base of tail causes flinching

Question
hello Sandra.

one of my males is giving me trouble, I've been an owner for 2 years and bred 6 times for a total of 67 babies (only 3 pinkies didn't make it, yay me!), so I've had a lot of practise and learnt a lot from observation as well as a total of reading hours well past 24.

however, my big friendly giant, Malius, seems to flinch and squeal lightly whenever i rub the base of his tail, he's nearing a year old now, and for the life of me i cant figure out how he could have got injured there.

so my question is, what do you know of that could cause this and do any of these causes warrant a vet visit, he seems fine so long as i don't touch his base, he's acting fine in every single other way, eating well, sleeping fine, playing as any lazy male does, still gets aroused by my girls, no inflammation, no lumps that i can feel (though i can't be sure, considering the weird shape of the vertebrae).

i should note, he had this sensitivity a few weeks back, but only for a few days, only it came back this evening. I'm fine to let it go for now but I'm concerned and if your knowledge can point me to either a vet or to just be careful with his tail ill be very thankful.

Answer
I would have the vet check it out for sure. Without checking him myself it is too difficult to say since details are sketchy.  It could be an abscess underneath that is causing some discomfort but an injury is not out of the question.  Hope this helps.