By Amy Plankenhorn, DVM
We’d like for you to meet Diablo, a very sweet and beloved 8-year-old Chihuahua. I met Diablo about a month ago when he came in because he was having difficulty breathing. His mom said that she’d noticed his abdomen getting larger over a few weeks, but she wasn’t sure why. When I saw him, I was concerned that his belly enlargement might be fluid, and wondered if he might be in congestive heart failure. But when I felt his abdomen, I knew it wasn’t fluid. Instead he had a large, firm growth in his abdomen. He was having trouble breathing because he couldn’t expand his diaphragm against the mass.
I did an ultrasound of his abdomen to try to find out what organ was abnormal, but it was very hard to tell. I talked to Mom about doing surgery to remove the mass, and she agreed. Fortunately, Dr. Duncan was able to do the surgery that day. We were all curious to know what this big lump was!
The most common large abdominal masses in dogs are associated with the spleen, liver or kidney, and that’s what Dr. Duncan was expecting. But he located the spleen and it was normal, and the lump wasn’t attached to the liver. He was able to bring the large lump out of Diablo’s abdomen and found a normal kidney underneath it. Then he realized that only one of Diablo’s testicles had descended into the scrotum. This huge growth was the undescended testicle! You can see in the photo below the difference in size between the normal descended testicle and the undescended testicle that was removed.
During normal development of dog and cat male reproductive organs, the testicles start out in the abdomen and gradually move into the scrotum by the time he is 6 months old. This external location keeps the testicles at their optimum temperature, which is lower than the internal body temperature. When a testicle remains in the abdomen, also known as a cryptorchid testicle, it is usually sterile and it is more susceptible to forming a tumor. Some testicle tumors are benign, but some have the potential to spread. And one form of testicular tumor produces estrogen at high levels, which can cause a variety of symptoms including enlargement of breast tissue, thinning hair coat, attractiveness to other male dogs, and even severe anemia. Diablo’s tumor was a seminoma, which is likely to be cured by the surgery. Tumors can also occur in descended testicles.
The best prevention for testicular tumors is castration. We at Animal Hospital of North Asheville are fortunate to have the ability to find and remove undescended testicles using the minimally invasive laparascope, which is much less traumatic than having to open the abdomen. Many people think that if the testicle hasn’t descended, it’s not going to cause any problems since it’s sterile. They will sometimes ask us to remove the descended testicle and leave the abdominal one. Diablo serves as a good reminder that what you can’t see CAN hurt you!
Diablo is doing great after his surgery, and is happy to be back to having his slender figure again.