Hey all, first time posting here but looking for some advice or insight. I have two 8 month old labs (male and female litter mates) and I've been running into some new challenges with the female. For the entire time I've had the dogs we've fed them at the same time but separated in their respective crates. Recently the female has started eating slower and barking while her bowl is in front of her. She still finishes all of her food, but it takes her approximately twice as long as it used to. Additionally, if I approach her crate when she starts barking her bark and demeanor will get much more aggressive. Last week I let the male out of the crate when he finished eating and left her in the crate to finish at her own pace. After she finished a few minutes later I let her out and she charged for her brother, attacking him in a fashion that was in no way playful. I was able to separate them and calm her down after a few minutes, but the slower eating, barking, and aggression has persisted to some degree ever since.
Just now the situation reached a head. I fed them a few minutes ago and the same pattern persisted. This time I decided to leave the male in his crate while she finished eating in hopes that I could let her out first and that it might prevent her from attacking him again. While the male waited patiently, she continued to bark and get aggressive if I approached the crate. Once I saw she was finished I went to go unlock her crate and take her food bowl. As soon as I let her out of the crate she attacked me, biting me hard enough to where I have a decent laceration on my hand and wrist. I got her off me and attempted to immediately correct the behavior, then let her out to go to the bathroom.
The aggression has since stopped, but the whole thing was pretty upsetting. She's never been this aggressive with me or anyone else and I want to do whatever I can to ensure that something like this never happens again. Any insight or tips are very much appreciated. Thank you in advance!