(a).

By AKC group
	OR	95% CI	p value
Sex
Female	1.056	(1.069, 1.044)	<10−6
Male	1.0 R	—	—
Season of birth
Autumn	1.025	(1.042, 1.008)	<10−6
Winter	1.131	(1.149, 1.112)	0.081
Spring	1.146	(1.165, 1.128)	<10−6
Summer	1.0 R	—	—
Latitude
<30°N	2.116	(2.203, 2.034)	<10−6
30–39°N	1.428	(1.477, 1.381)	<10−6
40–49°N	1.552	(1.605, 1.501)	<10−6
≥50°N	1.0 R	—	—
AKC group
Herding	1.535	(1.602, 1.470)	<10−6
Toy	1.675	(1.788, 1.570)	<10−6
Working	1.882	(1.965, 1.804)	<10−6
Sporting	1.504	(1.569, 1.442)	<10−6
Nonsporting	1.348	(1.415, 1.284)	<10−6
Terrier	1.236	(1.311, 1.164)	<10−6
Hound	1.0 R	—	—