My friends horse pees ALOT. He peed 4 times last time we were on a trail for an hour and a half. He peed twice today in the 45 minutes he was getting his feet done. He has peed alot his whole life (5 years) but this is a little more than usual. He will usually go about twice on our trails. She called the vet and the vet wasn't too concerned because they were out last week and did a sheath cleaning. My friend has also been monitoring his feed and temp and such and everything is normal. Now we are in south florida and the temp is over 100 with heat index and all the horses are drinking alot, including as the vet told us her own horses. Is there anything else anyone can think of she should ask her vet about that could cause this?