I know there are tons of feeding threads and I've read a bunch of them but figured I'd check some opinions anyhow.

So Loeki will be 2yrs old in a few days. He has always been a fairly picky eater but it seems he hasn't been eating much for the past few weeks. He has always been thin (he is tall and right around 55lbs) but his hip bones seem to be more prominent than in the past. Now a few things have changed over the last few months that I need help weening down to figure out what his deal is:

In September we brought home a new puppy (Miila). He loves his new sister but she loves to eat from his bowl... When she eats his food he kind of wimpers and barks at her from a distance... I've moved her aside and placed him in front of the bowl and he nibbles but seems to keep an eye on her. We've tried leaving the food in his crate during the day and he doesn't touch it then either.

He was on TOtW (Lamb) since he was a puppy and when we got her we  tried switching her to the same food and it didn't go well... we gradually made the transition and she just had horrible stools so we ended up switching both of them to what the breeder was giving her (Diamond Naturals Lamb). Her stools return to normal and he ate it for the most part initially without too much protest. His stools continued to be normal through the transition.

If I fill his Kong genius toy with food he will throw it around and eat the kibble from it pretty much 100% of the time. If you hand feed him he will eat a few mouthfuls then walk away or lay down.

I've tried getting a small bag of the TOtW to see if he would go back to eating that and it didn't make a difference.

He is probably 75-80% more active now that he has a sibling that he romps around the house with most of the day so I would have expected him to eat more if anything and maybe put on a bit more muscle. But in second though is this maybe the reason for him thinning out more?

Now....He BEGS and is constantly in your face when we are eating so it is obvious he has an appetite for everything and anything we put in our mouths. If he hears us open the pantry door he will sprint from the other end of the house to see what we are getting. He does everything in his power to get to things he is not supposed to be eating, up on the sink licking dishes, opens the lid to the garbage (darn puzzle toys for teaching him that) to get whatever he thinks he can scavenge...

So in summary... is he not eating because maybe Miila is showing some signs of ownership to his food? (she isn't aggressive but will sort of nudge him out of the way).

Doesn't like the food? Wants something better like treats or some of the human snacks he has tasted? (baby carrots are his favorite).
He will eat boiled chicken if we give it to him but I want to avoid that habit at all costs.

Bored with eating in general because he seems to eat better if it is made into some kind of challenge?

This is his current build: Tall/lanky 55lbs

I think he needs his time and his space. This puppy has come in and upset his world. She has taken away the food he liked and forced him to something else, she tries to own his bowl, and she is taking his time with his people. He probably feels like he is now playing second fiddle to her and it naturally is going to make him act a little different while he processes this new structure. Make sure he is getting one on one time with you without the puppy and not only just for long walks, but for petting and just general play. Don't let the puppy near his bowl. While it is great that he isn't food aggressive and isn't going to tear into her over the food, you don't want to send the message to her or him that it is okay for her to just rule over his stuff. I would possibly even feed them in different rooms. I would check the protein content of Diamond Naturals vs. TOTW. I think diamond tends to be a little lower so if you are feeding the same amount of Diamond that you were TOTW you may need to up the amount. Having a new dog is going to lean him out and take off some weight. When I got my second it took some off my girl as well.

Thank you. I'll try moving his bowl to a different location or keeping her away while he seems like he wants to eat. I really hoped that putting some of the TOtW back in his bowl would spark something but it didn't seem to make a difference.

The two foods are relatively comparable on fat/protein/carb balance and he vary rarely will eat the entire bowl put in front of him (at least recently). I'd definitely prefer putting them both back on the TOtW but she just does absolutely horrible on it right now.

In time she may build up a constitution that can handle it. Did you try any other flavors of TOTW before switching to Diamond? It seems a little odd though that she is fine on DN lamb but not TOTW lamb since they are both made by the same company. I wouldn't think that the formula would be all that different that she could handle one but not the other.

Yes, the small bag I bought to try to get Loeki to eat is the Wetlands formula (duck/chicken) and she had a few mouth fulls from his bowl and it softened her stool for a day or two so I made sure she could not get any more of it. She is 6 months old.

I agree with every ones advice. I will add, that many female huskies tend to have a more dominate personality, so your male needs to know he doesn't need to submit to his baby sister. I would feed in separate areas and never allow her to be near him while he is eating. I'm guessing if he has his own space without having to be bothered by her, her will resume his appetite.

Btw, every dog is different in the tummy area, try feeding the TOTW, when she is slightly older, it may be that you will have to feed two different kibbles.

Just one little note... you might want to try the totw high prairie.  Has higher protein, fat and calories than the lamb.  Not a lot but enough so that when I switched my boy to the lamb, he doesn't chunk up like on the bison.

We actually started Loeki on the high prairie, first with puppy blend then the all life cycle. He did ok on it a first but seemed to pretty much give up on it after a few bags. He was on the Sierra blend for over a year until we got the puppy... again, never really chowed down on it.

We had some success last night with some cut up pieces of beef, rice and raw egg on his food he gobbled down the whole bowl. If it takes moving him to a partially raw diet then that is what we will do...

Pens....raw is great, and partial raw, is pretty much how I feed....I am not sure if you are aware, but you must feed raw separate from kibble, they digest at different rates, I would try feeding one in the am and the other pm. This may cause a new problem in that Loeki may decide to eat only the raw. Take a look at the raw feed section here to help with raw feeding. If all else fails, a trick that I do is boil about 2-4 ounces of turkey burger or hamburger with about a half cup of water, this will make a gravy, mix in with about a cup of kibble (if he's very active a cup and a half), this will also help put some weight on Loeki. Once he's consistently eating slowly ween him off the burger, it has helped me immensely on putting weight on my girl, she now get's this meal half the week, the other half she eats plain kibble, and eats it very happily plain.

Thank you for the advice. I didn't realize that any raw should be fed separately from kibble. I gave him a few small pieces of beef last night just to see his reaction to the meat and he immediately was looking for more of it. I like the idea with the ground turkey/beef in his dry food, I think we will try this.