Dog Breeding by LowchensAustralia.com

  Pregnancy

  Pregnancy Length - Dogs:

• Highly variable

• 58-68 days from last breeding.

• 57 days from first day of diestrus.

• 64-66 days from the Luetenizing hormone peak blood levels

  Implantation

• Dogs – 13-15 days after ovulation.

  Pregnancy Diagnosis Techniques

1.  Palpation of the Abdomen

• Best done at 20-30 days because distinct round masses are more easily palpated.

• Pregnancy diagnosis after >30 days is difficult because the uterus becomes diffusely enlarged.

• Pregnancy diagnosis is possible again after about day 50 because individuals can again be palpated.

• Pregnancy detection by palpation is an art; difficult to do. Limited by the temperament of the female, obesity, abdominal tenseness, size of the female, small litter size, etc.

2.  Radiography (X-ray)

• Useful in diagnosis of pregnancy, predicting dystocia, and giving a rough idea of littler size.

• By day 21-42 fluid filled uterine horns may be detected.

• After day 42 various degrees of fetal ossification (bone formation) may be detected.

3.  Ultrasound

• By day 16-20 fetal vesicles can be visualized within uterine horns.

• After day 25 fetal heart beats can be detected.

4.  Mammary engorgement

• An inconsistent indicator of pregnancy.

• Many females will not display mammary development till near term, especially primiparous females.

5.  Behavior

• Many pregnant females will show decreased appetite – sometimes even total anorexia – for a few days during either the third or fourth week of pregnancy.

• This seems to be a fairly reliable, if non-specific, indicator of pregnancy.

TABLE 2.
The techniques to determine pregnancy in the bitch and the range through which the procedure is accurate. The days listed are after the luteinizing hormone (LH) peak.

References:

1. A study guide to small animal reproduction. Barton & Herron. Texas A & M University