First a little background information. We adopted Precious at 3 months of age. Precious seemed normal and loving as any basset would be and she and Molly were as tight and loving together as two dogs could be. I don't recall how old Precious was exactly but in adulthood, suddenly that changed. And I do mean sudden. Now these two would normally play tug o war with toys, bones, whatever, eat together the whole deal without a single issue, they even slept curled up together. At first Precious started to snap and snarl when Molly would attempt to play or pick up a bone. A warning growl out of Molly would back her down. But it got worse, not better. Soon I had to separate them for meals. I couldn't leave bones on the floor because Precious would go after Molly if she so much as looked at one. There would be a scuffle. But I tried to let them work it out. When it got to the point the Precious began to inflict injury and it went from scuffles to all out going for the throat, it was time to rehome Precious to a family with no other pets. Which we did. Precious was in no way shape or form abused or neglected. She never went hungry. There was no reason for the sudden change in personality. Betsy is Precious' pup, Rowdy is her Dad. We kept her because she had the mildest personality of all the pups and seemed to really have bonded with Molly. Betsy was sweet and loving with Molly for years just as her Mom before her. Then I noticed issues over bones, toys, food, snacks, and later attention......especially mine or Nichole's attention. Now I was in school for many of those years as was Nichole. Fred was unemployed during large chunks of those years and he never liked to be bothered with the dogs so tended to put them into the yard and forget about them. (literally) So my working theory with Betsy was perhaps it was an attention issue. I never let it escalate to the point it got with her Mom because by then Molly was older and so bonded with Betsy she simply refused to fight back. I kept them separated. When Nichole took Betsy after Fred passed away I thought it the perfect solution. Betsy adores Nichole and Aubrey, she loves cats (which she has). She'd be the only dog and regardless of other pets I knew she'd get more than enough attention/affection. A while after she'd been there Oliver reached for Betsy's bone and Betsy growled and snapped. Nichole went full blown Mamma bear on her (she was sitting right there when it happened) and it has not happened since. But she does her best to keep bones up unless the kids are in bed or gives them to Betsy in her crate. It was the first time in her life (age 5) of ever showing aggression toward a human. Aubrey had spent her whole toddlerhood feeding Betsy this or that and playing with her bone with her for Pete's sake. I was stunned, as was Nichole. We decided perhaps it was the new environment and the loss of Fred ect that had her stressed. However, while she's not gone after Oliver or Aubrey.......there have been incidences with the cats. Normally she plays just fine with them. She has always loved cats. Then she started snarling and snapping and chasing them down if they went near her food or her bones. Now there had been an occasion or two when she'd done that with Bruce here but Bruce is so touchy with other animals that he'd hiss and scratch without much provocation. So it was difficult to tell if the issue was Betsy or Bruce. Nichole says it's progressed to where there are times when they just walk across the floor that she'll go after them, and she is not playing. Here in recent weeks if Oliver comes up to Nichole.......Betsy will come over and while she won't be physically aggressive the way she looks at Oliver and her body language makes Nichole nervous. Nichole has spent nearly her whole life around dogs and other animals and is quite adept at reading their body language. If she is nervous, she has good reason to be. Nor is it like Betsy is the first dog with aggressive behavior we've dealt with. Right or wrong, Nichole adopted a 7 wk old beagle pup today. I tried to talk her out of it, but she took the risk. However she did discuss with the breeder the potential issues with Betsy and he did volunteer that if Betsy couldn't adapt to the new addition that he'd like Nichole to return her to him and he'd even refund the money. Nichole has had long practice at introducing dogs. She knows how to do it correctly. First introduction Betsy ignored the pup. Second she really went after her. Nichole has them separated safely. However it seems to have triggered something in Betsy as she's being aggressive with the cats too now. She's trying to go after the pup through the gate for pete's sake. Betsy has been raised with other dogs. During her first 3 years there have been numerous foster dogs/pups come into the home without a single issue. (which reminds me I think it's about 3-4 when Betsy started having issues with Molly) She's lived with a wide variety of other animals as well. There really is no valid reason for the sudden change in personality. The worst Fred ever did was put them into the yard for the day, and I hardly call that "abusive" or neglectful. She's never missed a meal. Until she went after Oliver she's never had a hand laid on her. I find it counter productive with dogs. Nichole would not have normally done so but it was pure reaction. Here I thought it might be an "attention" or "dominance" issue. I don't think so now. It doesn't explain why she is now going after cats whom she used to adore. Nichole can return the pup without a problem. However that doesn't solve her problem with Betsy. Her worry is not just over the pup but Oliver, Aubrey, and the other animals. Most especially Oliver whom she's been giving the weird body language to lately. The pup has just brought the issue front and center again. I've had a life long experience with dogs of a rather wide variety. I can't say I've ever run in to the outright aggression with a pup issue. We did not introduce pups to Precious, so I have no clue if she would've done the same or not. This pup is tiny defenseless and obviously poses no threat, yet she is all out going for her, not just growling. It's not necessarily a territory issue either as she's progressed to doing this with other dogs on a walk as well. Nichole could rehome Betsy but the dog does not take to strangers, period. She does not warm up to them over time either. She will not even eat from them, even people food. She is not going to rehome well with those issues on top of the aggression. Nichole does not want to put her to sleep because, well, she loves Betsy deeply just as I do. But I don't know what else she's going to be able to do because Betsy's behavior is becoming more and more unpredictable, which is dangerous. Training most likely will not work. I did research trying to solve this issue long before she went to live with Nichole and tried the techniques suggested and it didn't do a thing. It's personality, not behavior per se. After Precious and now her daughter displaying the same behaviors, I'm sort of wondering if there is mental illness in dogs. lol (not sure if I'm joking here) I should add, Betsy submits immediately if another animal takes on her challenge, but the moment the dog (especially) shows her it's not going to fight, the attack is on. It's as if she figures they're fair game.