PER RECTAL PORTAL SCINTIGRAPHY IN THE DIAGNOSIS AND MANAGEMENT OF FELINE CONGENITAL PORTOSYSTEMIC SHUNTS

Five cats with a congenital portosystemic shunt (CPSS) were examined u sing transcolonic portal scintigraphy before and after surgical ligati on of the shunting vessel. The mean shunt index before surgery was 52 per cent (range 45 to 61 per cent). Repeat portal scintigraphy, six to eight weeks after surgery, indicated a significant reduction in shunt index (mean 13 per cent, range 5 to 25 per cent) in four cats. In one of these cats a marked reduction in the shunt index, as determined by scintigraphy, preceded normal fasting blood ammonia. In the fifth cat there was no significant change in the shunt index, fasting serum bil e acids and blood ammonia six months after surgery, although its clini cal signs of hepatic encephalopathy had improved. Portal scintigraphy is useful in the diagnosis of CPSS and enables a quantitative assessme nt of the effects of surgery and may be a more accurate indicator of t he degree of shunting after surgery than blood ammonia and serum bile acids.