Case report: Chylopericardium secondary to dialysis catheter related jugular venous thrombosis in two dogs receiving long-term hemodialysis.

Chylopericardium is a rare entity in veterinary medicine. In this report we document the development of chylopericardium in two dogs undergoing chronic hemodialysis. An 11-year-old female spayed Labrador retriever (Case 1) presented with acute coughing and lethargy 2 months following initial dialysis catheter placement and initiation of dialysis therapy for severe azotemia. Echocardiography demonstrated severe pericardial effusion and cardiac tamponade. Pericardial fluid analysis was consistent with chylous effusion. The dog underwent a subtotal pericardiectomy with thoracic duct ligation, and a PleuralPort™ was placed. The patient continued to receive outpatient hemodialysis therapy after pericardiectomy for several months until she died acutely at home. A 4-year-old male neutered Doberman (Case 2) was being treated for 2 months with outpatient hemodialysis for management of chronic kidney disease. On presentation for the 17th hemodialysis treatment, the patient had increased respiratory rate. Echocardiography demonstrated pleural and pericardial effusions, and fluid analysis in both cavities was consistent with chylous effusion. Use of tissue plasminogen activator (TPA), clot removal and replacement of the catheter was attempted; however pleural and pericardial effusion continued. The patient was euthanized after 25 hemodialysis sessions as owners elected not to pursue more procedures. In both cases, the cause of the chylopericardium was suspected to be secondary to catheter-associated thrombosis and/or stenosis based on multiple imaging modalities. Despite use of rivaroxaban and clopidogrel concurrently in each case, the chylous effusion persisted. This case report describes clinical details of a rare complication of long-term indwelling dialysis catheters in two dogs.

Computed tomography findings of nasal cryptococcosis in Australia (2008-2020): 12 dogs and 9 cats.

OBJECTIVE: To describe the CT findings of Australian dogs and cats with nasal cryptococcosis over a 12-year period. ANIMALS: 12 dogs and 9 cats diagnosed with nasal cryptococcosis from 2008 through 2020. METHODS: CT findings were compared among enrolled cases from Australian veterinary referral centers. Disease severity was compared between a subset of patients with cryptococcal speciation performed (n = 6 dogs; n = 3 cats) and geographic domicile. RESULTS: Dogs demonstrated diffuse disease affecting numerous nasal regions and sinuses. Cats displayed more focal nasal and nasopharyngeal disease. Dogs were more likely to have a nasal mass, whereas cats were more likely to have a nasopharyngeal mass. Cribriform plate lysis was common in dogs but not observed in cats. Sinonasal osteolysis was a common feature in both species. Mandibular lymph nodes were commonly enlarged in dogs, whereas in cats, the retropharyngeal lymph nodes were more likely enlarged. There was no obvious difference in disease severity or lesion distribution in relation to the causal species of Cryptococcus, although to determine if this finding is robust, an appropriately powered prospective study is warranted. CLINICAL RELEVANCE: There are numerous studies describing the clinical features, treatment, and outcomes of dogs and cats with cryptococcosis. To the best of our knowledge, there is only 1 previous study describing the CT features of nasal cryptococcosis, undertaken in one part of North America. Our study describes the CT features of nasal Cryptococcus sp in an Australian canine and feline cohort, adding new pertinent observations while reinforcing reported radiological observations.

Brain magnetic resonance imaging and computed tomography findings in cats and dogs with central nervous system cryptococcosis in Australia: 23 cases (2009-2020).

OBJECTIVE: To describe the imaging findings in Australian cats and dogs with CNS cryptococcosis. ANIMALS: 23 cases (10 cats; 13 dogs) with CNS cryptococcosis and brain MRI or CT studies available to review. METHODS: Retrospective, multi-institutional case series. Brain MRI or CT studies were reviewed by a board-certified radiologist. Imaging findings were described and the differences between cats and dogs explored. RESULTS: Morphologic features were consistent with extra-axial lesions in all (n = 13) dogs and either intra-axial (5/10) or extra-axial (4/10) lesions in cats, with 1 cat having no detectable lesions in low-field brain MRI scans. Meningeal abnormalities were most common, followed by forebrain and cerebellar lesions. Intracranial MRI lesions were typically T2 hyperintense and T1 hypo- to isointense. Four cases had T2 hypointense lesions affecting the brain, sinonasal cavity, or regional lymph nodes. Intracranial CT lesions were mostly soft tissue attenuating. Contrast enhancement was present in all cases with contrast series available, with ring enhancement shown only in cats. Osteolysis was more common in dogs than cats, particularly affecting the cribriform plate. All 13 dogs and many (6/10) cats had at least 1 lesion affecting sinonasal or contiguous tissues, and locoregional lymphadenomegaly was common (7/10 cats; 11/13 dogs). CLINICAL RELEVANCE: Imaging lesions in cryptococcal meningoencephalitis were extra-axial in dogs but could be intra-axial or extra-axial in cats. Careful examination for extracranial lesions (sinonasal, retrobulbar, facial soft tissue, tympanic bullae, or locoregional lymph nodes) is important to provide alternative safe biopsy sites. T2 hypointense lesions, while rare, should prompt consideration of cryptococcosis.

Bilateral external jugular vein anomalies preventing hemodialysis catheter placement in a cat with anuria secondary to Lilium species intoxication.

Case series summary: A 2-year-old female spayed Abyssinian cat was evaluated for lethargy and inappetence that first occurred approximately 4 days prior. In addition, urination had not been observed by the owner for 5 days. A Lilium species plant had been brought into the house approximately 5 days before initial evaluation, and intoxication was therefore suspected. Bloodwork revealed anemia, severe azotemia and hyperkalemia. As the cat was anuric with severe azotemia, hyperkalemia and fluid overload, intermittent hemodialysis was recommended. Attempts were made to place a hemodialysis catheter into the external jugular veins bilaterally, but after initial successful venipuncture, the instrumentation would not pass into either vein. During fluoroscopic angiography, no internal jugular veins or external jugular veins caudal to the thoracic inlet were visualized and venous drainage from the head occurred via the vertebral veins. Owing to the anomalous anatomy in the cervical region, a hemodialysis catheter could not be placed into either jugular vein. Alternative sites for the placement of an extracorporeal catheter were discussed with the owner, but humane euthanasia was elected. Relevance and novel information: To the authors' knowledge, this is the first report of a cat with bilateral external jugular vein anomalies resulting in blind endings that did not communicate with the vena cava. This was discovered during attempts to place a hemodialysis catheter for the management of anuric renal failure secondary to Lilium species intoxication. While this anatomical variation is likely uncommon, it is an important differential to consider when faced with challenging external jugular vein catheterizations in feline patients.

Characteristics of Extended-Spectrum ß-Lactamase Producing Enterobacterales Isolated from Dogs and Cats, 2011-2021.

The rising prevalence of extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales is a significant threat to animal and human health. This study aims to describe the clinical features, antimicrobial susceptibility patterns, and genotypic features of infections associated with ESBL-producing Enterobacterales in dogs and cats seen at a tertiary referral veterinary teaching hospital. Enterobacterales isolated from dogs and cats that underwent ESBL testing during the study period were identified using a search of the hospital antimicrobial susceptibility test software database. Medical records of confirmed ESBL isolates were reviewed, and the source of infection, clinical findings, and antimicrobial susceptibility were recorded. Genomic DNA from bacterial isolates was evaluated for antimicrobial resistance genes with whole genome sequencing. Thirty ESBL-producing isolates were identified based on phenotypic testing (twenty-nine from dogs, one from a cat); twenty-six were Escherichia coli and the remainder were Klebsiella spp. Bacterial cystitis was the most commonly identified (8/30, 27%) clinical problem associated with infection. Resistance to three or more antimicrobial classes was identified in 90% (27/30) of isolates, and all isolates were susceptible to imipenem. Over 70% of isolates were susceptible to piperacillin-tazobactam, amikacin, and cefoxitin. BlaCTX-M-15 was the most common ESBL gene identified, present in 13/22 (59%) isolate genomes. A wide range of clinical infections were identified. Piperacillin-tazobactam and amikacin may be alternatives to carbapenem therapy. Further, larger-scale studies are needed.

Clinical features, outcomes, and long-term survival times of cats and dogs with central nervous system cryptococcosis in Australia: 50 cases (2000-2020).

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.

Pharmacokinetics of isavuconazole in healthy cats after oral and intravenous administration.

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/y2 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.

Mandibular metastasis of a prostatic carcinoma in a dog.

Skeletal metastasis is a common finding in dogs with prostatic carcinoma and most frequently involves the lumbar vertebrae and pelvis. In the present report, we describe the case of a prostatic carcinoma in a 6-year-old Labrador retriever, who developed apparent oral sensitivity and pain within a week of initial diagnosis. Computed tomography of the skull revealed a mixed osteoproductive and osteolytic mass of the condylar process of the left mandible, and cytologic evaluation of the mass was consistent with metastatic prostatic carcinoma. To our knowledge, this is the first published report of mandibular metastasis of a prostatic carcinoma in a dog.

Partial resolution of chronic unilateral sinonasal obstructive disease in a cat using a temporary polyvinylchloride stent.

CASE SUMMARY: A 3-year-old male neutered domestic shorthair cat presented for further investigation of a swollen left eyelid and a hard, non-painful bony swelling over the left frontal sinus. Physical examination revealed no nasal discharge or airflow through the left nostril. A CT of the head revealed a left frontal sinus obstruction with expansile remodelling and osteolucency. Drainage of the frontal sinus obstruction was alleviated via placement of a temporary polyvinylchloride (PVC) stent that was left in place for 6 weeks. Purulent material removed from the frontal sinus returned a positive culture for Pseudomonas aeruginosa susceptible to marbofloxacin that was continued for 4 weeks, and for an additional 2 weeks after stent removal. A left-sided mucoid nasal discharge returned 3 months after removal of the stent. Repeat CT performed 20 months after surgery found the presence of a gas-filled frontal sinus and partial resolution in the amount of fluid within the mid and rostral nasal cavity. A repeat positive culture for P aeruginosa was also obtained. The exact cause of the chronic unilateral sinonasal obstruction remains unclear, but an underlying chronic rhinitis with secondary obstructive frontal sinusitis or sinus mucocoele with secondary nasal extension was suspected. RELEVANCE AND NOVEL INFORMATION: Chronic rhinosinusitis in cats can be a challenging condition to treat and cure. This case illustrates the partial resolution of chronic unilateral sinonasal obstructive disease in a cat using a temporary PVC stent.

Oesophageal obstruction due to trichobezoars in two cats.

CASE SERIES SUMMARY: This case series describes two cats diagnosed with oesophageal obstruction due to trichobezoars. Both cases presented for acute dyspnoea, with thoracic radiographs revealing changes consistent with oesophageal foreign material causing ventral displacement of the trachea. Endoscopic removal was unsuccessful and both cases required surgical intervention. Case 1 died within 24 h of trichobezoar removal, likely from aspiration pneumonia. Case 2 developed laryngeal collapse 10 days after trichobezoar removal and required a permanent tracheostomy. Case 2 has been followed up for >1 year without any further complications. RELEVANCE AND NOVEL INFORMATION: There is minimal published information on oesophageal trichobezoars in cats. These cases provide information on presentation, radiographic findings and complications associated with oesophageal trichobezoars. The intention of this case series is to increase the index of suspicion for this syndrome among clinicians treating feline patients.

Frontoethmoidal encephalocele in a cat.

CASE SUMMARY: An 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 INFORMATION: This 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.

Susceptibility of rapidly growing mycobacteria isolated from Australian cats to ivermectin, moxidectin, ceftiofur and florfenicol.

OBJECTIVES: Rapidly growing mycobacteria (RGM) infections in cats typically manifest as a panniculitis, requiring long-term antimicrobial therapy for resolution. The search for novel antimicrobial therapies to reduce treatment duration and improve the rate of clinical resolution is imperative. Accordingly, RGM isolates underwent susceptibility testing to some avermectins and other antibacterial drugs currently available. METHODS: Five Mycobacterium fortuitum and six Mycobacterium smegmatis isolates obtained from Australian cats underwent susceptibility testing by microbroth dilution to ivermectin, moxidectin, ceftiofur and florfenicol. RESULTS: All isolates were resistant to the highest concentrations of ivermectin, moxidectin and ceftiofur tested (1024 µg/ml, 256 µg/ml and 32 µg/ml, respectively). All isolates of M fortuitum were resistant to the highest concentration of florfenicol tested (128 µg/ml). The minimum inhibitory concentration range of florfenicol that inhibited growth of M smegmatis isolates was 32-64 µg/ml. CONCLUSIONS AND RELEVANCE: All drugs appear to have no efficacy in vitro for the treatment of RGM infections.