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Guinea Pigs/Guinea Pig Genes?


I have a male Dalmatian guinea pig, and I have noticed some things about him that my other 4 pigs don't have. One thing is that he poops way more than all my pigs, when my other pigs poop its 1 or 2 poops, but when he poops its at least 5 poops per poop, i know it sounds weird, any way another thing is that he has no hair on his testicles only the top were his back turns into them. The rest is naked. All my other males have hair all over except for their penis and anus. Now my question is, is It possible that my dalmatian guinea pig has the skinny pig gene? I don't know much about him as i rescued him, but i believe he is about 6 months to a year old. If you have any information for the reasons why he is different that would help. and no i am not planning on breeding him, i just want to know more about him.

Adult Baldwin
Adult Baldwin  

Skinny Pig
Skinny Pig  
No, he does not have the gene for Skinny Pigs. The bald spot above his scrotum is a something that all male pigs have but is more prominent is some than others. There is a very tiny gland that it barely visible that we call a 'grease gland.'  

Boars will sometimes secrete so much of this greasy oil that it builds up on the fur and is unsightly but harmless. Sometimes if you're brushing the area or combing it that grease will get caught in the teeth of the comb and pull out the hair with it.

Senior pigs (anything over 6 months of age) tend to have it more frequently than younger boars. It's not present in sows and nobody really knows the purpose of that gland other than it makes a mess when you're trying to show your pig on the judge's table.  Some judges will take points off for the dirty hair over that gland, others do not.  It's a grooming issue.

If the hair over the gland is light in color you can see the tiny indentation where the gland is, especially if for some reason the hair over it was pulled out.  As far as the quantity of the poo that too is often a senior boar thing. It has nothing to do with the pig's health, it's just the way it is. It seems to get worse as they age, but it's not a health issue.

Skinny pigs and Skinny carriers came originally from Teddies. Baldwins, which are completely without hair, originated in White Crested pigs and in fact the person who first discovered this gene in her line happens to be someone I know well.  

Both of those breeds started with a gene mutation that was passed on to their young. Baldwins are born fully furred and begin to lose their hair after a week or so. Skinny's are born with the fuzz at the base of the ears, feet and nose.  

When first discovered the founders of each of the breeds repeated the same breedings with the two parents and found that the same odd mutation was hereditary. Thus was created a new breed. Same is true of cats and dogs that are hairless. They were genetic mutations that were able to be repeated.

A carrier of either of those genes looks perfectly normal as would the coated counterparts.  But when bred to another carrier that gene is expressed or exposed and the babies will either be hairless or partly hairless (as is the case with Skinnys).  In a litter there can be both coated pups and hairless.  But those born with coats are still carriers of the gene.

So to sum it up your boar is perfectly normal. He just has different bowel habits than the others just as humans do. Male humans tend to have similar issues.

Here are a couple of pictures of both Baldwin and Skinny pigs, just in case you had not seen them.  

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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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