To be quite honest, I kind of brushed off the notion of dogs having PMS. Then I met Lilliibelle the GSD and my mind has been opened! She's a very cage aggressive dog to begin with, but these past couple days have been even worse than usual. Then Thursday we noticed some blood in her cage, found out where it was coming from and since she's been in heat, she's eased up charging the bars. I just had to laugh and say that I'm converted.