Treatment of Hydrocephalus with Ventriculoperitoneal Shunting in Twelve Dogs Nadia Shihab 1 , MA VetMB, Emma Davies 1 , BVSc MSc Diplomate ECVN, Patrick J. Kenny 1 , BVSc Diplomate ACVIM (Neurology) & ECVN, Shenja Loderstedt 1 , DrMedVet, and Holger A. Volk 1 , DVM Diplomate ECVN, PhD 1 Department of Veterinary Clinical Sciences, Royal Veterinary College, North Mymms, UK Corresponding Author Nadia Shihab, MA VetMB, Department of Veterinary Clinical Sciences, Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, UK E-mail: nshihab@rvc.ac.uk Submitted November 2009 Accepted July 2010 DOI:10.1111/j.1532-950X.2011.00832.x Objective: To report use of ventriculoperitoneal shunt in dogs for management of hydrocephalus for which no cause could be identified. Study Design: Case series. Animals: Dogs with hydrocephalus (n = 12). Methods: Medical records (June 2003–June 2009) were reviewed to determine pre- operative clinical findings, initial postoperative, and long-term outcome. Additional follow-up information was obtained from owners and referring veterinarians. Results: All dogs had signs of forebrain dysfunction, 7 had vestibular signs and 3 had signs of spinal pain. Postoperative complications included pain (n = 4), under- shunting because of shunt kinking (n = 1) and seizures (n = 1). Initial improvement occurred in all dogs and was sustained in 9 dogs, 1 of which required revision surgery. Conclusions: Sustained clinical improvement can be achieved in hydrocephalus with no active underlying cause by use of ventriculoperitoneal shunting. Hydrocephalus, a common congenital or acquired neuro- logic disorder in dogs, 1 is primarily defined as an increased cerebrospinal fluid (CSF) volume within the cranial cavity. 2 Medical management predominately involves re- ducing CSF production through the use of glucocorticoids or diuretics. Although some dogs may be managed long term with medication, typically it provides only temporary palliation of clinical signs. 3–5 Surgical management, the treatment of choice in people with hydrocephalus, 2 aims to provide a controlled flow of CSF from the ventricles into another body cavity, most commonly the peritoneal cavity or occasionally the right atrium. 3,6 In animals, surgical management is recom- mended when hydrocephalus results in severe or progres- sive neurologic deficits or when medical intervention has failed. 3,7 If there is a demonstrable active underlying cause (eg, an intracranial mass), shunt placement may help palli- ate clinical signs; however, it is more commonly performed for congenital hydrocephalus or when no underlying cause can be identified. 3 In dogs with hydrocephalus, a success rate of 75% has been reported with ventriculoatrial shunt placement 8 ; how- ever, there is a lack of data and long-term follow-up on ventriculoperitoneal shunt placement. Several case reports document successful management of individual dogs with hydrocephalus (some with additional malformations) through placement of ventriculoperitoneal shunts. 9–13 Pub- lished abstracts include a study where 4 of 5 adult dogs with hydrocephalus had a sustained improvement but blockage of the intracranial catheter resulted in clinical deterioration in 1 dog with shunt failure. 14 In another abstract reporting outcome in 14 dogs, 5 had congenital and 9 had acquired (intraventricular tumors, hemorrhage, and inflammatory disease) hydrocephalus. 15 We report outcome in 12 dogs with progressive clinical signs attributed to the presence of hydrocephalus, with the aim of obtaining a comparable, more homogeneous popu- lation, all dogs had either a congenital malformation or no identifiable cause of the hydrocephalus and were treated by ventriculoperitoneal shunt placement with the same surgical technique. MATERIALS AND METHODS Medical records (June 2003–June 2009) were reviewed for dogs that were diagnosed with hydrocephalus, either caused by a demonstrable congenital malformation or where no active underlying cause for hydrocephalus was identified. Dogs were included if treated surgically by placement of a ventriculoperitoneal shunt. For placement of the ventriculoperitoneal shunt, dogs were positioned in right pelvic lateral recumbency with their head and shoulders in sternal recumbency. The head was positioned such that the hard palate was horizontal to the table. Using morphometric measurements on preoper- ative magnetic resonance (MR) images the ideal burr site on the parietal bone was determined and the insertion depth necessary for the catheter tip placement in the temporal horn of the lateral ventricle. Veterinary Surgery 40 (2011) 477–484 c  Copyright 2011 by The American College of Veterinary Surgeons 477