improved body condition score of 5/9 and resolution of clinical signs. The cat died acutely 1 year later from an unknown cause.
Relevance and novel information
Caecocolic intussusception is rare in cats and uncommon in dogs. This is the third report in a cat and the first associated with a caecal polyp. As reported in dogs, the outcome following surgery was good. Hepatocellular carcinoma is a rarely reported feline neoplasm, which may have a good prognosis with surgical resection.
Two castrated male cats, aged 8 months old (case 1) and 10 months old (case 2), showed a history of progressive paraparesis, an over-reaching pelvic limb gait, urinary incontinence and a palpable dermoid fistula. In case 1, the fistula was connected to the dural sac on the conus medullaris, and the tethered spinal cord was retracted caudally. In case 2, the tubular structure was connected to the dural sac on the thoracic spinal cord, and the tethered spinal cord was retracted dorsally. Tethered cord syndrome secondary to spina bifida aperta was suspected in both cats. Excision of the fistula and release of the tethered spinal cord was performed. A histopathological examination confirmed the diagnosis of a meningomyelocele in case 1 and a meningocele in case 2. Paraparesis improved postoperatively in both cats. However, urinary incontinence in case 1 remained partially unresolved.
Relevance and novel information
This is the first report to describe the imaging characteristics, surgical treatments and outcomes of two different types of tethered cord syndrome with spina bifida aperta in cats. Tethered cord syndrome with spina bifida aperta needs to be included in the differential diagnosis of slowly progressive paraparesis in younger cats with or without vesicorectal failure and a palpable dermoid fistula.
A 5-year-old female spayed Chinchilla cat presented with a 4 week history of weight loss and inappetence. A thorough clinical investigation confirmed the presence of a distal jejunal mass. Histopathological and immunohistochemical analysis was consistent with a small intestinal peripheral nerve sheath tumour.
Relevance and novel information
To the best of our knowledge, this is the first reported case of a small intestinal peripheral nerve sheath tumour in a cat. This case report demonstrates the use of immunohistochemistry in differentiating this entity from other mesenchymal neoplasms. The veterinary literature available in this field is very limited and this report adds a new differential diagnosis to feline patients presenting with an intestinal mass.
A 6-month-old spayed female domestic shorthair cat presented for evaluation of suspected bite wounds over the right caudal thorax and left cranial flank. Thoracic radiographs identified a mild right-sided pneumothorax, a small volume of right-sided pleural effusion, with increased soft tissue opacity in the right cranial and middle lung lobes. Abdominal ultrasound identified a very small gall bladder and several small pockets of free peritoneal fluid. Cytological analysis of peritoneal fluid was consistent with a modified transudate. Following initial diagnostic investigations, yellow–orange fluid began to emanate from the right-sided thoracic wound. Biochemical analysis of this fluid was consistent with bile. Exploratory coeliotomy revealed a right-sided radial diaphragmatic tear, with herniation of the quadrate liver lobe and a portion of the gall bladder into the right pleural space. The gall bladder was bi-lobed and avulsion of a single herniated lobe resulted in leakage of bile into the right pleural cavity, without concurrent bile peritonitis (biloabdomen). The cat underwent total cholecystectomy and diaphragmatic defect repair and recovered uneventfully.
Relevance and novel information
To our knowledge, at the time of writing non-iatrogenic isolated bilothorax without concurrent biloabdomen has not been previously reported in the cat. This case highlights the importance of thorough assessment of cats with seemingly innocuous thoracic bite wounds. Despite the rarity of its occurrence, bilothorax should be considered a differential in cats with pleural effusion, even in the absence of bile peritonitis. We believe that the optimal treatment of cases of bilothorax is multifactorial and should be determined on a case-by-case basis.
An 11-year-old female spayed domestic shorthair cat was presented with haematuria of 2 months’ duration followed by pollakiuria and stranguria. A firm, non-painful mass in the urinary bladder was palpated. Abdominal radiographs and ultrasound were suggestive of a urinary neoplasia. During explorative laparotomy, a partial cystectomy and surgical debulking were performed. Histopathology and immunostaining were consistent with a fibrosarcoma. The cat was discharged 10 days after surgery with a residual mass of about 1.8 cm on ultrasound re-examination. The cat was not given adjuvant therapy. The cat was euthanased 8 months after surgery because of tumour invasion of the urinary trigone and subsequent ureter dilation, hydronephrosis and severe azotaemia.
Relevance and novel information
Malignant urinary fibrosarcoma in this cat appeared to be only locally invasive. Palliative surgery without adjuvant postoperative chemotherapy in this cat resulted in an 8 month period of good quality of life.
This case series documents ultrasonographic and clinicopathologic features of four cats with marked segmental dilatations of the common bile duct (CBD). All cats had additional ultrasonographic changes to the hepatobiliary system, including hepatomegaly, tubular to saccular intra/extrahepatic biliary duct dilatation and biliary debris accumulation. Based on all available data the presence of extrahepatic biliary duct obstruction (EHBDO) was ruled out in 3/4 cases and was equivocal in one case. One cat underwent re-routing surgery to address the CBD dilatation after multiple recurrent infections, one cat was euthanized and had a post-mortem examination and two cats were medically managed with antibiotics, liver protectants, gastroprotectants and cholerectics.
Relevance and novel information
The ultrasonographic features of the CBD in this population of cats were supportive of choledochal cysts (CCs). The maximal diameter of the CBD dilatations exceeded 5 mm in all cases, a sign that has been previously reported to be consistent with EHBDO. In our study, dilatations were segmental rather than diffuse. Given the high morbidity and mortality associated with hepatobiliary surgery in cats, segmental dilatation of the CBD should not prompt emergency surgery. Some cats may respond to medical management. Careful planning for cyst resection was beneficial in one cat. Evaluation of CC morphology (eg, size, location, concurrent intrahepatic anomalies) may assist in selecting cats that could benefit from surgical intervention.
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