We have 2 Chocolate Labs (1 male/1 female) 6 yrs old. They sleep in the basement so they have access to the doggy-door during the night. A few minutes ago, my husband heard some banging around and the female started barking. He went downstairs and our male was lying on his side, unresponsive and drooling everywhere. My husband came to get me and when I got downstairs, the dog was up and pacing around (still with drool all over his face). When he finally noticed us, he started growling (which he has NEVER done). We've separated the two but don't know what to do. There's obviously something wrong but we can't even get close to him without him growling and frankly, he's 100 lbs and I don't want to chance it. Please help!

A couple of things come to mind.
Seizure is one possibility, if this was the case then you may have witnessed the post-ictal stage, this stage can cause disorientation for minutes to hours after the seizure, which would make the growling make more sense.
Besides that, could he have gotten to an electrical cord, or some sort of toxin?
Is he approachable this morning? More like himself?
He certainly needs to see a vet, but proceed carefully if the growling is still an issue.
Keep in mind that I am only guessing here, and I am not a vet.
Only his vet can give you answers you need.
Good Luck and keep us updated.

I agree with Lady Same. Labs are prone to seizures. My lab cross Indy (RIP) had daily seizures for years, sometimes up to 20 plus a day. From what you describe, it very much sounds like that's what happened.

Now, I'm not a vet, and you really should consult with a vet about this, to confirm that's what's going on. The vet will likely prescribe medication to stop this from happening.

Our dog was on medications for a long time. It changed who he was. He was lethargic, constantly had to pee, and worst of all, it didn't stop the seizures.

We went back to our vet clinic, and got lucky. A visiting vet was there, and that's who took our appointment. He was a holistic vet. He recommended green beans. Yup, green beans. Just a few green beans in his food every day (we did half a cup).

Our dog went from having seizures almost every hour, to being seizure free for for the last 10 years of his life, no medication, only green beans. He lived to the ripe old age of 16.

Definitely see your vet. From what you describe I wouldn't be at all surprised to hear it's epileptic seizures, but we can't diagnose online. If it is epilepsy, this won't be the only seizure he has.

Try green beans. It won't hurt your dog, and it could make all the difference. It doesn't work for every dog, I can't claim that, but it made all the difference for our Indy.

Nothing would separate me from my dogs. They are members of my family.

Something was going on with your pet, long before you heard the noise. If he had been with you, closer vicinity, you could have averted this situation.

Sorry. I had a problem with the situation. Are they guard dogs. Not trained well enough to stay with you at night?

Tickle, most people don't let their dogs sleep with them at night. The OP explained that they're in the basement so they can access the doggy door if they need to potty during the night.

If it was a seizure, there's no way to avert it. You can have your dog right beside you every minute of the day. If it's going to have a seizure, there's nothing you can do to stop it.

I kind of know about the seizure thing, Alty, my schnauzer had a seizure that ended her life, you couldn't have known that. I didn't mean 'sleep with them'; ,my dogs go out and do a final pee and sniff around before we all go bed; they are adult and don't need anything else until we all get up in the morning around 5am or so. I have never felt the need for a pet door.

You don't have to explain to me; it is my opinion.

Nothing would separate me from my dogs. They are members of my family.

Something was going on with your pet, long before you heard the noise. If he had been with you, closer vicinity, you could have averted this situation.

Sorry. I had a problem with the situation. Are they guard dogs. Not trained well enough to stay with you at night?

Wow! You seem to be assuming things that may not be close to the truth, and frankly I would be very offended if you were answering my question. Oh, and you forgot to do just that: Answer her question...