Blood?

Er, if it were me, I'd get my pig checked out, but someone else more experienced should probably answer, because I have all boars.

I'm assuming they're sows? I would suggest calling your vet & ask, or any cavy savy vet for that matter. Mine have never had a 'period' and they are not nuetered, so something could be wrong. But since i'm not sure, you may want to wait for someone who knows more about this to come along and post.

They're all sows and there's four of them living together. If I knew which one had a problem I would go to the vet but the bleeding has stopped now and they all seem healthy with no weightloss

strange....I really don't know to be honest. To find who it is, you could make four large pens(with food and water of course) then let them in their for a while, watching them. Then see who is doing it. But since I have never heard of this and I'm not really experienced at this sort of thing, maybe you should talk to some others.

I'm pretty sure guinea pigs don't have periods; most animals don't, and their anatomy is completely different to ours, and I've certainly never heard anything about it before.

How much blood was there?

If it's only a little bit, it's more likely to be from a small wound, rather than internal bleeding.
Have any of your guinea pigs been fighting or nipping each other more than usual lately?

Or have any of them been scratching more than usual?

If I were you, I'd have another look over all of them, sometimes very small cuts and wounds can be extremely difficult to see, especially of the guinea pig has particularly thick hair.

Maybe one of them hurt them selfs, just like Cherish said. Im sure thats the problem.

Sows do not have periods. You need to try to figure out where the blood is coming from.

I have two sows (sisters) who spot a tiny bit of blood every time they go into heat. They have both been checked out thoroughally by a cavy savy vet and all is well - they just spot blood. I have definitely connected it to their heat cycle and so far it's happened every time.

However, this is an unusual case and I would urge you to go to the vet and get to the source of the blood.

Oh, and I never see any blood on the bedding or anything like that. It's only a tiny bit and it's on their genitals when I pick them up. They clean most of it off. It's only because I'm aware of the issue, and I check on purpose when they are in heat, that I even see it. I would never know otherwise.

This happens to me too, but I have a boy! He is happy and healthy and it only happens occasionally so I'm not really sure?? We went to the vet when we still had my other boy, Spike, and he said it could be a ruptured blood vessel (i guess in the urinary tract kind area). Maybe that's it.
And I guess I should say that Spike died a while after...he was all wet with pee underneath, we got him antibiotics but he didn't eat and was all sluggish and died one or two days later. I've no idea if it was related to the blood though. I hope I'm not worrying you lol I'm sure they're fine but I'd get it checked out.

Theres been no more blood thankfully but I'm trying to hold each pig daily to look out for it again and see who's doing it. It was quite a large stained area but only visible on the underside of the vetbed. Had I not been using white fabric I would have never known.

Is it at all possible that it is not blood but tomato juice or oxidized urine?

Could be gallstones. My girl is having the same problem and the vet gave her an antibiotic that we used for a week. 2 weeks later the bleeding happened again. and now another 2 weeks later. He is suggesting an xray to check for gallstones! Money will be flying.

It is possible that it could have been tomato juice. The stains I've seen since I'm pretty sure were so maybe the ones I thought were blood were too.

Foppie sorry to hear about your girl. Hope she's better soon.

My two sows do that two a little... They're young (5 and 8 weeks) Could it maybe be from dehydration? They only seem to drink water at night...