BackgroundProgressive myelomalacia (PMM) is a catastrophic disease associated with acute intervertebral disc extrusion (IVDE). Published data on the clinical characteristics of this disease are limited.ObjectiveTo describe the onset and progression of clinical signs of PMM in a large case cohort.AnimalsFifty‐one dogs, 18 with histopathologically confirmed PMM, 33 presumptively diagnosed based on clinical signs and diagnostic imaging.MethodsRetrospective 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.ResultsTwenty‐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.Conclusion and Clinical ImportanceThe 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.

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.

Understanding the common practices in the management of canine acute intervertebral disc herniation can provide a springboard for future discussions regarding the best practices in diagnosing and treating this disease.

BackgroundAcute 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.HypothesisPolyethylene glycol will improve the outcome of severe spinal cord injury caused by IVDH compared to MPSS or placebo.AnimalsClient‐owned dogs with acute onset of thoracolumbar IVDH causing paralysis and loss of nociception for <24 hours.MethodsDogs 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.ResultsSixty‐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.ConclusionsThis 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.

BackgroundExperimental evidence shows benefit of rehabilitation after spinal cord injury (SCI) but there are limited objective data on the effect of rehabilitation on recovery of dogs after surgery for acute thoracolumbar intervertebral disc herniations (TL‐IVDH).ObjectiveCompare the effect of basic and intensive post‐operative rehabilitation programs on recovery of locomotion in dogs with acute TL‐IVDH in a randomized, blinded, prospective clinical trial.AnimalsThirty non‐ambulatory paraparetic or paraplegic (with pain perception) dogs after decompressive surgery for TL‐IVDH.MethodsBlinded, prospective clinical trial. Dogs were randomized (1:1) to a basic or intensive 14‐day in‐house rehabilitation protocol. Fourteen‐day open field gait score (OFS) and coordination (regulatory index, RI) were primary outcomes. Secondary measures of gait, post‐operative pain, and weight were compared at 14 and 42 days.ResultsOf 50 dogs assessed, 32 met inclusion criteria and 30 completed the protocol. There were no adverse events associated with rehabilitation. Median time to walking was 7.5 (2 – 37) days. Mean change in OFS by day 14 was 6.13 (confidence intervals: 4.88, 7.39, basic) versus 5.73 (4.94, 6.53, intensive) representing a treatment effect of −0.4 (−1.82, 1.02) which was not significant, P=.57. RI on day 14 was 55.13 (36.88, 73.38, basic) versus 51.65 (30.98, 72.33, intensive), a non‐significant treatment effect of −3.47 (−29.81, 22.87), P = .79. There were no differences in secondary outcomes between groups.ConclusionsEarly postoperative rehabilitation after surgery for TL‐IVDH is safe but doesn't improve rate or level of recovery in dogs with incomplete SCI.

This crossover study compared the pharmacokinetics of cytarabine in six healthy dogs following intravenous constant rate infusion (CRI) and subcutaneous (SC) administrations, as these are two routes of administration commonly employed in the treatment of meningoencephalitis of unknown etiology. Each dog received a SC cytarabine injection of 50 mg/m(2) or an 8 h CRI of 25 mg/m(2) per hour, with a 7-day washout before receiving the alternative treatment. Blood samples were collected for 16 h after CRI initiation and for 8 h after SC injection. Plasma concentrations were measured by high-pressure liquid chromatography (HPLC). Pharmacokinetic parameters were estimated using the best-fit compartmental analysis for both CRI and SC routes. Terminal half-life (T(1/2) ) of cytarabine was 1.35 ± 0.3 and 1.15 ± 0.13 h after SC administration and CRI, respectively. Mean peak concentration (Cmax ) was 2.88 and 2.80 μg/mL for SC and CRI administration, respectively. Volume of distribution was 0.66 ± 0.07 l/kg. The 8-h CRI produced steady-state plasma concentrations as determined by consecutive measurement that did not decline until the end of the infusion. The SC administration did not achieve steady-state concentrations because cytarabine administered by this route was rapidly absorbed and eliminated quickly. The steady state achieved with the cytarabine CRI may produce a more prolonged exposure of cytarabine at cytotoxic levels in plasma compared to the concentrations after SC administration.

Background Steroid‐responsive meningitis‐arteritis (SRMA) is a common inflammatory neurologic disorder of dogs for which certain breeds are predisposed. Objectives To determine whether breed differences exist in clinical features, treatment response, and relapse in a population of North American dogs with SRMA, and to evaluate the effect of disease on dogs' quality of life (QoL). Animals Sixty‐one client‐owned dogs with SRMA: 29 dogs identified through an American Kennel Club‐Canine Health Foundation survey and 32 dogs from North Carolina (NC) State Veterinary Hospital. Methods Retrospective case series. Caregivers completed an online survey to assess QoL. Results Breeds represented most often included the Golden Retriever (n = 12), Bernese Mountain Dog (10), Wirehaired Pointing Griffon (9), Boxer (9), and Beagle (6). No breed differences were identified with respect to clinical severity, diagnostic findings, or outcome. Twenty‐nine dogs (48%) had ≥1 disease relapse. There was a significant effect of cerebrospinal fluid nucleated cell count on the frequency of disease relapse ( P = .003), but no relationship was identified between treatment protocol and relapse. Dogs' QoL was associated with the severity of corticosteroid‐related adverse effects ( P = .03), which were dose‐related ( r = .24, P = .02) and more prevalent in Wirehaired Pointing Griffons than in other breeds ( P = .04). Conclusion and Clinical Importance Golden Retrievers and Wirehaired Pointing Griffons should be considered among the breeds recognized to develop SRMA. Treatment with higher corticosteroid dosages is correlated with more severe adverse effects and worse QoL, but it may not improve clinical outcome.

BackgroundProgressive myelomalacia (PMM) is a usually fatal complication of acute intervertebral disc extrusion (IVDE) in dogs but its risk factors are poorly understood. The objective of this retrospective case-control study was to identify risk factors for PMM by comparing dogs with complete sensorimotor loss following IVDE that did and did not develop the disease after surgery. We also investigated whether any risk factors for PMM influenced return of ambulation. Medical records of client-owned dogs with paraplegia and loss of pain perception that underwent surgery for IVDE from 1998 to 2016, were reviewed. Dogs were categorized as PMM yes or no based on clinical progression or histopathology. Walking outcome at 6 months was established. Signalment, onset and duration of signs (categorized), steroids, non-steroidal anti-inflammatory drugs (yes or no), site of IVDE (lumbar intumescence or thoracolumbar) and longitudinal extent of IVDE were retrieved and their associations with PMM and walking outcome were examined using logistic regression.ResultsOne hundred and ninety seven dogs were included, 45 with and 152 without PMM. A 6-month-outcome was available in 178 dogs (all 45 PMM dogs and 133 control dogs); 86 recovered walking (all in the control group). Disc extrusions at the lumbar intumescence were associated with PMM (p = 0.01, OR: 3.02, CI: 1.3–7.2). Surgery performed more than 12 h after loss of ambulation was associated with PMM (OR = 3.4; CI = 1.1–10.5, p = 0.03 for 12-24 h and OR = 4.6; CI = 1.3–16.6, p = 0.02 for the > 24 h categories when compared with the ≤12 h category). Treatment with corticosteroids was negatively associated with PMM (OR: 3.1; CI: 1.3–7.6, p = 0.01). The only variable to affect walking outcome was longitudinal extent of IVDE (OR = 2.6; CI = 1.3–5.3, p = 0.006).ConclusionDogs with lumbar intumescence IVDE are at increased risk of PMM. Timing of surgery and corticosteroid use warrant further investigations. PMM and recovery of walking are influenced by different factors.