Still, it makes me question the basis of the chart. They're less expensive than fetal pigs, seem to be readily available, and there are plenty of lab materials available. A large number of amphibians are declining today all over the earth. I would venture to say that none of this is due to frog dissections. Matter of fact, there is a group of herpetologists that are trying to find out where the problem originates.
Many suggestions are habitat loss, increased UV light, pollution, and over collecting.
It seems that there may be multiple reasons depending on the species. In New Mexico and Arizona, one of the main reasons for leopard frog decline is the introduction and spread of the bullfrog. Bullfrogs in the west do not have any natural enemies as they do in the east where they are native, so consequently they multiply uncontrollably. Dissecting bullfrogs collected from the west could help, but I doubt it. We as science teachers need to be better informed about the animals that we work with.