MANAGEMENT OF INFERTILITY IN MALE DOGS
K.P.Singh1 and Praneeta Singh2
Veterinary Officer, Government Veterinary Hospital, Deoranian, Bareilly, Uttar Pradesh Email: drkpsvet@rediffmail.com
2: Assistant Professor, Department of Livestock Products Technology, C.V.A.Sc., GBPUAT, Pantnagar, U.S.Nagar, Uttrakhand Email: vet_praneeta12@rediffmail.com
*Corresponding Author: Veterinary Officer, Government Veterinary Hospital, Deoranian, Bareilly, Uttar Pradesh Email: drkpsvet@rediffmail.com
Infertility is defined as incapacity to procreate (reproduce). When dealing with infertility, both the dog and the bitch must be considered. Ninety percent of infertility is due to poor breeding management such as breeding at the wrong time or not breeding often enough and the male could have poor sperm quality. Acquired infertility is very common in the dog. If more than a couple of months have passed since the dog’s last litter, it may now be infertile. Illness before, during or after breeding could explain why the bitch did not conceive, likewise, a fever or other illness can adversely affect semen production and it takes about 60 days for the sperm cells to regenerate after such an insult.
Breeding soundness examination of male dogs
A breeding soundness examination can be conducted to evaluate the male dog. It typically includes a general physical examination and an examination of the external genitalia. Abnormalities such as severe arthritis or spinal problems may not allow a dog to mount. Hormonal diseases such as Cushing’s disease can also reduce fertility. The penis and prepuce should be examined for abnormalities, such as a persistent frenulum, growths or inflammation of the prepuce (posthitis),that may prevent normal intromission. The ospenis should be palpated for fractures. Abrasions or lacerations on the penis may bleed during coitus causing blood to be in the semen. The prostate should be palpated via the rectum. Inflammation of the prostate (prostatitis) may be painful and can prevent the dog from finishing mating or make him appear to have a lowered libido. White blood cells (WBCs), red blood cells and bacteria from the prostate may damage sperm viability. Also, an infection in the prostate can potentially ascend to cause an infection in the testicles (orchitis). The scrotum, testicles, and epididymides are also palpated. The size of the testicles correlates with the amount of sperm seen on collection of an ejaculate. Small and soft testicles are often associated with poor semen quality. Greatly enlarged testicles suggest an infection and lumps in the testicles are suggestive of tumours. Scrota abnormalities such as dermatitis, may adversely affect sperm quality.
An ejaculate of semen should be collected and evaluated for colour, volume, total and progressive motility, concentration, shape (morphology) and the total number of normal sperms should be calculated. There are three distinct outcomes of a breeding soundness examination: (1) normal sperm parameters, (2) abnormal sperm parameters and (3) no sperm seen in the ejaculate. Volume varies with the amount of prostatic fluid collected but is generally 2 to 20 ml. Sperm motility should be evaluated immediately and normal dogs should have 75% to 80% progressively motile sperm (i.e. sperm that are moving in a forward direction). A sample of the sperms should be prepared for microscopic evaluation. It is important that the shape of the sperm be evaluated so that the total number of normal shaped progressively motile sperm inseminated is known as only these will fertilize an oocyte or egg.
Sperm concentration (number of sperm/ml) can be determined by using a special sperm cell-counting device (called a densimeter) or other methods. The total number of sperm in the ejaculate is calculated by multiplying the concentration by the volume; normal is about 10 x 101 sperm/lb of body weight. Therefore, a small dog can be expected to produce about 20 x 106 sperm ejaculate and a large dog about 70 x 106. Infertility is very rare in dogs with normal semen parameters. Management problems and bitch infertility should be considered when sperm findings are normal.
If abnormal sperm parameters are found, the dog should be rechecked in 2 to 3 months to see if the problem is transient. The veterinarian should be informed of any recent illness and any medications (especially anabolic steroids) that the dog has received. Although the actual cause for abnormal sperm parameters is often never found. Possible causes, including inflammation of the scrotum, testicular neoplasia, trauma, brucellosis, should always be ruled out. Inflammation of the scrotum can cause a high scrotal temperature that is deleterious to sperm production. An ultrasound of the testicles can be performed to evaluate for testicular neoplasia, as some tumors of the testicle are not palpable. This problem can be treated as unilateral castration of the affected testicle often restores normal sperm parameters. If no inciting cause of the sperm abnormalities can be found, the case becomes very frustrating for both the owner and the veterinarian.
The absence of sperm in the ejaculate (azoospermia) can have three possible causes: (1) the dog’s testicles are not making sperm, (2) the testicles are making sperm, but the sperm cannot get out because the epididymides are blocked and (3) the testicles are making sperm (which can get out) but a complete ejaculate was not collected. When there are no sperm in the ejaculate, the fluid can be tested for alkaline phosphatase, which is made by the epididymides. A high level of alkaline phosphatase indicates that epididymal fluid was collected. If epididymal fluid was collected and there are no sperm, it is likely that the testicles are not producing sperm. A low level of alkaline phosphatase indicates that the epididymis is blocked or that a complete ejaculate was not obtained. In this case, repeated samples should be collected and an estrous bitch can be used as a teaser to obtain an ejaculate. A careful palpation and ultrasonography of the epididymides should be performed to detect any abnormalities. If the azoospermia persists, a testicular biopsy can determine whether the testicles are producing sperm. However, this procedure is rarely performed. The biopsy procedure itself may severely damage the testis and it does not seem to matter whether the testes are producing no sperm or sperm are being produced but cannot get out neither condition is treatable.
