Antiepileptic drugs' tolerability and safety--a systematic review and meta-analysis of adverse effects in dogs

Towards a better understanding of idiopathic epilepsy through metabolic fingerprinting of cerebrospinal fluid in dogs

Cerebrospinal fluid metabolomics is a promising research technology in the elucidation of nervous system disorders. Therefore, in this work, a cerebrospinal fluid (CSF) metabolomics method using liquid chromatography coupled to mass spectrometry was optimized and validated to cover a wide range of metabolites. An acceptable coefficient of variance regarding instrumental, within-lab and intra-assay precision was found for 95, 70 and 96 of 102 targeted metabolites, together with 1256, 676 and 976 untargeted compounds, respectively. Moreover, approximately 75% of targeted metabolites and 50% of untargeted compounds displayed good linearity across different dilution ranges. Consequently, metabolic alterations in CSF of dogs with idiopathic epilepsy (IE) were studied by comparing CSF of dogs diagnosed with IE (Tier II) to dogs with non-brain related disease. Targeted metabolome analysis revealed higher levels of cortisol, creatinine, glucose, hippuric acid, mannose, pantothenol, and 2-phenylethylamine (P values < 0.05) in CSF of dogs with IE, whereas CSF of dogs with IE showed lower levels of spermidine (P value = 0.02). Untargeted CSF metabolic fingerprints discriminated dogs with IE from dogs with non-brain related disease using Orthogonal Partial Least Squares Discriminant Analysis (R2(Y) = 0.997, Q2(Y) = 0.828), from which norepinephrine was putatively identified as an important discriminative metabolite.

Effects of sodium valproate and levetiracetam on posterior segment parameters in children with epilepsy

PURPOSE

To evaluate changes in posterior segment parameters in pediatric patients with epilepsy using sodium valproate or levetiracetam monotherapy for at least 12 months.

METHODS

This study included 45 children with generalized epilepsy aged 6-17 years and 32 age- and gender-matched healthy subjects. The patients were assigned to three groups: Group 1 included patients using valproate monotherapy at a dose of 20-40 mg/kg/day, group 2 included patients using levetiracetam monotherapy at a dose of 20-40 mg/kg/day, and group 3 consisted of healthy controls. Peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell layer-inner plexiform layer (mGCIPL) thicknesses were measured using spectral-domain optical coherence tomography (OCT).

RESULTS

No significant differences were noted between the groups regarding age, gender distribution, visual acuity, spherical equivalent, and intraocular pressure (p > 0.05). The average and temporal, nasal, and superior quadrants RNFL values were significantly thinner in group 1 than in group 2 (p = 0.001, p = 0.023, p = 0.011, and p = 0.001, respectively) and group 3 (p < 0.001, p = 0.032, p < 0.001, and p = 0.001, respectively). The OCT parameters were similar in groups 2 and 3 (p > 0.05). A negative correlation was observed in group 1 between only the average mGCIPL and the treatment dose (r =  - 0.501). In group 2, no significant correlation was found between OCT parameters and the duration of epilepsy treatment, dose of treatment, and age at treatment onset values (p > 0.05).

CONCLUSION

These findings support that there is an association between sodium valproate treatment and the reduction of RNFL thickness in epilepsy. Levetiracetam treatment appears to be a safe option, but care should be taken regarding ocular side effects that may occur with long-term and high-dose use of sodium valproate.

Epilepsy is more than a simple seizure disorder: Parallels between human and canine cognitive and behavioural comorbidities

Psychiatric and cognitive comorbidities have been known to play a major role in human epilepsy for a long time. People with epilepsy (PWE) frequently express signs of varying psychiatric and cognitive disorders affecting their quality and quantity of life (QoL/QaoL). Over the last few years, research on behavioural comorbidities and their effect on the underlying disease have been performed in canine epilepsy. The following article reviews manifestations of comorbidities in canine epilepsy with an emphasis on patterns of clinical signs and their effects on QoL and QaoL. Cognitive and behavioural alterations in epileptic dogs are mainly represented by fear-/anxiety related behaviour and cognitive impairment (CI). Reduced trainability and altered reactions to daily situations are common results of comorbid changes posing obstacles in everyday life of owners and their dog. In addition, clinical signs similar to attention deficit hyperactivity disorder (ADHD) in humans have been reported. Canine attention-deficit-hyperactivity-disorder-like (c-ADHD-like) behaviour should, however, be evaluated critically, as there are no official criteria for diagnosis of ADHD or ADHD-like behaviour in dogs, and some of the reported signs of c-ADHD-like behaviour could be confused with anxiety-associated behaviour. Many intrinsic and extrinsic factors could potentially influence the development of behavioural and cognitive comorbidities in canine epilepsy. In particular, seizure frequency/severity, signalment and factors concerning disease management, such as pharmacotherapy and nutrition, are closely linked with the presence of the aforementioned comorbid disorders. Further studies of behavioural alterations in epileptic dogs are needed to comprehend the complexity of clinical signs and their multifactorial origin.

Quantitative serum proteome analysis using tandem mass tags in dogs with epilepsy

This study included four groups of dogs (group A: healthy controls, group B: idiopathic epilepsy receiving antiepileptic medication (AEM), group C: idiopathic epilepsy without AEM, group D: structural epilepsy). Comparative quantitative proteomic analysis of serum samples among the groups was the main target of the study. Samples were analyzed by a quantitative Tandem-Mass-Tags approach on the Q-Exactive-Plus Hybrid Quadrupole-Orbitrap mass-spectrometer. Identification and relative quantification were performed in Proteome Discoverer. Data were analyzed using R. Gene ontology terms were analyzed based on Canis lupus familiaris database. Data are available via ProteomeXchange with identifier PXD041129. Eighty-one proteins with different relative adundance were identified in the four groups and 25 were master proteins (p < 0.05). Clusterin (CLU), and apolipoprotein A1 (APOA1) had higher abundance in the three groups of dogs (groups B, C, D) compared to controls. Amine oxidase (AOC3) was higher in abundance in group B compared to groups C and D, and lower in group A. Adiponectin (ADIPOQ) had higher abundance in groups C compared to group A. ADIPOQ and fibronectin (FN1) had higher abundance in group B compared to group C and D. Peroxidase activity assay was used to quantify HP abundance change, validating and correlating with proteomic analysis (r = 0.8796). SIGNIFICANCE: The proteomic analysis of serum samples from epileptic dogs indicated potential markers of epilepsy (CLU), proteins that may contribute to nerve tissue regeneration (APOA1), and contributing factors to epileptogenesis (AOC3). AEM could alter extracellular matrix proteins (FN1). Illness (epilepsy) severity could influence ADIPOQ abundance.

ACVIM Consensus Statement on the management of status epilepticus and cluster seizures in dogs and cats

BACKGROUND

Seizure emergencies (ie, status epilepticus [SE] and cluster seizures [CS]), are common challenging disorders with complex pathophysiology, rapidly progressive drug-resistant and self-sustaining character, and high morbidity and mortality. Current treatment approaches are characterized by considerable variations, but official guidelines are lacking.

OBJECTIVES

To establish evidence-based guidelines and an agreement among board-certified specialists for the appropriate management of SE and CS in dogs and cats.

ANIMALS

None.

MATERIALS AND METHODS

A panel of 5 specialists was formed to assess and summarize evidence in the peer-reviewed literature with the aim to establish consensus clinical recommendations. Evidence from veterinary pharmacokinetic studies, basic research, and human medicine also was used to support the panel's recommendations, especially for the interventions where veterinary clinical evidence was lacking.

RESULTS

The majority of the evidence was on the first-line management (ie, benzodiazepines and their various administration routes) in both species. Overall, there was less evidence available on the management of emergency seizure disorders in cats in contrast to dogs. Most recommendations made by the panel were supported by a combination of a moderate level of veterinary clinical evidence and pharmacokinetic data as well as studies in humans and basic research studies.

CONCLUSIONS AND CLINICAL RELEVANCE

Successful management of seizure emergencies should include an early, rapid, and stage-based treatment approach consisting of interventions with moderate to preferably high ACVIM recommendations; management of complications and underlying causes related to seizure emergencies should accompany antiseizure medications.

A review of the pharmacology and clinical applications of levetiracetam in dogs and cats

OBJECTIVE

To review and summarize the pharmacology of the antiepileptic drug (AED), levetiracetam (LEV), and to discuss its clinical utility in dogs and cats.

DATA SOURCES

Veterinary and human peer-reviewed medical literature and the authors' clinical experience.

SUMMARY

LEV is an AED with mechanisms of action distinct from those of other AEDs. In people and small animals, LEV exhibits linear kinetics, excellent oral bioavailability, and minimal drug-drug interactions. Serious side effects are rarely reported in any species. LEV use is gaining favor for treating epilepsy in small animals and may have wider clinical applications in patients with portosystemic shunts, neuroglycopenia, and traumatic brain injury. In people, LEV may improve cognitive function in patients with dementia.

CONCLUSION

LEV is a well-tolerated AED with well-documented efficacy in human patients. Although its use is becoming more common in veterinary medicine, its role as a first-line monotherapy in small animal epileptics remains to be determined. This review of the human and animal literature regarding LEV describes its role in epileptic people and animals as well as in other disease states and provides recommendations for clinical usage.

Clinical enzymology of the dog and cat

Clinical enzymology studies the enzyme activity in serum or other body fluids for the diagnosis, prognosis or monitoring of a variety of diseases. Clinical enzymology has greatly benefited from advances in technology and is now an integral part of laboratory analysis. However, to maximise the clinical benefits of serum enzyme measurement, clinicians and clinical pathologists must have a good understanding of the pathophysiology behind serum enzyme alterations. They must also be aware of the preanalytical and analytical factors that can affect the accuracy of serum enzyme activity measurement. This review article first covers the basic concepts of clinical enzymology and the general mechanisms related to serum enzyme alterations. Then, the review discusses the potential effects of various preanalytical and analytical factors on enzyme activity measurement. Lastly, it explores the pathophysiology and clinical use of various serum enzymes in canine and feline medicine. The present review article aims to be a comprehensive one-stop source for clinical pathologists and small animal practitioners.

The efficacy and safety of cannabidiol as adjunct treatment for drug-resistant idiopathic epilepsy in 51 dogs: A double-blinded crossover study

BACKGROUND

Approximately 30% of dogs with idiopathic epilepsy (IE) are drug-resistant. Recent studies have suggested cannabidiol (CBD) may be an effective anticonvulsant in dogs with IE.

OBJECTIVE

To evaluate the addition of CBD to antiseizure drugs (ASDs) on seizure frequency and to report adverse events in dogs with drug-resistant IE.

ANIMALS

Fifty-one dogs. Dogs having at least 2 seizures per month while receiving at least 1 ASD were included in the trial.

METHODS

Double-blinded placebo-controlled crossover study. The 5 mg/kg/day dosage met futility requirements after 12 dogs, and a dosage of 9 mg/kg/day was used in the next 39 dogs. Dogs were randomly assigned to receive CBD or placebo for 3 months, with a 1-month washout period between oils. Total numbers of seizures and seizure days were recorded. Diagnostic testing was performed periodically throughout the trial.

RESULTS

At the 9 mg/kg/day dose, the decrease in total seizure frequency was significant compared with placebo. A 24.1% decrease in seizure days occurred in dogs receiving CBD and a 5.8% increase occurred in dogs receiving placebo (P ≤ .05). No significant difference was found in the number of responders (≥50% decrease in total seizures or seizure days). Liver enzyme activities increased at both dosages. Decreased appetite and vomiting were more common in the CBD phase (P ≤ .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Cannabidiol decreased total seizures and seizure days compared to placebo when administered to dogs PO at 9 mg/kg/day. Liver enzymes should be monitored with administration of CBD in dogs.

Astaxanthin promotes locomotor function recovery and attenuates tissue damage in rats following spinal cord injury: a systematic review and trial sequential analysis

Spinal cord injury (SCI) is a catastrophic condition with few therapeutic options. Astaxanthin (AST), a natural nutritional supplement with powerful antioxidant activities, is finding its new application in the field of SCI. Here, we performed a systematic review to assess the neurological roles of AST in rats following SCI, and assessed the potential for clinical translation. Searches were conducted on PubMed, Embase, Cochrane Library, the Web of Science, China National Knowledge Infrastructure, WanFang data, Vip Journal Integration Platform, and SinoMed databases. Animal studies that evaluated the neurobiological roles of AST in a rat model of SCI were included. A total of 10 articles were included; most of them had moderate-to-high methodological quality, while the overall quality of evidence was not high. Generally, the meta-analyses revealed that rats treated with AST exhibited an increased Basso, Beattie, and Bresnahan (BBB) score compared with the controls, and the weighted mean differences (WMDs) between those two groups showed a gradual upward trend from days 7 (six studies, n = 88, WMD = 2.85, 95% CI = 1.83 to 3.87, p < 0.00001) to days 28 (five studies, n = 76, WMD = 6.42, 95% CI = 4.29 to 8.55, p < 0.00001) after treatment. AST treatment was associated with improved outcomes in spared white matter area, motor neuron survival, and SOD and MDA levels. Subgroup analyses indicated there were differences in the improvement of BBB scores between distinct injury types. The trial sequential analysis then firmly proved that AST could facilitate the locomotor recovery of rats following SCI. In addition, this review suggested that AST could modulate oxidative stress, neuroinflammation, neuron loss, and autophagy via multiple signaling pathways for treating SCI. Collectively, with a protective effect, good safety, and a systematic action mechanism, AST is a promising candidate for future clinical trials of SCI. Nonetheless, in light of the limitations of the included studies, larger and high-quality studies are needed for verification.

Pathophysiology of drug-resistant canine epilepsy

Drug resistance continues to be a major clinical problem in the therapeutic management of canine epilepsies with substantial implications for quality of life and survival times. Experimental and clinical data from human medicine provided evidence for relevant contributions of intrinsic severity of the disease as well as alterations in pharmacokinetics and -dynamics to failure to respond to antiseizure medications. In addition, several modulatory factors have been identified that can be associated with the level of therapeutic responses. Among others, the list of potential modulatory factors comprises genetic and epigenetic factors, inflammatory mediators, and metabolites. Regarding data from dogs, there are obvious gaps in knowledge when it comes to our understanding of the clinical patterns and the mechanisms of drug-resistant canine epilepsy. So far, seizure density and the occurrence of cluster seizures have been linked with a poor response to antiseizure medications. Moreover, evidence exists that the genetic background and alterations in epigenetic mechanisms might influence the efficacy of antiseizure medications in dogs with epilepsy. Further molecular, cellular, and network alterations that may affect intrinsic severity, pharmacokinetics, and -dynamics have been reported. However, the association with drug responsiveness has not yet been studied in detail. In summary, there is an urgent need to strengthen clinical and experimental research efforts exploring the mechanisms of resistance as well as their association with different etiologies, epilepsy types, and clinical courses.

Translational veterinary epilepsy: A win-win situation for human and veterinary neurology

Epilepsy is a challenging multifactorial disorder with a complex genetic background. Our current understanding of the pathophysiology and treatment of epilepsy has substantially increased due to animal model studies, including canine studies, but additional basic and clinical research is required. Drug-resistant epilepsy is an important problem in both dogs and humans, since seizure freedom is not achieved with the available antiseizure medications. The evaluation and exploration of pharmacological and particularly non-pharmacological therapeutic options need to remain a priority in epilepsy research. Combined efforts and sharing knowledge and expertise between human medical and veterinary neurologists are important for improving the treatment outcomes or even curing epilepsy in dogs. Such interactions could offer an exciting approach to translate the knowledge gained from people and rodents to dogs and vice versa. In this article, a panel of experts discusses the similarities and knowledge gaps in human and animal epileptology, with the aim of establishing a common framework and the basis for future translational epilepsy research.

Surgical treatment of cranial cruciate ligament disease in dogs using Tibial Plateau Leveling Osteotomy or Tibial Tuberosity Advancement-A systematic review with a meta-analytic approach

Tibial Plateau Leveling Osteotomy (TPLO) or Tibial Tuberosity Advancement (TTA) are commonly used surgical techniques for correction of cranial cruciate ligament (CCL) rupture in dogs. This systematic review aims to investigate whether one technique is superior to the other. Seventy-two studies on surgical management of CCL rupture have been identified and evaluated in regard of subjective and objective gait analysis criteria, development of osteoarthritis (OA), thigh circumference measurements, goniometry, joint stability, pain and complication rates. Almost half (47.2 %) of the studies were considered of low quality of evidence, leading to high heterogeneity in quality among studies; this posed a major limitation for an evidence-based systematic review of both surgical techniques. Out of 72 studies, there were only eleven blinded randomized clinical trials, of which five were rated with a low overall risk of bias. However, both techniques were considered to be successful management options. Subjective and objective gait analysis revealed no lameness at long-term evaluation for the majority of the patients. However, it appeared that TTA lead to better OA scores up to 6 months postoperatively, while TPLO had a lower rate of surgical site infections. In summary, no method can be clearly preferred, as most of the study evaluated were subpar. Studies with a high level of evidence are therefore urgently needed for such a common surgical procedure.

Metabolic fingerprinting of dogs with idiopathic epilepsy receiving a ketogenic medium-chain triglyceride (MCT) oil

Consumption of medium-chain triglycerides (MCT) has been shown to improve seizure control, reduce behavioural comorbidities and improve cognitive function in epileptic dogs. However, the exact metabolic pathways affected by dietary MCT remain poorly understood. In this study, we aimed to identify changes in the metabolome and neurotransmitters levels relevant to epilepsy and behavioural comorbidities associated with the consuming of an MCT supplement (MCT-DS) in dogs with idiopathic epilepsy (IE). Metabolic alterations induced by a commercial MCT-DS in a population of 28 dogs with IE were evaluated in a 6-month multi-centre, prospective, randomised, double-blinded, controlled cross-over trial design. A metabolic energy requirement-based amount of 9% MCT or control oil was supplemented to the dogs' stable base diet for 3 months, followed by the alternative oil for another 3 months. A validated, quantitative nuclear magnetic resonance (NMR) spectroscopy platform was applied to pre- and postprandially collected serum samples to compare the metabolic profile between both DS and baseline. Furthermore, alterations in urinary neurotransmitter levels were explored. Five dogs (30%) had an overall reduction in seizure frequency of ≥50%, and were classified as MCT-responders, while 23 dogs showed a ≤50% reduction, and were defined as MCT non-responders. Amino-acid metabolism was significantly influenced by MCT consumption compared to the control oil. While the serum concentrations of total fatty acids appeared similar during both supplements, the relative concentrations of individual fatty acids differed. During MCT supplementation, the concentrations of polyunsaturated fatty acids and arachidonic acid were significantly higher than under the control oil. β-Hydroxybutyric acid levels were significantly higher under MCT supplementation. In total, four out of nine neurotransmitters were significantly altered: a significantly increased γ-aminobutyric acid (GABA) concentration was detected during the MCT-phase accompanied by a significant shift of the GABA-glutamate balance. MCT-Responders had significantly lowered urinary concentrations of histamine, glutamate, and serotonin under MCT consumption. In conclusion, these novel data highlight metabolic changes in lipid, amino-acid and ketone metabolism due to MCT supplementation. Understanding the metabolic response to MCT provides new avenues to develop better nutritional management with improved anti-seizure and neuroprotective effects for dogs with epilepsy, and other behavioural disorders.

The effect of metformin on ameliorating neurological function deficits and tissue damage in rats following spinal cord injury: A systematic review and network meta-analysis

Spinal cord injury (SCI) is a devastating condition with few treatment options. Metformin, a classical antidiabetic and antioxidant, has extended its application to experimental SCI treatment. Here, we performed a systematic review to evaluate the neurobiological roles of metformin for treating SCI in rats, and to assess the potential for clinical translation. PubMed, Embase, China National Knowledge Infrastructure, WanFang data, SinoMed, and Vip Journal Integration Platform databases were searched from their inception dates to October 2021. Two reviewers independently selected controlled studies evaluating the neurobiological roles of metformin in rats following SCI, extracted data, and assessed the quality of methodology and evidence. Pairwise meta-analyses, subgroup analyses and network analysis were performed to assess the roles of metformin in neurological function and tissue damage in SCI rats. Twelve articles were included in this systematic review. Most of them were of moderate-to-high methodological quality, while the quality of evidence from those studies was not high. Generally, Basso, Beattie, and Bresnahan scores were increased in rats treated with metformin compared with controls, and the weighted mean differences (WMDs) between metformin and control groups exhibited a gradual upward trend from the 3rd (nine studies, n = 164, WMD = 0.42, 95% CI = −0.01 to 0.85, P = 0.06) to the 28th day after treatment (nine studies, n = 136, WMD = 3.48, 95% CI = 2.04 to 4.92, P < 0.00001). Metformin intervention was associated with improved inclined plane scores, tissue preservation ratio and number of anterior horn motor neurons. Subgroup analyses indicated an association between neuroprotection and metformin dose. Network meta-analysis showed that 50 mg/kg metformin exhibited greater protection than 10 and 100 mg/kg metformin. The action mechanisms behind metformin were associated with activating adenosine monophosphate-activated protein kinase signaling, regulating mitochondrial function and relieving endoplasmic reticulum stress. Collectively, this review indicates that metformin has a protective effect on SCI with satisfactory safety and we demonstrate a rational mechanism of action; therefore, metformin is a promising candidate for future clinical trials. However, given the limitations of animal experimental methodological and evidence quality, the findings of this pre-clinical review should be interpreted with caution.

The effect of phenobarbital treatment on behavioral comorbidities and on the composition and function of the fecal microbiome in dogs with idiopathic epilepsy

Phenobarbital (PB) is one of the most important antiseizure drugs (ASDs) to treat canine idiopathic epilepsy (IE). The effect of PB on the taxonomic changes in gastrointestinal microbiota (GIM) and their functions is less known, which may explain parts of its pharmacokinetic and pharmacodynamic properties, especially its antiseizure effect and drug responsiveness or drug resistance as well as its effect on behavioral comorbidities. Fecal samples of 12 dogs with IE were collected prior to the initiation of PB treatment and 90 days after oral PB treatment. The fecal samples were analyzed using shallow DNA shotgun sequencing, real-time polymerase chain reaction (qPCR)-based dysbiosis index (DI), and quantification of short-chain fatty acids (SCFAs). Behavioral comorbidities were evaluated using standardized online questionnaires, namely, a canine behavioral assessment and research questionnaire (cBARQ), canine cognitive dysfunction rating scale (CCDR), and an attention deficit hyperactivity disorder (ADHD) questionnaire. The results revealed no significant changes in alpha and beta diversity or in the DI, whereas only the abundance of Clostridiales was significantly decreased after PB treatment. Fecal SCFA measurement showed a significant increase in total fecal SCFA concentration and the concentrations of propionate and butyrate, while acetate concentrations revealed an upward trend after 90 days of treatment. In addition, the PB-Responder (PB-R) group had significantly higher butyrate levels compared to the PB-Non-Responder (PB-NR) group. Metagenomics of functional pathway genes demonstrated a significant increase in genes in trehalose biosynthesis, ribosomal synthesis, and gluconeogenesis, but a decrease in V-ATPase-related oxidative phosphorylation. For behavioral assessment, cBARQ analysis showed improvement in stranger-directed fear, non-social fear, and trainability, while there were no differences in ADHD-like behavior and canine cognitive dysfunction (CCD) scores after 90 days of PB treatment. While only very minor shifts in bacterial taxonomy were detected, the higher SCFA concentrations after PB treatment could be one of the key differences between PB-R and PB-NR. These results suggest functional changes in GIM in canine IE treatment.

Chronic sodium bromide treatment relieves autistic-like behavioral deficits in three mouse models of autism

Autism Spectrum Disorders (ASD) are neurodevelopmental disorders whose diagnosis relies on deficient social interaction and communication together with repetitive behavior. To date, no pharmacological treatment has been approved that ameliorates social behavior in patients with ASD. Based on the excitation/inhibition imbalance theory of autism, we hypothesized that bromide ions, long used as an antiepileptic medication, could relieve core symptoms of ASD. We evaluated the effects of chronic sodium bromide (NaBr) administration on autistic-like symptoms in three genetic mouse models of autism: Oprm1^-/-, Fmr1^-/- and Shank3^Δex13-16-/- mice. We showed that chronic NaBr treatment relieved autistic-like behaviors in these three models. In Oprm1^-/- mice, these beneficial effects were superior to those of chronic bumetanide administration. At transcriptional level, chronic NaBr in Oprm1 null mice was associated with increased expression of genes coding for chloride ions transporters, GABA_A receptor subunits, oxytocin and mGlu4 receptor. Lastly, we uncovered synergistic alleviating effects of chronic NaBr and a positive allosteric modulator (PAM) of mGlu4 receptor on autistic-like behavior in Oprm1^-/- mice. We evidenced in heterologous cells that bromide ions behave as PAMs of mGlu4, providing a molecular mechanism for such synergy. Our data reveal the therapeutic potential of bromide ions, alone or in combination with a PAM of mGlu4 receptor, for the treatment of ASDs.

Cross Sectional Survey of Canine Idiopathic Epilepsy Management in Primary Care in the United Kingdom

The aims of this study are to gain insight on how primary care veterinarians in the UK diagnose and treat canine idiopathic epilepsy (IE) and what they perceive as challenges in the management of canine IE. Two hundred and thirty-five primary care veterinarians took part in this survey. The questionnaire asked about the type of practice the respondent worked in, any relevant post-graduate qualifications, how many years' experience they had in practice and the participant's canine IE caseload. Participants were asked how they diagnose canine IE, how they select antiseizure drugs (ASDs) and how they assess outcome. The questionnaire also explored which information sources they have access to for deciding on canine IE treatment, challenges that may be faced when managing these cases and areas in which more support can be provided. 94.5% of participants (n = 222/235) managed <10 canine IE cases in a year and 87.8% (n = 206/235) used phenobarbital as their first line ASD. The reported mean initial phenobarbital dose was 2.1 mg/kg (standard deviation = 0.71) every 12 h. When considering how closely participants aligned with IVETF guidelines on the topics of diagnosis, ASD initiation and outcome assessment, on average participants would score around half of the available points. 53.2% (n = 125/235) of respondents recommended neutering in canine IE and 46.8% (n = 110/235) did not. 53.2% (n = 125/235) did not recommend any additional treatments for canine IE beyond use of ASDs. 23.4% recommended Purina Neurocare diet (n = 55/235), 12.8% recommended environmental modification (n = 30/235), and 6.8% (n = 16/235) recommend medium chain triglyceride supplements. In this study participants found managing client expectations to be most challenging alongside canine IE emergency management. The main limitation of this study is the relatively low response rate and therefore the results may not reflect the entire small animal veterinary profession in the UK. However, the results of this study represent a starting point to inform educational resources and support strategies to improve quality care of canine IE in primary care.

Evaluation of the effect of phenobarbital administration on the biochemistry profile, with a focus on serum liver values, in epileptic cats

OBJECTIVES

Phenobarbital (PB) is the most common antiseizure drug (ASD) used for the management of feline epilepsy. In dogs, PB is known to cause serum liver enzyme induction and hepatotoxicity, especially after administration long term or in high concentrations. In cats, insufficient evidence is available to draw similar conclusions. The aim of this study was to evaluate the effect of PB administration on the serum biochemistry profile of epileptic cats. As an additional objective, other adverse effects arising, related to PB treatment, were recorded.

METHODS

Medical records of four veterinary centres were retrospectively reviewed for epileptic cats receiving PB treatment. Cats were included if they had a diagnosis of idiopathic epilepsy or structural epilepsy; a normal baseline serum biochemistry profile; at least one follow-up serum biochemistry profile; no concurrent disease or had not received medication that could possibly influence liver function or lead to serum liver enzyme induction. Alkaline phosphatase, alanine aminotransferase (ALT), aspartate transaminase and gamma-glutamyl transferase activities, and total bilirubin, bile acids, glucose, albumin, total protein, urea and creatinine concentrations before and during PB administration were recorded. PB serum concentration was also recorded, when available.

RESULTS

Thirty-three cats (24 males, nine females) with a median age of 3 years (range 2 months to 12 years) met the inclusion criteria. Idiopathic or structural epilepsy was diagnosed in 25 (76%) and eight (24%) cats, respectively. The follow-up period ranged from 9 to 62 months. This study found an increase in ALT in three cats, possibly related to a PB serum concentration >30 µg/ml. No statistically significant increase in serum liver enzymes or other evaluated biochemistry parameters was found by comparing pre- and post-treatment parameters.

CONCLUSIONS AND RELEVANCE

PB administration did not result in hepatic enzyme induction or other biochemical abnormalities in cats. This strengthens the safety profile of PB as an ASD in cats.

Phenotypic Characterization of Idiopathic Epilepsy in Border Collies

The prevalence of idiopathic epilepsy (IE) within the Border Collie (BC) dog breed is high. The aim of this retrospective study was to describe the phenotype of BCs with IE and assess correlations between phenotypic variables and owner-provided quality-of-life (QoL) scores. Data of BCs diagnosed with IE during the period of five consecutive years were retrospectively analyzed. All the dogs were presented at least once to a veterinary neurology specialist at one of three veterinary referral hospitals and most were under the continued medical care of that specialist. Owners were requested to complete a standardized online questionnaire including quality-of-life (QoL) scoring questions. Data of a total of 116 BC dogs were included for analysis. The median age at onset of the first epileptic seizure (ES) was 33.5 months (6–188). A total of 34/86 (40%) of medically treated dogs received 1 antiseizure medication (ASM) and 52/86 (60%) received ≥2 ASMs. Phenobarbital was the most commonly employed ASM, used in 70/86 of treated dogs (81%). Four or more side effects were observed in 20/86 (23%) of treated dogs. Age at onset of first ES was significantly lower for dogs having experienced cluster seizures (CSs), status epilepticus (SE), or both (median 27 months) vs. dogs that had not experienced CS or SE (median 43 months). The QoL of BC with IE was scored with a median score of 7 out of 10. Owners scored their dog's QoL to have declined by a median of 30% during the course of life with IE with 39% (37/95) of owners scoring their dog's QoL to have declined by ≥50%. This study confirms the association of age at onset of first ES with the severity of epilepsy (e.g., presence of CS and/or SE) and further characterizes the phenotype of IE in BC dogs. QoL of BC can be heavily impacted by IE.

Questionnaire survey on the usage of antiseizure drugs for dogs and cats in Japanese veterinary hospitals (2020)

Epilepsy is the most common neurological disorder in veterinary medicine. Recently, evidence‐based recommendations or systematic reviews for using antiseizure drugs (ASDs) in dogs and cats have been published, but there are many differences in economic, geographical, and historical backgrounds and/or the availability of each ASD between countries. In the present study, we conducted a questionnaire survey on the usage of ASDs in 511 veterinary hospitals in Japan in 2020. As a result, zonisamide (ZNS) was the most commonly prescribed drug for idiopathic (83%) and structural epilepsy (76%) in dogs. In cats, phenobarbital was the most frequently prescribed drug for idiopathic (48%) and structural epilepsy (51%), but ZNS was also commonly prescribed (41% and 36%, respectively). Additionally, ZNS was the most frequently used ASD in combination therapy for canine idiopathic epilepsy. We also surveyed the frequency of measuring ASD blood levels; however, a relatively high percentage of hospitals (22%) did not perform such measurements. Although the evidence level for ZNS is still poor for both species, it is generally used as the first‐line ASD in Japan. A large‐scale and higher evidential study for ZNS and the education of practitioners for adequate antiseizure medication are required.

Response to Levetiracetam Treatment and Long-Term Follow-Up in Dogs With Reactive Seizures Due to Probable Exogenous Toxicity

Limited information is available on the long-term follow-up and seizure recurrence in dogs with reactive seizures due to suspected exogenous toxicity. The purpose of this study was to report the long-term follow-up of 13 dogs referred to a single referral hospital, diagnosed with reactive seizures and treated with a standardized levetiracetam protocol. All dogs received a loading levetiracetam dose of 60 mg/kg/IV once, followed by a maintenance dose of 20 mg/kg every 8 h as part of an open-label clinical study. Levetiracetam was withdrawn after a 6-months seizure-free period by reducing levetiracetam to 20 mg/kg every 12 h for a 4-week seizure-free period, followed by levetiracetam 20 mg/kg every 24 h for a 4-week seizure-free period, before levetiracetam treatment was stopped. No adverse effects of the treatment were reported. No dogs experienced any seizures after discharge or after levetiracetam withdrawal. Median follow-up time from time of discharge was of 78 months (=6 years 6 months). The result of this study supports the use of levetiracetam for treatment of reactive seizures due to exogenous substance intoxication. Moreover, our results do not support the need for long-term antiepileptic treatment in cases of reactive seizures due to exogenous intoxication.

Abnormal Behavior Episodes Associated With Zonisamide in Three Dogs: A Case Report

Psychiatric adverse effect associated with anti-seizure drugs has been well-recognized in human medicine. This case report describes three dogs with presumptive idiopathic epilepsy presented for abnormal behavior episodes. Abnormal behavior episodes included sudden rage and aggression to the family members, insomnia, restlessness, and/or constant attention-seeking behavior. MRI study and cerebrospinal fluid analysis in two dogs were unremarkable. The abnormal behavior episodes deteriorated along with gradual dose increment of zonisamide and these episodes almost completely disappeared within 5 days after discontinuation of zonisamide. The exact same episodes relapsed within days after re-administration of zonisamide and disappeared again shortly after discontinuation of zonisamide. Dose adjustments of other anti-seizure medications in case 2 did not result in significant changes in these behavior episodes. Although psychiatric adverse effects including aggressive behavior associated with zonisamide are widely recognized in humans, this is the first report in dogs in the clinical setting.

Owner compliance in canine epilepsy

BACKGROUND

Poor medication compliance by human epilepsy patients is one of the leading causes of treatment failure and increased seizure frequency. The aim of this cross-sectional study was to analyse owner compliance in pharmacological treatment of canine idiopathic epilepsy and to identify factors associated with poor compliance.

METHODS

The number of antiseizure drug tablets was recorded to determine if the patient received sufficient tablets to cover the time period between prescriptions and to assess compliant prescription cycles. Additionally, compliance was assessed by an online survey of owners.

RESULTS

For the prescription monitoring data from 94 cases from three small animal practices in the United Kingdom revealed an overall median compliance of 56%. Thirt-three per cent of owners were >80% compliant, while 21% were 100% compliant. During a non-compliant prescription cycle, a patient missed a median of 6 days (0.11-519 days) of treatment. Patients on polytherapy had higher compliance rates than on monotherapy (p = 0.031). The survey (229 respondents from online canine epilepsy groups) showed that low daily dosing was associated with better compliance (p = 0.049).

CONCLUSION

Owner compliance was subpar in this study and could represent a significant issue in epilepsy management, which needs to be considered by veterinary surgeons when treating canine epilepsy.

Ventrolateral temporal lobectomy in normal dogs as a counterpart to human anterior temporal lobectomy: a preliminary study on the surgical procedure and complications

Anterior temporal lobectomy (ATL) is a surgical procedure for drug-resistant mesial temporal lobe epilepsy that is commonly performed in human medicine. The purpose of this study was to determine whether ATL-like surgery, i.e., removal of the amygdala and hippocampal head, is possible in dogs, and to investigate its safety and postoperative complications. Eight healthy beagles underwent ATL-like surgery and were observed for 3 months postoperatively. Samples from the surgically resected tissues and postmortem brain were evaluated pathologically. The surgical survival rate was 62.5%. The major postoperative complications were visual impairment, temporal muscle atrophy on the operative side, and a postoperative acute symptomatic seizure. Due to the anatomical differences between dogs and humans, the surgically resected area to approach the medial temporal structures in dogs was the ventrolateral part of the temporal lobe. Therefore, the ATL-like surgery described in this study was named "ventrolateral temporal lobectomy" (VTL). This study is the first report of temporal lobectomy including amygdalohippocampectomy in veterinary medicine and demonstrates its feasibility. Although it requires some degree of skill, VTL could be a treatment option for canine drug-resistant epilepsy and lesions in the mesial temporal lobe.

Dietary medium chain triglycerides for management of epilepsy: New data from human, dog, and rodent studies

Many studies show that glucose metabolism in epileptic brain areas can be impaired. Energy is crucial to maintain normal brain function, including ion and neurotransmitter balances. Energy deficits can lead to disruption of ion gradients, which can trigger neuronal depolarization and generation of seizures. Thus, perturbed metabolic processing of glucose in epileptogenic brain areas indicates a specific nutritional need for people and animals with epilepsy, as they are likely to benefit from auxiliary brain fuels other than glucose. Ketogenic diets provide the ketone bodies acetoacetate and β-hydroxybutyrate, which can be used as auxiliary fuel by the brain. In approximately 50% children and adults with certain types of epilepsy, who can tolerate and maintain these dietary regimens, seizure frequency can be effectively reduced. More recent data demonstrate that addition of medium chain triglycerides (MCTs), which provide the medium chain fatty acids octanoic and decanoic acid, as well as ketone bodies as auxiliary brain energy, can be beneficial in rodent seizure models, and dogs and humans with epilepsy. Here, this evidence is reviewed, including tolerance in 65% of humans, efficacy studies in dogs, possible anticonvulsant mechanisms of actions of MCTs, and specifically decanoic acid as well as metabolic and antioxidant mechanisms. In conclusion, MCTs are a promising adjunct to standard pharmacological treatment for both humans and dogs with epilepsy, as they lack central nervous system side effects found with current antiepileptic drugs. There is now a need for larger clinical trials in children, adults, and dogs to find the ideal composition and doses of MCTs and the types of epilepsy that respond best.

Bromide toxicosis (bromism) secondary to a decreased chloride intake after dietary transition in a dog with idiopathic epilepsy: a case report

Background

Bromide is a halide ion of the element bromine usually administered in the form of potassium salt as monotherapy or add-on treatment in epileptic dogs. It is excreted unchanged in the urine and undergoes tubular reabsorption in competition with chloride. Thus, dietary chloride content affects serum bromide concentrations. This is the first published clinical report of bromide toxicosis secondary to a dietary modification of chloride content in an epileptic dog treated with potassium bromide.

Case presentation

A 3-year-old 55-kg neutered male Tibetan Mastiff was evaluated because of a 1-month history of progressive signs including ataxia, lethargy and behaviour changes. The dog was successfully treated for idiopathic epilepsy since the age of 1-year-old with phenobarbital and potassium bromide. Two months prior to presentation, the owners decided to change the dog’s diet without veterinary advice. Physical examination was unremarkable. A 12-kg weight gain was recorded since last follow-up (8 months). Neurological examination revealed severe symmetric 4-limbs ataxia with altered vigilance and intermittent episodes of hyperactivity and aggressive behaviour without significant abnormality of cranial nerves. Serum bromide concentration was high and increased by 103 % since last follow-up. Nutritional evaluation revealed a 53 % decrease of chloride content in the diet before and after dietary transition. Bromide toxicosis was suspected, due to bromide reduced clearance secondary to the decreased dietary chloride content. Potassium bromide treatment was lowered by 15 % without further dietary changes. Neurologic signs progressively improved over the next month, without any seizure. After two months, the serum bromide concentration lowered to the same level measured before dietary modification. After four months, neurological examination was unremarkable.

Conclusions

Dietary chloride content can directly influence serum bromide concentrations, therefore affecting seizure control or contributing to unexpected adverse effects. In the present case, a reduction in chloride intake markedly increased serum bromide concentrations causing bromism. Dietary changes should be avoided in dogs treated with potassium bromide to maintain stable serum bromide levels.

Daytime and nocturnal activity in treated dogs with idiopathic epilepsy compared to matched unaffected controls

BACKGROUND

In dogs, antiepileptic drugs (AED) cause lethargy but quantitative data regarding the effects of AED on activity levels are not available, and little is known about how AEDs affect sleep quality.

OBJECTIVE

To quantitatively compare activity levels and nocturnal activity in dogs previously diagnosed with idiopathic epilepsy (IE) receiving AEDs compared to age- and breed-matched control dogs.

ANIMALS

Sixty-two dogs with IE and 310 control dogs.

METHODS

This is a 3-month prospective parallel observational study. An activity monitoring device for dogs was used to measure daily activity levels and sleep scores in all dogs.

RESULTS

Dogs with IE treated with AEDs had an 18% average lower baseline activity level compared to control dogs (P = .005; point estimate = 0.82, 95% confidence interval [CI], 0.75-0.90). The combination of phenobarbital and potassium bromide (KBr) was associated with an average 28% decrease in activity in dogs with IE compared to control dogs (P = .03; point estimate = 0.72; CI, 0.62-0.82). Mean sleep scores were not significantly different in dogs with IE receiving AEDs compared to control dogs (P = .43). However, higher dosages of KBr were associated with lower sleep scores (P = .01).

CONCLUSIONS

Dogs with IE receiving AEDs have lower activity levels, but no difference in sleep scores, compared to controls. The combination of phenobarbital and KBr had the largest decrease in activity between groups. Higher doses of KBr may affect nocturnal activity in epileptic dogs.

Bone marrow, blood, and clinical findings in dogs treated with phenobarbital

BACKGROUND

Cytopenias have been reported in dogs treated with phenobarbital, but detailed descriptions of bone marrow findings and response to treatment are lacking.

OBJECTIVES

We aimed to characterize the hematologic findings and clinical outcomes of dogs that had been receiving phenobarbital at the time of marrow evaluation.

METHODS

Archived bone marrow slides and clinicopathologic data were reviewed in dogs undergoing marrow evaluation for any hematologic problems that developed while receiving phenobarbital (2008-2020). Dogs were excluded if marrow samples lacked diagnostic value, phenobarbital was withdrawn >1 day before marrow collection, a same-day complete blood count (CBC) was lacking, or dogs had concurrent illness or therapy known to cause cytopenias.

RESULTS

Thirteen dogs met inclusion criteria: eight pancytopenic, three anemic/thrombocytopenic, one neutropenic/thrombocytopenic, and one nearly neutropenic. Neutropenia was marked (<700/µL) in eight dogs; all neutrophil concentrations were low or low-normal. Of the 11 anemic dogs (Hct = 12%-42%, median = 29%), three had mild reticulocytosis (eight were tested). One dog had erythroid dysplasia in blood and marrow. All nine neutropenic dogs had evidence of ineffective neutropoiesis: neutrophilic hyperplasia with left shift (9) ± neutrophagocytosis (5). Eight of the 11 anemic dogs had evidence of ineffective erythropoiesis: erythroid hyperplasia (7), left shift (3), and/or rubriphagocytosis (6). No thrombocytopenic dog had megakaryocytic hypoplasia; seven dogs had megakaryocytic hyperplasia. One anemic/thrombocytopenic dog had marked collagen myelofibrosis. The noncytopenic dog had equivocal myeloid hypoplasia with neutrophagocytosis. Median maximal responses and resolution times for neutropenia (n = 6) were 14 days.

CONCLUSIONS

Phenobarbital-induced cytopenias should be considered in dogs with multilineage ineffective hematopoiesis, particularly when neutropenia and myeloid hyperplasia are present. However, findings in dogs with immune-mediated neutropenia or precursor-targeted immune-mediated anemia might be indistinguishable.

Update on Anticonvulsant Therapy in the Emergent Small Animal Patient

Seizures are common in veterinary patients and control is critical to the overall patient health. The benzodiazepine class of drugs (diazepam, midazolam, and lorazepam) often are the drug class of choice; however, levetiracetam and propofol also have been gaining favor as anticonvulsant drugs for acute seizure management. After cessation of seizures, practitioners then can discuss long-term seizure control on a case-by-case basis with clients.

A multicenter randomized controlled trial of medium-chain triglyceride dietary supplementation on epilepsy in dogs

BACKGROUND

Medium-chain triglyceride (MCT) enriched diet has a positive effect on seizure control and behavior in some dogs with idiopathic epilepsy (IE).

OBJECTIVE

To evaluate the short-term efficacy of MCTs administered as an add-on dietary supplement (DS) to a variable base diet to assess seizure control and antiseizure drug's (ASD) adverse effect profiles.

ANIMALS

Twenty-eight dogs with International Veterinary Epilepsy Task Force Tier II (IVETF) level diagnosis of treated IE with 3 or more seizures in the last 3 months were used.

METHODS

A 6-month multicenter, prospective, randomized, double-blinded, placebo-controlled crossover trial was completed, comparing an MCT-DS with a control-DS. A 9% metabolic energy-based amount of MCT or control oil was supplemented to the dogs' diet for 3 months, followed by a control oil or MCT for another 3 months, respectively. Dogs enrolled in this study satisfied most requirements of IE diagnosis stated by the IVETF II level. If they received an oil DS or drugs that could influence the metabolism of the investigated DS or chronic ASD, the chronic ASD medication was adjusted, or other causes of epilepsy were found, the dogs were excluded from the study.

RESULTS

Seizure frequency (median 2.51/month [0-6.67] versus 2.67/month [0-10.45]; P = .02) and seizure-day frequency were significantly (1.68/month [0-5.60] versus 1.99/month [0-7.42], P = .01) lower when dogs were fed MCT-DS in comparison with the control-DS. Two dogs were free of seizures, 3 had ≥50% and 12 had <50% reductions in seizure frequency, and 11 dogs showed no change or an increase in seizure frequency.

CONCLUSIONS AND CLINICAL IMPORTANCE

These data show antiseizure properties of an MCT-DS compared to a control oil and support former evidence for the efficacy of MCTs as a nutritive, management option for a subpopulation of drug-resistant dogs with epilepsy.

Behavioral Changes Under Levetiracetam Treatment in Dogs

In veterinary medicine levetiracetam (LEV) is a well-tolerated antiepileptic drug (AED) with only mild to moderate side effects. Behavioral changes are rarely reported in animals. In contrast, in human medicine the impact of LEV on behavior has frequently been described. Since in the Clinic for Small Animals at the University of Veterinary Medicine Hannover single canine patients were observed with behavioral abnormalities after LEV treatment, it was hypothesized that levetiracetam induces behavioral changes or causes an intensifying of pre-existing behavioral abnormalities in dogs with epileptic seizures. This monocentric retrospective study evaluated the incidence of behavioral changes in epileptic dogs treated with the antiepileptic drug LEV based on information obtained in a questionnaire completed by dog owners. Eighty-four client-owned dogs with recurrent seizures receiving LEV as monotherapy, add on treatment or pulse therapy met inclusion criteria. Approximately half of the dogs in the study population were reported to have preexisting behavioral changes before treatment with LEV, and some of these dogs were reported to experience a worsening of behavioral changes (14/44) or the emergence of new behaviors after initiation of LEV therapy (4/44). One quarter of the dogs without pre-existing behavioral abnormalities developed behavioral changes associated with the administration of LEV (10/40). Based on these results, the authors conclude that behavioral changes can occur in dogs being administered LEV, and this should be taken into consideration when discussing treatment options with owners.

Treatment of congenital extrahepatic portosystemic shunts in dogs: A systematic review and meta-analysis

Background

Several options have been proposed for the treatment of congenital extrahepatic portosystemic shunts (cEHPSS) in dogs, but formal comparisons among different treatment options are currently unavailable. A previous evidence‐based review (2012) found low quality of evidence for papers assessing the treatment of cEHPSS in dogs.

Objectives

To assess the quality of evidence available in the treatment of cEHPSS, summarize the current state of knowledge with respect to outcome after cEHPSS management, and compare different treatment techniques.

Animals

Not used.

Methods

A bibliographic search was performed without date or language restrictions. Studies were assessed for quality of evidence (study design, study group sizes, subject enrollment quality, and overall risk of bias) and outcome measures reported (perioperative outcome, clinical outcome, and surgical or interventional outcome), all reported with 95% confidence intervals. A network meta‐analysis was performed.

Results

Forty‐eight studies were included. Six retrospective studies (grade 4b) compared 2 techniques and 7 were abstracts (grade 5). The quality of evidence was low and risk of bias high. Regarding surgical outcome, statistically significant superiority of ameroid constrictor over thin film band was observed (P = .003). No other comparisons were statistically significant.

Conclusions and Clinical Importance

The evidence base of choice of treatment of cEHPSS in dogs remains weak despite recent publications on the subject. Ameroid is superior to thin film band in causing EHPSS closure. Blinded randomized studies comparing different treatment modalities, which routinely include postoperative imaging to assess cEHPSS closure and acquired portosystemic shunt development are essential.

A cross-species approach to disorders affecting brain and behaviour

Structural and functional elements of biological systems are highly conserved across vertebrates. Many neurological and psychiatric conditions affect both humans and animals. A cross-species approach to the study of brain and behaviour can advance our understanding of human disorders via the identification of unrecognized natural models of spontaneous disorders, thus revealing novel factors that increase vulnerability or resilience, and via the assessment of potential therapies. Moreover, diagnostic and therapeutic advances in human neurology and psychiatry can often be adapted for veterinary patients. However, clinical and research collaborations between physicians and veterinarians remain limited, leaving this wealth of comparative information largely untapped. Here, we review pain, cognitive decline syndromes, epilepsy, anxiety and compulsions, autoimmune and infectious encephalitides and mismatch disorders across a range of animal species, looking for novel insights with translational potential. This comparative perspective can help generate novel hypotheses, expand and improve clinical trials and identify natural animal models of disease resistance and vulnerability.

A double-blinded randomised dietary supplement crossover trial design to investigate the short-term influence of medium chain fatty acid (MCT) supplement on canine idiopathic epilepsy: study protocol

Background

Epilepsy is the most common brain disease in dogs. Recently, diets have been reported to have a positive impact on seizure activity and behaviour in various species including dogs with idiopathic epilepsy (IE). Historically, classic high fat ketogenic diets (KD) and medium chain triglycerides (MCT) KD have been successfully used to manage drug-resistant epilepsy. Similarly, an MCT enriched diet has been shown to improve seizure control and behavioural comorbidities in some dogs with IE. However, it is unknown whether an MCT dietary supplement (DS) may provide similar positive effects.

Methods

A 6-month prospective, randomised, double-blinded, placebo-controlled, crossover, multicentre dietary trial is designed comparing a 9% metabolic energy based calculated medium-chain triglyceride (MCT) oil supplement to a conventional ‘control’ DS. Only dogs which will have an International Veterinary Epilepsy Task Force Tier II level like diagnosis of IE which satisfied the following inclusion criteria are included: age between 6 months and ≤ 12 years; weighing between 4 and ≤ 65 kg; unremarkable interictal neurological examinations; no clinically significant findings on routine laboratory diagnostics; unremarkable brain MRI scan; have had at least 3 seizures in the previous 3 months prior to enrolment; treated with at least one ASD and being classified as resistant. All dogs are fed initially for 90 ± 2 days with either the control oil or the MCT oil alongside their normal diet, followed by 97 ± 2 days with the other supplement including a 7-day washout period. Overall, the aim is to recruit thirty-six patients at five different centres and to investigate the effect of MCTs as DS on seizure activity, tolerability, behavioural comorbidities and quality of life (QoL).

Discussion

Dietary interventions are rarely studied in a standardised form in veterinary medicine. The background diet, the cohort of animals and ASD received is standardised in this prospective diet trial to ensure representative data about the potential effect of MCT DS. If the study data confirms former findings, this would provide further evidence for the efficacy of MCTs as a management option for canine epilepsy. This publication should offer a repository of trial conditions and variable description with forecasted statistical analysis.

Electronic supplementary material

The online version of this article (10.1186/s12917-019-1915-8) contains supplementary material, which is available to authorized users.

Behavioral Interventions as an Adjunctive Treatment for Canine Epilepsy: A Missing Part of the Epilepsy Management Toolkit?

Epilepsy is a common, complex and often challenging neurological disorder to treat in the dog, with 20-30% of dogs resistant to conventional medical therapies, and associated with cognitive and behavioral comorbidities and early death. Behavioral interventions are an emerging area of focus in the adjunctive treatment of drug-resistant human epilepsy patients, with studies indicating positive effects of a variety of interventions including relaxation-based techniques and behavioral therapy interventions. Behavioral interventions have the potential not only to improve seizure control, but also improve behavioral comorbidities and general quality of life in this hard to treat patient group. Despite striking similarities between human and canine epilepsy patients, including the recognition of co-morbid anxiety in epilepsy patients, behavioral interventions have yet to be studied in dogs. This is compounded by several licensed psychopharmaceutical agents for dogs being contra-indicated in epilepsy patients. We present evidence from human studies of the efficacy of behavioral interventions to improve seizure control, psychiatric comorbidities and quality of life, and propose that adapting such interventions for canine patients may be a valuable addition to the epilepsy management toolkit. There is a need for multi-center, double-blinded, placebo-controlled trials to confirm the effects of behavioral interventions on seizure frequency in veterinary medicine. In the absence of such evidence to date, the use of established behavioral medicine techniques to reduce stress and improve the mental health of these often sensitive and challenging patients is advocated, with a greater role for behaviorists in the management of epilepsy patients alongside neurologists and general practitioners.

Serum levetiracetam concentrations after transdermal levetiracetam administration, 3 times daily, to healthy cats

Background

Repeated oral administration of antiepileptic drugs can be challenging for cat owners, resulting in reduced compliance, poor seizure control, and reduced quality of life for cats. Levetiracetam (LEV) has several properties that make it an appealing drug for transdermal application.

Objectives

The aims were to (1) determine if transdermal LEV, in a lipophilic, liposomic cream vehicle, resulted in serum concentrations above 5 μg/mL; (2) identify clinical adverse effects; and (3) evaluate the concentration of LEV in a lipophilic liposomic cream at set intervals.

Animals

Six healthy, client‐owned cats weighing ≤5 kg.

Methods

Prospective clinical trial. Transdermal LEV was applied to the inner pinna at a dosage of 60 mg/kg (400 mg/mL concentration) at home for 6 days. Day 7, cats were hospitalized for blood sample collection for LEV concentration at times 0 (before dose administration), 0.5, 1, 2, 3, and 4 hours after administration.

Results

Median (range) timed serum concentrations were 16.6 (8.6‐39.6) μg/mL, 16.1 (6.8‐34.4) μg/mL, 15.4 (10.1‐36.7) μg/mL, 17.4 (9.2‐32.7) μg/mL, 15.1 (8.3‐25.9) μg/mL, and 14.8 (11.9‐28.4) μg/mL, respectively. Adverse events were limited to sedation (1/6 cats) and pinna crusting (1/6 cats). The LEV, in the proposed vehicle, retained concentration above 95% at 400 mg/mL up to 5 weeks.

Conclusions and Clinical Importance

Thrice daily transdermal LEV resulted in median serum concentrations ≥5 μg/mL throughout the sampling period and clinical adverse events were minimal. Transdermal LEV can provide an alternative for cats resistant to administration of other forms of anticonvulsant medication.

Suspected phenobarbital-induced fever in a cat

CASE SUMMARY

A 3-year-old spayed female domestic shorthair cat developed a fever 1 week after starting the anticonvulsant phenobarbital. A diagnostic work-up for seizures and subsequent onset of fever of unknown origin, consisting of MRI of the brain, cerebrospinal fluid analysis and infectious disease testing, was unremarkable. The cat was switched from phenobarbital onto pregabalin with complete resolution of the fever within 24 h, consistent with a drug-induced fever following phenobarbital administration.

RELEVANCE AND NOVEL INFORMATION

While anticonvulsant hypersensitivities have been reported and studied in veterinary medicine, phenobarbital-induced fever outside of the context of systemic clinical signs has not been documented in the veterinary scientific literature. Drug-induced fever secondary to anticonvulsants should be considered in patients that develop a fever after starting anticonvulsant therapy with an unrewarding diagnostic work-up for fever of unknown origin.

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.

Effects of three infusion fluids with different sodium chloride contents on steady-state serum concentrations of bromide in dogs

Potassium bromide overdose (bromism) in the management of canine epilepsy has been known. However, a protocol to reduce bromide concentrations rapidly has not been previously established. The effects of three infusion fluids with different chloride contents on the steady-state serum concentrations of bromide in beagles were determined. After stabilization of the serum bromide concentrations, seven dogs were infused with saline (Na⁺ 154 mmol/L; Cl^- 154 mmol/L), lactated Ringer's (Na⁺ 131 mmol/L; Cl^- 110 mmol/L), or maintenance solutions (Na⁺ 35 mmol/L; Cl^- 35 mmol/L) at a rate of 2 or 10 ml kg^-1  hr^-1 for 5 hr. Serum and urine were collected hourly, and the bromide concentrations were measured. When saline and lactated Ringer's solutions were infused at a rate of 10 ml kg^-1  hr^-1 for 5 hr, serum bromide concentrations were decreased by 14.24% and urine bromide concentrations by 17.63%, respectively. Of all compositions of infusion fluids, only sodium and chloride contents were associated with the decreased serum concentrations and the increased renal clearance of bromide. In summary, saline and lactated Ringer's solutions reduced serum bromide concentrations in a sodium chloride-dependent manner in dogs were found when infused at 10 ml kg^-1  hr^-1 for 5 hr.

A review of treatment options for behavioural manifestations of clinical anxiety as a comorbidity in dogs with idiopathic epilepsy

Psychiatric comorbidities affect a large percentage of people with epilepsy and have a detrimental impact on their quality of life. Recently, behavioural comorbidities, with similar characteristics to human psychiatric diseases, have been identified in dogs with idiopathic epilepsy. In particular, behaviours motivated by the fear-anxiety emotional system have been found to be associated with the occurrence of idiopathic epilepsy in both dogs receiving anti-epileptic drugs, and drug-naïve dogs. There has been little research into the relationship between epilepsy and behavioural signs, and even less into potential treatment protocols. The following article will review available literature from human medicine to describe the current state of knowledge about the bi-directional relationship between anxiety and epilepsy, draw parallels from reported anxiogenic and anxiolytic properties of anti-epileptic drugs and attempt to provide pharmaceutical and behavioural guidance for veterinary patients with epilepsy and comorbid anxiety.

Preliminary assessment of cognitive impairments in canine idiopathic epilepsy

In humans, epilepsy can induce or accelerate cognitive impairment (CI). There is emerging evidence of CI in dogs with idiopathic epilepsy (IE) from recent epidemiological studies. The aim of our study was to assess CI in dogs with IE using two tests of cognitive dysfunction designed for use in a clinical setting. Dogs with IE (n=17) were compared against controls (n=18) in their performance in two tasks; a spatial working memory task and a problem-solving task. In addition, owners completed the Canine Cognitive Dysfunction Rating (CCDR) scale for their dog. The groups did not differ statistically with respect to age and breed. Dogs with IE performed significantly worse than controls on the spatial working memory task (P=0.016), but not on the problem solving task (P=0.683). CCDR scores were significantly higher in the IE group (P=0.016); however, no dogs reach the recommended threshold score for CCD diagnosis. Our preliminary data suggest that dogs with IE exhibit impairments in a spatial working memory task. Further research is required to explore the effect of IE on other cognitive abilities in dogs with a larger sample, characterising the age of onset, nature and progression of any impairments and the impact of anti-epileptic drugs.

Systematic review of antiepileptic drugs' safety and effectiveness in feline epilepsy

BACKGROUND

Understanding the efficacy and safety profile of antiepileptic drugs (AEDs) in feline epilepsy is a crucial consideration for managing this important brain disease. However, there is a lack of information about the treatment of feline epilepsy and therefore a systematic review was constructed to assess current evidence for the AEDs' efficacy and tolerability in cats. The methods and materials of our former systematic reviews in canine epilepsy were mostly mirrored for the current systematic review in cats. Databases of PubMed, CAB Direct and Google scholar were searched to detect peer-reviewed studies reporting efficacy and/or adverse effects of AEDs in cats. The studies were assessed with regards to their quality of evidence, i.e. study design, study population, diagnostic criteria and overall risk of bias and the outcome measures reported, i.e. prevalence and 95% confidence interval of the successful and affected population in each study and in total.

RESULTS

Forty studies describing clinical outcomes of AEDs' efficacy and safety were included. Only two studies were classified as "blinded randomised controlled trials". The majority of the studies offered high overall risk of bias and described low feline populations with unclear diagnostic criteria and short treatment or follow-up periods. Individual AED assessments of efficacy and safety profile showed that phenobarbital might currently be considered as the first choice AED followed by levetiracetam and imepitoin. Only imepitoin's safety profile was supported by strong level of evidence. Imepitoin's efficacy as well as remaining AEDs' efficacy and safety profile were supported by weak level of evidence.

CONCLUSIONS

This systematic review reflects an evidence-based assessment of the published data on the AEDs' efficacy and safety for feline epilepsy. Currently, phenobarbital is likely to be the first-line for feline epileptic patients followed by levetiracetam and imepitoin. It is essential that clinicians evaluate both AEDs' effectiveness and tolerability before tailoring AED to the individual patient. Further studies in feline epilepsy treatment are by far crucial in order to establish definite guidelines for AEDs' efficacy and safety.

Suspected Phenobarbital-Induced Pseudolymphoma in a Dog

Pseudolymphoma is a drug reaction to anti‐epileptics that is well recognized in humans; it has been reported in one cat but not dogs. In this report, lymphoma‐like clinical signs are suspected to be secondary to phenobarbital administration in a dog. A 2.5‐year‐old male, neutered Shepherd mix presented for a 3‐day history of progressive ataxia, dazed mentation, pyrexia, and lethargy. While hospitalized, the dog developed generalized lymphadenopathy and sustained pyrexia. The dog was receiving levetiracetam and phenobarbital for epilepsy, and serum concentrations of both were within standard therapeutic ranges. Abdominal ultrasound revealed hepatomegaly, splenomegaly, and generalized lymphadenopathy. Cytology of the peripheral lymph nodes was consistent with reactive lymph nodes, and aspirates of the liver and spleen revealed histiocytic‐neutrophilic inflammation. Phenobarbital was discontinued and replaced with zonisamide. Within 24 hours, the dog was normothermic, and other clinical signs resolved within a week. This case highlights a potentially serious yet reversible adverse reaction to phenobarbital in a dog. This idiosyncratic reaction could be mistaken for neoplasia and is an important differential for lymphoma‐like signs in any dog administered phenobarbital.

Investigating the potential of the anti-epileptic drug imepitoin as a treatment for co-morbid anxiety in dogs with idiopathic epilepsy

Background

Behavioural changes associated with idiopathic epilepsy (IE) have been identified in dogs, with fear and anxiety-related problems seen in both drug-naïve dogs and dogs treated with anti-epileptic drugs (AEDs). Treating anxiety-related behaviour in dogs with IE may be challenging, as seizures are a contraindication for many conventional anxiolytic drugs. In addition, many dogs with IE are already treated with AEDs to reduce their seizure frequency, which may have negative effects if used in polytherapy. Imepitoin is low-affinity partial agonist at the benzodiazepine (BDZ) site of the GABA_A receptor, and has been demonstrated to have both anticonvulsant and anxiolytic effects in laboratory rodents. Imepitoin has been developed for the treatment of IE in dogs, with demonstrated anticonvulsant effects and high tolerability and safety. To date, imepitoin’s potential to reduce anxiety in dogs with IE has not been investigated. An online survey was conducted to investigate the effect of imepitoin on fear and anxiety-related behaviours in dogs with IE. Eighty-five valid responses were received from owners of dogs with IE currently treated with imepitoin. Anxiety-related behaviour was quantified before and during imepitoin treatment using a validated questionnaire tool (C-BARQ).

Results

No differences were observed in the five fear/anxiety-related measures between the two time periods (before vs. during treatment) for dog directed fear, stranger directed fear, non-social fear, pain sensitivity and separation related behaviour. A median 45% reduction in seizure frequency/month was observed following imepitoin treatment; however, imepitoin did not appear effective in reducing seizure frequency in a minority of cases. Polyphagia was the most common chronic side effect, and more side effects were reported in polytherapy cases.

Conclusions

Imepitoin does not appear to improve anxiety-related behaviour in dogs with IE treated with this medication for its anti-epileptic effects. Investigating the effects of imepitoin upon the behaviour of dogs with recognised behavioural anxiety-related problems (e.g. specific fears and phobias, separation related behaviours), in both healthy dogs and dogs with epilepsy is required to further explore any potential anxiolytic effects of this medication.