Thesis (M.Sc.)--Chulalongkorn University, 2015

Hemangiosarcoma (HSA) is a common splenic malignant tumor in dogs. HSA accounts for approximately one third of dogs with splenic masses. The dogs suffering from splenic HSA usually have no specific clinical signs which resulted in the limitation of early detection and diagnosis. Therefore, the earlier HSA detection the more success of HSA treatment is. Currently, there are a few studies about the expression of specific protein or tumor marker for splenic HSA. This research aimed to investigate the serum angiopoietin-2 (Ang-2) concentration in dogs with splenic HSA. Blood samples without anticoagulants were collected from 40 dogs with splenic abnormalities and 10 healthy female dogs control presented for routine ovariohysterectomy (OVH); prior and 10 days after splenectomy or OVH, respectively. Serum were separated after centrifugation and used for Ang-2 analysis by ELISA. The Ang-2 concentration was performed by compared with the standard curve. In addition, 40 splenic masses were sent for histopathological evaluation of the microscopic features. When HSA was diagnosed, the growth pattern and other abnormalities of spleen were investigated. The results showed that serum Ang-2 level was not significantly related to between: (1) the control dogs and the dogs with splenic abnormalities, either prior or after surgery, (2) the dogs with and without splenic tumors, (3) the dogs with benign and malignant splenic tumors, (4) the control dogs and the dogs with HSA, and (5) different staging of HSA (P>0.05). However, there was significantly higher serum Ang-2 level in dogs with hemangioma when compared with the control group and the HSA suffering dogs (P<0.05). In conclusion, it can be assumed that serum Ang-2 expression was not a specific tumor marker for canine splenic HSA.