Orion's "brothers"

Back in December we adopted 2 dogs, a pekinese, and a Pomeranian mix. both are males. The pekinese is 8 years old and had lyme, the mix is 6 years and has really bad teeth.
Orion was fine with them for a while, but the past couple weeks he had started to get jealous of them. He is now food aggressive, and digs in the garbage can (It use to be pet proof, it's not anymore) he steals food off tables and the counter as well, more than he use to. When we have pizza we give each dog a small piece of crust, Orion now knows he no longer gets the entire crust and has started pacing around the table, barking and whining, expecting more food. The dogs are fed at 9 every morning, and 6 every evening, but despite this Orion acts as if he hasn't ate in days whenever we have pizza. Little dogs eat their food, Orion eats his food, then Orion begs for more food.
Other than this, and an occasional "fight" over who gets what toy, they get along. Orion is a chicken, if one of the little dogs start barking at him he stops what he's doing and runs into another room, that's normally how the little "fight over toys" are.
Pekinese is named Willie, the mix is named Chilly.

 

I don't have any advice about the behavior but I'm sure one of the wise and experienced people on the forum will be able to help. But I wanted to say you certainly have your hands full and good on you for adopting two older dogs with some health problems who obviously needed a good home

 

How old is Orion?

 

Behaviour that is reinforced will be repeated. He is reinforcing himself by finding food in the bin and on surfaces. So, you need to use management - keep him from being able to self-reinforce like this. Put the rubbish bin somewhere that he can't get to it and keep him out of the kitchen when there is unattended food on the surfaces.
When you are eating, teach him to lay on his mat with a long-lasting food toy, such as a frozen kong. This will enrich his day, give him food that lasts a relatively long time and allow you to eat in peace without the begging behaviour. You are reinforcing begging by feeding him while you're eating, so give him something better to do.

 

Orion is 3 years old.

 

Thanks.

 

How are you getting on with Orion now? Do you have a mat or dog bed in the room where you eat? If so, there is a neat way to teach your dog to lie in it at meal times - let me know if you are interested