Teratozoospermia is a morphological (referring to form and structure) reproductive disorder characterized by the presence of spermatozoal abnormalities. That is, 40 percent or more of the sperm are abnormally shaped. The sperm may have short or curled tails, double heads, or head that are too large, too small, or badly shaped.
The effect of specific abnormalities on fertility is largely unknown, but optimal fertility is expected in dogs that have at least 80 percent morphologically normal spermatozoa. Therefore, it is known that it is nearly impossible for sperm that are abnormally shaped to fertilize an egg.
This condition can affect dogs of any age, but older dogs are more likely to have other age-related diseases or conditions that affect overall sperm quality. There is no breed predilection, however, Irish wolfhounds have been reported to have significantly lower semen quality than dogs of other breeds.
Spermatozoal abnormalities are sometimes classified into primary and secondary defects. Primary defects occur during spermatogenesis, the development stage, and secondary defects occur during transport and storage within the epididymis (part of the spermatic duct system). Often there are no outward symptoms of this disorder. The most obvious symptom makes itself apparent in the breeding dog, when the male dog fails to impregnate a breeding partner.
You will need to give your veterinarian a thorough history of your dog's health, along with any possible incidents that might have led to this condition, such as trauma, infection, or travel (as other climates, especially hot climates, may have played a role).
A history of your dog’s infertility will help your veterinarian to make a diagnosis. For example, has he been infertile after appropriately timed mating to several reproductively-proven bitches? Have spermatozoal abnormalities been found during routine breeding soundness evaluation? Your veterinarian will probably do a hormonal profile as well as an examination of the ejaculates (the sperm cells). Your doctor will also test for bacterial infections, and may use visual diagnostic tools to examine the reproductive tract. An ultrasound examination may show whether there is a blockage, orchitis (inflammation of the testis), hydrocele, hemorrhage into a cavity, cyst of the epididymus, or tumor in the testicular region that is affecting the sperm ducts and sperm morphology.
The white fluid produced by males in the testicles for reproduction
An inflammation of the prostate gland
The sex cell of male animals; created in the testicles
The male sex organ used to produce spermatozoa
A condition of having only one side
A condition in which the testes become inflamed
Something that is related to the whole body and not just one particular part or organ
Something that is not capable of reproducing
A substance that causes chemical change to another
The collection of fluid in the tissue
Extreme loss of blood
Relating to a disease of unknown origin, which may or may not have arisen spontaneously
A passage in the body with walls
To make an animal pregnant
Transmitting genes from parent to child