Experimental animal toxicity data on clinical signs of choline overdosage include salivation, trembling, jerking, cyanosis, convulsions and respiratory paralysis. Estimates of the oral LD50 of choline chloride in rats varied from 3.4 to 6.7 g per kg (1.5 to 3.0 g per lb) (Chan, 1991).
Insufficient data are available to support precise estimates of maximum tolerable dietary levels of choline for dogs, and there are no available data for cats. Studies with dogs suggest a low tolerance for choline chloride and lecithin in that species. Adverse effects have been reported for levels of choline chloride equivalent to three times the apparent choline requirement (NRC, 1987). Davis (1944a) showed that administering daily dietary equivalent of 150 mg of choline to dogs resulted in a maximum number of erythrocyte reductions that took place after 12 to 25 days. Davis (1944b) found that choline chloride induced a hyperchromic anemia in about 15 of 17 dogs. The anemia was produced by giving the dogs single doses of 10 mg per kg (4.5 mg per lb) per day of choline chloride by stomach tube.
