In animals infected with heartworm, which blood cell type is likely elevated?

In animals infected with heartworm, which blood cell type is likely elevated?

• A. Eosinophils
• B. Leukocytes
• C. Lymphocytes
• D. Monocytes

Answer: (A)

Parasites trigger an eosinophilic response. Eosinophils are the white blood cells specialized to attack multicellular parasites like heartworms, releasing toxic granule contents to damage and kill helminths. When heartworms are present, the body increases eosinophil production and mobilizes them to sites of infection, so the eosinophil count in blood rises. While other white blood cells can increase with various infections, none are as strongly tied to parasite defense as eosinophils, making them the most likely elevated cell type in this scenario.

Parasites trigger an eosinophilic response. Eosinophils are the white blood cells specialized to attack multicellular parasites like heartworms, releasing toxic granule contents to damage and kill helminths. When heartworms are present, the body increases eosinophil production and mobilizes them to sites of infection, so the eosinophil count in blood rises. While other white blood cells can increase with various infections, none are as strongly tied to parasite defense as eosinophils, making them the most likely elevated cell type in this scenario.