They must have some way to deal with it. What about reptiles who eat up a whole litter of nursing mice? All that the babies have ever eaten is milk, so there's bound to be a lot of lactose in that meal for the reptile to digest.
By Pat Kendall, Ph.D., R.D.
Food Science and Human Nutrition Specialist
Colorado State University Cooperative Extension
The claim most substantiated is yogurt's beneficial effect on digestion in some individuals.
People who are lactose intolerant have a hard time digesting milk products because they lack the
enzyme that breaks down the main carbohydrate in milk. Yogurt is a unique dairy food because the
starter cultures actually produce that enzyme during fermentation. Thus, the milk sugar in
yogurt is more easily digested, even for lactose-intolerant individuals. Many people who
commonly experience gas, bloating or discomfort from dairy foods can digest yogurt more easily,
thanks to the starter cultures. This is especially true if the yogurt contains live cultures.
The same goes for reptiles - the enzyme is in the yogurt, so they can make use of it.
I've added yogurt to fruit mash for fruit eating geckos for over 15 years now, never had a problem. I'll even use it for slurry to feed sick or rescues, and those given medications that might mess with their digestive systems.