Today, my friend, while at her horse had her dog with her as usual. Another small dog came over and started playing with her. She says next thing he had mounted her  and they had tied. Her bitch does not appear to be in season, no signs at all. Is it possible to mate without being in season or could she be having a silent season? She was a maiden bitch. My friend has arranged to go to vets tomorrow for injection. Has anyone else ever experienced this?

There are two possibilities. If this bitch is young and healthy, chances are she had a "silent" season with no blood -and could very well be pregnant now. I have seen this happen in three of my own bitches. They all had normal seasons with bleeding the next time. The other possibility , usually in a more mature bitch, is pyometra. I had a bitch just on the verge of developing pyometra mate and tie despite absolutely not being in season. She was spayed urgently and was then fine.

She is about 6 and has heart problems which are being being treated by regular tablet taking, but normally has very regular seasons. Will tell her about pyo though just in case. Thanks

It's about text book age for Pyo, a middle aged maiden bitch.