Evaluation of Intestinal Barrier Dysfunction with Serum Iohexol Concentration in Dogs with Acute Hemorrhagic Diarrhea Syndrome

Simple Summary Acute hemorrhagic diarrhea syndrome (AHDS) is characterized by severe gastrointestinal fluid loss and necrotizing enteritis. This indicates an intestinal barrier dysfunction, altered intestinal permeability may indicate disease severity and might represent a risk factor for the development of chronic disorders. Serum iohexol measurement is utilized to assess intestinal permeability in dogs. Our study aimed to correlate intestinal permeability (measured by serum iohexol concentration (SIC)) with clinical severity in dogs with AHDS. We hypothesized increased intestinal permeability in dogs with AHDS, correlating with clinical severity. Fifty-three client-owned dogs, including those with AHDS and healthy controls, were enrolled. Clinical severity was assessed using the AHDS index and criteria for systemic inflammatory response syndrome (SIRS). Simultaneously, dogs were orally administered iohexol, and serum samples were collected for SIC measurement. The findings revealed significantly elevated SIC among dogs with AHDS compared to healthy controls, with a positive correlation between SIC and disease severity indices. These results highlight that dogs with a severe form of AHDS have an especially significant dysfunction of the intestinal barrier. Future studies are necessary to evaluate a potential association between an altered intestinal barrier at the phase of acute enteritis and the development of chronic intestinal disease later in life.Abstract Histopathologic examination of intestinal biopsies from dogs with acute hemorrhagic diarrhea syndrome (AHDS) reveals necrotizing enteritis and epithelial integrity loss. Serum iohexol measurement has been utilized to assess intestinal permeability. Our hypothesis is that dogs with AHDS have increased intestinal permeability, which is associated with the severity of clinical signs. In this prospective case-control study, 53 client-owned dogs (28 AHDS, 25 healthy controls) were evaluated. Clinical severity was assessed using the AHDS index and systemic inflammatory response syndrome (SIRS) criteria. Simultaneously, dogs received oral iohexol, and serum iohexol concentrations (SICs) were measured two hours later. Results indicated significantly higher (p = 0.002) SIC in AHDS dogs (median: 51 mu g/mL; min-max: 9-246) than in healthy controls (30 mu g/mL; 11-57). There was a significant positive correlation between AHDS index and SIC (rS = 0.4; p = 0.03) and a significant negative between SIC and serum albumin concentrations (Pearson r = -0.55; p = 0.01). Dogs with severe AHDS (mean 106 mu g/mL; range: 17-246) demonstrated significantly higher (p = 0.002) SIC than those with mild to moderate disease (29 mu g/mL; 9-54). These findings underscore the association between intestinal permeability and clinical severity in dogs with AHDS assessed by iohexol.