![Funny alone](https://upload.wikimedia.org/wikipedia/commons/9/92/Funny_alone.jpg)
A ridgling (also spelled ridgeling),
or rig, is a
cryptorchid
Cryptorchidism, also known as undescended testis, is the failure of one or both testes to descend into the scrotum. The word is from Greek () 'hidden' and () 'testicle'. It is the most common birth defect of the male genital tract. About 3% of ...
;
a
male
Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization.
A male organism cannot reproduce sexually without access to ...
animal with one or both testicles
undescended,
[ usually describing a ram, bull, or male horse,] but cryptorchidism also can be an issue in dogs and cats. Because the heat inside the body is too high for sperm to survive, an undescended testicle is non-functional.[ The condition is most often discussed in the ]horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...
world, as the health and behavioral issues surrounding adult males with the condition are of concern to owners and handlers of such animals.[
]
Dogs
In dogs, the toy and miniature breeds are considered more susceptible.[ The testicles usually descend by the time a puppy is 40 days old.]
In horses
Although the rate that testicles descend varies between individual animals, horses over three years with the condition are generally castrated
Castration is any action, surgical, chemical, or otherwise, by which an individual loses use of the testicles: the male gonad. Surgical castration is bilateral orchiectomy (excision of both testicles), while chemical castration uses pharmac ...
. Surgery called a cryptorchidectomy is used to remove the retained testicle, but different procedures are used, depending on the location inside the body cavity.
An undescended testicle is not a serious or life-threatening condition, though it may cause the animal discomfort at times. This condition can be corrected by surgery to place the testicle in the correct position, but most ridglings are gelded
A gelding is a castrated male horse or other equine, such as a pony, donkey or a mule. Castration, as well as the elimination of hormonally driven behavior associated with a stallion, allows a male equine to be calmer and better-behaved, makin ...
to remove the testicle altogether.
When a male horse thought to be a gelding exhibits aggressive or sexual behavior, cryptorchidism is suspected. Sometimes, a horse with an unknown medical history is actually a stallion with both testicles retained.[ An alternate definition of ridgling is a partially castrated horse.][ This can occur when a ridgling is gelded, but the retained testicle is not removed, resulting in an incomplete castration. Such animals may exhibit sexual behavior similar to intact males, either because the undescended testicle eventually dropped into the scrotum after the castration procedure or because the retained testicle may still produce some hormones. Retained testicles in such cases generally are removed.] There are blood tests that can determine if a horse is producing male hormones, though these do not detect a ridgling if hormone levels are too low. Palpation
Palpation is the process of using one's hands to check the body, especially while perceiving/diagnosing a disease or illness. Usually performed by a health care practitioner, it is the process of feeling an object in or on the body to determine ...
sometimes can detect a retained testicle, but is also of uneven reliability.[ There are also cases where true geldings exhibit aggressive or stallion-like behavior, sometimes called "false rigs", but their behavior is not hormone-driven and can sometimes be corrected with proper training and discipline.][
The condition is considered heritable,] but a genetic link has yet to be proven.[ Horses of any breed may be ridgelings, but Quarter Horses, ]Saddlebred
The American Saddlebred is a horse breed from the United States. This breed is referred to as the "Horse America Made". Descended from riding-type horses bred at the time of the American Revolution, the American Saddlebred includes the Nar ...
s, Percheron
The Percheron is a breed of draft horse that originated in the Huisne river valley in western France, part of the former Perche province from which the breed takes its name. Usually gray or black in color, Percherons are well muscled, and ...
s, and ponies
A pony is a type of small horse ('' Equus ferus caballus''). Depending on the context, a pony may be a horse that is under an approximate or exact height at the withers, or a small horse with a specific conformation and temperament. Compared ...
seem to be more likely to exhibit the condition.[ In dogs, the toy and miniature breeds are considered more susceptible.][ As a young male animal reaches ]puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a bo ...
, the testicles, which originally were inside the abdominal cavity, move down the inguinal canal
The inguinal canals are the two passages in the anterior abdominal wall of humans and animals which in males convey the spermatic cords and in females the round ligament of the uterus. The inguinal canals are larger and more prominent in males. ...
to the scrotum
The scrotum or scrotal sac is an anatomical male reproductive structure located at the base of the penis that consists of a suspended dual-chambered sac of skin and smooth muscle. It is present in most terrestrial male mammals. The scrotum co ...
. In a ridgling, either the testicles fail to descend, or they are trapped behind the external inguinal ring
The inguinal canals are the two passages in the anterior abdominal wall of humans and animals which in males convey the spermatic cords and in females the round ligament of the uterus. The inguinal canals are larger and more prominent in males. T ...
and cannot emerge. Usually both testicles in a horse have descended by the age of 16 months,[ but as many as 15% of all two- and three-year-old male horses may have a retained testicle.][
An example of a ridgeling that was gelded was the Kentucky Derby winner ]Funny Cide
Funny Cide (foaled April 20, 2000) is a champion American Thoroughbred racehorse who won the 2003 Kentucky Derby and Preakness Stakes. He is the first New York-bred horse to win the Kentucky Derby. He was an immensely popular horse and remai ...
.[ While the horse was gelded because the undescended testicle caused him noticeable discomfort and his manners also improved after castration, his success in horse racing has led to considerable discussion over whether it would have been better to opt for surgically correcting the condition instead. A number of notable racehorse stallions were ridglings, including Honor Code, A.P. Indy and Slew o’ Gold.]
Owners of a prized animal may opt for surgery to preserve the value of a horse as a breeding stallion. There is debate over whether to remove the undescended testicle in a stallion; some people believe it causes discomfort to the animal, others disagree. Proponents of surgery note that it is low-risk, and the undescended testicle is non-functional, and it can be removed with laparoscopy
Laparoscopy () is an operation performed in the abdomen or pelvis using small incisions (usually 0.5–1.5 cm) with the aid of a camera. The laparoscope aids diagnosis or therapeutic interventions with a few small cuts in the abdomen.Medlin ...
or a very small incision. Some stallions show improved behavior and athletic performance when the non-functional testicle is removed.[ Such animals are sometimes called ]monorchid
Monorchism (also monorchidism) is the state of having only one testicle within the scrotum.
Terminology
An individual having monorchism can be referred to as ''monorchid''.
Causes
This can be due to:
* One testicle not descending into the sc ...
s due to having only one testicle, but usually are fertile.
References
{{reflist
Types of horse
Horse health
Veterinary castration
Male horses