Comparison of gastric emptying times in healthy cats simultaneously evaluated with radiopaque markers and nuclear scintigraphy

Gastric emptying in 18 healthy cats was assessed simultaneously using scint igraphy and barium-impregnated polyethylene spheres (BIPS(R)), Canned Presc ription Diet(R) Feline c/d(R) (Hill's Pet Nutrition, Inc., Topeka, KS) labe led with Tc-99m-disofenin (Hepatolite, DuPont Merck Pharmaceutical Co., Bil lerica, Mass.) was fed on four separate days. Scintigraphic images were obt ained at time 0 and then every 30 minutes to 6 hours. On the fourth scan da y, 30 small (1.5 mm) and 10 large (5 mm) BIPS(R) (Chemstock Animal Health L td., Christchurch, New Zealand) were mixed with the labeled meal, and in ad dition to scintigraphy, radiographs were made at 60-minute intervals for 6 hours. Gastric emptying was 11 to 15% slower on the day of simultaneous rad iography as compared with the 3 days when only scintigraphy was performed ( p less than or equal to .05), Percentage retention of 1.5 mm BIPS(R) in the stomach was significantly greater than the percentage retained gastric act ivity at hours 1, 2, 3, 4, 5, and 6 (p less than or equal to .05), BIPS(R) were clustered in the pyloric region of the stomach by 3 hours in all cats. In 10/18 animals, all BIPS(R) were retained in pyloric region of the stoma ch at 6 hours, despite observable decreased size of the gastric silhouette and less than or equal to 15% retained gastric activity. In conclusion, gas tric emptying of 1.5-mm BIPS(R) does not parallel gastric emptying of Tc-99 m-disofenin labeled canned Prescription Diet(R) Feline c/d(R), Stress assoc iated with radiography may delay gastric emptying. Diet type should be cons idered when evaluating clinical radiographic studies where BIPS(R) have bee n used.