When I send my vet a Thank You card, I never expect a Thank You For The Thank You Card card back. Therapy ethics aside, if you're giving gifts with the expectation of getting something back, then you're (subconsciously, I'm sure) being manipulative.

As to ethics, gifts shouldn't exceed the occasional thank you card for exceptional breakthroughs and a holiday card with something inexpensive and not too personal. Anything beyond that is stalker-ish. Clinics typically send out a group holiday card to their clients. That is all.
Remember that what you have is a professional/client relationship. You're not best friends. Sorry to be so direct.

The bouquet with a thank you at completion of therapy mentioned by someone sounds wholly appropriate and awesome, though
The difference is that you're no longer a client at that point.
Make sense?
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