One of the definitions for the suffix 号 in 大辞林 looks like this:
I'm somewhat familiar with this suffix from fiction. For example, I remember it from the anime series ふしぎの海のナディア, which had a submarine called the ノーチラス号. And I've seen it used for other forms of transportation in fiction, too, like airships, and even a race car.
But I haven't seen it used for animal names, and the definition above says it can attach to the names of 動物 as well. Wikipedia's disambiguation page for 号 says something similar:
But it doesn't say when it would be used, and I can't remember having seen any pet or animal names ending in 号. So I'm curious: do people still use the suffix this way? If so, when would it be used?