Background: Thoracolumbar intervertebral disc extrusion (TL-IVDE) is the most common cause of acute paraparesis and paraplegia in dogs; however, guidelines on management of the condition are lacking. Objectives: To summarize the current literature as it relates to diagnosis and management of acute TL-IVDE in dogs, and to formulate clinically relevant evidence-based recommendations. Animals: None. Methods: A panel of 8 experts was convened to assess and summarize evidence from the peer-reviewed literature in order to develop consensus clinical recommendations. Level of evidence available to support each recommendation was assessed and reported. Results: The majority of available literature described observational studies. Most recommendations made by the panel were supported by a low or moderate level of evidence, and several areas of high need for further study were identified. These include better understanding of the ideal timing for surgical decompression, expected surgical vs medical outcomes for more mildly affected dogs, impact of durotomy on locomotor outcome and development of progressive myelomalacia, and refining of postoperative care, and genetic and preventative care studies. Conclusions and Clinical Importance: Future efforts should build on current recommendations by conducting prospective studies and randomized controlled trials, where possible, to address identified gaps in knowledge and to develop cost effectiveness and number needed to treat studies supporting various aspects of diagnosis and treatment of TL-IVDE.

Background: The diagnosis of encephalitis is usually presumptive based on MRI, cerebrospinal fluid analysis, or both. A definitive diagnosis based on histopathology, however, is required for optimizing treatment strategies. Objective: To investigate the diagnostic yield and adverse effects of minimally invasive brain biopsies in dogs with encephalitis. Animals: Seventeen dogs with suspected encephalitis, based on MR imaging and cerebrospinal fluid analysis. Methods: Retrospective study. Minimally invasive, free-hand brain biopsy specimens were taken from forebrain lesions through a 4-mm burr hole using a Sedan side-cutting needle. Routine histopathological examination was performed. The adverse effects were assessed by MRI evaluations after biopsy procedure (12/17) and by sequential neurological examinations. Results: The overall diagnostic yield with regard to a specific type of encephalitis was 82%. Encephalitis was evident in an additional 12%, but a specific disease could not be determined. There were no deaths caused by the biopsy procedure itself, but the indirect case fatality rate was 6%. Morbidity was 29%, including stupor, seizures, tetraparesis, hemiparesis, ataxia, and loss of conscious proprioception. All these signs resolved within 3–14 days. Conclusions and Clinical Importance: Minimally invasive brain biopsy in dogs with suspected encephalitis leads to a definite diagnosis in the majority of dogs, allowing for a specific treatment. The advantages of a definite diagnosis outweigh potential case fatality rate and temporary neurological deficits.

Diagnosing necrotizing encephalitis, with its subcategories of Necrotizing Leukoencephalitis and Necrotizing Meningoencephalitis, based on MRI alone can be challenging. However, there are breed specific imaging characteristics in both subcategories that allow establishing a clinical diagnosis with a relatively high degree of certainty. Typical breed specific imaging features, such as lesion distribution, signal intensity, contrast enhancement and gross changes of brain structure (midline shift, ventriculomegaly, brain herniation) are summarized here, using current literature, for the most commonly affected canine breeds: Yorkshire Terrier, French Bulldog, Pug and Chihuahua.

Objective—To compare oral administration of lomustine and prednisolone with oral administration of prednisolone alone as treatment for granulomatous meningoencephalomyelitis (GME) or necrotizing encephalitis (NE) in dogs. Design—Retrospective cohort study. Animals—25 dogs with GME and 18 dogs with NE (diagnosis confirmed in 8 and 5 dogs, respectively). Procedures—Records of dogs with GME or NE were reviewed for results of initial neurologic assessments and clinicopathologic findings, treatment, follow-up clinicopathologic findings (for lomustine-treated dogs), and survival time. Dogs with GME or NE treated with lomustine and prednisolone were assigned to groups 1 (n = 14) and 3 (10), respectively; those treated with prednisolone alone were assigned to groups 2(11) and 4 (8), respectively. Results—Prednisolone was administered orally every 12 hours to all dogs. In groups 1 and 3, mean lomustine dosage was 60.3 mg/m², PO, every 6 weeks. Median survival times in groups 1 through 4 were 457, 329, 323, and 91 days, respectively (no significant difference between groups 1 and 2 or between groups 3 and 4). Within the initial 12 months of treatment, median prednisolone dosage was reduced in all groups; dosage reduction in group 1 was significantly larger than that in group 2 at 6, 9, and 12 months. Combination treatment most frequently caused leukopenia, but had no significant effect on liver enzyme activities. Conclusions and Clinical Relevance—In dogs with GME and NE, oral administration of lomustine and prednisolone or prednisolone alone had similar efficacy. Inclusion of lomustine in the treatment regimen was generally tolerated well.