Redox Status in Canine Leishmaniasis.

Area of Science:

• Veterinary Medicine
• Parasitology
• Biochemistry

Background:

• Leishmaniasis is a priority disease, with dogs as the primary reservoir for *Leishmania infantum*.
• Understanding pathogenesis requires investigating host-parasite interactions and physiological changes.

Purpose of the Study:

• To assess redox status in dogs naturally infected with *Leishmania infantum*.
• To correlate changes in reactive oxygen species (ROS), reactive nitrogen species (RNS), and antioxidant capacity with leishmaniasis clinical stages.

Main Methods:

• Plasma and serum from 45 dogs in endemic areas were analyzed.
• Measurements included superoxide anion (O2-), nitric oxide (NO), hydroperoxides (ROOH), superoxide dismutase (SOD) activity, and ferric reducing-antioxidant power (FRAP).
• Dogs were grouped by clinical stage based on LeishVet guidelines.

Main Results:

• Superoxide anion generation was significantly reduced in affected dogs.
• Nitric oxide production was stimulated in stages II and III of the disease.
• Hydroperoxides and SOD activity showed no significant differences; FRAP was lower in stage II.

Conclusions:

• Canine leishmaniasis alters several plasma redox status parameters.
• Observed oxidative stress changes may be primarily linked to cellular blood components, such as neutrophils.
• Further research is needed to determine the clinical significance of these findings.