Join Date: Aug 2015
Location: Milky Way Galaxy
*dog trainer hat on* Before next water change, I would teach the dog 'trade.' You keep a handful of appropriate toys and/or treats with you and every time the dog picks up a toy, you trade the dog for another toy or treat. Soon the dog will let go of something very quickly to take another thing from your hand and then you can transition to 'drop it' from trade by asking for 'trade' and then delaying the reward.
Also, teach a very strong 'leave it' using the water hose. To teach leave it, drop the thing you don't want them to touch on the floor right in front of their nose and say 'leave it.' When they inevitably try to go for it, put your foot/leg/whole body as necessary between the dog and the item you do not want them to touch. This is called body blocking. Remove your body/leg/foot from between the dog and the item and body block again when they go for it. Don't speak to the dog except that very first time you say 'leave it' at the beginning. When the dog no longer goes for the thing on the floor when you remove your foot, immediately pick up the item and give the dog a treat. Then drop the item and start over with body blocking until the dog no longer immediately goes for the thing. Do this every day until the next water change and the dog will rapidly learn that when you say leave it, they are not going to be allowed access to the thing. If the dog does NOT require a body block to keep them from going towards the thing anymore, then you continue to practice regularly. You drop the thing and say leave it, watch them not go for the thing, then pick up the thing and give them a treat. Increase the duration between saying leave it and picking up the thing.
Dogs don't generalize well, but once you have the most important thing taught under 'leave it' (in this case the water hose) continue teaching so they understand that leave it means leave it no matter what the object is. Throw hot dogs on the ground, dog treats, anything they're really, really going to want and keep increasing the duration. Regular practice is very important, but this way you can end up with a dog under voice command no matter how excited. Puppies as young as just 4 or 5 months old can learn this skill completely solidly and they can begin learning it as young as eight weeks.
*dog trainer hat off*
Sorry if that seemed insulting, it's just an important skill and a hard one to teach. Because you never know. Today the item might be a water change hose. Tomorrow the item might be a medication that could kill the dog within minutes.