Behavioral changes in dogs associated with the development of idiopathic epilepsy

Quality-of-life aspects in idiopathic epilepsy in dogs

Quality of life (QoL) plays a significant role in the treatment of dogs with idiopathic epilepsy (IE), yet is so far understudied. This study describes the outcome evaluation of an online questionnaire based on the carer's perception focusing on 62 QoL questions in 159 dogs with IE. Results showed that seizure frequency, but not seizure severity or presence of cluster seizures, was significantly associated with carer-perceived dog's QoL. Dogs receiving third-line antiepileptic drugs had a significantly lower perceived QoL than those that did not. Generalised linear mixed model analysis demonstrated that severity of the side effects sleeping more and ataxia were significantly associated with carer-perceived dog's QoL, with higher severities predicting lower QoL scores. The degree of carer acceptability of seizure frequency and severity was significantly associated with the dog's reported seizure frequency and severity. Moreover, there was a significant association between IE-related QoL changes of the dog and the carer, with reductions in perceived canine QoL scores associated with reductions in carer QoL, and vice versa. In conclusion, aspects of canine IE can affect both the carer and their dog's QoL. This has implications for the management and requires consideration when treatment options and outcomes are discussed.

Effects of a ketogenic diet on ADHD-like behavior in dogs with idiopathic epilepsy

OBJECTIVES

Epilepsy in humans and rodent models of epilepsy can be associated with behavioral comorbidities including an increased prevalence of attention-deficit/hyperactivity disorder (ADHD). Attention-deficit/hyperactivity disorder symptoms and seizure frequency have been successfully reduced in humans and rodents using a ketogenic diet (KD). The aims of this study were (i) to describe the behavioral profile of dogs with idiopathic epilepsy (IE) while on a standardized nonketogenic placebo diet, to determine whether ADHD-like behaviors are present, and (ii) to examine the effect of a ketogenic medium chain triglyceride diet (MCTD) on the behavioral profile of dogs with idiopathic epilepsy (IE) compared with the standardized placebo control diet, including ADHD-like behaviors.

METHODS

A 6-month prospective, randomized, double-blinded, placebo-controlled, crossover dietary trial comparing the effects of the MCTD with a standardized placebo diet on canine behavior was carried out. Dogs diagnosed with IE, with a seizure frequency of at least 3 seizures in the past 3months (n=21), were fed the MCTD or placebo diet for 3months and were then switched to the alternative diet for 3months. Owners completed a validated behavioral questionnaire to measure 11 defined behavioral factors at the end of each diet period to report their dogs' behavior, with three specific behaviors hypothesized to be related to ADHD: excitability, chasing, and trainability.

RESULTS

The highest scoring behavioral factors in the placebo and MCTD periods were excitability (mean±SE: 1.910±0.127) and chasing (mean±SE: 1.824±0.210). A markedly lower trainability score (mean±SE: 0.437±0.125) than that of previously studied canine populations was observed. The MCTD resulted in a significant improvement in the ADHD-related behavioral factor chasing and a reduction in stranger-directed fear (p<0.05) compared with the placebo diet. The latter effect may be attributed to previously described anxiolytic effects of a KD.

CONCLUSIONS

These data support the supposition that dogs with IE may exhibit behaviors that resemble ADHD symptoms seen in humans and rodent models of epilepsy and that a MCTD may be able to improve some of these behaviors, along with potentially anxiolytic effects.

Efficacy of Attribution Retraining on Mental Health of Epileptic Children

Background:

Epilepsy affects children’s quality of life and leads to social and mental problems. Promoting the mental health of children, especially epileptic ones, and preventing problems affecting them constitute major concerns for every country. Mental health promotion requires intervention programs.

Objectives:

We sought to assess the efficacy of attribution retraining on the mental health of epileptic children.

Patients and Methods:

The present study is a semi-experimental investigation with a pretest and posttest design and includes a control group. Thirty children, comprising 17 boys and 13 girls, were selected randomly from the Iranian epilepsy association in Tehran and assigned to experimental and control groups. They answered to the general health questionnaire (Goldberg and Hiller, 1979). The experimental group participated in 11 training sessions (twice a week; 45 minutes for each session) and received attribution retraining. The data were analyzed using the multiple analysis of covariance.

Results:

The findings showed that the experimental group, in comparison with the control group, experienced a reduction in physical symptoms, anxiety and insomnia, social dysfunction, and depression and an increase in mental health significantly (P < 0.01) after the training sessions. There were no significant differences, however, between the two groups at 6 weeks’ follow-up.

Conclusions:

Attribution retraining improved mental health in the epileptic children in our study. It, therefore, seems to be an appropriate intervention for promoting the mental health of children.

International veterinary epilepsy task force consensus proposal: outcome of therapeutic interventions in canine and feline epilepsy

Common criteria for the diagnosis of drug resistance and the assessment of outcome are needed urgently as a prerequisite for standardized evaluation and reporting of individual therapeutic responses in canine epilepsy. Thus, we provide a proposal for the definition of drug resistance and partial therapeutic success in canine patients with epilepsy. This consensus statement also suggests a list of factors and aspects of outcome, which should be considered in addition to the impact on seizures. Moreover, these expert recommendations discuss criteria which determine the validity and informative value of a therapeutic trial in an individual patient and also suggest the application of individual outcome criteria. Agreement on common guidelines does not only render a basis for future optimization of individual patient management, but is also a presupposition for the design and implementation of clinical studies with highly standardized inclusion and exclusion criteria. Respective standardization will improve the comparability of findings from different studies and renders an improved basis for multicenter studies. Therefore, this proposal provides an in-depth discussion of the implications of outcome criteria for clinical studies. In particular ethical aspects and the different options for study design and application of individual patient-centered outcome criteria are considered.

International veterinary epilepsy task force consensus proposal: diagnostic approach to epilepsy in dogs

This article outlines the consensus proposal on diagnosis of epilepsy in dogs by the International Veterinary Epilepsy Task Force. The aim of this consensus proposal is to improve consistency in the diagnosis of epilepsy in the clinical and research settings. The diagnostic approach to the patient presenting with a history of suspected epileptic seizures incorporates two fundamental steps: to establish if the events the animal is demonstrating truly represent epileptic seizures and if so, to identify their underlying cause. Differentiation of epileptic seizures from other non-epileptic episodic paroxysmal events can be challenging. Criteria that can be used to make this differentiation are presented in detail and discussed. Criteria for the diagnosis of idiopathic epilepsy (IE) are described in a three-tier system. Tier I confidence level for the diagnosis of IE is based on a history of two or more unprovoked epileptic seizures occurring at least 24 h apart, age at epileptic seizure onset of between six months and six years, unremarkable inter-ictal physical and neurological examination, and no significant abnormalities on minimum data base blood tests and urinalysis. Tier II confidence level for the diagnosis of IE is based on the factors listed in tier I and unremarkable fasting and post-prandial bile acids, magnetic resonance imaging (MRI) of the brain (based on an epilepsy-specific brain MRI protocol) and cerebrospinal fluid (CSF) analysis. Tier III confidence level for the diagnosis of IE is based on the factors listed in tier I and II and identification of electroencephalographic abnormalities characteristic for seizure disorders. The authors recommend performing MRI of the brain and routine CSF analysis, after exclusion of reactive seizures, in dogs with age at epileptic seizure onset <6 months or >6 years, inter-ictal neurological abnormalities consistent with intracranial neurolocalisation, status epilepticus or cluster seizure at epileptic seizure onset, or a previous presumptive diagnosis of IE and drug-resistance with a single antiepileptic drug titrated to the highest tolerable dose.

This consensus article represents the basis for a more standardised diagnostic approach to the seizure patient. These recommendations will evolve over time with advances in neuroimaging, electroencephalography, and molecular genetics of canine epilepsy.

Behavioral Abnormalities in Lagotto Romagnolo Dogs with a History of Benign Familial Juvenile Epilepsy: A Long-Term Follow-Up Study

Background

Lagotto Romagnolo (LR) dogs with benign juvenile epilepsy syndrome often experience spontaneous remission of seizures. The long‐term outcome in these dogs currently is unknown. In humans, behavioral and psychiatric comorbidities have been reported in pediatric and adult‐onset epilepsies.

Hypothesis/Objectives

The objectives of this study were to investigate possible neurobehavioral comorbidities in LR with a history of benign familial juvenile epilepsy (BFJE) and to assess the occurrence of seizures after the remission of seizures in puppyhood.

Animals

A total of 25 LR with a history of BFJE and 91 control dogs of the same breed.

Methods

Owners of the LR dogs in the BFJE and control groups completed an online questionnaire about each dog's activity, impulsivity, and inattention. Principal component analysis (PCA) served to extract behavioral factors from the data. We then compared the scores of these factors between the 2 groups in a retrospective case–control study. We also interviewed all dog owners in the BFJE group by telephone to inquire specifically about possible seizures or other neurological problems after remission of seizures as a puppy.

Results

Lagotto Romagnolo dogs with BFJE showed significantly higher scores on the factors Inattention and Excitability/Impulsivity than did the control group (P = .003; P = .021, respectively). Only 1 of the 25 BFJE LR exhibited seizures after remission of epilepsy in puppyhood.

Conclusions and Clinical Importance

Although the long‐term seizure outcome in BFJE LR seems to be good, the dogs exhibit behavioral abnormalities resembling attention deficit hyperactivity disorder (ADHD) in humans, thus suggesting neurobehavioral comorbidities with epilepsy.

Idiopathic epilepsy in the Italian Spinone in the United Kingdom: prevalence, clinical characteristics, and predictors of survival and seizure remission

Background

There is lack of data on idiopathic epilepsy (IE) in the Italian Spinone (IS).

Objectives

To estimate the prevalence of IE in the IS in the United Kingdom (UK) and to investigate predictors of survival and seizure remission.

Animals

The target population consisted of 3331 IS born between 2000 and 2011 and registered with the UK Kennel Club (KC). The owners of 1192 dogs returned phase I questionnaire. Sixty‐three IS had IE.

Methods

Population survey. The owners of all UK KC‐registered IS were invited to complete the phase I questionnaire. Information from the phase I questionnaire and veterinary medical records was used to identify IS with IE and obtain data on treatment and survival. Additional information was obtained from owners of epileptic IS who completed the phase II questionnaire.

Results

The prevalence of IE in the IS in the UK was estimated as 5.3% (95% CI, 4.03–6.57%). Survival time was significantly shorter in IS euthanized because of poorly controlled IE compared with epileptic IS that died of unrelated disorders (P = 0.001). Survival was significantly longer in IS with no cluster seizures (CS) (P = 0.040) and in IS in which antiepileptic medication was initiated after the second seizure rather than after ≥3 seizures (P = 0.044). Seizure remission occurred only in 3 IS.

Conclusions and Clinical Importance

The prevalence of IE in IS (5.3%) is higher than in dogs (0.6%) in the UK. Idiopathic epilepsy in IS has a severe phenotype. Antiepileptic medication initiation after the second seizure and aggressive treatment of CS may improve survival.

Assessment into the usage of levetiracetam in a canine epilepsy clinic

Background

Retrospective studies can complement information derived from double-blinded randomized trials. There are multiple retrospective studies reporting good efficacy and tolerability of the anti-epileptic drug levetiracetam (LEV) in human patients with epilepsy; however, reports of LEV's tolerability and efficacy in dogs with epilepsy remain limited. The purpose of this retrospective study was to describe the use of LEV in a canine epilepsy clinic and determine the long-term efficacy and tolerability of LEV in veterinary clinical practice. The electronic database of a UK based referral hospital was searched for LEV usage in dogs with seizures. Information and data necessary for the evaluation were obtained from a combination of electronic and written hospital records, the referring veterinary surgeons’ records and telephone interviews with dog owners. Only dogs that were reportedly diagnosed with idiopathic epilepsy were included in the study.

Results

Fifty-two dogs were included in this retrospective study. Two treatment protocols were recognised; 29 dogs were treated continuously with LEV and 23 dogs received interval or pulse treatment for cluster seizures. LEV treatment resulted in 69% of dogs having a 50% or greater reduction of seizure frequency whilst 15% of all the dogs were completely free from seizures. Seizure frequency reduced significantly in the whole population. No dog was reported to experience life-threatening side effects. Mild side effects were experienced by 46% of dogs and a significantly higher number of these dogs were in the pulse treatment group. The most common side-effects reported were sedation and ataxia.

Conclusions

LEV appears to be effective and well tolerated for reduction of seizures.

The influence of sex hormones on seizures in dogs and humans

Epilepsy is the most common chronic neurological disorder in both humans and dogs. The effect of sex hormones on seizures is well documented in human medicine. Catamenial epilepsy is defined as an increase in frequency and severity of seizures during certain periods of the menstrual cycle. Oestradiol increases seizure activity and progesterone is believed to exhibit a protective effect. The role of androgens is controversial and there is a lack of research focusing on androgens and epilepsy. Indeed, little is known about the influence of sex hormones on epilepsy in dogs. Sterilisation is believed to improve seizure control, but no systematic research has been conducted in this field. This review provides an overview of the current literature on the influence of sex hormones on seizures in humans. The literature on idiopathic epilepsy in dogs was assessed to identify potential risk factors related to sex and sterilisation status. In general, there appears to be an over-representation of male dogs with idiopathic epilepsy but no explanation for this difference in prevalence between sexes has been reported. In addition, no reliable conclusions can be drawn on the effect of sterilisation due to the lack of focused research and robust scientific evidence.

The pharmacology of imepitoin: the first partial benzodiazepine receptor agonist developed for the treatment of epilepsy

Although benzodiazepines (BZDs) offer a wide spectrum of antiepileptic activity against diverse types of epileptic seizures, their use in the treatment of epilepsy is limited because of adverse effects, loss of efficacy (tolerance), and development of physical and psychological dependence. BZDs act as positive allosteric modulators of the inhibitory neurotransmitter GABA by binding to the BZD recognition site ("BZD receptor") of the GABAA receptor. Traditional BZDs such as diazepam or clonazepam act as full agonists at this site, so that one strategy to resolve the disadvantages of these compounds would be the development of partial agonists with lower intrinsic efficacy at the BZD site of the GABAA receptor. Several BZD site partial or subtype selective compounds, including bretazenil, abecarnil, or alpidem, have been developed as anxioselective anxiolytic drugs, but epilepsy was not a target indication for such compounds. More recently, the imidazolone derivatives imepitoin (ELB138) and ELB139 were shown to act as low-affinity partial agonists at the BZD site of the GABAA receptor, and imepitoin was developed for the treatment of epilepsy. Imepitoin displayed a broad spectrum of anticonvulsant activity in diverse seizure and epilepsy models at tolerable doses, and, as expected from its mechanism of action, lacked tolerance and abuse liability in rodent and primate models. The more favorable pharmacokinetic profile of imepitoin in dogs versus humans led to the decision to develop imepitoin for the treatment of canine epilepsy. Based on randomized controlled trials that demonstrated antiepileptic efficacy and high tolerability and safety in epileptic dogs, the drug was recently approved for this indication in Europe. Hopefully, the favorable profile of imepitoin for the treatment of epilepsy in dogs will reactivate the interest in partial BZD site agonists as new treatments for human epilepsy.

Characterization of a dopamine transporter polymorphism and behavior in Belgian Malinois

BACKGROUND

The Belgian Malinois dog breed (MAL) is frequently used in law enforcement and military environments. Owners have reported seizures and unpredictable behavioral changes including dogs' eyes "glazing over," dogs' lack of response to environmental stimuli, and loss of behavioral inhibition including owner-directed biting behavior. Dogs with severe behavioral changes may be euthanized as they can represent a danger to humans and other dogs. In the dog, the dopamine transporter gene (DAT) contains a 38-base pair variable number tandem repeat (DAT-VNTR); alleles have either one or two copies of the 38-base pair sequence. The objective of this study was to assess frequency of DAT-VNTR alleles, and characterize the association between DAT-VNTR alleles and behavior in MAL and other breeds.

RESULTS

In an American sample of 280 dogs comprising 26 breeds, most breeds are predominantly homozygous for the DAT-VNTR two-tandem-repeat allele (2/2). The one-tandem-repeat allele is over-represented in American MAL (AM-MAL) (n = 144), both as heterozygotes (1/2) and homozygotes (1/1). All AM-MAL with reported seizures (n = 5) were 1/1 genotype. For AM-MAL with at least one "1" allele (1/1 or 1/2 genotype, n = 121), owners reported higher levels of attention, increased frequency of episodic aggression, and increased frequency of loss of responsiveness to environmental stimuli. In behavior observations, Belgian Military Working Dogs (MWD) with 1/1 or 1/2 genotypes displayed fewer distracted behaviors and more stress-related behaviors such as lower posture and increased yawning. Handlers' treatment of MWD varied with DAT-VNTR genotype as did dogs' responses to handlers' behavior. For 1/1 or 1/2 genotype MWD, 1) lower posture after the first aversive stimulus given by handlers was associated with poorer obedience performance; 2) increased aversive stimuli during protection exercises were associated with decreased performance; 3) more aversive stimuli during obedience were associated with more aversive stimuli during protection; and 4) handlers used more aversive stimuli in protection compared with obedience exercises.

CONCLUSIONS

The single copy allele of DAT-VNTR is associated with owner-reported seizures, loss of responsiveness to environmental stimuli, episodic aggression, and hyper-vigilance in MAL. Behavioral changes are associated with differential treatment by handlers. Findings should be considered preliminary until replicated in a larger sample.

Public perception of epilepsy in dogs is more favorable than in humans

OBJECTIVES

With the use of YouTube™, this study provides results on both the demographics and public perception for a sample of videos of canine epilepsy.

METHODS

A random sample of 150 videos was collected, the uploader description was recorded, and viewers' comments were coded according to their emotional and informational content.

RESULTS

More comments were found to be sympathetic than derogatory, and there were more information-providing than information-seeking comments. The number of sympathetic comments was found to correlate positively with the number of derogatory comments, and the number of information-providing comments correlated positively with the number of information-seeking comments.

CONCLUSION

These findings shed light on the variation in perceptions of seizures in dogs, which are interestingly more sympathetic towards dogs with epilepsy than towards humans with epilepsy. This highlights the potential future use of YouTube in investigating public views as well as in informing and educating.

Canine epilepsy as a translational model?

Dogs with spontaneous diseases can exhibit a striking similarity in etiology, clinical manifestation, and disease course when compared to human patients. Therefore, dogs are intensely discussed as a translational model of human disease. In particular, genetic studies in selected dog breeds serve as an excellent tool to identify epilepsy disease genes. In addition, canine epilepsy is discussed as a translational platform for drug testing. On one hand, epileptic dogs might serve as an interesting model by allowing the evaluation of drug efficacy and potency under clinical conditions with a focus on chronic seizures resistant to standard medication, preventive strategies, or status epilepticus. On the other hand, several limitations need to be considered including owner-based seizure monitoring, species differences in pharmacokinetics and drug interactions, as well as cost-intensiveness. The review gives an overview on the current state of knowledge regarding the etiology, clinical manifestation, pathology, and drug response of canine epilepsy, also pointing out the urgent need for further research on specific aspects. Moreover, the putative advantages, the disadvantages, and limitations of antiepileptic drug testing in canine epilepsy are critically discussed.

A systematic review of the safety of potassium bromide in dogs

OBJECTIVE

To critically evaluate and summarize available information on the safety of potassium bromide in dogs.

DESIGN

Systematic review.

SAMPLE

111 references reporting safety information relevant to potassium bromide published between 1938 and 2011.

PROCEDURES

PubMed searches without date limitations were conducted with the terms "potassium bromide" and "sodium bromide" in December 2009 and October 2011. Additional articles were identified through examination of article reference lists and book chapters on seizures in dogs and pharmacology.

RESULTS

Reversible neurologic signs were the most consistently reported toxicoses and were generally associated with adjunctive potassium bromide treatment or high serum bromide concentrations. Dermatologic and respiratory abnormalities were rare in dogs. Insufficient information was available to assess the effects of potassium bromide on behavior or to determine the incidence of vomiting, weight gain, polyphagia, pancreatitis, polyuria, polydipsia, or reproductive abnormalities associated with potassium bromide administration. Evidence suggested that administration of potassium bromide with food may alleviate gastrointestinal irritation and that monitoring for polyphagia, thyroid hormone abnormalities, and high serum bromide concentrations may be beneficial.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that potassium bromide is not an appropriate choice for treatment of every dog with seizures and that practitioners should tailor therapeutic regimens and clinical monitoring to each dog. Abrupt dietary changes or fluid therapy may compromise seizure control or increase the likelihood of adverse events. Availability of an appropriately labeled, approved potassium bromide product could provide better assurance for veterinarians and their clients of the quality, safety, and effectiveness of the product for veterinary use.