She had a REALLY mucky bum. Rang the vet, made an appointment, all is well. Washed off her mucky bum so it didn't burn and the vet was out yesterday to drench her for sand (not REALLY necessary, as she came from clay-based soils, but it's not a lot to pay for peace of mind) and do her teeth. Our vet is a qualified equine dentist.
So we have photos of one mucky baby getting a bath! Excuse the quality, taken with my phone.
Edit; forgot to say, that's my Mum in the photos. I can't afford to get wet and cold at the moment with the nasty cough I have.