Client with two English Bulldogs who were constantly in the clinic for one reason or another:
Client: "What would you do if I told you I was thinking of getting a third Bulldog?"
Dr. Snarky: "I'd go shopping for a boat."
Client whose Golden Retriever presented for staph pyoderma of the dorsal midline:
Client: "I'm pretty sure it's fungal".
Dr. Snarky: "It's not fungal."
Client: "Well, a while ago I had a pretty bad case of jock itch. Could I have passed it to the dog?"
Dr. Snarky: "Not unless you're in the habit of riding him around the house bareback and naked".
Client: "My dog needs one of those bordello shots."
Dr. Snarky: "You take your dog with you to the whorehouse?"
Client of ancient Dachshund with generalized paresis that knuckled over on his right front paw when walking (client was a retired circuit court judge of very sober demeanor):
Client (proudly): "I figured out the perfect way to protect his paw."
Dr. Snarky: "Do tell."
Client: "I went to the drug store and bought a single condom. It's waterproof, and protects the paw perfectly!"
Dr. Snarky: "I bet they're impressed when you ask for the one foot size."
(No reaction from da judge. Not a smile, nothing - just awkward silence. This same client came in for an appointment a few years later sporting a t-shirt that had a picture of a Dachshund, and the logo "Beware of my weiner". I'm certain the double-entendre sailed right over his head. I happily imagined him wearing it to church).