Serum Concentrations of Monocyte Chemoattractant Protein-1 in Healthy and Critically Ill Dogs

Background: The chemokine monocyte chemoattractant protein-1 (MCP-1) is a primary regulator of monocyte mobilization from bone marrow, and increased concentrations of MCP-1 have been associated with sepsis and other inflammatory disorders in critically ill people. The relationship between MCP-1 and disease in dogs has not been evaluated previously.

Objective: The purpose of this study was to assess serum concentrations of MCP-1 in healthy dogs, dogs in the postoperative period, and critically ill dogs. We hypothesized that MCP-1 concentrations would be significantly increased in critically ill dogs compared with postoperative or healthy dogs.

Methods: Serum concentrations of MCP-1 were measured in 26 healthy control dogs, 35 postoperative dogs, and 26 critically ill dogs. Critically ill dogs were further subgrouped into dogs with sepsis, parvovirus gastroenteritis, immune-mediated hemolytic anemia, and severe trauma (n=26). MCP-1 concentrations were determined using a commercial canine MCP-1 ELISA. Associations between MCP-1 concentrations and disease status were evaluated statistically.

Results: MCP-1 concentration was significantly higher in critically ill dogs (median 578 pg/mL, range 144.7-1723 pg/mL) compared with healthy dogs (median 144 pg/mL, range 4.2-266.8 pg/mL) and postoperative dogs (median 160 pg/mL, range 12.6-560.4 pg/mL) (P<.001). All subgroups of critically ill dogs had increased MCP-1 concentrations with the highest concentrations occurring in dogs with sepsis. However, differences among the 4 subgroups were not statistically significant.

Conclusion: Critically ill dogs had markedly increased serum concentrations of MCP-1 compared with postoperative and healthy dogs. These results indicate that surgery alone is not sufficient to increase MCP-1 concentrations; thus, measurement of MCP-1 may be useful in assessing disease severity in critically ill dogs.