Hi there, im a new member and i have a question about strange behavior my sheltie is exhibiting. A bit of history first about this dog, i've known Riley for about 4-5 years, and his owner recently passed away. I took him in almost 3 weeks ago and everything was going great, until yesterday. I have a 13 year old Cocker Spaniel named Daisy, she tolerates him, no aggressiveness shown to Riley,maybe a look sometimes. Yesterday, i was cleaning Daisy's ears (allergies) and Riley started barking at me, spinning and running up to us. I'd tell him no and he' just bark more. Then later, he started following her everywhere! He's since try'd to hump her (both fixed). It's like he's fixated on her, he will walk along side her, if i take her in another room to clean ears or give meds he barks at the door. My poor 13 year old cant get any rest. I want to nip this odd behavior in the bud before he gets bitten by Daisy. Hes been around other dogs before but just for a few days at a time,and i dont think he was disciplined much. Any ideas or tips on how to stop this would be much appreciated.