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I have 2 pet guineas. I've had them for about a month and purchased them from a local pet store. I believe one is male & one is female. This afternoon I went to check the cage & there were spots of blood throughout their pen. It is mainly in & around their "house" but I've noticed it in other spots as well. I've checked both of them thoroughly & can't see any cuts or blood on their fur. The female is albino & the male is brown & white, so they were fairly easy to check. The only thing I can think is that maybe the female has started her menstrual cycle?? I do not know if that is the case b/c I don't know how old they are. I can tell you they are about 6" long and are a little bigger around than a paper towel roll. They don't seem to be hurt, they are eating fine & all seems normal...except for the obvious. Please give me your thoughts & maybe if you could throw in a tid bit of knowledge as well it would be much appreciated.
Thank you....Nick

Well let's address the first issue, female guinea pigs do not have a menstrual cycle. The can however, get pregnant as young as two or three weeks old. If you have a male and a female the obvious is that either she was pregnant when you got her or the male has since bred her.

That amount of blood typically comes from giving birth or in this case having a spontaneous abortion also known as a miscarriage. When a female delivers they also come back into heat within a few hours of giving birth, so chances are the male may have already bred her back.

Unless you're trying to breed these pigs you need to separate them. Since you saw no evidence of babies she may have aborted them then eaten them. The other possibility is that they were so small you didn't recognize them and may have tossed out the fetus with the shavings.

A sow comes into heat about every two to three weeks. They aren't on a regular cycle, nor do they have any discharge that would be obvious enough for you to know they're in heat. You would probably hear the boar making purring noises and pestering her. It's fairly common for many pet stores to not know how to sex the babies and they get put into a cage with the opposite sex.

It's also possible that pet store got these pigs from a breeder who did the same thing and the result is a pregnant pig. In any event what you are seeing is the remains of a delivery.

As for the color of the female just for that 'bit of knowledge' there is no albino gene in guinea pigs.  There are all white pigs and they can have either pink or dark eyes. They are called Pink Eyed Whites or Dark Eyed Whites. An albino has no pigment whatsoever but these white pigs with pink or red eyes actually have pigment in their skin.

Occasionally a pure white pig is born into a litter of broken colored pigs and that white baby is called a 'masked broken.'  When bred back to a broken colored pig that masked broken will throw colored babies. It's because the white gene is overshadowing the gene for the other colors giving it the appearance of being totally white.

As they get older they will sometimes get shading variations in the white and to a judge that makes it obvious that the pig is not a true genetic white but a masked broken.  The reason the PEW pigs have red eyes is because of a dilution gene that dilutes the color in the iris of the eye causing you to see the blood that's behind the eye, thus making it appear to be a red eye. The iris is actually clear, so what you see is the blood flow behind the eye that you wouldn't see if the eyes were dark.

Is that enough trivia for you?  If not I have plenty more I'd be happy to share.  

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As is sometimes the case, people in urgent need of information have a higher degree of expectation than those of us as experts are able to give. The experts on this site do their best to give the most accurate and responsible answers possible. We ask that you remember that it is not our intention nor place to criticize the professional advice given by your veterinarian, nor is it appropriate for us to comment on the correctness of a diagnosis made by a licensed physician. Our knowledge is experience based. Although many years of breeding and showing cavies gives me a wealth of experience it cannot change the fact that we as experts are not veterinarians and therefore may occasionally have to reject questions that appear to be asking us to criticize advice given by the licensed professional. Having raised and exhibited cavies for many years I have extensive experience in cavy care and husbandry. I currently have an active breeding program for pedigreed show animals but do not encourage backyard breeding for inexperienced owners. Although I don't encourage breeding for fun I'm always happy to answer any questions from an owner who is in sincere need of help. Pet owners wanting to breed should understand that even experienced breeders have litter losses. The mortality rate is high in cavies. The chance for losing both sow and pups is always present, even with experience. Although this is a site for experts to assist owners, there is no expert in any field who has all the answers. The wisest thing a good expert can know is their limitations. Not having an answer does not diminish one's ability or knowledge. It simply shows that we recognize our limitations and operate within them.


Raised and shown cavies for many years, having aquired my first cavies in the early 1970's as pets. My caviary currently handles 65 + animals in two different breeds and several varieties. Having been in the health care industry as a licensed nurse for 35 years I have hands on experience with care and needs in both humans and cavies. Member of American Rabbit Breeders Association and American Cavy Breeders Association.

Awarded Lifetime Membership in of one of the oldest cavy clubs in the United States, on whose Board I served as Sec/Treas for six years and currently serving as President. Also editor/publisher of the club's quarterly newsletter. We are strong supporters of our youth exhibitors, most of whom are 4H members who are working on cavy projects. Through these projects they become good responsible citizens. We deal with all aspects of showing, breeding, caring for and sharing experiences in the fancy. The cavy fancy is not a new one but in some areas is still relatively unknown. Our goal is to inspire interest in high quality, responsible breeding to improve the species, not just the reproduction of guinea pigs. Our job is to educate owners to help them make the right decisions and choices in the care of their cavies.

Graduate in nursing. Certified in emergency medicine.

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