Published: 12 Dec 2024 | Last Updated: 12 Dec 2024 12:37:35

The findings led by the Royal Veterinary College are key in helping vets offer more information and support to pet owners when managing their dog’s epilepsy

Researchers from the Royal Veterinary College (RVC) working in collaboration with the University of Cambridge have found that anti-seizure drugs (ASD) increase appetite in dogs with epilepsy. This often results in these medicated dogs becoming overweight or obese. As well as having higher food drive, epileptic dogs on treatment are more likely to be given treats to help administer medication and to be less active. The research will help veterinary teams support owners to avoid these risks from the point they start medication and highlight the importance of helping owners monitor and manage their dog's weight over time.

Idiopathic epilepsy is the most common chronic neurological disease in dogs and often requires lifelong administration of ASD to reduce the frequency and severity of seizures. Even so, treatment rarely leads to seizure freedom, and many dogs undergoing chronic ASD treatment experience adverse effects between seizures. Some of the long-lasting side effects of these medications include decreased levels of energy and increased food intake and weight gain.

Although increased appetite has been reported as a side effect of many ASD in the veterinary literature, this effect had not been quantified or studied in detail. To assess this in greater detail, the research team analysed food motivation through a validated Dog Obesity Risk Assessment questionnaire created by University of Cambridge. The study compared 222 dogs diagnosed with Idiopathic Epilepsy with a control population of 7,086 healthy dogs. The survey was designed to determine if epilepsy and ASD were associated with increased food motivation, weight gain and decreased activity, and to assess if and how caregivers managed weight gain in this population.

Analyses revealed that dogs with idiopathic epilepsy receiving ASD had significantly higher food motivation in comparison to healthy dogs – they had increased interest in food, were less selective about food, were more interested in food between meals, and wanted more food than usually offered. In response, carers of dogs on medication put greater effort into restricting how much their dogs ate, particularly of human food. Despite this, these dogs had significantly greater fat mass.  

More than half of owners of dogs with epilepsy always used treats to administer their dog’s ASD medication (53%) and did not compensate for it by reducing the dog’s main food ration (34%). Given the epilepsy treatment often involves medication two or three times a day, this has the potential to increase calorie intake substantially, an issue compounded by epileptic dogs also being less active. It is therefore important for vets to advise and support owners to continually monitor and manage their dog's weight.

Dr Rowena Packer, Lecturer in Companion Animal Behaviour and Welfare Science at the RVC, and principal investigator of this research, said:

“The findings of this research are key in helping the veterinary team provide greater information and support to pet owners managing their dog’s epilepsy. Although anti-seizure drugs are an essential part of the epilepsy treatment toolkit, ensuring owners are aware of the side-effects and long-lasting impact of these medications is key in treatment decision-making, ensuring a balance between negative side effects such as increased food motivation against potential positive effects such as reduced seizure frequency, to maintain quality of life. Excessive drive to eat can lead to undesirable behaviours such as begging and scavenging, which can also have a negative impact on dog-caregiver bonds. Supporting owners experiencing these side effects in their dog is essential in reducing caregiver burden, which is already documented to be high in this population of caregivers managing dogs with this highly stressful disease.”

Dr Eleanor Raffan of the University of Cambridge, and senior author of this study, said:

“Pet obesity is often blamed on owners not paying attention to how they feed and exercise their dogs. But our research shows that many factors can affect dogs’ appetite, which has knock-on effects in the home. Very ‘foodie’ dogs tend to pester their owners for food, scavenge scraps and eat even unappealing food. Over time, this leads to weight gain unless owners maintain constant vigilance to restrict what their dogs eat.

“In epileptic dogs, anti-seizure drugs drive an increase in appetite, driving more intake. At the same time, owners often give treats to help with getting tablets down and the medications make dogs less active. Put together, this is a ‘triple whammy’ that predisposes to weight gain. It is a lot to think about for owners of dogs with a chronic health problem. As vets, we can head off obesity by supporting owners on how to effectively restrict calories, recognising this is harder after we give the medication.”

Dr Anna Morros-Nuevo of the University of Cambridge, and primary author of this study, said:

"Idiopathic epilepsy, and in particular seizure episodes, have such an overwhelming impact on these dogs' families that side effects such as weight gain often get overlooked, both by vets and the pet's families. But unfortunately, obesity has lifelong negative impact on health and quality of life, since it predisposes dogs to suffer from joint problems and respiratory diseases, as well as metabolic disorders and urinary incontinence. Obese dogs have also been shown to have a shorter lifespan than dogs with a normal weight.

While ASD are non-negotiable for many of these dogs, their caregivers and veterinarians should be aware of the lifelong impact of their side effects and manage them carefully. We hope these findings will help to increase awareness for both veterinary professionals and dog carers of the side effects of ASD and their impact for the patient."

This research was funded by the Universities Federation for Animal Welfare and Morris Animal Foundation.

Notes to Editors

Morros-Nuevo, A., Packer, R. M. A., Reagan, N. & Raffan, E. ‘Caregiver-reported increased food motivation and adiposity in dogs receiving antiseizure dogs’, Vet Record, 195(12) doi: http://doi.org/10.1002/vetr.4907

Link to article: https://bvajournals.onlinelibrary.wiley.com/doi/10.1002/vetr.4907

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About the RVC

• The Royal Veterinary College (RVC) is the UK's largest and longest established independent veterinary school and is a Member Institution of the University of London. 
• It is one of the few veterinary schools in the world that hold accreditations from the RCVS in the UK (with reciprocal recognition from the AVBC for Australasia, the VCI for Ireland and the SAVC for South Africa), the EAEVE in the EU, and the AVMA in the USA and Canada. 
• The RVC is ranked as the top veterinary school in the world in the QS World University Rankings by subject, 2024. 
• The RVC offers undergraduate and postgraduate programmes in veterinary medicine, veterinary nursing and biological sciences. 
• The RVC is a research-led institution, with 88% of its research rated as internationally excellent or world class in the Research Excellence Framework 2021. 
• The RVC provides animal owners and the veterinary profession with access to expert veterinary care and advice through its teaching hospitals and first opinion practices in London and Hertfordshire.