Table 4. Prevalence and risk of glial tumors in each dog breed.

Breed	No. of dogs examined	No. of primary intracranial tumors	No. of glial tumors a)	% Glial tumors of the breed within the total number of glial tumors	% Glial tumors within the breed	% Glial tumors within all primary intracranial tumors of the breed	Odds ratio	95% CI	P value b)
	(A)	(B)	(C)	(C/34 × 100)	(C/A × 100)	(C/B × 100)
Bouvier des Flandres	4	1	1 (1 GC)	2.9	25.0	100.0	93.263	9.455–919.891	<0.001†
French Bulldog	293	25	22 (1 GB, 2 O, 19 AO)	64.7	7.5	88.0	60.649	29.708–123.814	<0.001†
Newfoundland	9	1	1 (1 AO)	2.9	11.1	100.0	34.955	4.252–287.383	<0.001†
Bulldog	17	1	1 (1 AO)	2.9	5.9	100.0	17.462	2.250–135.508	<0.001†
Boxer	18	1	1 (1 A)	2.9	5.6	100.0	16.433	2.125–127.084	<0.001†
Boston Terrier	83	1	1 (1 AO)	2.9	1.2	100.0	3.383	0.457–25.028	0.205
Mixed breed dog	852	12	1 (1 GB)	2.9	0.1	8.3	0.299	0.041–2.186	0.206
Shih Tzu	456	5	1 (1 GB)	2.9	0.2	20.0	0.585	0.080–4.285	0.593
Chihuahua	443	8	1 (1 AA)	2.9	0.2	12.5	0.603	0.082–4.418	0.615
Pembroke Welsh Corgi	422	16	1 (1 GB)	2.9	0.2	6.3	0.634	0.087–4.650	0.652
Labrador Retriever	406	9	2 (2 AO)	5.9	0.5	22.2	1.366	0.326–5.721	0.668
Yorkshire Terrier	320	2	1 (1 AO)	2.9	0.3	50.0	0.847	0.115–6.231	0.870
Total	3,323	82	34 (1 A, 1 AA, 4 GB, 2 O, 25 AO, 1 GC)	100.0

a) A, astrocytoma; AA, anaplastic astrocytoma; GB, glioblastoma; O, oligodendroglioma; AO, anaplastic oligodendroglioma; GC, gliomatosis cerebri. b) Breeds with a P<0.05 (†) were considered to have a significantly higher risk of the occurrence of glial tumors than the rest of the evaluated population.