Gil: Are you a man or a mouse?
Dr. Hackenbush: You put a piece of cheese down there and you'll find out.

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)

Whitmore: Just a minute, Mrs Upjohn. That looks like a horse pill to me.
Dr. Hackenbush: Oh, you've taken them before.
Mrs. Upjohn: Are you sure, Doctor, you haven't made a mistake?
Dr. Hackenbush: You have nothing to worry about. The last patient I gave one of those to won the Kentucky Derby.
Whitmore: May I examine this, please? Do you actually give those to your patients? Isn't it awfully large for a pill?
Dr. Hackenbush: Well, it was too small for a basketball, and I didn't know what to do with it. Say, you're awfully large for a pill yourself.

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)

Whitmore: The doctor seems reluctant to discuss his medical experiences.
Dr. Hackenbush: Well, medically, my experiences have been most unexciting. Except during the flu epidemic.
Whitmore: Ah, and what happened?
Dr. Hackenbush: I got the flu.

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)

Dr. Hackenbush: [to Dr. Steinberg] Don't point that beard at me! It might go off!

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)

Dr. Hackenbush: And I've got a question for you: Steinberg, what do you do with your old razor blades?

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)

Dr. Hackenbush: Dr. Hackenbush:
[examining Stuffy with an auriscope]
Dr. Hackenbush: I haven't seen anything like this in years. The last time I saw a head like that was in a bottle of formaldehyde.
Tony: Told you he was sick.
Dr. Hackenbush: [pointing to Stuffy's neck] That's all pure desecration along there. He's got about a 15% metabolism, with an overactive thyroid and a glandular affectation of about 3%.
Tony: That's bad.
Dr. Hackenbush: With a 1% mentality.
[Stuffy grins]
Dr. Hackenbush: He's what we designate as the crummy moronic type. All in all, this is the most gruesome looking piece of blubber I've ever peered at.
Tony: Hey doc. Hey doc!
Dr. Hackenbush: Huh?
Tony: You gotta the looking glass turned around, you're looking at yourself.

- Chico Marx (as Tony) in A Day at the Races (1937)

Dr. Hackenbush: Emily, I have a confession to make. I really am a horse doctor. But marry me, and I'll never look at another horse.

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)

Dr. Hackenbush: Here's a ten-dollar bill and shoot the change, will you?
Tony: I got-a no change. I'll have to give you nine more books.

- Chico Marx (as Tony) in A Day at the Races (1937)

Dr. Hackenbush: I haven't seen so much mudslinging since the last election!

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)

Dr. Hackenbush: If I hold you any closer, I'll be in back of you.

- Groucho Marx (as Dr. Hackenbush) in A Day at the Races (1937)