Cryptorchidism: Testicle not found

Hello, Today I took my 6 month old cryptorchid kitten in for neutering.  They removed his regular testicle with no problem, then proceeded to do an abdominal search for the other one.  It was not found.  The vet told me either he was born without it completely, or it's somewhere stuck in the inguinal canal/muscle layers there. My question is: why would he not have searched the inguinal canal during surgery? Is that too much all at once/can that area not be accessed during the abdominal search?   A little background on the kitten: he was born with a rare and undocumented deformity. He has no hip joints or knee caps, and his legs are kind of backwards. He still gets around fine but he does have a severe disability that could definitely have to do with the cryptorchidism. So to conclude with what I'm really wanting to understand - why couldn't the inguinal canal have been searched?  And how likely is it that he was truly born with only one testicle?   I believe in a few months we will be doing a hormonal test to measure testosterone.  It's really important to me that if the testicle is hidden somewhere, that it be removed. Because of his disability, he has to be indoor only, and I cannot have him spraying in the house.  I also can't deny that it was disappointing to hear I may have to do another serious surgery to look for it again, instead of all at once, with how expensive it is and knowing he may have to go through this recovery all over again.   Thank you so much for your time and for reading!

Hello!  You have put your finger right on one of the frustrating, challenging and yet addictive things about being a vet.  As one of my mentors used to say, 'Not all your patients read the textbook to see how their bodies are supposed to go wrong.' This was his slightly sarcastic way of saying that although, for example, it would be nice to open up every cryptorchid cat and find the missing testicle neatly tucked into a fold of ligament between the kidney and scrotum, real life is sometimes more difficult than that.  Finding an underdeveloped testicle in a small pet can sometimes be like searching for a needle in a haystack.  This is compounded by the nagging possibility that the testicle might be completely absent, or indeed tucked away in one of the parts of the body that is difficult / disruptive to access, for example the inguinal canal.  In cases where the anatomy is abnormal anyway, finding a testicle might be even harder. It is indeed a good idea in such a case to go back later and check the hormone levels, because if a testicle were to be hiding somewhere, there would be huge advantages to finding it (eg to prevent unexpected fertility or testicular cancer within the abdomen).  If your vet were unsure a to which levels to check, they could consult with a veterinary pathologist about the tests available for a recommendation. I do hear your frustration though.  It is likely that your vet is equally frustrated to have opened the abdominal cavity with nothing to show for it and I guess that the choices are to ask for a referral to an expert in abdominal imaging or surgery, or to follow your vets' course of action.  Vets are usually honest about their capabilities in this regard. Best of luck - and please do let us know if the testicle is found!