So very, very sorry for the sudden and devastating loss of your little baby. I don't know if jerking her collar would have caused this, something you should have asked the vet. In the future NEVER walk small breed dogs on a collar, use harness ONLY, collar can be used to keeps tags on.
Small breed dogs are at risk of collapse trachea (wind pipe) reason they should be walked on a harness only.
__________________ Joan, mom to Cody  RIP Matese  Schnae  Kajon Kia  forever in my  A House Is Not A Home Without A Dog |