Infertility in Male Dogs
What would cause my dog to have a low sperm count?
We don’t often think about our dogs’ sperm count until they miss a breeding, or we have them collected for freezing and the numbers are low. The first determination to make is whether this is a medical problem or a performance issue.
Canine semen is a cloudy, white fluid and ranges in volume between 1 milliliter to 30 milliliters. A normal canine sperm count is 300 to 2,000 million sperm per ejaculate, of which more than 70 percent are motile and normal in structure.
Experienced stud dogs will perform well for breeding or collection with any teaser bitch, or even without one. Younger, less experienced males have better results when they have a bitch of their same size or breed, even if the bitch is not in season, as a visual cue for breeding.
In order to get the best semen collection, the stud dog should feel as relaxed as possible. A calm environment with stable, non-slip footing helps. Familiar items such as a rug or rack can let the dog know what is expected.
The ejaculate of dogs consists of three fractions. The first fraction is a clear or slightly cloudy pre-sperm fraction which is released while the dog is vigorously thrusting. The second fraction is the thick, creamy, white sperm-rich fraction that is released just as the thrusting ends and the stud dog steps over. The third fraction is the clear prostatic fluid that follows in varying amounts.
The color of the semen can indicate a problem. Normal sperm-rich canine semen is whitish in color. Yellow semen means there is urine in the sample, which is toxic to sperm. Red or brown semen indicates the presence of blood, which is not toxic to sperm, but it is important to identify the source of the blood. It may be from trauma to the penis during the collection or breeding, but could also be the result of inflammation or infection.
A clear second fraction indicates azoospermia, or lack of sperm. This may occur if the dog’s libido is poor, such as when the dog is not interested in the teaser or is uncomfortable with the collection procedure. Repeating the collection attempts with efforts to improve his libido will show whether the dog is not releasing or not producing sperm.
What medical conditions would cause my dog to have a low sperm count?
There are several medical conditions that may affect your dog’s reproductive system and lead to a low sperm count. Any infection or inflammation of the testes, epididymis (a duct behind the testis through which the sperm passes), spermatic cords, prostate, penis or prepuce (skin that covers the penis) can reduce your dog’s ability to produce sperm. A fever is often a symptom of these conditions, and the elevated body temperature is harmful to sperm.
Prostatitis is an inflammation of the prostate and the most common site of inflammation in older male dogs. Infections are caused by different strains of bacteria, including staphylococcus, streptococcus, E. coli, proteus, pseudomonas, Pasteurella and mycoplasma.
Brucellosis is a contagious bacterial infection caused by the bacterium Brucella canis. Infected dogs develop reproductive problems and become sterile. Male dogs can suffer with inflamed, swollen testicles that shrivel over time. Infected female dogs abort puppies and are unable to get pregnant. Both dogs and bitches should be tested for brucellosis before breeding.
Some physical abnormalities may lead to infertility. Granulomas are plugs of sperm that block the outflow tracts. If one side is affected, the numbers of sperm in the ejaculate will be low. If both sides are affected, there will be no sperm in the ejaculate. Obesity can cause overheating of the testes, killing any stored sperm and reducing the ability to produce new swimmers.
Trauma to any part of the reproductive tract can lead to bleeding, swelling and scarring. This may alter sperm production, testicular function and the dog’s ability to ejaculate or breed naturally.
Environmental toxins, medications, anabolic steroids, and pesticides or insecticides may affect fertility. Certain types of metabolic diseases also have an impact on the reproductive system. These include diabetes, low thyroid levels and epilepsy.
Tumors of the testes, including seminomas, Sertoli cell tumors, interstitial cell tumors, lymphoma and teratomas, will diminish sperm production. Castration is usually recommended for these cases.
Age is a major factor in dogs with a low sperm count. Studies clearly show that sperm production decreases in older male dogs. Arthritis and injury can make mounting and thrusting painful. This can result in lower libido and poor results. If you want to preserve your dog’s genetic material for future breedings, the time to collect and freeze the semen is when the dog is two to five years of age. You will get better quality semen with a higher sperm count and more breedings per collection when the dogs are young.
What tests are needed to determine the cause of a low sperm count?
The absence of sperm in the ejaculate fluid may be due to incomplete ejaculation (performance anxiety), an outflow obstruction of the male reproductive passages, or failure of the testicles to produce sperm. If the ejaculate has little or no sperm, a sample can be sent to the laboratory to test for semen plasma alkaline phosphatase levels.
A low level (less than 100 IU/I) suggests incomplete ejaculation. A medium level (between 100 and 2000 IU/I) indicates the presence of an outflow obstruction. A normal level (above 5000 IU/I) indicates complete ejaculation, open male reproductive passages, and that the cause of low numbers or no sperm in the ejaculate is testicular failure.
Other testing may include bloodwork, both general and specific for hormonal conditions, including low thyroid levels. An ultrasound scan can detect abnormalities in the prostate gland and testes. Bacterial culture and microscopic examination of semen and urine are important diagnostic tests. In some cases, a biopsy of the testicle may be required.
Is there treatment for infertile dogs?
The prognosis for recovery depends on the underlying condition. Some problems are definitely easier to resolve. If infection is the cause, antibiotics usually resolve the problem. Some cases may require long-term antibiotic treatment. In severe cases, surgical removal of the infected reproductive part may be necessary.
When sperm plugs are to blame, regular collection can keep the passages open. Weight reduction for obese dogs is good for both their physical and reproductive health. Hormonal imbalances can be corrected by giving replacement hormones, such as thyroid supplements.
Anti-inflammatory medication may help older dogs with spine-related issues regain some of their lost libido. Performing artificial insemination instead of natural breeding makes it less stressful for older or less confident male dogs.
If a tumor is the reason for a low sperm count, removal of the affected testicle is the best course of action. The remaining testicle may still be able to produce sperm.
A visit to your veterinarian or a reproductive specialist (called a theriogenologist) will help ensure the soundness of your stud dog. They can suggest supplements that may help increase sperm production and quality. Make sure the dog is not being overused. Studies have shown that dogs that are ejaculated for as few as five days in a row can experience a drop in their sperm count.