A novel form of intracranial coccidioidomycosis is present in dogs and exhibits characteristic clinical and magnetic resonance imaging findings.

The neurological examination findings, clinical pathology (including Coccidioides immitis IgG/IgM serology) and magnetic resonance imaging (MRI) findings in 13 dogs with a novel form of intracranial coccidioidomycosis are described in a retrospective case series, with long-term clinical resolution documented in 11/13 dogs (84.6% of cases) with oral fluconazole therapy. The medical records of the Veterinary Neurological Center in Phoenix, Arizona from the years 2000 to 2017 were utilized to search for dogs with appropriate inclusion criteria. Magnetic resonance imaging findings were highly consistent across all cases and characteristically demonstrated bilaterally symmetric T2 hyperintensity throughout the frontal lobes, caudate nuclei, and rostral internal capsule, ±faint, wispy contrast enhancement on T1-postcontrast images. These findings were in stark contrast to previously reported MRI findings in dogs with intracranial coccidioidomycosis, which were typically characterized by a focal, strongly contrast enhancing granuloma and extensive vasogenic edema, typically unilateral. Schnauzer breeds represented eight of 13 (61.5%) cases, possibly suggesting a breed predilection. Three cases underwent repeat MRI after resolution of neurological signs and documentation of a decreased Coccidioides titer in response to fluconazole therapy. All demonstrated complete resolution of previously identified lesions, but with marked, severe atrophy of the caudate nuclei and frontal lobes bilaterally. Findings from this study document a variant appearance for intracranial coccidioidomycosis that, to the author's knowledge, has not been previously described in dogs. Authors propose that, although this variant demonstrates extensive pathological changes within the forebrain, the clinical outcome and response to treatment is favorable in a majority of cases.

Cerebrospinal fluid inflammatory cytokines and chemokines in naturally occurring canine spinal cord injury.

Canine intervertebral disk herniation (IVDH) is a common, naturally occurring form of spinal cord injury (SCI) that is increasingly being used in pre-clinical evaluation of therapies. Although IVDH bears critical similarities to human SCI with respect to lesion morphology, imaging features, and post-SCI treatment, limited data are available concerning secondary injury mechanisms. Here, we characterized cerebrospinal fluid (CSF) cytokines, and chemokines in dogs with acute, surgically treated, thoracolumbar IVDH (n=39) and healthy control dogs (n=21) to investigate early inflammatory events after SCI. A bioplex system was used to measure interleukin (IL)-2, -6, -7, -8, -10, -15, and -18, granulocyte macrophage colony-stimulating factor (GM-CSF), interferon gamma (IFN-γ), keratinocyte chemoattractant (KC)-like protein, IFN-γ-inducible protein-10, monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor alpha. Cytokine and chemokine concentrations in the CSF of healthy and SCI dogs were compared and, in SCI dogs, were correlated to the duration of SCI, behavioral measures of injury severity at the time of sampling, and neurological outcome 42 days post-SCI as determined by a validated ordinal score. IL-8 concentration was significantly higher in SCI cases than healthy controls (p=0.0013) and was negatively correlated with the duration of SCI (p=0.042). CSF MCP-1 and KC-like protein were positively correlated with CSF microprotein concentration in dogs with SCI (p<0.0001 and p=0.004). CSF MCP-1 concentration was negatively associated with 42-day postinjury outcome (p<0.0001). Taken together, these data indicate that cytokines and chemokines present after SCI in humans and rodent models are associated with SCI pathogenesis in canine IVDH.