Hi Darcy,
Thanks for your question.
The answer to your question is quite simple. Some dogs will be attracted and others won’t. It depends on their age, sexual status and energy level. Its possible they are older and lack the ability to sense that another dog is in heat.
Cats are more classically attracted to females in heat, especially if they’re Tomcats. Being territorial, they tend to be more aggressive about these things.
But in general, our pets are a lot like people in that way. After 15 years of being a vet, I have no idea why some dogs eat poop and others don’t. Some dogs eat bags of onions and others don’t. Some dogs dive for rocks and other don’t. Some dogs never bark and others never stop.
Sometimes there is no real answer.
All the best,
Dr. Clayton Greenway