Puzzling post-neutered behavior- II

Question
Dr. Krempels, I read the 2/12/2012 Q&A and it stimulated a new train of thought:
We switched to feeding our rabbits orchard hay about 1-1.5 years ago. We used to use regular Kaytee rabbit/timothy hay until 1) It gave the male bunny a bloated tummy & 2) I read about the kidney stone issues that excessive minerals can cause. Subsequently the rabbits started preferring the orchard hay, ESPECIALLY loving the batches which have a fragrant green tea scent. They even stopped eating the Timothy, and we gave away a bale of it. Then we switched from buying bales of orchard hay from local store 'Red Barn' to smaller bags of "Oxbow" brand orchard hay. We ended up using Kaytee Pellets less & less frequently; adding them only on long weekends when we know they'll eat the hay before we get back home. That is when we give them a bowl of Kaytee pellets. I DO notice they drink a LOT more water when eating the hay; and they pee in & out of the litter box. [They used to be angelic and not pee outside their litter box]. Now they will pee in it & just outside it, at one of the corners.
I think we too need to experiment with the effect of hay only VS pellets only and observe/correlate the peeing, spraying and humping behavior during each experiment period. Thoughts?
Thank you in advance for your time & advice. Gratefully,
AV

Answer
Dear Anisha,

Well, it's a longshot.  But unless the hay is organic, there is the possibility that there are pesticide residues in/on the hay that are acting as hormone mimics.  These might cause hormone-related problems, though I'd be alarmed if the hay had enough residue to have a significant effect.  Maybe try organic hay and see if that makes a difference?

The excessive drinking is a concern, as it can indicate renal disease.  I would have both rabbits checked by an experienced rabbit vet and have bloodwork done to check kidney and liver function.

But yes, you might try switching hay and see if there's a relationship.  It could just be a coincidence, but you won't know 'til you test it.

Dana