Research by the Royal Veterinary College (RVC) canine epilepsy clinic has highlighted the difficulty of diagnosing seizures in dogs and cats from videos recorded by pet owners.
Practices are now commonly presented with videos of unusual and unexpected “funny turns” or “fits” (seizure-like paroxysmal events) by dog and cat owners, but whether vets interpreted these videos in the same way was not known.
The study was carried out by the canine epilepsy clinic alongside some of the world’s leading experts in this area of veterinary medicine. It investigated whether vets could agree a dog or cat was having an epileptic seizure when presented with a video without any further information.
The study also looked at what kind of seizure vets thought was occurring, and which characteristics of a seizure they thought were present.
Fifteen vets (10 neurology specialists and five non-specialists) watched about 100 videos of dogs and cats exhibiting seizure-like events, without knowing the history, results of diagnostic work-up or treatment outcomes.
Results showed a relatively low level of agreement between vets on whether the episodes were epileptic seizures. Neurology specialist vets were less likely to diagnose a seizure than non-specialists, instead diagnosing less common disorders such as idiopathic head bobbing or episodic falling.
In addition, vets often disagreed about the type of seizure. Vets agreed most upon diagnosing “generalised seizures”, those where both halves of the brain are involved and dogs often lose consciousness and shake throughout their whole body, but disagreed the most upon the diagnosis of “focal seizures”, those where only part of the brain is affected and the animal may appear to stay conscious.
The only seizure characteristic to achieve good agreement was whether the dog salivated or not during the episode, which vets associated with generalised seizures.
In contrast, neurobehavioural signs such as aggression, fear/anxiety and hallucination were least agreed upon, and vets often disagreed over the consciousness status of the dog.
The authors emphasised the need for robust seizure classification systems, with poor agreement between observers potentially highlighting deficiencies in current classification systems.
Holger Volk, clinical director of the RVC’s small animal referral clinic and specialist in neurology and neurosurgery, said neurologist specialists received a video every day and were asked to make a diagnosis.
“This study highlights this is not trivial,” Prof Volk said. “Video-EEG studies, where electrical activity in the brain is recorded alongside videos of seizure-like events could be a tool to unravel this riddle and are often used as a diagnostic tool in human neurology, and could be used more widely in veterinary medicine to aid characterisation of episodes beyond what can be observed on a video alone, and lead to more objective, definitive diagnoses.”
Rowena Packer, co-author of the study and clinical investigations research assistant at RVC, said that although owners might be tempted to upload videos of their pet online to ask others what is happening to them, “it was no substitute for taking their pet to the vets for a full diagnostic work-up.”
Reference: Packer R M A, Berendt M, Bhatti S et al (2015). Inter-observer agreement of canine and feline paroxysmal event semiology and classification by veterinary neurology specialists and non-specialists, BMC Veterinary Research 11: 39 doi:10.1186/s12917-015-0356-2