The seizuring cat. Diagnostic work-up and therapy

Abstract

Practical relevance: Although seizures occur less commonly in cats compared with dogs, they are one of the most common forms of neurological disease in the feline patient. Cats may experience both focal (partial) and generalized seizures and causes are divided into primary disorders, in which there is no underlying cause (ie, idiopathic epilepsy), and secondary disorders. Cats with secondary seizure disorders have either an underlying structural lesion or metabolic disease.

Patient group: Seizures affect cats of all ages. Cats with idiopathic epilepsy tend to be younger (approximately 3.5 years) than cats with secondary seizure disorders (approximately 8 years).

Audience: This review of feline seizures is directed at all veterinarians who treat cats, both in an emergency setting as well as in general practice.

Clinical challenges: Refractory seizures are often a diagnostic and therapeutic challenge. A systematic approach to the seizuring cat is described, easing the task of diagnosing the cause of the seizures. In addition, novel antiepileptics are discussed, which can be used as add-on drugs in challenging feline seizure cases.

Evidence base: Compared with the canine counterpart, the literature regarding treatment of feline seizures is less established. Recent clinical trials and studies are focusing on new treatment options for feline seizures. Specifically, these studies, some of which are ongoing, have led to the use of levetiracetam, zonisamide and pregabalin as add-on antiepileptics in cases that are refractory to phenobarbital.

Fig 1

Cat displaying opisthotonus, which may be a result of increased intracranial pressure and herniation of the brain, either under the tentorium cerebelli or through the foramen magnum. Note the extended neck and thoracic limbs

Fig 2

MRI scans from a cat with intracranial lymphoma, (a) T2-weighted axial image at the level of the interthalamic adhesion. The hyperintensity noted in the left cerebral hemisphere represents cerebral/peritumoral edema, (b) T1-weighted image at the same level acquired after the administration of gadolinium. A surface-oriented mass is identified

Fig 3

Cat being treated with a propofol infusion for cluster seizures. Note that she is intubated during treatment and kept on a well padded surface. She was turned regularly, kept clean and dry, and had her lungs auscultated frequently to monitor breath sounds and effort