Seizure Activity In Dogs Research Articles

Cerebrospinal fluid lactate concentrations in dogs with seizure disorders.

BackgroundCerebrospinal fluid (CSF) lactate concentrations increase after seizure activity in many human patients independent of the underlying disease process. The effect of seizure activity on CSF lactate concentration in dogs is unknown.Hypothesis/ObjectivesCerebrospinal fluid lactate concentration is unaffected by seizure activity in dogs and is more dependent on the underlying disease process causing the seizures.AnimalsOne‐hundred eighteen client‐owned dogs with seizure disorders.MethodsCase series. Cerebrospinal fluid lactate concentration was determined using a commercially available lactate monitor. Seizure semiology, time from last seizure to CSF collection, number of seizures within the 72 hours preceding CSF collection, and clinical diagnosis were recorded.ResultsDogs with focal seizures had higher CSF lactate concentrations than did those with generalized seizures (P = .03). No differences in lactate concentrations were found among dogs with single seizures, cluster seizures or status epilepticus (P = .12), among dogs with CSF collection at different time points after the last seizure activity (P = .39) or among dogs having different numbers of seizures within the 72 hours preceding CSF collection (P = .42). A significant difference (P = .001) was found in CSF lactate concentrations among diagnostic groups, and dogs with inflammatory and neoplastic disease had higher concentrations than did dogs with idiopathic or unknown epilepsy.Conclusions and Clinical ImportanceCerebrospinal fluid lactate concentration is minimally affected by seizure activity in dogs and increased concentrations are more likely associated with the underlying disease process.

Feasibility of Non-Invasive Vagus Nerve Stimulation (gammaCore VET™) for the Treatment of Refractory Seizure Activity in Dogs.

Idiopathic epilepsy is the most common chronic neurologic condition in dogs. Approximately 20–30% of those dogs are refractory to standard medical therapy and commonly experience side effects from antiepileptic drugs. Non-invasive vagus nerve stimulation (nVNS) has been frequently used in human medicine as an adjunct seizure therapy with low incidence of adverse events. Canine studies are limited to invasive surgical implants with no non-invasive evaluations currently published. We investigated the feasibility and efficacy of nVNS (gammaCore VET) as an adjunct treatment for refractory epilepsy in dogs. In total, 14 client-owned dogs completed the trial of either 8- or 16-week treatment periods during which they received 90–120 s stimulation three times per day in the region of the left cervical vagus nerve. Owners recorded seizure type (focal or generalized) and frequency as well as any adverse effects. Out of 14 dogs, nine achieved a reduction in seizure frequency and four were considered responders with a 50% or greater reduction in seizures from baseline to the final treatment period. However, there was no statistically significant difference in overall seizure frequency (p = 0.53) or percent change in seizure frequency between groups (p = 0.75). Adverse effects occurred in 25% of dogs originally enrolled, with reports of a hoarse bark and limb trembling, lethargy, behavioral changes, and an increase in seizure frequency. Non-invasive VNS was found to be safe and easy to administer with mild adverse events. It is considered a feasible treatment option as an adjunct therapy in refractory seizures and should be further investigated.

Investigating owner use of dietary supplements in dogs with idiopathic epilepsy

Epilepsy is the most common chronic neurological disorder in dogs. Some diets have been shown to have a positive impact upon the seizure activity in dogs with idiopathic epilepsy (IE), while other diets and dietary supplements (DS), although marketed as providing health benefits, lack conclusive scientific evidence on their actual beneficial effects.A web-based owner questionnaire was designed to assess how and why owners of dogs with IE use different dietary regimes and DS. The study cohort, with 297 valid responses, consisted mainly of pure-breed (82.5%) male neutered (52.9%) dogs. Over two-thirds of owners (67.7%) changed their dog's diet after their dog received a diagnosis of IE. Nearly half of the owners (45.8%) reported giving DS, the most common being coconut oil or derived medium-chain triglyceride oil (71.3%). Some owner justifications of DS use included improvement of seizure frequency (88.2%), seizure severity (61.8%) and protection from potential drug side effects (62.5%).Many owners give DS to their dog with IE. The pharmacokinetic properties of anti-epileptic drugs, such as efficacy, absorption and clearance can be influenced by other medications, diets and possibly by DS. We propose that use of DS should be considered and monitored by veterinary surgeons in epilepsy management.

Physiological reactivity to spontaneously occurring seizure activity in dogs with epilepsy and their carers

There is a complex bidirectional relationship between stress and epilepsy. Stressful stimuli and subsequent cortisol release act as a trigger for seizure activity in some individuals with epilepsy, and seizure activity itself may act as a stressor to the affected individual. Epilepsy is the most common chronic neurological condition in domestic dogs and requires chronic management by their human carers, impacting upon the quality of life of both dog and carer. Seizures occur unpredictably and may be stressful for carers to witness and manage. In the present study we investigated the role of seizure activity as a stressor, measuring the effect of spontaneously occurring seizure activity in dogs with epilepsy upon their own cortisol levels and that of their carers. Furthermore, we tested whether individual differences in HPA reactivity were associated with owner personality characteristics and the quality of the dog–carer relationship. Saliva samples were obtained from sixteen dog-carer dyads in the home setting 20 and 40minute post-seizure, and at time-matched points on the following (non-seizure) day. Significant differences in cortisol levels were found in dogs at 40minute post-seizure (265.1% increase), and at 20minute post-seizure in their carers (40.5% increase). No associations were found between cortisol reactivity and the strength of the dog-carer bond. Carers with higher neuroticism scores exhibited higher cortisol levels at both post-seizure sampling points. As there was a gender bias in the carer sample (15/16 were female), and there are known sex differences in cortisol reactivity in response to psychological stress, the conclusions of this study may be limited to female carers. These findings are the first to objectively demonstrate the acutely stressful effects of seizures in dogs with epilepsy and their carers.

Seizure activity in dogs is associated with enhanced TIMP-2 expression of microglia

In the pathogenesis of epilepsy aberrant synaptic plasticity plays an important role. Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are responsible for nervous tissue remodelling resulting in synaptic plasticity in the central nervous system (CNS) and might therefore be crucially involved in epileptogenesis. To assess the potential pathogenetic role of microglial MMPs and TIMPs in seizure induction, twenty-four dogs suffering from different intracranial diseases with and without seizure activity were comparatively examined. Microglial cells were isolated by density gradient centrifugation and their expression profiles of MMP-2, MMP-9, MMP-12, MMP-13, MMP-14, TIMP-1, TIMP-2, and RECK (reversion-inducing cysteine-rich protein with Kazal motifs) were examined via quantitative real-time PCR (qPCR). Interestingly, a significant up-regulation of TIMP-2 expression was found for the first time in dogs suffering from seizures. In conclusion, microglial TIMP expression might be involved in seizure generation.

Improving seizure control in dogs with refractory epilepsy using gabapentin as an adjunctive agent

To assess whether there is a change in seizure activity in dogs with refractory epilepsy that are receiving appropriate doses of phenobarbitone and/or potassium bromide, when gabapentin is added to the therapeutic regimen. A prospective study of 17 dogs with a refractory seizure disorder, 16 of which have idiopathic epilepsy. Patients were stabilised using phenobarbitone and/or potassium bromide to produce tolerable therapeutic serum concentrations and dosed additionally with gabapentin at 35 to 50 mg/kg/d (divided twice or three times daily) for 4 months. Owners recorded seizure activity and side effects during this period in a standardised diary. Patients underwent monthly physical examinations and venepuncture to assess selected serum biochemical analytes, as well as phenobarbitone and bromide concentrations. Patients were further monitored for long-term response to adjunctive gabapentin therapy. There was no significant decrease in the number of seizures over the study period for the entire cohort, however three dogs stopped seizuring completely. There was a significant increase in the number of patients who showed an increase in the interictal period (P > 0.001). Serum alkaline phosphatase activity and triglyceride concentrations were elevated at baseline. There were no significant changes in biochemical analytes during the course of the study period. Side effects observed initially on addition of gabapentin included sedation and hind limb ataxia. The former resolved spontaneously after a few days; the latter after a slight reduction in bromide dose. Long-term, a further two patients became seizure free and ten patients remained on gabapentin indefinitely. No long-term side effects have become apparent. Addition of gabapentin to phenobarbitone and/or potassium bromide increased the interictal period and shortened the post-seizure recovery in some canine epileptics. In some dogs, seizures were prevented completely, while in others there was an increase in interictal period. The short-half life of gabapentin has advantages for seizure control, however its present high cost may prohibit therapy in large dogs.

Characteristics and phenomenology of epileptic partial seizures in dogs: similarities with human seizure semiology

Dogs with spontaneous occurring epilepsy with partial seizures express symptomatology resembling what is found in humans with partial epileptic seizures. Questionnaires on clinical signs from 70 dogs, with a confirmed diagnosis of epilepsy with partial seizures with or without secondary generalization, were reviewed in order to characterize and classify clinical signs of partial seizure activity in dogs and compare them to partial seizure phenomenology in humans. Signs of partial seizure activity were distributed into three categories: motor signs, autonomic signs and paroxysms of behavioral signs. Motor signs were described in 48 dogs (69%), autonomic signs in 16 dogs (23%) and paroxysms of behavioral signs in 56 dogs (80%). The majority of dogs expressed signs from more than one group. Sixty-one dogs (87%) had partial seizures with secondary generalization. Nine dogs (13%) had partial seizures without secondary generalization. The study shows a remarkable resemblance between the seizure phenomenology expressed in humans and canines with partial epileptic seizures.

THE USE OF ACEPROMAZINE IN DOGS WITH A HISTORY OF SEIZURES

Acepromazine (ACE) is a phenothiazine derivative used for its sedative properties. The primary mechanism of action of ACE is through inhibition of dopaminergic‐2 receptors in the brain. It is a common belief that ACE lowers the seizure threshold. The purpose of this clinical study is to retrospectively evaluate the occurrence of seizures in dogs presenting with a history of seizures that were treated with ACE during hospitalization. A retrospective review of records from dogs that had a chronic or acute seizure history and received ACE was done. Factors evaluated included the presenting complaint, historical seizure information, ACE dosage and route of administration, reason for giving and length of hospitalization following ACE, occurrence of seizure activity post‐ACE administration, time interval between ACE and seizure activity, and use of other medications. Thirty‐one dogs qualified for the study, 20 males and 11 females. Age range was 3 months ‐ 14.9 years. Presenting complaint was seizure in 28 patients, bite wound in 1 patient, ruptured cranial cruciate ligament in 1 patient, and hind limb paresis in 1 patient. Twenty‐seven dogs did not seize after ACE administration within an average of 16.4 hours of observation (range: 0.25–66 hours). There was a known history of seizures in 22/31 prior to the day of presentation, and 15/22 were currently on maintenance anti‐epileptic medication. Of the 16 not on anti‐seizure medication at the time of presentation, 13 were started on phenobarbital. One was also started on potassium bromide, and 3 received no anti‐seizure medication during hospitalization. All received at least one dose of ACE while in the hospital (range 1–5). Mean ACE dose was 0.029 mg/kg IV (range: 0.008–0.057 mg/kg; n=46), 0.036 mg/kg IM (range: 0.017–0.059 mg/kg; n=14), 0.53 mg/kg PO (n=2). Twenty‐three received some form of anti‐seizure medication in the hospital prior to being given ACE. Eight seizure episodes occurred 0.3–10 hours after ACE administration in 4. All 4 presented for seizures. The time interval between ACE administration and seizure activity was greater than that expected for measurable effects to be seen in one dog (10 hours). In conclusion, there is no clinical evidence that ACE administration at the listed dosages is associated with increased seizure activity in dogs with seizure disorders. A larger study group is needed to more thoroughly evaluate the safety of short‐term ACE use in dogs with a seizure history.