Case Report Long-term evaluation of a new ventriculoperitone shunt valve system in a dog Richard da Rocha Filgueiras, DVM, PhD, DCBCAV; Christine de Souza Martins, DVM, MSc; Ricardo Miyasaka de Almeida, DVM, PhD, DCBCAV; Rosana Marques Silva, DVM, PhD; Martha de Souza Teixeira da Rocha, DVM; Fernanda de Paula Firmino, DVM, MSc; Samara Maguilnik, DVM and Luı´za Quinta ˜o Medeiros,DVM Abstract Objective – To report on the use of a new ventriculoperitoneal shunt (VPS) valve system utilized in a dog with hydrocephalus and to describe the clinical course over 20 months after implantation. Case Summary – A 3-month-old female Lhasa Apso dog was presented with lateral strabismus,domed calvarium,and visual deficits.A lateral skull radiograph revealed a persistent fontanelle. Transfontanellar ultrasonographic examination and computed tomographic examination showed excessive accumulation of fluid within the ventricles.The owner had observed symptoms as early as 1 month after birth, suggesting congenital hydrocephalus. A VPS with a new valve system that inhibits cerebrospinal fluid overdrainage and obstruction of the catheter was implanted. The dog showed clinical improvement 48 hours after the procedure. Twenty days after shuntimplantation,another computed tomography scan was performed that showed reduction in ventricle size.The evaluation ofVPS patency was carried out20 months after surgery and demonstrated that the system was working properly without obstruction. New or Unique Information Provided – There are reports in the literature describing the use of several devices to perform VPS in dogs. A new device not previously described in the veterinary literature was used in this case report,and according to the manufacturer’s description, this device inhibits proteinaceous build-up, which is usually responsible for subsequent catheter obstructions. (J Vet Emerg Crit Care 2009; 19(6):623–628) doi: 10.1111/j.1476-4431.2009.00484.x Keywords: cerebral drainage, cerebrospinal fluid, congenital hydrocephalus, ventricular catheter Introduction The term hydrocephalus implies the presence of an excessive accumulation of cerebrospinalfluid (CSF) within the cranial cavity with dilation of the ventricular system. 1 CSF protects, supports, and nourishes the centralnervous system. It originates from the choroid plexus of the lateral,third, and fourth ventricles di- rectly from the brain by way of the ependymal lining of the ventricular system and pial-glial membrane cover- ing the external brain surface as well as from the blood vessels of the pia and arachnoid. 2 Causesof hydrocephaluscan be congenitalor ac- quired.In veterinary patients, congenital hydrocephalus is more common than acquired. 1 Causes ofcongenital hydrocephalus are reported as follows: fusion of rostral colliculi with secondary mesencephalic aqueductal steno- sis; prenatal inflammation with lesions of the ependymal surface;and malformationsof the cerebellum, as in caudaloccipitalmalformation syndrome. In the latter 2 causes,secondary cerebellar herniation and syringo- hydromyelia may occur and obstruct CSF drainage. 1 Clinical signs of hydrocephalus reflect the anatomic level of disease involvement. Forebrain,vestibular,or cerebellar signs are most common. A ventral or lateral strabismus or both, alterations in cognition, dementia, circling gait, paresis, and seizures are common in dogs with hydrocephalus. Congenital hydrocephalus is typically recognized in patients 2–3 months of age. An- imals with congenital hydrocephalus are often smaller than their littermates and show calvarium distortion according to the rate of fluid accumulation and stage of ossification of cranial sutures. 2 The work was carried out at the Veterinary Teaching Hospital of University of Brasilia. The authors declare no conflicts of interest. Address correspondence and reprint requests to Dr. Richard da Rocha Filgueiras, Hospital Veterina ´rio de Pequenos Ani- mais,Campus Universita ´rio Darcy Ribeiro, Avenida L4 norte, Asa Norte, Brası ´lia – DF. Cep:70330-050, Brazil. Email:richardfilgueiras@gmail.com Faculdade de Agronomia e Medicina Veterina ´ria, Campus Universita ´rio Darcy Ribeiro, Universidade de Brası ´lia, Asa Norte,DF 70 879-130, Brazil Journal of Veterinary Emergency and Critical Care 19(6) 2009, pp 623–628 doi:10.1111/j.1476-4431.2009.00484.x & Veterinary Emergency and Critical Care Society 2009 623