Originally Posted by Aleron
Yes that is exactly it. If they are asleep and are startled, they might snap. They don't all have the issue but it's worth mentioning because I don't think a lot of rescues talk much about it.
The sleep aggression in rescue greys isn't a breed trait, it's an environmental one. At the track, once they are separated from mom they spend the night in individual crates sleeping totally alone and separate. When you consider that some retired racers are 4-5+ years old when they come off the track, most probably don't remember a time when any living thing touched them while they were sleeping. Greys raised in homes don't develop that problem.
Dog aggression is pretty uncommon, but it can happen. Once in a while you can have a serious bitch fight, but those are really really rare and usually between siblings raised together. In some breeds males can be SSA or intolerant. Ibizan hounds, borzoi, and deerhounds I know for sure can be SSA. It tends to run in lines, so it's something to research and ask a breeder about if it might be an issue. Strider became male intolerant when he matured, but after he got epilepsy he became overly defensive with other males to the point of being a jerk.
Borzois are awesome. Giant couch potatoes, yet they love to go for 10 mile hikes and run full blast for two hours if you give them the chance. Pretty much the most perfect dog ever except that they're totally oblivious to prowlers unless the prowler is a raccoon.
Zois have a long silky single coat. I rarely brush mine and they look nice. Some zois tend to get mats behind their ears and in their skirts. Mine don't, except Kaia behind the ears so I just take some thinning shears and trim a little out once or twice a year to keep it manageable. She seems more comfy that way.
They do shed, but it's not bad. You know how a lab or GSD has short bristly hair that pokes into couch upholstery and carpets? They leave long silky hair, like human hair, and it vacuums up really easily. Mine go months without any significant shedding and then blow their coats. Strider blows his once a year-ish and Kaia blows hers a couple of months after she goes into season. Spayed females won't blow coat like that and end up coated like males.
They are really easy to live with. I specifically looked for biddable individuals, and they're independent but they listen to me. They don't usually listen to other people and that drives my parents nuts. A couple of Kaia's puppies were giant hellions. lol. I'm helping one puppy buyer get through the terrible teens right now. Z is very feisty and independent. When you get a dog like that, the best thing is NILIF whenever they get too full of themselves and tricking them into thinking the stuff you want them to do is really their idea. And they're wicked smart, so that can be a lot harder than it sounds.