Impact of combined unilateral mastectomy and ovariohysterectomy on acute phase response and wound healing in dogs with mammary gland tumors

Canine mammary gland tumors (CMTs) are among the most common neoplasms in female dogs, and surgical excision is the standard modality for treatment of CMTs. Unilateral mastectomy (UM) is frequently combined with ovariohysterectomy (OVH), which may lead to different levels of systemic inflammation and wound-healing. This study aimed to evaluate pain intensity, serum acute phase proteins (APPs), proinflammatory cytokines, and wound healing in dogs submitted to OVH (control), UM, or UM concomitant with OVH (BT). Twenty-nine female dogs were prospectively enrolled and divided into three groups: control (n = 8), UM (n = 10), and BT (n = 11). Pain was measured using the Glasgow Composite Pain Scale. Serum C-reactive protein (CRP), amyloid A (SAA), haptoglobin, interleukin (IL)-1β, and IL-6 levels were determined at five time points, including pre-surgery, after emergence from anesthesia, and on postoperative days 1, 3, and 7, using enzyme-linked immunosorbent and fluorescent immunoassays. Pain scores peaked after emergence from anesthesia in both the UM and BT groups compared to controls (P < 0.05), with non-significant differences between UM and BT groups. In the UM and BT groups, serum CRP and SAA levels rose significantly following surgery, peaking on day 1 and gradually dropping subsequently. On day 1, both the UM and BT groups exhibited significantly higher CRP and SAA levels than the control group (P < 0.05), whereas the difference between the UM and BT groups was non-significant. Wound healing was slower in the BT group, which had a significantly higher wound score on day 3 than the control group (P < 0.05). UM, performed alone or in combination with OVH, was associated with transient increases in postoperative pain, APP responses, and wound scores compared with OVH alone, particularly during the early postoperative period. SAA and CRP were the most consistent and sensitive biomarkers for detecting postoperative inflammation under the present sampling schedule, whereas IL-1β and IL-6 showed limited discriminatory capacity, likely due to their rapid and transient kinetics. Therefore, monitoring blood CRP and SAA levels provides supportive information for assessing postoperative inflammatory responses in dogs undergoing mammary tumor surgery.