Objective-To determine whether pharmacokinetic analysis of data derived from a single IV dose of iohexol could be used to predict creatinine clearance and evaluate simplified methods for predicting serum clearance of iohexol with data derived from 2 or 3 blood samples in clinically normal foals. Animals-10 healthy foals. Procedure-Serum disposition of iohexol and exogenous creatinine clearance was determined simultaneously in each foal (5 males and 5 females). A 3-compartment model of iohexol serum disposition was selected via standard methods. Iohexol clearance calculated from the model was compared with creatinine clearance. Separate limited-sample models were created with various combinations of sample times from the terminal slope of the plasma versus time profile for iohexol. Correction factors were determined for the limited-sample models, and iohexol clearance calculated via each method was compared with exogenous creatinine clearance by use of method comparison techniques. Results-Mean exogenous creatinine clearance was 2.17 mL/min/kg. The disposition of iohexol was best described by a 3-compartment open model. Mean clearance value for iohexol was 2.15 mL/min/kg and was not significantly different from mean creatinine clearance. A method for predicting serum iohexol clearance based on a 2-sample protocol (3- and 4-hour samples) was developed. Conclusions and Clinical Relevance-Iohexol clearance can be used to predict exogenous creatinine clearance and can be determined from 2 blood samples taken after IV injection of iohexol. Appropriate correction factors for adult horses and horses with abnormal glomerular filtration rate need to be determined.

The aim of the present study was to determine and to compare through an indirect enzyme linked immunosorbent assay (ELISA) test, the presence of anti-Neospora caninum antibodies in city and farm dogs, as well as in farm cows, and the relationship among them. The correlation between anti-N. caninum antibodies in farm dogs and cattle was also assessed. The research was conducted in the dairy region of Tizayuca, Hidalgo, Mexico. The frequency of anti-N. caninum antibodies was significantly higher in farm dogs (n = 14) (51%) when compared to those from the city (n = 6) (20%) (P < 0.05), suggesting that farm dogs have a higher risk of exposure to the parasite. There was no significant difference in seropositivity between males (n = 11) (39%) and females (n = 9) (33%) (P > 0.05). The frequency of anti-N. caninum antibodies in farm cattle was significantly higher in farms with dogs (n = 158) (58%) when compared to those with no dogs (n = 43) (35%) (P < 0.05). These results suggest the possible transmission of the parasite from dogs to cattle.