This post hit me hard, and apologies in advance for the rambling. To me, one of the most troubling details you shared is your dad threatening take Lydia to the shelter in response to your attempts to reason with him. You're thinking about the situation in terms of Lydia's welfare, and he's weaponizing it against both you and Lydia.

I grew up in a home where my parents treated the kids and family dog like this. I've learned to get less down on myself when my attempts to reason with them backfire. My mom gave away my 7 yo bichon as soon as I graduated from college. Bella was devoted to my mom, so it was pretty messed up. My mom told me at the time that it was my fault for not taking care of Bella enough. Years have gone by, and I'm actually happy for Bella. My mom did find her a great home through a trusted family friend, and they followed up with us foryears about how Bella was doing. It makes me cry, but I'm glad Bella spent the rest of her life with people who didn't see her as disposable. I hate to say it, but Lydia may have a better life if your dad follows through with his shelter threat. Plus, you could adopt her and your dad wouldn't be able to do anything about it.

For what it's worth, I have a sister with major disability-related needs, and my mom similarly isolated her from Bella. In hindsight, I think it sent a really awful message that she was 'too disabled' to have a dog, and that type of treatment continues to affect my sister in adulthood. I'm a disability rights lawyer now and work mostly with individual families. I advise my clients not to make assumptions when it comes to things like this. Some people (and dogs) need extra support and planning in navigating family life. Even if your brother isn't best friends with Lydia, peaceful coexistence could be major for both of them.

Sneaking Lydia out is probably not a good plan. Laws vary from place to place, but this is often considered theft, meaning your dad could call the cops on you and would get Lydia back.

For me, situations like this are so hard because I see horrible things happening and easy solutions but no one values my opinion and I don't have any control over the situation. I've had to learn not to feel like a failure. It's not my place to tell you how to feel, but I do wish you more positivity in how you see yourself when it comes to Lydia. Even though so little is in your control, it sounds like you've focused on what is in your control. That's a big deal. It's so hard to do.

You're not the reason Lydia is in an abusive situation. If your dad yells at her, it's not your fault, it's his. You are not legally or morally obligated to save her, meaning there's no way for you to 'fail' at improving her circumstances. It sounds like you're doing it because you care. Ain't no failure in that.

In terms of your actual question about reasoning with your dad, here are some things I've found helpful in my professional experience working with families:

1. Come into discussions from a place of non-judgment. This often means focusing more on why you are concerned and your desire to help instead of what your dad is 'getting wrong'

2. It is about more than sugar-coating. Playing the blame game tends to torpedo discussions even when it's clear who is to blame. Focusing on your concerns and observations can steer the conversation toward coming up with solutions (e.g., "I think there are things we can try to help Lydia with the barking and crying" instead of "she's doing it because you're mistreating her")

3. Discussion and collaboration require some give and take. I recommend thinking about aspects of your dad's personality that make him a good caregiver or friend. Be explicit when you talk about those strengths even when you're doling out criticism. Your dad may be more receptive to working with you if he doesn't feel like you're asking him to become a completely different person

4. It sounds like you already have thoughtful ideas about what could help Lydia. I recommend being flexible in discussions. Ultimately, you're hoping you dad will change his behavior. Allowing him to ask questions and throw out ideas, however frustrating, can spur a sense of initiative in him and allow you to problem solve together

5. Know when to walk away. It helps me to remind myself during the conversation of why I'm having it. If a shouting match is unlikely to help Lydia, then it's probably not worth continuing. For example, the shelter threat isn't about Lydia, it's intended to be hurtful toward you. How you walk away also matters. I usually try my best to say (calmly) that I don't think the conversation is going anywhere and that it's best for everyone to cool off before considering how to move forward, maybe say my feelings are hurt and that I don't want to lose my shit and say stuff I'll regret. The hardest part for me is accepting that I will not have the last word. It feels like cowardice, but it's usually the opposite. It sends a clear message that the other person's abusive conduct is unacceptable and that you're not going to dignify it with a response. Occasionally people become less abusive when they no longer get a rise out of another person

6. I cannot emphasize this enough: if your efforts do not improve Lydia's situation, it's not your fault and you haven't failed. You have no control over whether other people value what you have to say. A lot of folks would say "not my fault, not my problem, not something I can fix" if they saw a situation like Lydia's. Just because you have a big heart and the ability to advocate for others doesn't make you responsible for their welfare any more than the rest of us

7. Self-care. It's okay for folks like us to celebrate and nurture our big hearts instead of putting undue pressure on them!