Table 3.

Tumour site and histological type

Site	Tumour	ICD-O code	Number of cases	Dog-years	IR	95% CI
Mammary gland	Complex Carcinoma	8010/3	60	31,113	193	147–248
	Carcinoma Simplex	8231/3	36	31,113	116	81–160
	Tubulopapillary Carcinoma	8263/3	18	31,113	58	34–91
	Carcinoma In Situ	8010/2	18	31,113	58	34–91
	Solid Carcinoma	8230/3	16	31,113	51	29–84
Skin	Mastocytoma	9740/3	73	68,865	106	83–133
	Hemangiopericytoma	9150/1	28	68,865	41	27–59
Genital tract	Seminoma	9061/3	25	37,748	66	43–98
	Sertoli Cell Tumour	8640/1	13	37,748	34	18–59
Spleen	Hemangiosarcoma	9120/3	13	68,865	19	10–32

Incidence rates of malignant tumours (cases per 100,000 dog-years at risk) by histological type and site (only the higher incidence rates are shown). CI denotes confidence interval, IR incidence rate ICD-O International Classification of Diseases for Oncology