Assessment of Reproductive Problems in Male Dogs
Recent Advances in Small Animal Reproduction is a 14 page research report presented by C.M. Gradil, Veterinary and Animal Sciences, University of Massachusetts, A.Yeager, Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, and P.W. Concannon, International Veterinary Information Service, Ithaca, N.Y.
The following is a synopsis of the article.
Routine reproductive evaluations of male dogs are often requested of veterinarians by breeders to confirm fertility prior to purchase or sale, to check daily sperm output particularly in older dogs, to assess the potential of a stud dog as a provider of semen for frozen-semen or chilled semen artificial insemination, or to address problems of apparent infertility and/or testicular abnormalities.
Lack of breeding success is often multifactorial. Thus, a comprehensive reproductive exam or Breeding Soundness Evaluation (BSE) will include the following:
A medical and reproductive history. Including breeding management records.
A general exam including examining for inherited conditions such as cryporchidism, and fetal development problems such as intersexuality (true hermaphroditism , psuedohermaphroditism).
Clinical Pathology exam, including CBC, blood chemistry, urinalysis, etc.
An examination of the genitalia, testis measurement, and palpation of the testes and prostate gland.
Semen evaluation. The sperm output in an ejaculate is influenced by age, size of testes, frequency of ejaculation, sexual rest and degree of sexual stimulation. Semen will be evaluated in terms of volume, color, sperm motility and percentage of progressively motile, sperm concentration and percentage of morphological normal sperm, calculated total sperm number, pH, cytology, and presence of WBC’s, and alkaline phosphatase activity. Results should be compared to normal ejaculate values. Things that can adversely effect sperm quality include bacterial infections, seasonal effects, tumors, orchitis, fever, prostatitis, abstinence or overuse, obesity with increase of intrascrotal temperature, residues from manufacture latex, lubricants, anabolic steroids, trauma, brucellosis, etc.
Brucellosis Testing. Note that routine Brucella canis testing every 6 months is recommended if the dog is used for breeding more than five bitches annually. Chronically infected animals are only intermittently bacteremic and have intermittent decreases in titers and therefore may test negative falsely with any test. Three negative tests at monthly intervals are required to call a suspicious animal truly negative. Treatments and management include castration on infected animals that are not euthanized because neutered animals shed fewer organisms. Consider euthanasia, especially in kennel situations. Otherwise isolation from other dogs, especially breeding animals is important. Antibiotic therapy may decrease titers but is not a cure.
Canine Herpesvirus. Causes fatal bleeding disease in newborn puppies. Also causes genital lesions, embryonic resorption, abortion, and stillbirth. Oral/nasal transmission and venereal transmission are considered as the main routes of infection, but fetuses can also be infected in utero. Interpretation of serum requires caution as many factors can affect titer levels.
Ultrasound of the testes and prostate . Can reveal orchitis (inflammation), torsion, tumors, and location of cryptorchid (missing testis), prostate disease (and help differentiate between benign and neoplastic), prostate infection and inflammation,and prostate cysts.
Endocrine Blood Tests. Testosterone, Estradiol, LH, and FSH serum levels.
Thyroid Blood Tests. Hypothyroidism may be the cause of infertility in some dogs. However, many hypothyroid dogs have normal fertility. The cause-effect is poorly understood but testing merits consideration in obvious infertility.
Prolactin Assays, Adrenal Disease Evaluation, and Testis Stimulation Tests.
Testis Biopsy. Usually only done in dogs found to have no or very low sperm in the semen and only after less invasive tests have been performed, including semen evaluation, testis diameter measurements, and assays of serum concentrations of gonadotropin and testosterone.
Test for Retrograde Ejaculation. This is a problem in which the dog ejaculates some or all of the sperm-rich second fraction of the semen into the urinary bladder. This problem may be chronic, acute, or intermittent. Suspect animals can be catheterized and post ejaculate urine examined. Drug treatment before of this condition before breeding or semen collection is an option.
Synopsis written and submitted by Connie Wardell, Member Education Chair 2005-2006