Losing a pet to people like me is tragic, I am sure your brother understood what you could offer as support.
Don't feel you "glossed over" his grief, sometimes the unspoken words have the most meaning, especially when families have shared loss of our pets and loved ones in the past.
My brother and I can have or share the same feelings, with brief words, but we do keep in touch at least once or twice a week by phone, it is interesting how him and I can have experienced the same or similar feelings as we both still grieve the loss of my dad.
The loss of our family dogs we have all shared in our family, and for us it has been as tragic as the loss of a human loved one.
What I am trying to say, is just know that I am sure in your brother's heart he knows how you feel for him.
Please take care,
DE

In giving advice seek to help, not please your friend
SOLON