Tortuga Gazette 25(7): 10, July 1989

Poisonous Plants

By Carl S. Hornfeldt

There is a widely held belief among the general public that animals instinctively know not to eat poisonous plants. This, unfortunately, is definitely not the case. Our experience at the Hennepin Regional Poison Center indicates that plants represent the major source of poisoning in small animals. In addition, plants are a major cause of poisoning among grazing animals as well. In a review of seventy cases of illness in tortoises, the authors of the following article cite an incident which may be the only reported case of possible plant poisoning in a reptile. The following information is excerpted from that report.

One tortoise was presented having died suddenly with no apparent illness. The carcass was in good condition and there were no external or oral lesions. Post-mortem examination revealed a pale liver and slight yellow discoloration of the body fat. No gross abnormalities were observed on initial examination of other viscera and both stomach and bowel were distended with ingesta. The large and small intestines were found to contain partly-digested green plant material (mostly dandelions and grass). The stomach, however, was packed with buttercup flowers Ranunculus sp. and there was a 1.5 cm diameter, hemorrhagic area in the mucosa of the greater curvature of the gastric fundus. No other lesions were found.

The owners admitted feeding large numbers of buttercup flowers to the tortoise immediately prior to death and the gastric lesions were similar to those described in buttercup poisoning cases in mammals.

The gastric lesion appeared macroscopically to be acute and histopathology showed submucosal, hemorrhage associated with edema of the underlying muscle. There was no inflammatory reaction. suggesting that this was indeed an acute lesion, and a variety of staining techniques failed to demonstrate microorganisms (1).

Since virtually nothing is known about poisoning reptiles, it may be wise to feed reptiles only those plants known to be safe to other animal species.

Reference

1) Holt, P. E., Cooper, J. E., Needham, J. R. Diseases of Tortoises: A review of seventy cases. Journal of Small Animal Practice, 20:269, 1979.

Carl S. Hornfeldt, R. Ph., Hennepin Regional Poison Center, Minnesota

Read CTTC's Poison Plant list for more information on toxic plants to avoid around tortoises.