Although endoscopy is the definitive diagnostic method for the detection of colonic ulcers, the equipment required for performing the test is costly and difficult to use. Therefore, a simple cost-effective and reliable screening test for intestinal tract bleeding is needed. To this end, we measured carbonic anhydrase isozymes (CA-I and CA-II) originating from erythrocytes by ELISA in order to determine if they could be used as markers of occult blood in feces. For fecal extract preparation, 2 g of feces were mixed with 4 ml of 0.01 M Tris-HCl (pH 8.0) containing 0.01% thimerosal. The concentrations of CA-I and CA-II in the fecal samples of 13 clinically normal racehorses were found to be 30.0 ± 10.0 and 34.0 ± 13.0 ng/ml, respectively. Increased concentrations of CA-I were detected in the fecal samples of 5 horses after blood administration; however, no increase was observed in CA-II. The concentrations of CA-I and CA-II in the fecal samples of 88 racehorses with clinical signs of equine gastric ulcer syndrome (EGUS) were 115.3 ± 79.0 and 41.0 ± 42.0 ng/ml, respectively. Thus, our results indicate that CA isozymes can be useful as markers of occult blood in the fecal samples of horses with intestinal tract bleeding.
Percentile growth curves are often used as a clinical indicator to evaluate variations of children’s growth status. In this study, we propose empirical percentile growth curves using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Individual horses and residual effects were included as random effects in the growth curve equation model and their variance components were estimated. Based on the Z-scores of the estimated variance components, empirical percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and age measurements were used in the analyses. The developed empirical percentile growth curves using Z-scores are computationally feasible and useful for monitoring individual growth parameters of body weight and withers height of young Thoroughbred horses, especially during compensatory growth periods.
Non-specific hemolysis has often been observed during complement-fixation (CF) tests for equine herpesvirus type-1 (EHV-1), even when the sera have virus-specific CF antibodies. This phenomenon has also been reported in CF tests for various infectious diseases of swine. We found that the sera from 22 of 85 field horses (25.9%) showed non-specific hemolysis during conventional CF testing for EHV-1. Because pretreatment of swine sera with potassium periodate (KIO4) improves the CF test for swine influenza, we applied this method to horse sera. As we expected, horse sera treated with KIO4 did not show non-specific hemolysis in the EHV-1 CF test, and precise determination of titers was achieved.
To establish blood and biochemical references for the endangered Kiso horse, blood samples were collected from 111 adult Kiso horses, 74.5% of the existing breed. The samples were analyzed for 23 hematological and biochemical parameters to determine their means and standard deviations (SD). We compared the mean ± 2SD with the reference values cited in one of the most commonly used veterinary textbooks in Japan. The hematology of Kiso horses is characterized by lower erythrocyte count and hematocrit and hemoglobin levels. In addition, their serum biochemistry showed lower levels of aspartate transaminase, alkaline phosphatase, and γ-glutamyl transferase. Whether these propensities are attributed to breed-specific factors or are acquired factors remains unclear. Nevertheless, this study provides useful diagnostic indices for the endangered Kiso horse.