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.

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.

Cystoscopic-guided scissor transection of intramural ectopic ureters as a novel alternate minimally invasive treatment option to laser ablation in female dogs: 8 cases (2011-2020).

OBJECTIVE: To evaluate the safety and efficacy of cystoscopic-guided scissor transection of ectopic ureters (CST-EU) in female dogs. ANIMALS: 8 incontinent female dogs with intramural ectopic ureters. PROCEDURES: For this retrospective case series, data were collected from medical records of dogs that underwent CST-EU to relocate the ectopic ureteral orifice to an anatomically normal trigonal location between June 2011 and December 2020. Outcome after hospital discharge was determined using owner telephone questionnaires. RESULTS: Ectopic ureters were bilateral in 4 of the 8 dogs, and all dogs had other urogenital tract anomalies. Owner questionnaire follow-up was available for 7 dogs, and results indicated 6 dogs had improved urinary continence immediately following the procedure. At the last follow-up (44 to 3,384 days after CST-EU), 3 of the 7 dogs were completely continent with CST-EU alone, 3 others became continent or were markedly improved with the addition of medications for urethral sphincter mechanism incompetence, and 1 required ureteroneocystostomy, colposuspension, and an artificial urethral sphincter to become fully continent. Owners of 5 of the 7 dogs reported that they considered the outcome of CST-EU as good to excellent, and all owners reported that they would consider having CST-EU performed again should they have another incontinent dog. Complications were minor, and only 3 dogs showed transient lower urinary tract signs after CST-EU. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated CST-EU could provide a safe, effective, minimally invasive alternative in the absence of laser technology for the treatment of intramural ectopic ureters in female dogs.

Focal experimental injury leads to widespread gene expression and histologic changes in equine flexor tendons.

It is not known how extensively a localised flexor tendon injury affects the entire tendon. This study examined the extent of and relationship between histopathologic and gene expression changes in equine superficial digital flexor tendon after a surgical injury. One forelimb tendon was hemi-transected in six horses, and in three other horses, one tendon underwent a sham operation. After euthanasia at six weeks, transected and control (sham and non-operated contralateral) tendons were regionally sampled (medial and lateral halves each divided into six 3 cm regions) for histologic (scoring and immunohistochemistry) and gene expression (real time PCR) analysis of extracellular matrix changes. The histopathology score was significantly higher in transected tendons compared to control tendons in all regions except for the most distal (P ≤ 0.03) with no differences between overstressed (medial) and stress-deprived (lateral) tendon halves. Proteoglycan scores were increased by transection in all but the most proximal region (P < 0.02), with increased immunostaining for aggrecan, biglycan and versican. After correcting for location within the tendon, gene expression for aggrecan, versican, biglycan, lumican, collagen types I, II and III, MMP14 and TIMP1 was increased in transected tendons compared with control tendons (P < 0.02) and decreased for ADAMTS4, MMP3 and TIMP3 (P < 0.001). Aggrecan, biglycan, fibromodulin, and collagen types I and III expression positively correlated with all histopathology scores (P < 0.001), whereas lumican, ADAMTS4 and MMP14 expression positively correlated only with collagen fiber malalignment (P < 0.001). In summary, histologic and associated gene expression changes were significant and widespread six weeks after injury to the equine SDFT, suggesting rapid and active development of tendinopathy throughout the entire length of the tendon. These extensive changes distant to the focal injury may contribute to poor functional outcomes and re-injury in clinical cases. Our data suggest that successful treatments of focal injuries will need to address pathology in the entire tendon, and that better methods to monitor the development and resolution of tendinopathy are required.