veterinary surgeon vs Dr.

veterinary surgeon and Dr. both are nouns.

Word	Noun	Adjective	Verb	Adverb
veterinary surgeon	Yes	No	No	No
Dr.	Yes	No	No	No

As nouns, Dr. is a hypernym of veterinary surgeon; that is, Dr. is a word with a broader meaning than veterinary surgeon:

Other hypernyms of veterinary surgeon include doc, doctor, MD, medico, physician.

veterinary surgeon (noun)	Dr. (noun)
a doctor who practices veterinary medicine	a licensed medical practitioner
	a person who holds Ph.D. degree (or the equivalent) from an academic institution