Canine Epilepsy Research
Epilepsy is the most common long-term neurological disorder experienced by dogs, affecting around 50,000 dogs in the UK.
It is an extremely debilitating condition for dogs and greatly distressing for their owners. Research in this area, therefore, has enormous benefits for the canine population and also can have benefits for human patients and for other species.
Despite epilepsy affecting so many dogs, seizure activity can easily be misinterpreted. RVC research, published in BMC Veterinary Research, illustrated a lack of consistency among vets in the diagnoses of epilepsy. Many owners record their dog or cat having seizures, post footage online and show it to their vets in the hope of assisting diagnosis. The RVC research compared different vet’s interpretation of footage. As well as investigating if vets could agree if filmed animals were having epileptic seizures, without further case information, the study asked observing vets which type of seizures they thought had taken place.
Five non-specialist vets and 10 neurology specialists watched around 100 videos of dogs and cats exhibiting seizure-like events. There was a low level of agreement on whether or not the episodes were epileptic seizures. Specialists were less likely than non-specialists to diagnose a seizure and more likely to diagnose less common conditions. The only seizure characteristic to achieve good agreement between observers was that an animal salivated during an episode. Signs like aggression, anxiety and hallucinations were least agreed upon by participants. The journal article emphasised the need for improved seizure classification systems to help vets make better diagnoses.
Since the article was published, in February 2015, the RVC has driven international consensus on the research, diagnosis and treatment of canine and feline epilepsy. The consensus was facilitated by the establishment of an international body composed of veterinary practitioners and neuropharmacology, neuropathology and neurology experts. The International Veterinary Epilepsy Task Force, which was established and first chaired by Professor Holger Volk (Clinical Director of RVC Small Animal Referrals), has produced seven ‘consensus statements’ outlining recommendations and classifications on all aspects of the condition. The guidelines establish a framework and standards for future trials. Because classifications, definitions, therapeutic outcome measures, neuroimaging and neuropathological standards have historically differed between studies, it has been difficult to draw comparisons. This has limited their scientific and clinical impact.
Nutrition study
An RVC-led food trial involving dogs has implications for human diet and epilepsy management as well as veterinary patients. A six-month dietary trial compared a ketogenic (high fat, low carbohydrate) medium-chain TAG [triacylglycerol] diet (MCTD) with a standardised placebo diet in dogs treated for idiopathic epilepsy. Dogs were fed either a MCTD or placebo diet for three months, followed by a switch of diet for the remaining three months. Clinical and laboratory data were collected and evaluated for 21 participating dogs.
The researchers found that seizure frequency was significantly lower when dogs were fed the MCTD. The study demonstrated that medium chain triglycerides are effective in treating drug-resistant epilepsy in dogs, and a similar diet could make a difference for epilepsy in human patients.
Epilepsy app helps dogs and aids research
This year RVC researchers launched the first ever app that allows owners of dogs with epilepsy to monitor their pet to improve the quality of their lives, inform veterinary decisions and support research into the condition. The ‘RVC Pet Epilepsy Tracker’ enables owners to map seizure activity and medication requirements on mobile phones and tablet devices. It was developed in collaboration with the Epilepsy Society, which previously created one for human patients.
The app contains information about the condition, diagnostic methods and practical advice on what to do in the event of a seizure. It can also remind owners about each medication their dog is due. The app supports vets because owners can convert their dog’s medical history, seizure diary and medication diary into a pdf file and send it directly to practices. There is also the option of recording detailed information of epileptic episodes, including what happened during and after the seizure, how long it lasted and how severe the owner rated it to be.
The epilepsy app could lead to breakthroughs in the understanding of how epilepsy progresses in dogs and patterns of seizure activity because owners can share seizure diaries with RVC researchers. This enables data to be collected from long-term studies of seizure activity, something that researchers have previously been unable to collect for a large number of dogs.
References
International Veterinary Epilepsy Task Force consensus report on epilepsy definition, classification and terminology in companion animals (chaired by Prof. Mette Berendt)
International Veterinary Epilepsy Task Force Consensus Proposal: Diagnostic approach to epilepsy in dogs (Chaired by Drs. Luisa De Risio and Sofie Bhatti)
International Veterinary Epilepsy Task Force current understanding of idiopathic epilepsy of genetic or suspected genetic originin purebred dogs (Chaired by Dr. Velia-Isabel Hülsmeyer)
International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe (Chaired by Drs. Sofie Bhatti and Luisa De Risio)
International Veterinary Epilepsy Task Force Consensus Proposal: Outcome of therapeutic interventions in canine and feline epilepsy (Chaired by Profs. Heidrun Potschka and Andrea Fischer)
International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol (Chaired by Drs. Clare Rusbridge and Sam Long)
International Veterinary Epilepsy Task Force recommendations for systematic sampling and processing of brains from epileptic dogs and cats (Chaired by Profs. Kaspar Matiasek and Martí Pumarola Batlle).
Packer, R M; Berendt, M; Bhatti, S; Charalambous, M; Cizinauskas, S; De Risio, L; Farquhar, R; Hampel, R; Hill, M; Mandigers, P J; Pakozdy, A; Preston, S M; Rusbridge, C; Stein, V M; Taylor-Brown, F; Tipold, A; Volk, H A. (2015)
Inter-observer agreement of canine and feline paroxysmal event semiology and classification by veterinary neurology specialists and non-specialists. BMC Veterinary Research, 11;1:356.