Acute phase response in dogs with Dirofilaria immitis

Area of Science:

• Veterinary Medicine
• Immunology
• Parasitology

Background:

• Dirofilaria immitis infection, commonly known as heartworm disease, affects numerous dogs globally.
• Acute phase proteins (APPs) are crucial biomarkers for inflammation and infection in animals.
• Understanding APP changes in canine dirofilariasis can aid in diagnosis and management.

Purpose of the Study:

• To quantify specific positive and negative acute phase proteins in dogs diagnosed with Dirofilaria immitis.
• To investigate the relationship between APP concentrations and the presence of microfilariae or clinical signs of heartworm disease.

Main Methods:

• Blood samples were collected from 194 dogs, including 156 infected with D. immitis.
• Concentrations of C-reactive protein, haptoglobin, albumin, and paraoxonase-1 activity were measured.
• Dogs were assessed for circulating D. immitis antigens, microfilariae, and clinical signs.

Main Results:

• Dogs with D. immitis showed significantly elevated C-reactive protein and decreased albumin and paraoxonase-1 activity.
• These APP changes were independent of microfilariae presence or clinical symptoms.
• C-reactive protein levels differed between asymptomatic and symptomatic dogs, while haptoglobin decreased, especially in dogs with microfilariae.

Conclusions:

• Canine dirofilariasis induces a distinct acute phase response characterized by increased C-reactive protein and decreased albumin and paraoxonase-1.
• A notable divergence in C-reactive protein and haptoglobin behavior was observed, possibly linked to hemolytic anemia in heartworm-infected dogs.