F.K. Hollinshead1; R.O. Gilbert2; N. Krekeler2; D.W. Hanlon1; D.H. Volkmann3
The exact pathogenesis of canine peripartal uterine inertia has been studied in little detail. We examined periparturient changes in serum calcium and parathyroid hormone (PTH) concentrations. We postulated that subclinical hypocalcaemia could lead to uterine inertia with delayed delivery and intrapartal hypoxia of puppies. Bitches were selected from a colony of German Shepherds with a history of uncomplicated parturition (Group 1: Control; n=10) and from a Labrador colony experiencing an increased incidence of stillbirths (Group 2; n=20). Peripartal serum PTH and ionised calcium concentrations in Group 1 bitches are tabulated below.
|
Time (h) |
-96 |
-72 |
-48 |
-24 |
0 |
+4 |
+8 |
+12 |
+16 |
|
PTH (pmol/L) |
5.05 |
4.07 |
2.68 |
3.24 |
2.74 |
2.38 |
1.97 |
2.70 |
2.80 |
|
Ionised Calcium (mmol/L) |
1.38 |
1.36 |
1.38 |
1.41 |
1.36 |
1.39 |
1.43 |
1.34 |
1.37 |
Time 0h=whelping
Group 2 bitches had higher PTH (4.72 ± 2.45 vs 2.9 ± 1.44 ppmol/L; p<0.001) and lower ionised calcium concentrations (1.34±0.081 vs 1.38±0.056 mmol/L; p< 0.05) than Group 1 bitches.
This is the first report of normal changes that occur in ionised calcium and PTH during the immediate peripartal period of bitches. Our results suggest that low ionised calcium at the time of parturition may contribute to stillbirths in bitches.
Funded by Nestle Purina, USA.
Acknowledgements: The Guiding Eyes, NY and Dr Sydney Moise, Cornell University.