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Guinea Pigs/breast cancer in guinea pig


i'm writing you about my 3y.o boy, he has diagnosed with breast cancer about 3 months ago & our vet told me that there is nothing we can do because its pretty difficult to be on the surgery,  so there is nothing i am doing on except what i'm doing all these years, loving him, fead him and take him for walks(!) on my garden..
So the thing is that the nipple from THE breast  HAS STARTED to bleed, my vet told me that  probably antibiotic will be need and tomorrow i will visit her to see him.
any idea what could help him?
thank you in advance

We always think of breast cancer as a female thing, but in fact that's not true. Although not as common in males, it is certainly just as serious.

I don't know why an antibiotic would be indicated, but at this point it certainly can't hurt him.

Abnormal bleeding is one of the signs of many cancers. Whether or not an antibiotic will help will only be answered by trying. I suspect that the cancer has already metastasized, or spread and that your little fella's time is limited.

Mammary cancers in guinea pigs are typically so invasive by the time they're discovered that they're untreatable. These little creatures tend to hide illness from us until it has usually advanced to the point of being too late. Mammary cancer, aka breast cancer, is fairly aggressive and doesn't offer many choices.

Surgery is out of the question for a 2 lb guinea pig. Not just because of the prohibitive cost, but because the effect of lengthy anesthesia necessary to do the job would be extremely dangerous. They just don't tolerate anesthesia well. And to the best of my knowledge there have not been any studies on treating breast malignancies in guinea pigs.  

I wish I could give you something more positive to hang onto, but I'm sure you already know what is ahead. You will know when the time is right to say goodbye and not allow him to suffer. He will tell you, and when he does you'll know you will make the right choice.

I am so sorry you have to watch your little guy go through this.

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Pat VanAllen


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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