Background There is little evidence‐based information available to guide treatment of refractory epilepsy in dogs. The antiepileptic drug levetiracetam (LEV) is administered to dogs, although its safety and efficacy are unknown. Objective To evaluate the safety and efficacy of LEV as adjunctive therapy for refractory epilepsy in dogs. Animals Thirty‐four client‐owned dogs with idiopathic epilepsy. Methods Randomized, blinded trial involving dogs resistant to phenobarbital and bromide. Dogs received LEV (20 mg/kg PO q8h) or placebo for 16 weeks, and after a 4‐week washout were crossed over to the alternate treatment for 16 weeks. Owners kept records on seizure frequency and adverse events. Hemogram, chemistry profile, urinalysis, and serum antiepileptic drug concentrations were evaluated at established intervals. Results Twenty‐two (65%) dogs completed the study. Weekly seizure frequency during the 1st treatment period decreased significantly during LEV administration relative to baseline (1.9 ± 1.9 to 1.1 ± 1.3, P = .015). The reduction in seizures with LEV was not significant when compared to placebo (1.1 ± 1.3 versus 1.5 ± 1.7, P = .310). The most common adverse event was ataxia, with no difference in incidence between LEV and placebo (45 versus 18%, P = .090). No changes in laboratory parameters were identified and owners reported an improved quality of life (QOL) with LEV compared to placebo (QOL score 32.7 ± 4.3 versus 29.4 ± 4.5, P = .028). Conclusions and Clinical Importance Adjunctive treatment with LEV appears safe in epileptic dogs. Efficacy of LEV over placebo was not demonstrated, although the power of the study was limited. Further evaluation of LEV as treatment for epilepsy in dogs is warranted.

Background: Acute intervertebral disk herniation (IVDH) is a common cause of spinal cord injury in dogs and currently there is no proven medical treatment to counter secondary injury effects. Use of methylprednisolone sodium succinate (MPSS) or polyethylene glycol (PEG) as neuroprotectants is advocated but controversial because neither treatment has been tested in placebo-controlled, randomized, blinded trials in dogs. Hypothesis: Polyethylene glycol will improve the outcome of severe spinal cord injury caused by IVDH compared to MPSS or placebo. Animals: Client-owned dogs with acute onset of thoracolumbar IVDH causing paralysis and loss of nociception for <24 hours. Methods: Dogs were randomized to receive MPSS, PEG, or placebo; drugs appeared identical and group allocation was masked. Drug administration was initiated once the diagnosis of IVDH was confirmed and all dogs underwent hemilaminectomy. Neurologic function was assessed 2, 4, 8, and 12 weeks postoperatively using an open field gait score (OFS) as the primary outcome measure. Outcomes were compared by the Wilcoxon rank sum test. Results: Sixty-three dogs were recruited and 47.6% recovered ambulation. 17.5% developed progressive myelomalacia but there was no association with group. There was no difference in OFS among groups. Although full study power was not reached, conditional power analyses indicated the futility of continued case recruitment. Conclusions: This clinical trial did not show a benefit of either MPSS or PEG in the treatment of acute, severe thoracolumbar IVDH when used as adjunctive medical treatment administered to dogs presenting within 24 hours of onset of paralysis.

Background: Reports of histiocytic sarcoma (HS) involving the central nervous system (CNS) are sparse and consist mainly of case reports describing 1–3 animals. Objective: The objective of this study was to report the signalments, clinical signs, clinicopathologic and diagnostic imaging findings, treatment, and outcome of a series of dogs with HS and CNS involvement. Animals: Nineteen dogs with HS examined at veterinary referral hospitals. Methods: Retrospective case series. Medical records were reviewed and cases with a histopathological diagnosis of CNS HS were included in the study. Diagnostic imaging studies of the CNS were evaluated and histopathologic samples were reviewed to confirm the diagnosis. Results: Retrievers and Pembroke Welsh Corgis were overrepresented in this cohort of dogs. Tumors involved the brain in 14 dogs and the spinal cord in 5. In 4 dogs, HS was part of a disseminated, multiorgan process whereas it appeared confined to the CNS in 15 dogs. Diagnostic imaging had variable appearances although extraaxial masses predominated in the brain. There was meningeal enhancement in all dogs that was often profound and remote from the primary mass lesion. Pleocytosis was present in all dogs with CSF evaluation. Median survival was 3 days. Conclusions and Clinical Importance: Breed predispositions appear to vary from reports of HS in other organ systems. Some unique imaging and clinicopathologic characteristics, particularly brain herniation, profound meningeal enhancement, and pleocytosis in combination with 1 or more mass lesions, might help to differentiate this neoplasm from others involving the CNS, although this requires further study.

Objective—To determine clinical signs, results of diagnostic testing, underlying cause, and outcome in cats with seizures. Design—Retrospective study. Animals—17 cats with seizures. Procedure—Only those cats in which an underlying metabolic abnormality causing the seizures had been identified, diagnostic imaging of the brain and CSF analysis had been done, or a necropsy had been performed were included. Seizures were classified as being a result of metabolic disease, symptomatic epilepsy (ie, epilepsy resulting from a structural lesion of the brain), or probably symptomatic epilepsy (ie, epilepsy without any extracranial or identifiable intracranial disease that is not suspected to be genetic in origin). Results—3 cats had seizures associated with an underlying metabolic disease (hepatic encephalopathy), 7 had symptomatic epilepsy (3 with neoplasia and 4 with meningoencephalitis), and 7 had probably symptomatic epilepsy. Six of the 7 cats with symptomatic epilepsy died or were euthanatized within 3 months after the diagnosis was made, whereas 6 of the 7 cats with probably symptomatic epilepsy survived for at least 12 months after the diagnosis was made. Conclusions and Clinical Relevance—Results suggest that cats with probably symptomatic epilepsy may have a good long-term prognosis. (J Am Vet Med Assoc 2004;225:1723–1726)

Progressive myelomalacia (PMM) is a catastrophic disease associated with acute intervertebral disc extrusion (IVDE). Published data on the clinical characteristics of this disease are limited. To describe the onset and progression of clinical signs of PMM in a large case cohort. Fifty-one dogs, 18 with histopathologically confirmed PMM, 33 presumptively diagnosed based on clinical signs and diagnostic imaging. Retrospective study. Dogs with confirmed IVDE and either a histopathologic diagnosis of PMM or a high clinical suspicion were identified by medical record search. Data on nature and progression of signs were extracted. Twenty-four of 51 dogs were Dachshunds. T12–T13 was the most common site of disc extrusion (12 of 56), and 18 of 55 of mid-to-caudal lumbar discs (between L3 and L6) were affected. Onset of PMM signs ranged from present at first evaluation (17/51) to 5 days after presentation, with 25 of 51 cases developing signs within 48 hours. Progression of signs from onset of PMM to euthanasia or death, excluding 7 cases euthanized at presentation, ranged from 1 to 13 days with 23 being euthanized within 3 days. Nonspecific systemic signs were documented in 30 of 51 dogs. The majority of dogs developed PMM within 2 days of presentation and was euthanized within another 3 days. However, onset can be delayed up to 5 days after presentation with progression to euthanasia taking as long as 2 weeks. Mid-to-caudal lumbar discs might be associated with an increased risk of PMM.