I’m a life-long lover of most giant dog breeds. During college, I worked as a dog bather and familiarized myself with most dog breeds, with the giants always being among my favs, and we’ve had Newfoundlands since I was a kid.
What would be most helpful in advising you is to know what other kinds of attributes you’re looking for (and which are a turn-off). In particular, I’d be interested in what you’d prefer with respect to overall energy level, how much time and money you’re able to devote to grooming needs, what the climate is like in your area, and what your living situation is (e.g., if you live in an apartment, have access to a large yard, how many stairs the dog will need to traverse, etc).
I second everything Sunny Daze has said about Newfies, and will add my own two cents. Firstly, as far as getting a dog that’s non-aggressive, Newfoundlands certainly fit that bill. They’re perfectly suited for what you were describing in your follow-up post about wanting a service dog for PTSD support. I’m finishing my Ph.D in clinical psychology, and once I’m done with internship, I plan on training our next Newfie to do something similar to what you described.
The same temperament that makes them so well-suited for therapy work can be a downside on the protection front, which you also mention. They really love people (in a calm, less demonstrative kind of way than some other dogs) and are not at all wary of strangers. Additionally, they tend to be on the more laid back (or downright lazy) side and are not going to go on ‘high alert’ if someone walks down the sidewalk outside your home, at least not during the day; ours have always let us know when someone was on the property that at night. In fact, ours once altered us to an early-morning break-in happening next door.
Personally, I’ve always found this aspect of their temperament to be a plus, as I don’t want my dog to start barking uncontrollably every time the UPS driver leaves a box on the stoop. Even without the barking and ‘high alert’ attitude, though, Newfies can be a pretty powerful crime deterrent nevertheless… One day, a kid from the high school football team went around raising money for new uniforms or some such. I saw him come up the driveway, and was waiting for the doorbell to ring. A few seconds later, I saw him running full-tilt back down the driveway again, at which point he got back in his car and sped off. Perplexed, I went outside to try and figure out what happened…and there was our Newfie, stretched out on the porch. He’d slept through the entire encounter. At any rate, it really depends on what exactly you’re looking for as far as the ‘protection’ factor goes.
Yes, drool can be a problem, though not always horribly so (and that’s going to be true of many of the giant breeds). Worse than the drool, though, are the grooming requirements. Newfies have very dense coats and require brushing at least weekly or they will start to mat and can develop hot spots. The grooming can be extremely time consuming to maintain oneself (especially if you let it go for a while), and can be expensive if you have a groomer/bather do the bulk of the work for you. Shaving is not recommended unless the dog is really old or their coat is in horrible condition, as the fur is useful in making sure the dog doesn’t get sunburned and because the coat can grow in weirdly after it’s been shaved. Needless to say, they’re also not the most heat-tolerant dogs. I’ve lived with mine in Ohio and Michigan, and they tend to sleep a lot more often in the summer months (often directly on top of the air conditioning vent) and aren’t interested in exercising unless it’s at night or involves complete submersion in water.
English Mastiffs are similar in many ways to Newfies as far as the guard-dog and temperament issues go. The grooming requirements are certainly less, but they do shed a good bit, and if you’ve got a particularly wrinkly one it’s necessary to clean out the facial wrinkles regularly or they can get smelly or even infected. They’re also not great in the heat.
I’m not an expert on Irish Wolfhounds, though I’ve been around many…in my experience, they’ve been a little bit more aloof and willful than Newfies, and much more energetic (though this may have been more about the personality of their owners than a trait that’s truly inherent to the breed).
There have been many good suggestions about other breeds you might want to consider already. I’d second looking into Great Danes, Great Pyrennes, Cane Corsos, Neapolitan Mastiffs, and St. Bernards, and would also recommend Leonbergers and Bernese Mountain Dogs (I don’t think I saw those mentioned upthread).
He’s about 140-145. Looks bigger with fur. I’ve had people ask me if he’s a bear. I’ve had a few people refuse to come in the house (while he sleeps through the conversation). I think he’s a deterrent, but he’s not active protection.