Morphometric analyses of canine blood microfilariae isolated by the Knott’s test enables Dirofilaria immitis and D. repens species-specific and Acanthocheilonema (syn. Dipetalonema) genus-specific diagnosis
Background
In Europe the most common canine filarial species presenting blood circulating microfilariae (mf) are Dirofilaria immitis, D. repens, Acanthocheilonema (syn. Dipetalonema) dracunculoides and A. (syn. Dip.) reconditum [1]. They are transmitted by haematophagous arthropods: Dirofilaria spp. by mosquitoes, A. reconditum by fleas and lice and A. dracunculoides by ticks. D. immitis, the aetiological agent of canine heartworm disease, is the most pathogenic species for dogs: adults live in the right side of the heart and in the pulmonary artery, causing pulmonary hypertension and congestive heart failure. Adults of D. repens live in the subcutaneous tissue, occasionally causing dermatological problems [2].