What is ectopic testis?
Ectopic testis is characterized by the abnormal path followed by one or two testicles as they descend to the scrotum. The normal descent of one testicle ends in the dog’s scrotum.
During ectopic testis, one or both testicles are either found in the abdomen, stuck in the groin or under the skin, the testicles have gone down too low.
In cases of ectopic testis, this is referred to as lateral or bilateral cryptorchidism. Monorchidism is also referred to as ectopic testis, but in this case, the problem is slightly different from cryptorchidism.
The testicles, in male fetuses, are in the abdomen. At birth, the testicles normally descend to the bursae (scrotum) located outside the canine abdomen. From the abdomen to the scrotum, the testicles travel through the inguinal canal, which is later lined with blood vessels needed to nourish the testicles.
Around 10 weeks of age, the puppy’s testicles are theoretically descended to the bursae. However, palpation remains difficult during the first 10 weeks because of the fat inside the bursae and the small size of the testicles.
In puppies 3 months old, the testicles are generally easy to palpate. Sometimes the testicles may remain in the abdomen or get stuck in the inguinal canal that was previously supposed to ensure their descent to the bursae.
If at around 4 months of age, the testicles are out of place, the puppy is generally considered to have cryptorchidism. Cryptorchidism can affect both testicles, or only one organ.
The testicles found in the abdomen only produce testosterone and no sperm. In the presence of cryptorchidism, testosterone can be produced in excess quantity, which can possibly result in pain or behavioural problems in the dog.
If only one testicle has not descended, it is called lateral cryptorchidism; for both, it is called bilateral cryptorchidism. Monorchidism is often used when only one testicle has not descended.
However, monorchidism is not the term designating the failure of the testicle to descend but the total absence of testicle in the canine organism.
Cryptorchidism is unfortunately hereditary and easily transmitted to descendants.
The problem of monorchidism is associated with cryptorchidism, but it is slightly different from the latter. The puppy does not suffer from failure of the testicle to descend but is born with only one testicle.
The dog’s body therefore contains only one testicle whether or not it has descended into the scrotum. Generally, if the testicle has descended normally into the scrotum, the dog can reproduce and have normal sexual activity.
However, breeding is not recommended because monorchidism is also hereditary, like cryptorchidism, and can easily be transmitted to puppies that come from the breeding male.
Males, according to studies on the subject, are affected by ectopic testis in a proportion ranging from 1 to 15% of the entire canine population. Some males can develop testicular tumors as a result of ectopic testis. The tumors usually appear later, around the age of 6.
Causes of ectopic testis in dogs
Some risk factors have been identified for ectopic testis in humans but have not yet been attributed to dogs.
In humans, the mother’s obesity, a difficult delivery affecting testicular vascular irrigation, and a premature baby seem to be determining factors, but no such connection has yet been made in dogs. Ongoing studies have not yet been able to confirm the same risk factors in dogs.
The hereditary component is currently the main path to explain ectopic testis in male dogs. Certain anatomical factors in the dog may also be responsible in some cases.
- Testicle too large to pass the inguinal ring.
- Inguinal ring too small to allow the testicle to pass through.
Several genetic hypotheses are out there but they are not officially confirmed. It could be the intervention of several genes with incomplete penetrance or autosomal (relating to non-sexual chromosomes) recessive gene, but studies are still in progress on this subject.
Breeds mainly affected
Some races seem to be more affected than others by this pathology. There are different levels of risks assessed according to the statistics established for dog breeds in cases of ectopic testis. The risks can be high, intermediate or very low depending on the case.
- Sheltland Sheepdog
- Maltese Bichon
- Border Collie
- Border Terrier
- Cairn Terrier
- Miniature Poodle
- Standard Poodle
- Toy Poodle
- Siberian Husky
- Lakeland Terrier
- Loulou of Pomerania
- Pyrenean Mountain Dog
- Podenco of Ibiza
- Miniature Schnauzer
- Silky Terrier
- Miniature Spitz
- Miniature Dachshund
- Yorkshire Terrier
- German Shepherd Dog
- German Hound
- Cavalier King Charles Spaniel
- English Cocker Spaniel
- Japanese Spaniel
- English Pointer
- Shih Tzu
- Great Dane
- Golden Retriever
- Saint Bernard
- English Setter
Symptoms of ectopic testis
The puppy has no particular symptoms when he has ectopic testis. Since testicle descent is a normal growth process that occurs gradually, particular symptoms may appear later.
- Absence of one testicle in bursae.
- Absence of both testicles in bursae.
When the testicles have not descended correctly into the male scrotum, certain phenomena can occur. The risk of developing these conditions is increased by the presence of testicles elsewhere in the dog’s body than in the bursae.
- Up to 10-times higher risk of testicular tumors (compared to a dog with normally descended testicles).
- Torsion of the testicles when present in the dog’s abdomen.
The diagnosis of testicular ectopy may be made later in the puppy’s life. Since the testicles can take up to 10 weeks to position themselves, the diagnosis may not be done before 70 to 90 days.
Palpation of the testicles becomes possible later in the puppy’s life, at least 10 weeks after birth. At this time, the testicles should be in place and should not move upwards. If the veterinarian is unable to palpate them at this time, he can usually make the diagnosis of ectopic testis.
Care and treatment
Testicles found outside the dog’s bursae usually do not cause immediate problems for the dog. However, over time, the risk of developing tumors from the testicles is still 10 times greater compared to a normally descended testicle. The risk of torsion is also multiplied.
There is a hormone treatment that can help bring the puppy’s testicles down to where they should be, but it should be used on a puppy that has not reached puberty, preferably before the age of 3 months. However, this form of hormone treatment is highly controversial and not universally accepted.
Abnormal development can cause structural abnormalities in the dog and even once replaced, the testicles can suffer problems that can deteriorate the general condition of the animal. Surgery remains the best possible solution.
In adult dogs, the only treatment available to prevent tumors or torsion is surgery to remove the stagnant testicle located in the wrong place of the dog’s body.
In the presence of ectopic testis, even if the dog has only one testicle, it is preferable to remove both to protect the dog.
When buying a puppy, it’s best to check if a veterinarian’s examination has been done and get written confirmation.
Early castration of both testicles of the puppy is preferable and then prevents the risk of torsion and tumors.
Ectopic testis is not a contagious disease or zoonosis. However, it is a hereditary disease that a male, when able to reproduce through a descended testicle, can pass on to his offspring.
Ectopic testis is considered a hidden defect, but the conditions related to it are such that it is sometimes difficult to obtain legal recourse in more specific cases.
Usually, the hidden vice is for dogs over 6 months of age. Since warranty periods in pet sales are usually only 30 days, it is often difficult to enforce the law of hidden vices in puppies with ectopic testis.
The delays of confirmation of the disease being what they are, the hidden vices law is accessible but not always fair for the wronged buyers.
Breeding males with ectopic testis are generally removed from dog breeding herds to eliminate the risk of producing dogs that are not “complete”. Considered as a hidden vice, conscientious breeders avoid spreading ectopic testis in their dog breeding herds.
However, it can happen that dogs affected by ectopic testis are sold at a lower price but with the buyer promising to sterilize them to not contaminate potential offspring. Since neutered male dogs make excellent companion dogs, this solution is sometimes ideal for both parties.
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