1. It is normal for bacteria to be present in the vagina of the bitch at all stages of life.

  2. The type and number of bacteria change as the bitch comes into oestrus (into season). Bacterial numbers within the vagina increase during pro-oestrus and then diminish as the bitch reaches standing oestrus. Similar bacteria but in much lower numbers may be present in the uterus of the bitch and follow a similar changing trend to the bacteria present in the vagina. This change is due to local and generalised changes in the bitch's immune system as she goes through the hormonal changes of her oestrus cycle.

  3. As the bitch enters di-oestrus after ovulation, it is normal to have a mild vaginal discharge for one to two weeks (may be longer in some bitches).

  4. Very low numbers of bacteria are present in the vagina during this time.

Primary infectious causes of reproductive failure in the bitch

The following agents have been identified having a very high likelihood of causing reproductive failure in the bitch. NONE can be routinely identified by pre-mating bacterial cultures taken from the vagina.




Brucella canis


Exotic to Australia

Canine Herpes virus



Minute Virus of Canines


Not reported in Australia

Campylobacter jejuni


Not reported in Australia

Infectious agents "associated" with reproductive failure in the bitch

The following bacterial agents have been isolated from the bitches with reproductive failure but consistent proof of cause of reproductive failure has not been established. In most cases, there are significant other disease and/or processes occurring which are contributing to the reproductive failure such as cystic endometrial hyperplasia, genetic abnormalities, poor timing of mating and poor semen quality.

Escherichia coli

Streptococcus canis

Haemophilus species

Alcaligenes faecalis

Staphylococcus intermedius

Bacteroides species

a-haemolytic streptococci

Pasteurella species

Corynebacterium species

Proteus mirabilis

Mycoplasma / Ureaplasma


When is culture unlikely to be of value?

  1. Maiden bitches

  2. Proven bitches without history of reproductive failure

  3. No proven history of bacterial causes of reproductive failure

  4. Correct timing of mating and proven male have not been used previously

  5. Other undiagnosed causes of infertility present

When is culture likely to be of value?

  1. Uncommonly

  2. When the very concerned stud dog owner insists on a "CLEAR" swab prior to mating!

  3. Proven history of bacterial causes of reproductive failure in the bitch and/or primary bacterial causes of death in fading pups

  4. Introduction of Brucella canis into Australia

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Steven S.  Metcalfe BSc BVMS (Hons) MSc MACVSc
Applecross Veterinary Surgery
9 Sleet Road, Applecross,
Western Australia
PHONE: (08) 93647666



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