Journal of Feline Medicine and Surgery Open Reports最新文献

Case summary: A 16-year-old spayed female domestic shorthair cat with methimazole-treated hyperthyroidism presented with a chronic progressive history of a stiff gait progressing to recumbency. A neurological examination revealed continuous excessive muscle tone with myokymia, which exacerbated with exercise and persisted during general anaesthesia. An electromyographic study revealed myokymic discharges in all tested muscles, as well as complex repetitive discharges, fibrillation potentials and positive sharp waves. Blood tests, urinalysis and abdominal ultrasound did not reveal significant abnormalities. A histological examination of a muscle biopsy showed no specific abnormalities. A clinical diagnosis of acquired neuromyotonia with myokymia was formulated. Phenytoin treatment resulted in temporary improvement, but excessive muscle tone recurred resulting in episodes of dyspnoea. Euthanasia was elected 3 weeks after presentation.

Relevance and novel information: To the best of the authors' knowledge, this is the second report of an acquired neuromyotonia in a cat. In contrast with the previous report, treatment with phenytoin resulted in only partial and temporary improvement of signs. Subsequent progression of the disease, including signs of dyspnoea and dysuria, led to the decision to euthanase the cat. In humans, acquired neuromyotonia (Isaacs syndrome) is usually due to an autoimmune response to proteins associated with voltage-gated potassium channels. More rarely, it has also been described in humans with thyroid disorders. A link with methimazole treatment or hyperthyroidism in the cat reported here could not be excluded.

Case summary: A 6-month-old male entire domestic shorthair cat was presented to the ophthalmology department for nasolacrimal duct cannulation and flushing, and castration under general anaesthesia. On pre-anaesthetic assessment, the cat had a heart rate of 90 beats/min (bpm). Clinical examination was unremarkable, although the cat appeared stressed. The echocardiogram was within normal limits. An ambulatory electrocardiogram (ECG) monitor was fitted overnight, and analysis of the ECG revealed a sinus rhythm with a lower than normal heart rate. The mean 1 min rate was 98 bpm. There was a slower than normal sinus rhythm and frequent ventricular escape beats. Differential diagnoses included increased vagal tone and sinoatrial node dysfunction (SND). The latter was suspected as the cat demonstrated signs of stress although an atropine response test was not performed.

Relevant and novel information: SND is relatively common in dogs but extremely rare in cats. To the authors' knowledge, there is only one affected cat mentioned in the literature. In both dogs and humans, most cases described are in middle-aged and elderly patients. Although the condition is recognised in human infants and fetuses, it has not been reported in dogs under 2 years of age. This case is unusual because SND was suspected in an immature cat. On analysis of the ECG, the heart rate was considerably lower than those previously reported in hospitalised cats; however, findings on physical examination were subtle, highlighting the importance of pre-anaesthetic examination in identifying unexpected abnormalities.

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 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 15-year-old male castrated domestic shorthair cat was presented for acute lethargy, vomiting and hyporexia. Abdominal and thoracic radiographs revealed a caudal thoracic/esophageal soft tissue opacity with concern for an esophageal mass or an esophageal foreign body. Esophagoscopy confirmed the presence of a large, irregular, mid-esophageal mass. Laser ablation using esophagoscopy was utilized to debulk the mass. Approximately 80% of the mass was removed without complication and an esophagostomy feeding tube was placed. The cat was discharged the same day of the procedure. Histopathology and immunohistochemistry staining were consistent with a plasma cell tumor. Recheck esophagoscopy 2 weeks after the procedure revealed no evidence of regrowth and resolved clinical signs in the patient.

Relevance and novel information: Laser ablation of esophageal neoplasms in cats represents a novel, lower cost, minimally invasive, palliative treatment alternative to surgery. To the authors' knowledge, this is the first published report of successful partial laser ablation treatment of a large esophageal plasma cell tumor in a cat.

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 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.