If a mating or insemination does not result in a litter, it doesn't necessarily mean there is a fertility problem. As we've already stated, the main reason that a bitch does not have puppies after being mated is because mating hasn't occurred at the optimum time. Checking progesterone levels is the best way of ensuring that fresh sperm meet mature eggs at the right time.
Keeping accurate records is very important when trying to establish reasons for infertility. Dates when oestrus starts, blood test results, dates of matings and dates of scans can all provide useful information.
At Millhouse we can investigate 'silent heats', 'split heats', frequent oestrus episodes and anoestrus. Blood levels of progesterone as well as oestradiol, cortisol and thyroid hormones can be checked. We can use ultrasound to look for abnormalities of the ovaries and uterus. And vaginal cytology and endoscopy of the vagina can also show up abnormalities.
Bacterial culture of the female reproductive tract (using guarded swabs) is occasionally useful, but please note there are usually many different bacteria both in the vagina of the bitch and the prepuce of the dog - this is normal.
Some bitches are able to conceive but don't produce any puppies at term. Sometimes it is because there are defects with the pups, but infectious causes and hormonal problems are also thought to play a part in resorption (dogs rarely abort, unlike cats).
Male infertility problems are usually easier to diagnose. For example, locomotor problems and anatomical abnormalities of prepuce and penis. A good history is again very important, dates of previous litters and any injuries, illnesses or medication .
Checking a semen sample microscopically is essential. Palpation of prostate and testes followed by ultrasonography if necessary can often find a problem. Hormone levels in the blood and bacteriology of the semen can also be performed.
Recent advances in the field of small animal reproduction mean that pyometra in younger bitches can sometimes be treated medically without the need for ovariohysterectomy. Oestrus can be induced or delayed, prostatic hyperplasia can be targeted so that fertility may be improved, and temporary 'chemical castration' of males is also possible.