Case summaryAn 11-month-old female neutered domestic shorthair cat presented for further investigation of a 1 month history of generalised tonic–clonic seizures. Physical examination revealed microphthalmia of the left eye and right-sided hemiparesis. MRI of the brain and cranial neck was performed using a 1.5-Tesla system. MRI revealed a left frontoethmoidal encephalocele and microphthalmia of the left eye. Conservative treatment with antiepileptic medication was elected. The cat was managed on phenobarbitone and levetiracetam. Seizures have remained well controlled 12 months post-diagnosis.Relevance and novel informationThis is the first known case report of a frontoethmoidal encephalocele in a cat. This case was presented to increase clinical awareness of this congenital malformation and as a differential diagnosis for any young cat that presents with seizures.

OBJECTIVE To describe the clinical findings and outcomes of Australian cats and dogs with CNS cryptococcosis. ANIMALS 19 cats and 31 dogs with CNS cryptococcosis diagnosed between 2000 and 2020. PROCEDURES A case series and cohort study were performed using the same 50 animals. Both studies were multi-institutional and both retrospective and prospective. Disease features were compared between cats and dogs, and associations between putative risk factors and survival time (ST) were assessed. RESULTS Dogs were younger at initial presentation than cats and had lower latex cryptococcal antigen agglutination titers. Extraneurologic signs were common and frequently involved sinonasal and contiguous tissues. Neuroanatomic localization was predominantly forebrain, central vestibular (including cerebellum), multifocal, or diffuse. CSF analysis predominantly showed pleocytosis, with eosinophilic inflammation common in dogs. Seventy-eight percent (39/50) of patients received antifungal treatment. Median STs (from presentation) in treated patients were 1,678 days for cats and 679 days for dogs. Abnormal mentation at presentation (in dogs) and CSF collection (in cats) were associated with shorter STs. In treated dogs, those that received glucocorticoids prior to diagnosis, or single rather than multiple antifungal agents, had shorter STs. CLINICAL RELEVANCE The prognosis for feline and canine CNS cryptococcosis is guarded, yet long STs are possible with appropriate treatment. Presence of subtle upper respiratory tract signs may suggest cryptococcosis in patients with neurologic signs, while the absence of neurologic signs does not preclude CNS involvement.

All drugs appear to have no efficacy in vitro for the treatment of RGM infections.

Background: Isavuconazole is a triazole antifungal drug that has shown good efficacy in human patients. Absorption and pharmacokinetics have not been evaluated in cats.Objectives: To determine the pharmacokinetics of isavuconazole in cats given a single IV or PO dose.Animals: Eight healthy, adult research cats.Methods: Four cats received 100 mg capsules of isavuconazole PO. Four cats received 5 mg/kg isavuconazole solution IV. Serum was collected at predetermined intervals for analysis using ultra-high performance liquid chromatography-tandem mass spectrometry. Data were analyzed using a 2-compartment uniform weighting pharmacokinetic analysis with lag time for PO administration and a 2 compartment, 1/y 2 weighting for IV administration. Predicted 24 and 48-hour dosing intervals of 100 mg isavuconazole administered PO were modeled and in vitro plasma protein binding was assessed.Results: Both PO and IV drug administration resulted in high serum concentrations.Intravenous and PO formulations of isavuconazole appear to be able to be used interchangeably. Peak serum isavuconazole concentrations occurred 5 ± 3.8 hours after PO administration with an elimination rate half-life of 66.2 ± 55.3 hours. Intersubject variability was apparent in both the PO and IV groups. Two cats vomited 6 to 8 hours after PO administration. No adverse effects were observed in the IV group.Oral bioavailability was estimated to be approximately 88%. Serum protein binding was calculated to be approximately 99.0% ± 0.03%. Conclusions and Clinical Importance:Isavuconazole might prove to be useful in cats with fungal disease given its favorable pharmacokinetics. Additional studies on safety, efficacy, and tolerability of long-term isavuconazole use are needed.