Pepsinogen and protein concentrations were determined in blood samples, collected from the left gastroepiploic artery and vein, and in abomasal lymph from 15 steers naturally infected with Ostertagia ostertagi and 4 uninfected steers. In steers with type-1 ostertagiosis, the concentration gradient between the mucosal interstitium and the blood alone could account for higher than normal serum pepsinogen concentrations. High interstitial pepsinogen concentrations may have resulted from increased epithelial permeability or increased pepsinogen production and secretion. However, in steers with type-2 ostertagiosis, the concentration gradient could not entirely account for the high serum pepsinogen concentrations, suggesting that capillary permeability or surface area may have been altered. Lymphatic uptake contributed pepsinogen to the blood in all infected steers.

Twelve horses (6 Standardbreds and 6 Thoroughbreds) received IM injections of furosemide (250 mg) or physiologic saline solution and performed standard exercise tests, to assess the effects of furosemide and breed on blood gas values, PCV, plasma lactate concentration, and heart rate during exercise. After furosemide administration, arterial and venous blood pH values were significantly (P < 0.05) increased. Partial pressures of O2 and CO2 in arterial blood and of CO2 in venous blood (Pa(O2), Pa(CO2), and Pv(CO2), respectively) were unaffected by furosemide treatment, whereas venous partial pressures of O2 (Pv(O2)) were significantly (P < 0.05) less during exercise after furosemide treatment, suggesting an increase in oxygen uptake by the exercising muscles or a change in cardiac output. A significant (P < 0.05) difference was found between Thoroughbred and Standardbred values for arterial and venous pH, Pa(O2), Pa(CO2), plasma lactate concentration, and heart rate, suggesting that Standardbreds exercised at a relatively higher work rate than did Thoroughbreds.

To determine blood supply in the area, dye or radioopaque contrast material was injected into the named arteries supplying the terminal colon and rectum in 10 dogs. The cranial rectal artery appeared to supply most of the blood to the terminal colon and rectum. The middle and caudal rectal arteries supplied variable and relatively insignificant amounts. The intrapelvic rectum had a less adequate blood supply than did the terminal colon or proximal rectum. A ventral midline laparotomy and pubic osteotomy were performed in an additional 11 dogs to provide access to the terminal colon and rectum. When the cranial rectal artery was ligated and the colorectal junction was transected and anastomosed, the intrapelvic rectum developed marked congestion, edema, and discoloration. Rectal fluorescence, after IV administration of fluorescein, was either poor or absent. Histologically, partial- to full-thickness mucosal necrosis was evident in most tissue specimens taken from the rectum, and muscle necrosis was evident in some. These findings suggest that, in dogs, the cranial rectal artery should be preserved if at all possible and, if the cranial rectal artery is ligated, most of the intrapelvic rectum should be resected to ensure adequate blood supply to the anastomosis.