Ultrasound Determination of Gestational Age Using Placental Thickness in Female Dogs: An Experimental Study

Table 3

Comparison between expressions of curves adjustment determined with regard to placenta thickness for the studied breeds.

Breed	Curves adjustment
	Individual^(a)			𝑦=0.021𝑥−0.314			𝑦=0.006𝑥^1.185
	𝑟	𝑅^2	𝑃  value	𝑟	𝑅^2	𝑃  value	𝑟	𝑅^2	𝑃  value
Small size	0.895	0.828	<0.001^*	0.891	0.884	<0.001^*	0.898	0.756	<0.001^*
Medium size	0.922	0.876	<0.001^*	0.921	0.884	<0.001^*	0.923	0.756	<0.001^*
Large size	0.893	0.809	<0.001^*	0.893	0.884	<0.001^*	0.889	0.756	<0.001^*
Giant size	0.940	0.884	<0.001^*	0.940	0.884	<0.001^*	0.939	0.756	<0.001^*

^(a)𝑦=0.0087𝑥^1.0637 for the small size breed, 𝑦=0.0109𝑥^1.0412 for the medium size breed, 𝑦=0.0153𝑥−0.0737 for the large size breed, 𝑦=0.021𝑥−0.314 for the giant size breed, 𝑟: Pearson’s correlation coefficient, 𝑅²: determination coefficient.
^*Student’s 𝑡-test.