"Signs of MBD include stunted growth, bent legs bones, fractures of those bones (double elbows or knees), weakness, falling off branches, grabbing at its own legs, tongue not shooting as far, a 'rubber' jaw, the mouth doesn’t close all the way, etc."
Symptoms are pain, constipation and/or eggbinding, probably other not very specific things.
Out of the above signs only weakness and falling off branches (which are actually pretty similar to each other) in D3 overdose might make sense to me due to organ damage and buildup of waste products in the organism creating neural issues. The rest are all directly connected to calcium's role in muscle contraction, nerve conduction or bone strength.
Is there anything more specific for D3 toxicity? How does one test for it?