Table S6.

Model exploring the association between variables comprising Maternal behavior and outcome

Predictor variables	OR	Estimate	SE	Wald	P value
Ventral nursing per puppy	4.22	1.44	0.45	10.20	0.001**
Vertical nursing per puppy	0.25	−1.39	0.24	34.57	<0.001***
Licking/grooming per puppy	1.02	0.02	0.51	0.00	0.970
Golden score	0.84	−0.17	0.47	0.13	0.716
Labrador score	1.80	0.59	0.55	1.15	0.283
Maternal parity	1.21	0.19	0.18	1.05	0.305
Sex of puppy	0.47	−0.76	0.54	2.02	0.156
Age at return	0.75	−0.29	0.22	1.80	0.180

The dependent variable was outcome in the program: 1/0 (released from program or successfully placed as guide or breeder). Predictor variables were retained as follows: ventral nursing per puppy; vertical nursing per puppy; licking/grooming per puppy; Golden score, Golden Retriever compared with German Shepherd; Labrador score, Labrador Retriever compared with German Shepherd; maternal parity, 1–5; sex of puppy, 1/0 (male or female); and age at return, 14–17 mo. Litter ID was entered as a random effect. n = 98 (32 release dogs, 66 successes). Statistical tests of significance used GEE (***P < 0.001; **P < 0.01).