First of all, I am so sorry to hear about all the troubles you have had (besides your health). Machines can be such fickle things and are liable to stop working at the most inopportune times.

However, Snoopy is another worry altogether. The only thing that came to mind was maybe she is going into heat? With her little butt in the air and crying like that, it's the only thing I can think of.

At least you can talk to your vet; then she can put your mind at ease.

Feel better, little Snoopy! (and you, too, Lut!) Hugs to you both.