Pros
They provide some good free continuing education opportunities. There is the possibility, but not the guarantee, of great modern equipment. They have hospitals all over the country if you want to re-locate.
Cons
They prefer to pay "on commission"; proven in human health care to affect doctors' judgement. Intimidation of vets by use of non-compete agreements. (You will have to agree to restrictions on when and where you practice after you leave their employment, but they can fire you for any reason at any time without consequence.) They may expect many more hours of cont. educations per year than they will compensate you for or provide. In my opinion they mostly care about making their share holders happy through new acquisitions; they don't give much consideration to those in the "trenches" - they may even help your non-VCA competitor if it means they can get a lab contract. Read ALL of their paperwork carefully and think/research before you sign anything no matter how much they push.