How do you know if two dogs are making each other worse vs better?

Hi everyone, I’m posting because I’m really struggling and could use some experienced, thoughtful input.

About 6 months ago, my partner and I took in two dogs (not littermates, but close in age and from the same household). We were told they were a bonded pair at the time of adoption. We love them deeply and have put a lot of time, effort, money, and emotional energy into making this work. We’ve tried training, management strategies, routines, enrichment, etc.

Here’s where I’m stuck:

One of our dogs (Ty) is incredibly sweet, people-oriented, affectionate, and adaptable — but also very anxious, high-arousal, and often the instigator. AKA a Pug. He has a hard time settling, escalates play quickly, and seems to constantly disrupt our other dog’s ability to relax. Our other dog (Echo) is calmer by nature, but it feels like he rarely gets true peace because Ty is always “on.” Echo is a Border Collie / Lab mix and turned 1 in November. Ty will be 2 in March.

The energy between them is pretty constant. A lot of going after each other / riling each other up / only wanting what the other has. It keeps the stress levels in our home pretty high at all times. At the same time, they do occasionally cuddle up to sleep together and can coexist peacefully side by side sometimes. That being said, I’m starting to wonder if this is a dynamic problem where one dog’s nervous system keeps the other unregulated, and neither is actually thriving.

My questions are:

• How do you tell the difference between a healthy relationship vs genuinely making each other worse?

• What are signs that one dog might do better as an only dog – or in a different environment altogether?

• If you’ve gone from two dogs to one, did the remaining dog struggle long-term, or did they eventually seem more relaxed?

• Are there cases where rehoming one dog (thoughtfully, not impulsively) actually improved quality of life for both dogs?

This is incredibly painful to even consider. We love them both. This isn’t about convenience or lack of attachment, it’s about whether the current setup is fair or healthy for anyone involved.

For added context: I truly believe Ty would adjust well in another home. He loves people, bonds quickly, and can settle and snuggle with almost anyone. That belief doesn’t make this easier – it actually makes it harder – but it feels relevant.

I’m asking because I want to make the most ethical, compassionate decision possible, whatever that ends up being.

Thank you for reading.