Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

448 •DOG OWNER’S HOME VETERINARY HANDBOOK
found in urine collected from the bladder shortly after ejaculation. The semen
and prostatic fluid are cultured to rule out infection.
Baseline laboratory tests screen for chronic diseases. Measuring the sex and
thyroid hormones (testosterone, FSH, LH, and a complete thyroid panel) provides
information on possible endocrine causes of infertility. Testicular biopsy
gives information on causes of low sperm count, as well as the likelihood the
dog will respond to medical treatment.
TREATING MALE INFERTILITY
Stress, sexual overuse, heat, and temporary injury to sperm-producing cells are
potentially reversible and often improve with a period of prolonged sexual
rest. Treating prostatitis, sheath infections, orchitis, and undescended testicles
are discussed later in this chapter.
A male of marginal fertility should be bred at the peak of female fertility
(72 hours after ovulation), as determined by vaginal cytology and progesterone
measurements (see The Estrous Cycle, page 436).
Hormone therapy and drugs to correct retrograde ejaculation and immunemediated
orchitis have been of benefit in some cases. Genetic and chromosomal
abnormalities associated with intersex may be accompanied by genitalia
that appear abnormal. The diagnosis is made by karyotyping (analyzing the
number, size, and shape of the paired chromosomes).
Dogs with congenital infertility, and those with acquired infertility who
do not produce sperm after six months of treatment, usually do not become
fertile.
Female Infertility
The most common cause of reproductive failure is improper breeding management—particularly
in detecting the heat cycle, determining when to breed,
and the number of breedings per cycle. These topics have been discussed earlier
in this chapter. Other important factors that influence the outcome of a
breeding are the general health and nutrition of the bitch, the effectiveness of
vaccination and parasite control programs, maintaining wholesome surroundings,
and avoiding overcrowding.
Diseases of the uterus (endometritis, cystic endometrial hyperplasia, and
pyometra) are other important causes of female infertility.
EVALUATING INFERTILITY IN THE BITCH
This involves a comprehensive review of the bitch’s past breeding performance,
as well as a family history of breeding problems. Other factors to consider