A Practical Guide to Seizure Disorders in Dogs and Cats

Seizure disorders are commonly encountered in small animal practice. The goal of this book is to provide a comprehensive, evidence-based resource to assist in the successful management of recurrent seizures in dogs and cats. Practical information on every aspect of seizure management is presented and is supported with a review of the available literature. The book’s format is designed to provide a logical, clinically relevant approach to the seizure patient, with in-depth information on the broad range of topics involved in the diagnosis and treatment of seizure disorders in dogs and cats. The first five chapters describe the clinical and diagnostic approach to the seizure patient, and include thorough descriptions of seizure classification with video case examples, canine idiopathic epilepsy, the genetics of epilepsy, feline epilepsy and quality of life. There are separate chapters devoted to advanced imaging and electroencephalography, both of which contain numerous images to complement the discussion of the material. The remaining chapters focus on epilepsy treatment and include a review of general treatment guidelines and pharmacological principles, as well as a comprehensive review of antiseizure drugs, adjunctive therapies for drug-resistant epilepsy, and the management of cluster seizures and status epilepticus in dogs and cats. The 19 book chapters are authored by veterinary specialists from around the globe. Algorithms are included throughout the book, and each chapter contains a summary of key points, providing easy access to information to support clinical decision making and patient care. Our aim was to create a comprehensive reference that would be of value to primary care veterinarians, veterinary students, interns, residents, and veterinary specialists alike.

Table of contents:

01 The Clinical and Diagnostic Approach to the Seizure Patient....... 1

Luisa De Risio, Karen R. Muñana

Terminology........................................................................... 1

Phases associated with a seizure................................... 4

Disorders that can mimic seizures and discriminators ............................................................... 5

Systematic diagnostic approach to the patient with seizure disorders.................................................... 8

02 Canine Idiopathic Epilepsy.................... 33

Andrea Fischer

Types of epileptic seizures................................................ 34

Diagnostic approach .......................................................... 38

Breed-related differences ................................................. 39

and lifespan in canine idiopathic epilepsy .................................................................................. 63

03 Quality of Life Issues in Canine Epilepsy................................................................. 77

Rowena MA Packer

What is quality of life?........................................................ 77

Impact of epilepsy on canine QoL.................................. 78

Impact of epilepsy on caregiver quality of life.............. 85

04 Genetics of Epilepsy in Dogs and Cats................................................................ 93

Edward (Ned) E. Patterson

Genetic or suspected genetic idiopathic epilepsy in dogs................................................................ 93

Structural epilepsies in dogs ............................................ 96

L-2-Hydroxyglutaric aciduria.............................................. 97

Genetic counseling for breeding dogs with epilepsy ...................................................................... 100

Feline epilepsy genetics .................................................... 100

05 Feline Epilepsy................................................ 103

Akos Pakozdy, Borbala A. Lörincz

Prevalence of seizure disorders in cats......................... 103

Terminology........................................................................... 103

Diagnostic approach to seizure disorders in cats....... 104

Antiseizure treatment of feline epilepsy......................... 110

Outcome of feline epilepsy................................................ 112

06 Advanced Diagnostic Imaging in Epilepsy........................................................... 117

Daisuke Hasegawa

Conventional MRI................................................................ 118

Structural MRI for diagnosis of epilepsy........................ 129

Advanced and functional imaging................................... 133

Imaging findings of structural epilepsies ....................... 140

Degenerative diseases....................................................... 140

07 Electroencephalography.......................... 155

Fiona M.K. James

How does EEG work? ....................................................... 156

How to record EEG? .......................................................... 158

How to interpret EEG?....................................................... 164

How to report EEG?........................................................... 175

Where to learn more on EEG?........................................ 176

08 Fundamental Principles of Pharmacokinetics for Antiseizure Medications............................... 185

Mark G. Papich

Important definitions............................................................ 185

Principles of drug disposition in animals....................... 185

Drug elimination (elimination half-life, t½)....................... 188

Drug distribution (volume of distribution)....................... 190

Drug clearance..................................................................... 192

Drug absorption................................................................... 194

09 Principles of Antiseizure Drug Use... 201

Karen R. Muñana, Luisa De Risio

Initiating therapy................................................................... 201

Choosing an appropriate antiseizure drug.................... 204

Devising a rational treatment plan .................................. 207

Drug resistance.................................................................... 213

Epilepsy remission ............................................................. 214

10 Phenobarbital.................................................... 219

Fabio Stabile, Luisa De Risio

Mechanism of action ......................................................... 219

Pharmacokinetics ............................................................... 219

Efficacy .................................................................................. 221

Clinical use ........................................................................... 223

Adverse effects and drug interactions............................ 229

11 Potassium Bromide...................................... 239

Michael Podell

Mechanism of action ......................................................... 239

Pharmacokinetics................................................................ 239

Efficacy................................................................................... 240

Clinical use............................................................................ 241

Adverse effects and drug interactions............................ 243

12 Levetiracetam................................................... 247

Karen R. Muñana

Mechanism of action .......................................................... 247

Pharmacokinetics................................................................ 248

Efficacy................................................................................... 249

Clinical use ........................................................................... 252

13 Imepitoin................................................................ 257

Andrea Tipold

Mechanism of action .......................................................... 257

Pharmacokinetics................................................................ 258

Efficacy................................................................................... 258

Clinical use ........................................................................... 261

Adverse effects and drug interactions............................ 262

14 Zonisamide......................................................... 267

Daisuke Hasegawa, Miyoko Saito

Mechanism of action .......................................................... 267

Pharmacokinetics................................................................ 268

Clinical use ........................................................................... 271

Adverse effects and drug interactions ........................... 273

15 Other Antiseizure Drugs .......................... 279

Kari Foss, Devon Hague

Clorazepate and Clonazepam ......................................... 281

Felbamate.............................................................................. 282

Gabapentin .......................................................................... 283

Topiramate............................................................................. 284

Pregabalin.............................................................................. 286

Rufinamide ............................................................................ 287

Lacosamide........................................................................... 287

Brivaracetam......................................................................... 288

16 Cannabidiol in Canine Epilepsy......... 291

Stephanie McGrath

Mechanism of Action ......................................................... 291

Pharmacokinetics................................................................ 293

Efficacy .................................................................................. 295

Clinical use............................................................................ 296

Adverse effects and drug interactions............................ 296

17 Dietary Management of Canine Epilepsy ............................................................... 301

Elliott S. Neal, Weizhi Xu, Karin Borges

Pathophysiology and mechanism of action.................. 301

“Pharmacology and pharmacokinetics” of ketogenic diets and medium chain triglycerides............. 305

Efficacy................................................................................... 306

Manipulations of macronutrients – practical considerations for the treatment of dogs with epilepsy.. 309

18 Neurostimulation for Canine Epilepsy................................................................. 313

Sofie F.M. Bhatti Contributors: Marios Charalambous, Luc Van Ham

Vagus nerve stimulation .................................................... 314

Transcranial magnetic stimulation .................................. 318

Conclusions........................................................................... 321

19 Management of Status Epilepticus and Cluster Seizures in Dogs and Cats.................................... 325

Marios Charalambous Contributor: Sofie F.M. Bhatti

Status epilepticus ................................................................ 325

Cluster seizures ................................................................... 340