Managing canine status epilepticus in practice

Status epilepticus is a common emergency encountered in general practice, and one that can be daunting for many to manage. Not only must we expect these dogs to arrive at the clinic at unpredictable times, the presentation causes great distress to the accompanying owners, and we may not always have access to the full spectrum of recommended medications to treat it. This article will briefly review the disease as well as the common underlying causes and explore options for treatment available to most general practitioners. Specifically, this article will focus on patients who do not initially respond to first- and second-line interventions.

Status epilepticus is defined as seizure activity that lasts for longer than 5 minutes, or the occurrence of two or more seizures without complete recovery of consciousness in between. Two or more seizure episodes that occur within a 24-hour period with complete recovery of consciousness in between are termed cluster seizures (Berendt et al, 2015). Status epilepticus represents a life-threatening emergency that requires emergency intervention. Prolonged seizure activity is associated with cerebral damage, characterised by neuronal cell necrosis and gliosis (Shorvon and Ferlisi, 2011) as well as cerebral oedema secondary to blood–brain barrier disruption (Hong et al, 2004). These may contribute to longer durations of status epilepticus and becoming less responsive to anticonvulsant medication (Podell et al, 1995). Systemic effects of status epilepticus are mainly mediated by systemic release of catecholamines, commonly leading to hypertension, tachycardia, hyperglycaemia, hyperthermia, and subsequently can cause cardiac arrhythmias, acidosis, rhabdomyolysis, hypotension, shock, noncardiogenic pulmonary oedema, and acute tubular necrosis. If the seizure continues for over 30 minutes, the risk of hypoglycaemia, hyperthermia, hypoxia, respiratory failure, acidosis, hyperkalaemia, hyponatraemia, and uraemia increases (Tesoro and Brophy, 2010).