Cytogenetic characterization of a fibroma and three haemangiopericytomas in domestic dogs.

Cytogenetic evaluation of tumour cells taken from an 11-year-old mixed breed birth with a fibroma, showed trisomy 1 (2n = 79) and often the presence of a third copy of chromosome 4. In a 13-year-old mixed breed Boxer bitch with a haemangiopericytoma, trisomy 9 (2n = 79) was present. In contrast, another haemangiopericytoma (in a 15-year-old rough-haired Dachshund bitch) showed a deleted chromosome 1, several centric fusions and trisomy 2. Trisomy 2 and trisomy 29 were detected in a third haemangiopericytoma from an 11-year-old rough-haired Dachshund bitch.