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Cryptorchidism
by Fred Lanting
Copyright February, 2009 -
[note: this first appeared as "Cryptorchidism in the German Shepherd Dog", but is applicable to all breeds.]
The most common congenital* anomaly of the scrotum and testicles is the apparent absence of one or both gonads. I use the word "apparent" because the missing testicle(s) usually are actually present inside the body cavity of the dog. The Greek kryptos means hidden, secret, or covered, and the Greek orchi- is a combining form referring to the testicles. The condition is therefore called cryptorchidism and the dog so afflicted is called a cryptorchid. If one testicle is retained, he is a unilateral (one-sided) cryptorchid and if both, a bilateral cryptorchid. A word commonly applied to the former is monorchid but this is a misnomer, as monorchidism would mean the presence of only one testicle anywhere in the body, not just in the scrotum. True monorchids are quite rare, as are anorchids (males with no testicles), and either condition can be verified only be extensive surgery.
A dog whose testicles have been removed is commonly but inaccurately referred to as having been "neutered", but more accurately he is called a castrate. Such a dog generally has no (or greatly reduced) response to sexual stimuli, while a sterile bilateral cryptorchid may have normal sex urge, and a unilateral cryptorchid is usually both virile and fertile.
Show Rules
The AKC and almost every other club require every dog competing in shows to have two normal testicles in the scrotum. Judges are supposed to examine the scrotum, and usually a quick pass of the hand between the thighs will let them know if one is too spongy, hard, or abnormally small, indicating the possibility of disease or chicanery. In some countries testicle abnormalities are more severely penalized and in some places less is demanded of the judge than is the case in the United States. I have excused, placed at the end of a class, or disqualified dogs (depending on the Standard and country's rules) with unequal testes, in spite of the fact that they have been given awards or not penalized by previous judges. But I have also seen the same thing in regard to dentition — I have disqualified dogs for DQ faults listed in their Standard that had already amassed championship points from judges who either did not understand the Standard or gave the typical AKC cursory look at incisors and little else.
Examining the Pups
A tube called the vaginal process runs from the parietal peritoneum (the inner lining of the abdomen) to the scrotum which that lining encloses. Inside this tube are the spermatic cord, artery, vein, nerves, vas deferens, and the cremaster muscle. It is the function of this muscle to pull the testicle closer to the body in cold environs, and to allow the scrotum to hang lower in warmer conditions. In the abdominal wall, there is a ring-like passageway through which the testicles move sometime soon after birth; in cryptorchidism, one or both stay inside that wall while the opening gets too small for later passage. It may be a genetic defect in the length of the spermatic cord that is the most important reason. In puppies under eight weeks of age, the cremaster muscle also may function to keep the testicles in the tubes but still outside that "vaginal ring" of the abdominal wall, instead of allowing them to descend all the way to the scrotum. Perhaps a defect in this muscle is responsible for the fairly common "elevator testicle" in certain family lines: in this phenomenon, one goes up, comes down, and goes back up again. Usually this is outgrown rather early, but I knew of one pup that still exhibited this condition at the age of five months. In some breeds, such as Toy Fox Terriers, it is not uncommon to find testicles absent from any scrotum, but present just outside the vaginal ring, very hard to palpate.
People who can't find the testicles in young puppies may be holding the little shoelace-tuggers in the wrong position. The testicles should descend before birth, but are so small and mobile they may be nearly impossible to find on a wriggling pup that doesn't want to be constrained. But if you cradle the pup's upper body in the bend of your arm and let his bottom half hang, you should be able to feel them, especially if thumb and index finger are run down the prepuce, one on each side of the penile sheath, pushing the tiny gonads toward the scrotum. You can use the middle finger to feel for them while the other two fingers slide downward and push in that direction. It's a little like squeezing toothpaste from one end toward the opening of the tube. In some pups, they simply will have to be pushed into the scrotum this way in order to be noticed. Some folks panic when only one can be found; they run to the veterinarian for some magic shot of hormone to make the other appear. While the synthetic hormone APL (anterior pituitary-like) has had some success in humans, its efficacy is probably zero in dogs. First, it definitely is of no benefit once the testicle has grown too large to squeeze through the vaginal ring, and therefore the need would have to be discovered at or soon after the time of birth, which is all but impossible even if one has the most sensitive fingers in the world. Then, if the other testicle does appear in the scrotum, it's probably coincidental and not due to the APL: the testicle was going to drop anyway, or it was in the inguinal canal outside of the abdominal wall and held up by a tight cremaster which loosened as the pup aged. (There is no evidence that APL works as a relaxant on the cremaster.) Even if APL were a successful way to induce testicles to drop, the pup's genetic makeup would remain the same and he would pass the defect along to many of his offspring. As a responsible breeder you would find a pet (non-breeding) home for him.
Inheritance
In Germany for a short while, unilateral cryptorchids were eligible for showing and breeding, as the fault seemed to have no effect on utility or beauty in the GSD and other working breeds. By 1930, the SV prohibited not only showing, but registration as well. For a long time, one could still show unilateral cryptorchids in many countries... I remember it was allowed in Canada during my early years as a handler. By 1956 the AKC applied the disqualification to all breeds. Even today some feel that cryptorchidism is an imported or German bloodline problem, forgetting that most working breeds derived from Germany, and not knowing that the SV, and later other breed clubs, really led the way in prohibiting the fault. In fact, cryptorchidism is as common in one country as another, and has about the same incidence in one breed as any other. For those who are considering a sport/working life for such a dog, there should be no deterrent.
The most recent studies on the subject of missing or hidden testicles indicate that there can be several genetic causes. Retractile testicles, a feature of the dog with an overactive or short cremaster, may be due to a genetic determinant quite different from that which causes classic unilateral cryptorchidism, as I have indicated and observed from personal observation. Bilateral cryptorchidism may also be genetically slightly different, since both testes are usually found in almost the same ovarian position as they are in the early fetal life of normal males. It seems that this phenomenon may be caused by two or more genes. Such may be the case in unilateral cases too, although there is reliable data to suggest the possibility of a simple Mendelian recessive in the case of classic unilateral cryptorchidism. If two normal-phenotype dogs actually carry the recessive, on an average one might expect 25 percent of the litter to show the condition. But since about half of each litter is female, the average would only be 12½ percent. With such breedings that produce one-apparent-testicle dogs not being often repeated, it's difficult to find meaningful statistics. I have observed that when unilateral cryptorchids are bred, there is a high probability of them siring both unilateral and bilateral cryptorchids.
According to one researcher, it is the right testicle that is most often retained, being the more cranial (more toward the head) of the two in the early embryonic stage. The retained testicle in unilaterally affected dogs is usually found near the bladder or at the entrance to the inguinal canal on the inside of the abdominal wall, as if it had been arrested on its way to join its mate. In Angora goats, it is also the right testicle that is commonly retained, though this is not hard evidence that all species have the same genetic cause for the same effect. Similarly, the right ovary of females and the right kidney in both sexes are further forward than the left organs. In the normal male, the left testicle in the scrotum is usually carried slightly higher and behind the right one. (Not always, so don't write me correction letters on that!) I have checked that out in many a show ring when judging Rotties, American Pit Bull Terriers, and other sizeable, not-heavily-coated breeds.
As mentioned, unilateral cryptorchidism often seems as if it were a simple, recessive, one-gene Mendelian trait, though possibly it is not. If the problem of unilateral cryptorchidism is indeed simply recessive, the occurrence of bilateral cryptorchids might have to be explained by the action of other, modifying genes, and many geneticists today do not find that idea appealing. But for the purpose of explanation, let's use it as an example. If the pup inherits one gene for the trait from one parent and one normal allele from the other parent, he will not show the disorder but will be a carrier. If the normal gene is represented by the capital letter C, and the defective gene is identified by the lowercase c, his genetic constitution on that chromosome is Cc. On the other hand, if a dog is a cryptorchid, his genetic constitution at that locus on that chromosome is cc (two defective genes). If this dog is bred to a bitch that also inherited two such genes, (she is also a cc), all of their offspring will either be cryptorchids like the sire or homozygous carriers like their dam. It is possible that a testicle found in the scrotum of some very young pups from such a union may later retract and be trapped inside the peritoneum. In some breeds this happens fairly frequently, and some believe it is caused by the same set of genes that cause more typical cryptorchidism. The difference between unilateral and bilateral cryptorchids may also be due to the presence of certain modifier genes".
In addition, some breeds with brachiocephalic skulls seem to have a much greater than 25 percent incidence of orchidism when "supposed" (phenotypically) normal dogs (who are actually carriers) are bred. Knowing what we do about such breeds and their pituitary defects, would it not be reasonable to say that maybe many breeds and species have in their population a very slight hereditary pituitary defect that acts not only on the development of the spermatic cord and other structures in the genital system, but other traits as well? Breeds that have been selected by fancy to be what Noah would have considered grotesque include the ("English") Bulldog, said to be a compilation of all the disqualifying and serious faults of most other breeds. The reason for these "defects" stems from genetic defect s in the hypophysis or pituitary gland, the "master gland" deep in the base of the brain. It is the master of the other endocrine glands including those others with functions related to growth of various and all parts of the body. In the GSD, for example, we have a particular defect that results in pituitary dwarfism (see pictures in "The Total German Shepherd Dog", www.Hoflin.com and other sources) and such dogs, while nearly perfect in proportions, often have serious thyroid gland problems with resultant loss of hair that makes some of them look like Chinese Crested hairless dogs. Remember what I said about the interconnection between endocrine glands. Other defects produce the Bullmastiff face, the Cocker or Corgi dwarf legs, etc.
I believe it is safe to say that cryptorchidism is genetic, that it is in some way recessive, and that there is some sort of connection between bilateral cryptorchids and unilateral ones. Perhaps there is also a connection between the pituitary and floating testicles. At any rate, the unilateral condition at least is so widespread in many families and breeds that an all-out effort to combat it would take our minds and efforts away from more serious disorders, which would consequently increase. It's just a minor thing we have to put up with. Simply remove the affected ones from the gene pool, and shift your preference away from breeding any (including females) that come from litters in which the defect occurred.
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General info on The Sieger Show Experience with tour guide Fred Lanting
The SV Bundessieger-Zuchtschau (BSZS or Sieger Show) in Germany is generally held in the last week of August or first week in September at a different location each year, depending on stadiums available. (The cost of stadium for this one-weekend event, and the competition with soccer/football events that sign contracts for many per year, determine the choice.) For the past 20 years or so, I have offered my non-profit 6-7-day guided tour of the show and sightseeing, including visits to kennels and training clubs. Get an SV judge's perspective of the bloodlines and procedures, along with experienced introductions to Germany's culture and beauty. My groups come from all parts of the globe, so even just the companionship is like a world-travel experience. We usually arrive on the Wednesday or Thursday before the show, and return the following Wednesday.
Looking for a great dog-related experience combined with seeing a different part of the world? Whatever your breed or activity in dogs, the annual Lanting guided show-and-sightseeing tour could be the experience of a lifetime. Read my annual “Impressions” articles on various websites for an idea of what we've seen in recent years. Tours centered on other countries’ Sieger Shows, the BSP, and world Schutzhund trials are also available if enough people sign up.
None of "my people" have ever been sorry, and all have wished they had done it earlier! You will see the best of the breed, meet important GSD people, sometimes see another country or two, and have the over-all greatest dog show experience of your life. I also include, if you decide to join us, a variety of travel tips. I offer an SV conformation judge's perspective of the show (I also have AKC, UKC, and foreign judging experience). One year, when a travel-agency tour leader again deserted his group, they came to where my group was sitting and asked me questions. References available from previous tour participants. Testimonials are numerous. I hope you will join us and recommend this tour to your friends and acquaintances. As a judge with much experience in Schutzhund training and competition, and being very familiar with Western Europe, I am able to give the best tour possible. People going it on their own cannot see the important parts of the country (sometimes we tour adjacent countries, too), and paying for your rental car is more than chipping in to pay for the van and my expenses. Read my "Impressions" on various websites for an idea of what we've seen in recent years.
There will be 3 long days of the big show, and about 3 to 4 days of sightseeing and visits. Please let me know as soon as you can, with a $400 (US) deposit, so I can start putting my notification list together and finalize (hold) hotel reservations for you. There is a lot of work involved in putting together such a tour! I will make the hotel plans based on your deposits, & arrange the visits and van(s). Easy, fun, educational and, for most --- the unique trip of a lifetime. You will not be any younger next year, and if you don't make the decision to get out there and smell the roses NOW, while you think of it, you're more likely than not to lose the opportunity and desire. Join the group! Tell others about it, too. Fred
Contact me at Mr.GSD[at]netscape.com and tell your friends and Internet contacts.
Postal mail: 3565 Parches Cove, Union Grove, AL 35175-8422 USA
Editor’s Note: A well-respected and frequent GSD specialty and all-breed judge for many clubs around the world, with KC and other-country credentials, Mr. Lanting since 1966 has lectured on Gait-and-Structure, Canine Orthopedic Disorders, and other topics, and has judged in about 30 countries, including the prestigious FCI Asian Shows hosted by Japan Kennel Club and the KC of India, the Scottish Kennel Club, and many National Specialties in the USA and elsewhere. He has been described by a former OFA director as the world’s leading non-veterinarian authority on hip dysplasia. A dog breeder since 1945, a GSD owner since 1947, and a show judge since 1979, he has lectured at numerous veterinary schools in the USA and abroad. He is the author of “must read” books for the dog owner (see below for ordering info). Curriculum Vitae available upon request.
Announcing the new “Canine HD and Other Orthopedics Disorders” book: The expanded revision is a comprehensive (nearly 600-page), amply illustrated, annotated, monumental work that is suitable as a coffee-table book, a reference work for breeders and veterinarians, and a study adjunct for veterinary students. It is equally valuable for the owner of any breed. It covers every aspect of HD and other orthopedic, bone, or spinal disorders, and includes genetics, diagnostic methods, treatment options, and the role of environment. Your autographed copy will be mailed from the USA as soon as the appropriate amount is received and is processed. Pricing: US $68, plus $5 postage in the U.S., or ask about mail overseas. Combine orders with “The Total German Shepherd Dog” by the same author ($50 plus postage). 17 of the 20 chapters are suitable for owners of any breed.
