There is one particular problem that some boars get which is very uncomfortable indeed and if it is not dealt with can lead to cystitis and worse. It is when the penis is found to be extruding.
Nine times out of ten this is because he has become sexually excited at some stage, ejaculated and the semen has congealed around the penis and prevented it returning to it’s normal position, sheathed up inside it’s body out of harm’s way!.
I was once asked by a very precocious child at a school why a guinea pig’s penis cannot be seen. He, it had to be a boy of course, was obviously trying to put me in the spot, but not for the first time, his, like many other children’s questions, was one I should have asked myself. The answer came easy enough for I had been talking about the low centre of gravity guinea pig have which makes them so stable when they run at high speeds. If anything dangled it would not only slow it down it would also be in danger of damage, somewhat.
Guinea pig semen sets like super glue and very quickly too and this is why this problem sometime occurs. The most likely scenario is when a boar is suddenly housed close to sows and becomes over excited.
The penis is usually red raw and in cases where the problem has not been detected early, it can have hard scabs on the tip and become pusy. It is usually detected before this if it has indoor accommodation for it will squeak in pain and lift it’s bottom high when it passed urine for the semen can restrict the flow when it is clamped around the shaft.
Wash thoroughly in warm soapy water, then extrude the penis fully. The ring of semen is usually very easy see and has to be broken off for I have never come up with any kind of solvent to break it down!. Needless to say this is a bit of a delicate operation which I am sure the male of any species would appreciate!. It is wise to make this a four handed job, with someone to hold the boar firmly and still while ring of semen is broken with the finger and thumb of both hands. I coat the shaft in calendula oil and it usually slips back in easy enough and with obvious great relief to the boar!.
If the penis has become badly infected then an antibiotic ointment is recommended and it may be advisable for the animal to be put on a course of antibiotic orally.