Do I need to worry about this? (snarling when woken up)

Well, I'm not very experienced with this, but I would think that snarling is a problem. Does he actually snarl at you/ try to snap? It could be that he is still 'sleeping' and doesn't realize what he's doing, but it's hard to tell. I think you did the right thing by making him get out/off when he does that. Hope you can get some better answers from some other people!

Is it possible that Roscoe cannot hear well? My mom's dog is 13 next month, and is losing his hearing. He occasionally startles awake, with a snarl. My friend had a 16 yr old Shepherd mix, who was blind and deaf, and snarled when you woke him up.

Maybe Roscoe was startled?

This is a total switch in his behavior, so I'd want the vet to check him out just to be sure that it's not a medical problem.

Barring a physical reason for the change in behavior (which I would look into first), I think (and I am no expert) that if he is snarling, more than once (ie - it wasn't just one time, when he was rudely surprise and really startled out of sleep), it is the beginning of a problem and needs to be nipped int the bud.  Welsey used to do this, we made excuses for him and it got worse... on strict NILIF, we have taken some of the leadership back (we are still not there and are still working on it), but I have noticed that we can walk by, move around him, make noises and touch Wesley while sleeping and get no snarls any more... 

Great response schleide.  Make sure not to make excuses for your dog and get handling this right away!

I think you do have reason to be worried.  My dog is 15 and almost totally deaf - when I wake her up to go outside she is startled, but never snarls or snaps - I try to be gentle and just nudge her or clap my hands sharply.  Your dog is snarling because he is either highly aggravated or not feeling well - either way - please check it out!
 
dianeg[8|]

Thanks, all.  Roscoe does do NILIF 'cause he can be a bit pushy, but he's never done this to me (to the cat, yes).  Usually I can wake him up and even go into his crate to retrieve something while he's sleeping.  But I've never startled him awake. It's usually a gentle pat.  And it wasn't a snap, "just" a snarly growl. I've seen him snap at Scout (the cat), and this was different.
 
When I first started allowing him on the furniture, he guarded it against Scout by lunging at her with a growl but when I made him get off every time he did it, he eventually figured it out and now they both snuggle on my lap together.  This is worse 'cause it's against me, so Roscoe has lost his sofa and desk privileges for now, and we'll try again later.  Too bad, I liked having him near me
 
I've often wondered about his hearing, Jennie, 'cause there are times when I have to wave my hand in front of his face or touch him to get his attention. But I don't know if it's selective hearing or not. []   How do you test a dog's hearing? You can't have them raise their right or left paw when they hear a beep in their ears. [8|]
 
 

Uh oh, is Roscoe developing Grey's couch syndrome? lol A few months ago, I posted about how Grey actually physically protected his couch from me, and after that, I booted him off the couch. Of course, he's since won back his couch time after showing he could handle the situation.
 
When I first read this last night, I couldn't believe sweet, laid-back Roscoe was actually snarling. I pictured him doing something more like Brown's grumbling when I accidentally touch his foot (or when he accidentally touches me but grumbles like *I'm* responsible for touching him). There must be something about dogs and couches...

ORIGINAL: marlania
There must be something about dogs and couches...

 
Yep, the couch is really high-value to him, apparently.  
 
Even though he's not allowed on furniture anymore, he remains indulged.  He was standing next to the sofa looking forlorn because the sunny spot was on the sofa.  So I moved it out of the way, so he could lie in the sun on the floor. Nooo, he's not spoiled at all.[8|]

I've often wondered about his hearing, Jennie, 'cause there are times when I have to wave my hand in front of his face or touch him to get his attention. But I don't know if it's selective hearing or not. How do you test a dog's hearing? You can't have them raise their right or left paw when they hear a beep in their ears.

BAER testing Google it, and you might find somebody near you who does it. It's par for the course to BAER JRT pups, as inherited deafness is a problem within the breed.

ORIGINAL: jennie_c_d

BAER testing Google it, and you might find somebody near you who does it. It's par for the course to BAER JRT pups, as inherited deafness is a problem within the breed.

 
Cool. I just did, and there's someone within 15 minutes of me who does it!

Cool. I just did, and there's someone within 15 minutes of me who does it!

Very cool! Lemme know what you find out!

Even if you BAER test him, please also have the vet examine him to rule out physical stuff before you deal with the behavioral problem.  You guys lead an active life, and he might have pulled a muscle or something.