Do dogs remember their siblings?

I really don't think they would. It's something that would be very hard to figure out anyway. Even if the dog seemed extra excited, could be that the siblings smell similar to himself, kind of like how some breeds seem to prefer other dogs of their same breed. Just my thoughts...

Not in my experience.
When I was breeding Huskies people would bring their dogs back for me to see how they had turned out, and I didn't notice any familiarity between the dogs.

My pup still recognizes his littermates, mom, and former home - but we see them about every week. I suspect if we didn't see them for a full year after 8 weeks old he wouldn't.

we got our previous dog, Sadie, when she was 3 months old. A friend of mine had gotten her brother when he was 8-10 weeks old so they hadn't seen each other in awhile. We tried to get them together. WRONG!!!! Sadie, although still a pup, nailed her bro upon seeing him. She chased him about, nipping at him, making him yelp and cry out. Wasn't good.
They'd only been separated a few weeks. She wasn't happy to meet him at all

My dog and his brother hate each other now and I don't think its sibling rivalry.  The last time they saw each other they were both intact and on his property.  13 months old and Crusher actually drew blood from Eclipse.  

ORIGINAL: TinaK

If I puppy leaves his home at 8 weeks old, do you think he would recognize his litter mates, mother, or the house if he is back to see them in a year?

 
Well I can't comment on siblings but I can comment upon something similar.
 
Xerxes was raised by a trio of adult female PHs (Edie-mom, Glitter-aunt and litter sister of Gaia, and Reddy-aunt.)  He had 3 siblings, two of which remained with the breeder (Ralph and Binti.) 
 
Xerxes does not remember or care much for Binti or Ralph.  He does remember Edie and Glitter, and they remember him and gush all over him.  The reason I can tell that they remember him is that if you try to put any PH or other dog into an X pen with Edie or Glitter those two would try to kill that other dog (they really don't like intruders!)  But instead, Edie tries to clean Xerxes' ears and Glitter is all playbows and "please sniff my butt" and "OMG, OMG OMG IT IS YOU!!!" 
 
Binti likes Xerxes alot but X thinks she's just this crazy girl that needs to settle.  Ralph and X don't get along and if left alone in the X pen they'd probably sort things out right quickly (ala who's dominant.) 
 
Xerxes also remembers his breeder and acts like she's the best human he's ever known.
 
Also one of our friends at the dog park has a golden and we found out that another visitor to the park has a golden from the same litter (they picked the dogs up about an hour apart.)  These two do not remember each other at all.

If I were separated from my family at 3 or 4 years old, its unlikely I'd remember/recognize any of them either.

It does seem though that the dogs that M met when he was a puppy and has maintained contact with, he is ecstatic to see when we run into them at the park. Its obvious that he's very excited to see them through the play bowing, barking, etc. He has a much more reserved greeting for dogs who he has either met recently or is just meeting.

I never took my dog to see his siblings. But, on the back of my mind I thought that, since so much is inprinted in pups' minds during these early periods of their development, there is a chance that something would 'click' and they'll remember a familiar smell of his brother or home.

I guess not!

Beau loves seeing his sister Sable, but then again, she lives only a ways away, taught his obedience class (How sad is that, the younger sister was the teacher and the older brother one of the pupils), and they get together quite often to play.  Harry hasn't seen Gigi in months, so I'm not sure about him.  He loves his cousin (Beau), though. 
 

There they are at obedience on their 2nd birthday. 
 
It's fun to keep in touch. 
 
On another note, Trey never acted like he remembered his sisters and brother or his cousins and aunts or even breeder when he went to see them a year after we got him.  He lived with them until he was 10-11 months old too.  However he's a really unemotional dog who rarely shows outward emotional expression, so that may be it.  Nikki, however, ran up to Trey's breeder and befriended all her dogs right away.  It was so bad because between that and Trey suddenly turning black, the breeder thought that Nikki was Trey (They were the same size then) and was like 'Oh, Trey remembers me'  Then we had to promptly tell her that that wasn't Trey and she had never seen Nikki before in her life.  xD

I`m saying no. This what I have read but I have never done a test with my dogs. So ?

Indy does- we ran into his litter sister at the dog park a few weeks ago- they haevn't seen each other since they were 9 weeks old (Maddie is PQ (mismark, never had a chance of being show-able) and went home at 9 weeks, and the breeder held onto Indy until he was 16 weeks to either show him herself or find the perfect show/performance home for him.) He was THRILLED- he likes other corgis but generally won't romp with them unless the park is pretty empty, but he and Maddie were complete idiots for over two hours until her humans had to leave.

Mal is too young to know, but we've gone back to visit his breeder a few times for ear-taping status checks (ie "Can I quit taping yet?" LOL) and he's always happy to see his relatives. (I'm not sure that's not just typical collie, though. )

We got Nina when she was 9 weeks old and went back and got Zoey around 16 weeks,  they are the best of friends, do everything together. I would like to think it's because they "remember" their first 9 weeks of life playing and snuggling with each other. []  

Yesterday, a girl came into work with this Russell and I knew the dog, but couldn't place her name.  The the girl turned around and it was my mentor's son's girlfriend.  The dog was Olive who is one of our puppies who lives with Kristen.  I haven't seen Olive in a few months, but she was VERY happy to see me!  More so than anyone else in the store.  She peed everywhere, which isn't like her.  She just could not stop wiggling when she saw me.  So, I think she does remember me at least.  My dogs remember their "doggy friends" out at my mentor's, but they go there almost every day.

ORIGINAL: Pwca
Mal is too young to know, but we've gone back to visit his breeder a few times for ear-taping status checks (ie "Can I quit taping yet?" LOL) and he's always happy to see his relatives. (I'm not sure that's not just typical collie, though. )

I think the dogs can tell.  Several years ago I took Smidgen to see her sister who she hadn't seen for 6 mos and she saw her before I did and went crazy (happy) .  She doesn't react this way to most dogs, even other Collies.  What is funny is that dogs from our bloodline seem to all like each other, but they don't always like unrelated Collies.  Go figure.