That's where it gets tricky.
Good news: the mass is nothing of tissue and feels symmetrical. Bad news: the x-rays show that parts of her vertebrate are thickening. He has concerns that the section near her shoulder blades may be trying to fuse. Same x-ray showed that Gauge's pelvis is losing bone density. I didn't know that was possible in a BTS, especially at her age.
Diagnosis: He has no idea. The vet is consulting a few specialists to pinpoint a possible diagnosis. All he can tell me right now is that it is nearly impossible that she had MBD, and a birth defect has been ruled out. I should know the results of his consultation within a couple of days.
On the bright side, she is fine otherwise. If her condition(s) are bothering her, she is not showing it, and is pigging out on Merrick's Puppy Plate as I type this
.