The effect of prophylactic treatment with levetiracetam on the incidence of post-attenuation seizures in dogs undergoing surgical management of single congenital extrahepatic portosystemic shunts

Objectives: To report (1) the incidence of post-attenuation seizures (PAS) in dogs that underwent single congenital extrahepatic portosystemic shunt (cEHPSS) attenuation and (2) to compare incidence of PAS in dogs that either did or did not receive prophylactic treatment with levetiracetam (LEV).Study Design: Multi-institutional retrospective study.Sample Population: Nine-hundred-and-forty dogs.Methods: Medical records were reviewed to identify dogs that underwent surgical attenuation of a single cEHPSS from January 2005 through July 2017 and developed PAS within seven days postoperatively. Dogs were divided into three groups: no LEV (LEV-); LEV at >15mg/kg TID for >24 hours or a 60mg/kg intravenous loading dose preoperatively, followed by >15mg/kg TID postoperatively (LEV1); ); and LEV at less than 15mg/kg TID, for less than 24 hours preoperatively, or continued at less than 15mg/kg TID postoperatively (LEV2).Results: Nine-hundred-and-forty dogs were included. Seventy-five (8.0%) developed PAS. Incidence of PAS was 35/523 (6.7%), 21/188 (11.2%) and 19/228 (8.3%) in groups LEV-, LEV1 and LEV2, respectively. This difference was not statistically significant (p=0.14). No significant differences between groups of dogs that seized with respect to variables investigated were identified.Conclusions: The overall incidence of PAS was low (8%). Prophylactic treatment with LEV according to the protocols investigated in our study was not associated with a reduced incidence of PAS.Clinical Significance: Prophylactic treatment with LEV does not afford protection against development of PAS. Surgically treated dogs should continue to be monitored closely during the first seven days postoperatively for seizures

Hyperammonemia and systemic inflammatory response syndrome predicts presence of hepatic encephalopathy in dogs with congenital portosystemic shunts

Hepatic encephalopathy (HE) is an important cause of morbidity and mortality in patients with liver disease. The pathogenesis of he is incompletely understood although ammonia and inflammatory cytokines have been implicated as key mediators. To facilitate further mechanistic understanding of the pathogenesis of HE, a large number of animal models have been developed which often involve the surgical creation of an anastomosis between the hepatic portal vein and the caudal vena cava. One of the most common congenital abnormalities in dogs is a congenital portosystemic shunt (cpss), which closely mimics these surgical experimental models of HE. Dogs with a cPSS often have clinical signs which mimic clinical signs observed in humans with HE. Our hypothesis is that the pathogenesis of HE in dogs with a cPSS is similar to humans with HE. The aim of the study was to measure a range of clinical, haematological and biochemical parameters, which have been linked to the development of HE in humans, in dogs with a cPSS and a known HE grade. One hundred and twenty dogs with a cPSS were included in the study and multiple regression analysis of clinical, haematological and biochemical variables revealed that plasma ammonia concentrations and systemic inflammatory response syndrome scores predicted the presence of HE. Our findings further support the notion that the pathogenesis of canine and human HE share many similarities and indicate that dogs with cPSS may be an informative spontaneous model of human HE. Further investigations on dogs with cPSS may allow studies on HE to be undertaken without creating surgical models of HE thereby allowing the number of large animals used in animal experimentation to be reduced

SIRS score plotted against log (odds ratio) of HE relative to reference value of SIRS 0.

<p>SIRS score plotted against log (odds ratio) of HE relative to reference value of SIRS 0.</p