Yes, animals probably know when we're high.

Yes, drugs will affect them.

No, touching them doesn't get them high.

If touching an animal got it high, that would mean you are releasing active alkaloids. One, this means YOU'RE not getting as high. And two, it means your body is metabolizing an active alkaloid into an active alkaloid. LSD doesn't break down into more LSD via sweat glands. If that we're true, you could keep reabsorbing your sweat...