vet

Etymology 1

Clipping of veterinarian.

noun

1. (colloquial) A veterinarian or veterinary surgeon.
   Colin Cameron, a vet who examined the dead animal, said there was "no doubt the kitten would have suffered unnecessarily" before dying. December 14, 2011, Steven Morris, “Devon woman jailed for 168 days for killing kitten in microwave”, in Guardian

Etymology 2

Clipping of veteran.

noun

1. (colloquial, US) A veteran (a former soldier or other member of armed forces).
   A former soldier, sir. A vet. Theyʼre all vets, a little shellshocked. 1952, Ralph Ellison, Invisible Man, Penguin Books (2014), page 73

Etymology 3

Possibly by analogy from Etymology 1, in the sense of "verifying the soundness [of an animal]"

verb

1. To thoroughly check or investigate particularly with regard to providing formal approval.
   The FBI vets all nominees to the Federal bench.