Get referrals
By all means, ask your friends, but expand your circle of contacts.
Call the local breed club in your area and ask the secretary whom most club members use, ask local rescues, humane societies and other reputable animal welfare organizations who they recommend.

Make sure the veterinarian works with your pet’s species/breed

Not all veterinarians work well with or want to work with certain species or breeds.
The ideal veterinarian is one who owns, has owned, or has years of experience seeing patients of the same species/breed as your pet. 

Check your province’s Veterinary Medical Board website

See if it has an area called “enforcement” or “complaints” or something
that indicates which veterinarians have been disciplined by the board.
The vets you’re considering using should be licensed but not have any
disciplinary actions.

Plan an inspection visit to the prospective vet (without your dog)

Stop by the office of each veterinarian you are considering during the
day (not after work or on Saturday morning when the office is apt to
be packed) and tell the receptionist you are looking for a veterinarian.
Reputable vets do not object to this; in fact they expect it.

Ask where routine exams are done and if owners are allowed to be with
their animals. You should be shown everything including any back rooms
and any areas used for recovery after surgeries as well as kennels
and boarding facilities (if applicable). 

Check the staff’s credentials and behavior

Ask if there are any registered/licensed technician(s) and if they are members
of their provincial veterinary associated or North American Veterinary Technicians Association (NAVTA).

Practices that want to reduce operating costs often won’t pay the additional
costs to hire licensed, experienced technicians and have them participate in continuing education required by groups such as NAVTA.

Ask who gives the shots and takes the X-rays

The vet or licensed technicians should be doing these. You don’t want
some recent high school graduate with minimal training giving shots
to your dog.

Check the staff’s behavior

See how the staff, including the receptionist, greets patients and their
owners. Does the vet and staff speak and write the same language
you do (literally)?

In many offices, a staff member writes out the prescription, and the
vet just signs it. Make sure these staff members can understand you,
and you can understand them. Mistakes can be deadly.

Find out about emergency service

You’re going to have your dog for 12-17 years. At least once, you’re
going to need emergency, middle-of-the-night service. Any Vet who
cares about his/her patients will have some standard practice or
referral system to handle emergencies.

Check out the vet’s credentials and experience

This is especially vital if your vet is a recent graduate. Many
veterinary schools no longer require students to operate on live dogs
except spay/neuter.

Do you want your dog to be the vet’s first joint replacement? 

Find out if the Vet makes referrals to specialists

No one veterinarian can do everything. If s/he claims to do it all themselves,
go to the next name on the list.

Ask about the Vet’s fees

There is no reason you can’t call your list of possible Veterinarians
and ask how much they charge for:
cccc1) vaccinations;
cccc2) an X-ray of a hip with a possible fracture; and
cccc3) treatment of parasites
4) Exam Fees
This is also a good opportunity to get a feel for the friendliness and helpfulness of the veterinary support staff on the other end of the phone. 

Listen to your gut

Do you feel that you can openly communicate with the vet or does s/he
brush off your questions?
Is s/he calm and pleasant or rushed and curt? If the personality,
communication skills and ambiance aren’t right, don’t hesitate to
go another vet.