Gelatin given by vein during 1 to 2 weeks (total 3 to 17 gm. per kilo) usually causes serious disturbances—inhibition of blood protein production, signs of intoxication, much weight loss, and even death.

Gelatin given by vein for 2 to 3 days (total 1 to 3 gm. per kilo) may not cause any recognizable abnormalities, but dogs vary greatly in their response to gelatin by vein. Some dogs may tolerate a total of 7 gm. per kilo without significant disturbance and other dogs may be seriously intoxicated by 2 to 3 gm. per kilo. No one can predict which animal will be least tolerant.

Some experiments with gelatin by vein for 2 to 3 days (total gelatin 1 to 2 gm. per kilo) given with and followed by amino acids or casein digests do show absence of intoxication and ample production of new hemoglobin and plasma protein during the weeks following the injection of gelatin. This may suggest possible usefulness of gelatin with amino acids or casein digests in acute emergencies (shock, hemorrhage).

These doubly depleted dogs are very susceptible to various injurious agents as compared to normal dogs. They may serve as sensitive testing machines for evaluating plasma substitutes.

Where the gelatin by vein inflicts its damage is not clear and there is little if any significant histological evidence but the disturbance of blood protein production implicates the liver.

Gelatin of smaller molecular weight (degraded by autoclaving) is no less toxic than the standard gelatin.

Gelatin by mouth may contribute to but cannot alone support the production of new hemoglobin and plasma protein.

Gelatin by vein has definite limitations in dogs and, by implication, when used in human cases the amount given should be very carefully watched.