𝗗𝗶𝗿𝗼𝗳𝗶𝗹𝗮𝗿𝗶𝗮 𝗿𝗲𝗽𝗲𝗻𝘀 is a filarial nematode of dogs (and cats) transmitted by mosquitoes.
The adult worm commonly found in sub-cutaneous tissue deposit microfilariae that circulate in blood.
Dirofilaria repens is zoonotic.
𝗗𝗶𝘀𝘁𝗿𝗶𝗯𝘂𝘁𝗶𝗼𝗻
Dirofilaria repens has been reported in Africa, the Middle East, Europe and Asia.
𝗖𝗹𝗶𝗻𝗶𝗰𝗮𝗹 𝘀𝗶𝗴𝗻𝘀
Infection may be asymptomatic or most commonly present as generalised dermatological lesions as a result of a hypersensitivity reaction to microfilariae.
This includes pruritus, erythema, papule formation and secondary alopecia and excoriations Subcutaneous nodules harbouring adult worms are occasionally observed.
𝗗𝗶𝗮𝗴𝗻𝗼𝘀𝗶𝘀
Identification of circulating microfilariae in whole blood using a microfilarial concentration technique (e.g. the modified Knott’s method (SOP 5)) is the diagnostic test of choice.
If a nodule is observable, cytological examination of the fine needle aspirate may reveal the presence of microfilaria.
𝗧𝗿𝗲𝗮𝘁𝗺𝗲𝗻𝘁
Treatment is indicated in all positive cases to eliminate the dog as a source of infection to other animals as well as humans.
No adulticide therapy for this parasite is registered.
An off-label use of two doses of melarsomine hydrochloride at 2.5 mg/kg IM into the lumbar epaxial musculature, 24 hours apart, combined with a single sub-cutaneous injection of doramectin as a microfilaricidal treatment at 0.4 mg/kg 5 days after the initial adulticide therapy, was shown effective as an adulticidal and microfilaricidal therapy