I saw a puppy today and was wondering a few things.

How does a dog end up with only one testicle and is it common?
Is it genetic? Are these dogs unfertile? What is the reason that if fails to come down? Do these dogs think the same about humping females or would you not have to worry about him being with a female? I have read that dogs with only one testicle are more likely to get cancer, is that true and if so what is the chance?

Typically it's not that they have only one, it's that only one has dropped. It can be genetic (you don't EVER breed a cryptorchid). They are like most other intact dogs when it comes to mating behaviors but often the testicle still in the body does not produce viable sperm (to hot)..though don't count on that for birth control. The "myth" of behavioral problems is mostly because often when fixed the vet misses the other testicle so the dog is still "intact" and shows studdy behaviors.

The testicle that does not come down is prone to cancer. To avoid this you get the dog fixed early (by which I mean you don't wait until they're 2 most of the time). The surgery is more invasive and expensive since it's often exploritory (it's amazing where they testicles end up...we were doing a lab for one of my classes and our professor found a testicle in our test animal hanging out with the kidneys)

the testicle that is retained inside has been known to wrap around the intestine leading to the rectum and causing the dog to impact and rupture and die.

dogs with retained testicles are 50% more likely to get cancer.

like Jamie said, it is genetic and passed in the male line and monorchid (1 testicle)males should never be bred.

refer to http://www.peteducation.com for more info

 Quote: jamie craig

They are like most other intact dogs when it comes to mating behaviors but often the testicle still in the body does not produce viable sperm (to hot)..though don't count on that for birth control.)

This is what I thought... Someone told me that they could not be fertile to a female but just because one is still up does not mean that they don't have a 50/50 chance of getting it right? correct? (to hot)?

Is it more likely with pure breeds? Like a defect that comes from bad breeding? or just a "chance" thing?

Some breeders are more apt to not disclosing it. They may have to much tied up in their stud to admit to it.
Nobody really cares about the mutts from a prospective of breeding. Just the individual dog's health so no reason to hide/deny it.
A dog can have both and still be a producer of pups with only one.

"found a testicle hanging out by the kidneys"

That's where they start, in the embryo. Like ovaries. Somehow hormone influence causes migration to the scrotum.

There are many reasons that a testicle won't drop. The most common is that the cord is not of sufficient length to allow it to drop into the scrotum.

It is thought to be highly heritable. The condition is often propogated through bitches.

In other words, it's not very often that someone would use a monorchid as a stud dog, but many might use a sister as a brood bitch.

The dog can be fertile from the remaining testicle, and the retained testicle (as others have said) is at a much higher risk to become cancerous.

Tracy

 Quote: Bob Scott

Some breeders are more apt to not disclosing it. They may have to much tied up in their stud to admit to it.
Nobody really cares about the mutts from a prospective of breeding. Just the individual dog's health so no reason to hide/deny it.
A dog can have both and still be a producer of pups with only one.

I think the disclosure is a biggie. In Florida we are required to sell any dog with a health certificate and that is one of the things that is noted on the paperwork.

For some reason Florida has more cases of undescended testicles. <grin>

I've talked to breeders in other states that do their own vac's and generally a litter does not see a vet. Surprisingly they report very few cases.

This is just my own observation........

so could you leave this type of dog until two to neuter him or should it really be done before that? What are the chances of a vet even finding the "lost" one?

I'm no expert, but I'll share my personal experience here. My puppy came to me at seven weeks with undescended testicles. That was okay since I had no plans to show him in conformation or breed him, anyway. I wanted a companion and obedience dog. The breeder was a little concerned but said to give it some time and they should come down. She remembered one dog she bred where they didn't come down until he was almost a year old.

For a long time, one or both testicles could be felt but not seen. The first one did not fully descend until he was six and a half months old. When this dog was only about eight weeks old, I had one vet (not my regular one) tell me he absolutely had to be neutered when he was four months old. I was going to give it more time than that. I did not want to neuter too early as I wanted to give him time to reach sexual maturity, along with all the other reasons that have been discussed in other threads here.

He was 19 months old when we had the surgery done. I felt that was a fair compromise under the circumstances. We were very lucky in that the second testicle was sitting right above the descended one, and so the vet did not have to "dig around" for it. I too have heard of them being found up around the kidneys, where they originate in the fetus.

My understanding is that the vet will do their absolute best to find the retained one(s), as those are the ones more prone to cancer in later life.

Edited by Cheri Grissom (01/24/2011 11:34 AM)
Edit reason: added last paragraph