We have noticed a significant change in our 2 yr old beagle/treeing walker coonhound mix. He went from playing carefree in the yard all day to (seems like) on a scent that travels a certain pattern in our yard this has been going on since the end of March. He is completly fine, acting normal in the house but as soon as he goes outside he does this repetitive "scent trail" we have also had so much rain in the passed month our yard has flooded there is no way the same scent trail can be there since March. Our vet precribed him Elevil( that did nothing except make him throw up) we did that for 2 months and she said to take him off and take him to a behaviorist?? We cannot leave him outside for long periods because he will not stop for water and he looks like he is killing himself his skin is going into his ribs when he's breathing. I let it go for as long as I could stand to see if he would stop, he didnt it went on for 2 1/2 hrs before It got so bad I had to bring him in the house. Help! Any thoughts?