Epilepsy In Dogs Research Articles

Zonisamide monotherapy for idiopathic epilepsy in dogs

AIM: To evaluate the efficacy of zonisamide as a monotherapy in dogs with idiopathic epileptic seizure. METHODS: The experiment was conducted on 10 dogs with idiopathic epilepsy that were treated at the Seoul National University Hospital for Animals. A diagnosis was conducted based on physical and neurologic examination, complete blood count and chemical analysis, magnetic resonance imaging and cerebrospinal fluid analyses. Idiopathic epilepsy was diagnosed when all of these examinations were normal. Oral zonisamide was administrated to 10 dogs with idiopathic epilepsy at 5–15 mg/kg per os every 12 h to achieve a concentration of zonisamide in serum of 10–40 μg/mL. The frequency of seizures before and after the administration of zonisamide therapy was recorded and the concentrations of zonisamide in serum were measured. RESULTS: Six (60%) of the dogs were favourable responders to treatment, showing a ≥50% reduction in monthly frequency of seizures. Of the remaining four, two dogs did not show a reduction and the other two showed an increase in frequency of seizures. The mean dosage of zonisamide for favourable responders was 7.92 (SD 3.79) mg/kg, which was administered orally twice a day. Only one dog, which was one of the unfavourable responders in the whole study, experienced mild side effects. CONCLUSIONS: Among the dogs treated with oral zonisamide, 60% responded favourably. The effect of zonisamide as an anticonvulsant drug was demonstrated in this study. CLINICAL RELEVANCE: Based on these results, zonisamide monotherapy is effective in some dogs with idiopathic epilepsy.

Comparison of phenobarbital with bromide as a first-choice antiepileptic drug for treatment of epilepsy in dogs

To compare efficacy and safety of treatment with phenobarbital or bromide as the first-choice antiepileptic drug (AED) in dogs. Double-blinded, randomized, parallel, clinical trial. 46 AED-naïve dogs with naturally occurring epilepsy. Study inclusion was based on age, history, findings on physical and neurologic examinations, and clinicopathologic test results. For either phenobarbital treatment (21 dogs) or bromide treatment (25), a 7-day loading dose period was initiated along with a maintenance dose, which was adjusted on the basis of monthly monitoring. Efficacy and safety outcomes were compared between times (baseline and study end [generally 6 months]) and between drugs. Phenobarbital treatment resulted in eradication of seizures (17/20 [85%]) significantly more often than did bromide (12/23 [52%]); phenobarbital treatment also resulted in a greater percentage decrease in seizure duration (88 ± 34%), compared with bromide (49 ± 75%). Seizure activity worsened in 3 bromide-treated dogs only. In dogs with seizure eradication, mean ± SD serum phenobarbital concentration was 25 ± 6 μg/mL (phenobarbital dosage, 4.1 ± 1.1 mg/kg [1.9 ± 0.5 mg/lb], p.o., q 12 h) and mean serum bromide concentration was 1.8 ± 0.6 mg/mL (bromide dosage, 31 ± 11 mg/kg [14 ± 5 mg/lb], p.o., q 12 h). Ataxia, lethargy, and polydipsia were greater at 1 month for phenobarbital-treated dogs; vomiting was greater for bromide-treated dogs at 1 month and study end. Both phenobarbital and bromide were reasonable first-choice AEDs for dogs, but phenobarbital was more effective and better tolerated during the first 6 months of treatment.

Investigating epilepsy in dogs

WHEN a dog is presented with recurrent seizures, investigation proceeds to find an underlying cause. Symptomatic epilepsy occurs secondarily to a structural disorder of the central nervous system (CNS), eg,...

Evaluation of Levetiracetam as Adjunctive Treatment for Refractory Canine Epilepsy: A Randomized, Placebo‐Controlled, Crossover Trial

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. To evaluate the safety and efficacy of LEV as adjunctive therapy for refractory epilepsy in dogs. Thirty-four client-owned dogs with idiopathic epilepsy. 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. 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). 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.

LGI2 Truncation Causes a Remitting Focal Epilepsy in Dogs

One quadrillion synapses are laid in the first two years of postnatal construction of the human brain, which are then pruned until age 10 to 500 trillion synapses composing the final network. Genetic epilepsies are the most common neurological diseases with onset during pruning, affecting 0.5% of 2–10-year-old children, and these epilepsies are often characterized by spontaneous remission. We previously described a remitting epilepsy in the Lagotto romagnolo canine breed. Here, we identify the gene defect and affected neurochemical pathway. We reconstructed a large Lagotto pedigree of around 34 affected animals. Using genome-wide association in 11 discordant sib-pairs from this pedigree, we mapped the disease locus to a 1.7 Mb region of homozygosity in chromosome 3 where we identified a protein-truncating mutation in the Lgi2 gene, a homologue of the human epilepsy gene LGI1. We show that LGI2, like LGI1, is neuronally secreted and acts on metalloproteinase-lacking members of the ADAM family of neuronal receptors, which function in synapse remodeling, and that LGI2 truncation, like LGI1 truncations, prevents secretion and ADAM interaction. The resulting epilepsy onsets at around seven weeks (equivalent to human two years), and remits by four months (human eight years), versus onset after age eight in the majority of human patients with LGI1 mutations. Finally, we show that Lgi2 is expressed highly in the immediate post-natal period until halfway through pruning, unlike Lgi1, which is expressed in the latter part of pruning and beyond. LGI2 acts at least in part through the same ADAM receptors as LGI1, but earlier, ensuring electrical stability (absence of epilepsy) during pruning years, preceding this same function performed by LGI1 in later years. LGI2 should be considered a candidate gene for common remitting childhood epilepsies, and LGI2-to-LGI1 transition for mechanisms of childhood epilepsy remission.

Effects of essential fatty acid supplementation in dogs with idiopathic epilepsy: A clinical trial

The effects of essential fatty acid supplementation (EFA) on the control of idiopathic epilepsy in dogs were investigated in a blinded, placebo-controlled trial. Fifteen dogs were treated with triple purified Ω-3 oil containing 400 mg eicosapentaenoic acid, 250 mg docosahexaenoic acid and 22 mg vitamin E per 1.5 mL at a dose of 1.5 mL/10 kg once daily for 12 weeks, followed by a 12 week placebo period of supplementation with olive oil. Owners recorded seizure frequency and severity and any adverse events. EFA supplementation did not reduce seizure frequency or severity in dogs with idiopathic epilepsy.

Behavioral changes in dogs associated with the development of idiopathic epilepsy

Objectives The aim of the study was to demonstrate behavioral changes with the development of epilepsy in dogs, a species proposed as a naturally occurring animal model for human epilepsy. Methods Owners of dogs diagnosed with idiopathic epilepsy ( n = 80) completed a modified, previously-validated behavioral and seizure questionnaire. Principal axis factor analysis identified behavioral factors, the scores for which were compared before and after the development of epilepsy. Results Drug-naïve dogs showed an increase in the behavior factors Fear/Anxiety, Defensive Aggression, and Abnormal Perception. In dogs receiving antiepileptic medication, there were still increases in Fear/Anxiety and Abnormal Perception, but no longer in Defensive Aggression. Additional increases were observed in Abnormal Reactivity, Attachment Disorder, Demented Behavior, and Apathetic Behavior. Pharmacoresistant dogs had larger increases in Controlling Aggression, Abnormal Perception, and Demented Behavior than drug responders. Conclusion Our data suggest that dogs, like humans and rodents, exhibit neurobehavioral comorbidities with the development of epilepsy.

Refractory epilepsy in dogs

Refractory epilepsy in dogs

Positive impact of omega-3 fatty acid supplementation in a dog with drug-resistant epilepsy: A case study

Epilepsy is the most common neurological disorder in both dogs and humans. Although the pharmacological options for treatment of epilepsies have increased, it has been reported that two-thirds of dogs with epilepsy are refractory to antiepileptic drug therapy. To our knowledge, there are no experimental studies in the literature that show an effect of omega-3 supplementation on epilepsy in dogs. Our case study describes the effectiveness of daily intake of a moderate amount of fish oil in a case of canine epilepsy.

Getting touch on seizures

Abstract Simon Platt explores the increasing number of options available for treatment epilepsy in dogs.

Premature Death, Risk Factors, and Life Patterns in Dogs with Epilepsy

Background: Epilepsy in dogs is often difficult to medically control, resulting in premature death of dogs with epilepsy. However, the risks of premature death are not known. Hypothesis: Dogs with epilepsy have an increased risk of premature death as compared to a general population of dogs. Animals: Sixty‐three dogs diagnosed with epilepsy between 1993 and 1996 were included in this study. Methods: A prospective longitudinal study of the population was performed from the diagnosis of epilepsy until the time of euthanasia, death, or a maximum of 12 years to investigate mortality and risk factors. Information about sex, onset, type, frequency, and control of seizures, remission of epilepsy, death, cause of death, and owner's perspective was collected and analyzed. Results: The median age at death of dogs was 7.0 years. The life span of dogs in which euthanasia or death was directly caused by their epileptic condition was significantly shorter as compared with epileptic dogs that were euthanized because of other causes (P= .001). The median number of years that a dog lived with epilepsy was 2.3 years. Females lived longer with epilepsy than males (P= .036). Seizure type (primary generalized versus focal seizures) was not significantly associated with survival time. The remission rate of epilepsy (spontaneous remission and remission with treatment) was 15%.Conclusion and Clinical Importance: The diagnosis of epilepsy implies an increased risk of premature death. The prognosis for dogs with epilepsy is dependent on a combination of veterinary expertise, therapeutic success, and the owner's motivation.

Prospective study of zonisamide therapy for refractory idiopathic epilepsy in dogs

Investigation of the efficacy of zonisamide as an add-on therapy in dogs with refractory epilepsy. Thirteen dogs fulfilled the inclusion criteria of poor seizure control despite adequate serum levels of phenobarbital, potassium bromide or both. One further dog was treated with zonisamide as monotherapy because of severe blood dyscrasia due to phenobarbital treatment. Various seizure parameters were evaluated retrospectively for a four month period without zonisamide and prospectively for the same time period under zonisamide add-on therapy. The study time period was extended by up to 17 months to evaluate long-term outcome. Data of 11 dogs could be evaluated: nine of them were responders. The median reduction of seizure frequency of all dogs on zonisamide add-on therapy was 70 per cent (range 14 to 100 per cent). Only transient central nervous system side effects were reported. No further increase of liver enzymes occurred. In three of the responder dogs, seizure control subsided after individual time periods (between 69 days and seven months). In dogs with refractory epilepsy, zonisamide may have a beneficial effect on seizure control. In three responder dogs, seizure activity relapsed possibly because of an induction of tolerance. Limiting factors are the high costs.

Outcomes from homeopathic prescribing in veterinary practice: a prospective, research-targeted, pilot study

Background and aims Targeted research development in veterinary homeopathy is properly informed by the systematic collection and analysis of relevant clinical data obtained by its practitioners. We organised a pilot data collection study, in which 8 Faculty of Homeopathy veterinarians collected practice-based clinical and outcomes data over a 6-month period. Methods A specifically designed Excel spreadsheet enabled recording of consecutive clinical appointments under the following headings: date; identity of patient and owner (anonymised) ; age, sex and species of patient; medical condition/complaint treated; whether confirmed diagnosis, chronic or acute, new or follow-up case; owner-assessed outcome (7-point Likert scale: −3 to +3) compared with first appointment; homeopathic medicine/s prescribed; other medication/s for the condition/complaint. Spreadsheets were submitted monthly by e-mail to the project organisers for data checking, synthesis and analysis. Results Practitioners submitted data regularly and punctually, and most data cells were completed. 767 individual patients were treated (547 dogs, 155 cats, 50 horses, 5 rabbits, 4 guinea-pigs, 2 birds, 2 goats, 1 cow, and 1 tortoise). Outcome from two or more homeopathic appointments per patient condition was obtained in 539 cases (79.8% showing improvement, 6.1% deterioration, 11.7% no change; outcome not recorded in 2.4% of follow-ups). Strongly positive outcomes (scores of +2 or +3) were achieved in: arthritis and epilepsy in dogs and, in smaller numbers, in atopic dermatitis, gingivitis and hyperthyroidism in cats. Conclusions Systematic recording of data by veterinarians in clinical practice is feasible and capable of informing future research in veterinary homeopathy. A refined version of the spreadsheet can be used in larger-scale research-targeted veterinary data collection.

Premature Death, Risk Factors, and Life Patterns in Dogs with Epilepsy

Epilepsy in dogs is often difficult to medically control, resulting in premature death of dogs with epilepsy. However, the risks of premature death are not known. Dogs with epilepsy have an increased risk of premature death as compared to a general population of dogs. Sixty-three dogs diagnosed with epilepsy between 1993 and 1996 were included in this study. A prospective longitudinal study of the population was performed from the diagnosis of epilepsy until the time of euthanasia, death, or a maximum of 12 years to investigate mortality and risk factors. Information about sex, onset, type, frequency, and control of seizures, remission of epilepsy, death, cause of death, and owner's perspective was collected and analyzed. The median age at death of dogs was 7.0 years. The life span of dogs in which euthanasia or death was directly caused by their epileptic condition was significantly shorter as compared with epileptic dogs that were euthanized because of other causes (P = .001). The median number of years that a dog lived with epilepsy was 2.3 years. Females lived longer with epilepsy than males (P = .036). Seizure type (primary generalized versus focal seizures) was not significantly associated with survival time. The remission rate of epilepsy (spontaneous remission and remission with treatment) was 15%. The diagnosis of epilepsy implies an increased risk of premature death. The prognosis for dogs with epilepsy is dependent on a combination of veterinary expertise, therapeutic success, and the owner's motivation.

Clinical management of idiopathic epilepsy in dogs with homeopathic Belladonna 200C: a case series

Epilepsy is an important neurological disorder in dogs. Belladonna 200C was evaluated in 10 dogs with idiopathic epilepsy. During the seizure phase, 3–4 drops of Belladonna 200C were administered orally at 15 min intervals until considerable reduction in seizure activity, then four times daily. Four dogs with head shaking syndrome in addition to seizures were given Cocculus 6C, 3–4 drops orally weekly for 3 months in addition. Numbers of fits reduced to 2–3 during first 2 weeks post-therapy and then became occasional in next 2 weeks. With continuation of Belladonna therapy, no fits were observed during 2–7 months follow-up. In two cases epileptic fits reappeared within 15–25 days of cessation of therapy. Belladonna therapy was resumed and seizure control was again achieved. Owners were advised to continue the therapy at least twice daily until there were no fits for 2–3 months. Liver specific enzymes were monitored, no abnormalities were observed.

Idiopathic epilepsy in dogs: owners’ perspectives on management with phenobarbitone and/or potassium bromide

To explore seizure management from the perspective of the owners of dogs with idiopathic epilepsy. Questionnaires were mailed to owners of 29 dogs under management for suspected or diagnosed idiopathic epilepsy through the clinics of the Small Animal Hospital of the University of Glasgow Veterinary School, using either phenobarbitone or potassium bromide alone or in combination. The postal survey had an 86 per cent response rate. Analysis of the responses demonstrated that "the dog's quality of life", "adequate seizure frequency" and "acceptable side effects of antiepileptic drugs" were the three greatest concerns for owners; 52 per cent of owners strongly agreed that the seizure management for their dog was adequate, though the seizure frequency reported varied within this group; the majority of owners did not consider the administration of medication a nuisance. However, approximately 60 per cent of owners reported that caring for an epileptic dog had an effect on the organisation of their free time, though this was not dependent on perception of seizure control. Opinions as to the value of further diagnostic procedures, in particular intracranial imaging, were significantly affected by having pet health insurance. From the owners' perspective, adequacy of seizure control is determined by the balance between "the dog's quality of life", "adequate seizure frequency" and "acceptable side effects of antiepileptic drugs". A frequency of less than one seizure every three months is associated with the perception by owners of adequate seizure control.

Use of vagal nerve stimulation as a treatment for refractory epilepsy in dogs

To evaluate safety and efficacy of vagal nerve stimulation in dogs with refractory epilepsy. Placebo-controlled, double-masked, crossover study. 10 dogs with poorly controlled seizures. A programmable pacemaker-like device designed to deliver intermittent stimulation to the left cervical trunk of the vagus was surgically implanted in each dog. Dogs were assigned randomly to two 13-week test periods, 1 with nerve stimulation and 1 without nerve stimulation. Owners recorded data on seizure frequency, duration, and intensity, as well as adverse effects. No significant difference in seizure frequency, duration, or severity was detected between overall 13-week treatment and control periods. During the final 4 weeks of the treatment period, a significant decrease in mean seizure frequency (34.4%) was detected, compared with the control period. Complications included transient bradycardia, asystole, and apnea during intraoperative device testing, and seroma formation, subcutaneous migration of the generator, and transient Horner's syndrome during the 14-day period between surgery and suture removal. No adverse effects of stimulation were detected, and most owners were satisfied with the treatment. Vagal nerve stimulation is a potentially safe approach to seizure control that appears to be efficacious in certain dogs and should be considered a possible treatment option when antiepileptic medications are ineffective.

Absence of temporal lobe epilepsy pathology in dogs with medically intractable epilepsy.

Epilepsy is a common neurological problem in dogs. In some dogs, seizures cannot be controlled adequately with anticonvulsant medication. Temporal lobe epilepsy is the most common type of epilepsy in adult humans, it is frequently resistant to anticonvulsant therapy, and it is commonly associated with characteristic neuropathological abnormalities in the hippocampal dentate gyrus. We sought to test the hypothesis that dogs with medically intractable epilepsy have temporal lobe epilepsy. The hippocampi of 6 dogs that were euthanized because of chronic, recurrent seizures were compared with those of 8 nonepileptic controls. In control and epileptic dogs, stereological cell counting showed similar numbers of neurons in the hilus of the dentate gyrus, somatostatin immunoreactivity identified numerous immunopositive neurons in the hilus, and Timm staining showed the normal pattern of granule cell axon projections. These findings demonstrate a lack of hilar neuron loss and granule cell axon reorganization, suggesting that temporal lobe epilepsy is not a common cause of medically intractable epilepsy in dogs.

Absence of Temporal Lobe Epilepsy Pathology in Dogs with Medically Intractable Epilepsy

Epilepsy is a common neurological problem in dogs. In some dogs, seizures cannot be controlled adequately with anticonvulsant medication. Temporal lobe epilepsy is the most common type of epilepsy in adult humans, it is frequently resistant to anticonvulsant therapy, and it is commonly associated with characteristic neuropathological abnormalities in the hippocampal dentate gyrus. We sought to test the hypothesis that dogs with medically intractable epilepsy have temporal lobe epilepsy. The hippocampi of 6 dogs that were euthanized because of chronic, recurrent seizures were compared with those of 8 nonepileptic controls. In control and epileptic dogs, stereological cell counting showed similar numbers of neurons in the hilus of the dentate gyrus, somatostatin immunoreactivity identified numerous immunopositive neurons in the hilus, and Timm staining showed the normal pattern of granule cell axon projections. These findings demonstrate a lack of hilar neuron loss and granule cell axon reorganization, suggesting that temporal lobe epilepsy is not a common cause of medically intractable epilepsy in dogs.

Idiopathic Epilepsy in Dogs

Idiopathic epilepsy is a chronic condition characterized by recurrent seizures for which there is no identifiable cause. It is the most common neurologic disorder in the dog. This article discusses the diagnostic evaluation and rational treatment of dogs with recurrent seizures. Types of seizures, client education, choice of therapy, use of specific drugs, therapeutic monitoring, and nondrug treatments are reviewed.