The Effect of Size and Clinical Staging of Mammary Tumors on Blood Parameters in Bitches
Authors: Satilmis Fatma , Suvarikli Alan Beyza , Altunok Vahdettin , Bugra Kivrak Mehmet , Demirsöz Mert , Alkan Hasan , Aydin Ibrahim 
Published: December 2024

Background: Mammary tumors are the most common type of tumor in female dogs and account for 50% of all tumors in dogs. The clinical prognosis of canine mammary tumors is strongly affected by the size, stages, histological type, and grade of tumor; mitotic index; and nearby and distant metastasis. In canine mammary tumors, it is recommended that prognostic evaluation should also include complete blood count, serum biochemistry, and blood gases in addition to tumor size and stage. This study aimed to investigate the effect of tumor size, volume, and clinical stage on complete blood count, blood gas analysis, and serum biochemical parameters in bitches with mammary tumors and the correlation between them.
Materials, Methods & Results: The study included a total of 18 bitches of different breeds, aged 6-15 years, of which 12 had mammary tumors and 6 were healthy. Thoracic X-rays were performed on bitches with mammary tumors in ventrodorsal and laterolateral positions to evaluate lung metastasis. Blood samples were collected from the cephalic vein from bitches in both groups in 2 different tubes (with plastic gel and ethylenediaminetetraacetic acid), 5 mL each, to perform complete blood count and evaluate blood gases and serum biochemical parameters. Blood samples were collected from the animals at the time of initial examination without any intervention. Analysis of the blood showed that bitches with mammary tumors had decreased levels of RBC, HCT, HGB, potassium, TCO2, base excess, THbc, and ALT enzyme activity and increased levels of lactate, total protein, cholesterol, triglyceride, LDL, uric acid, and ALP and LDH enzyme activities compared with those in the control group. Furthermore, the dogs with a primary tumor of > 5 cm were found to have significantly higher levels of WBC, lactate, total protein, triglyceride, LDL, uric acid, and ALP and LDH enzyme activities and significantly lower levels of RBC and THbc compared with those in the control group. Bitches with tumors in multiple mammary lobes were found to have significantly higher levels of WBC, total protein, triglyceride, LDL, and ALP and LDH enzyme activities and significantly lower levels of RBC, HCT, HGB, TCO2, THbc, and ALT enzyme activity compared with those in the control group. Based on the laboratory findings and approval of the owners of the dogs, mammary tissues containing the tumor and lymph nodes were surgically removed. After the operation, the removed mammary tissues were evaluated for size and volume. Clinical staging of the tumors was performed based on the size of the primary tumor (T), nearby lymph nodes (N), and metastasis (M) in accordance with the criteria set by WHO. Clinical staging of the tumors was, thus, based on the tumor, nodes, and metastases (TNM) score obtained according to the following system: Stage I: T1N0M0, Stage II: T2N0M0, Stage III: T3N0M0, Stage IV: TanyN1M0, Stage V: Made as TanyNanyM1.
Discussion: Mammary tumors are the most common type of neoplasm in bitches and, thus, cause serious problems in veterinary medicine. Tumors are significantly correlated with better prognosis compared with larger tumors. Based on this finding, this study investigated the effect of size, volume, and stage of mammary tumors in bitches on some blood parameters and the correlation between them. It was, thus, concluded that clinical staging and evaluation of blood parameters could be useful in the diagnosis, treatment, and prediction of prognosis in canine mammary tumors. This study found that bitches with mammary tumors exhibited significant changes in their blood parameters (complete blood count, blood gas analysis, and serum biochemistry). The results obtained from this study may contribute to the development of approaches to the diagnosis, prediction of prognosis, and treatment of canine mammary tumors.
Keywords: blood gas analysis, complete blood count, dogs, mammary tumor, serum biochemistry, tumor volume.