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

Table 1 Measures (μm) of microfilariae determined after fixation with the modified Knott’s technique

Microfilariae species identified by histochemical staining and partially confirmed by PCR^a	Total number and origin of dogs	Mean length ± standard deviation (μm)	Mean width ± standard deviation (μm)
Dirofilaria immitis	60 (GR 1; IT 6; PT 33; ES 16; TR 2; UO 2)	301.77 ± 6.29	6.30 ± 0.26
Dirofilaria repens	171 (BG 1; FR 1; GR 5; IT 10; RO 3; ES 2; HU 141; UO 8)	369.44 ± 10.76	8.87 ± 0.58
Acanthocheilonema dracunculoides	133 (PT 69; ES 55; UO 9)	259.43 ± 6.69	5.09 ± 0.47
Acanthocheilonema reconditum	13 (IT 13)	264.83 ± 5.47	4.63 ± 0.52

Mean length and mean width (μm) of microfilariae determined after fixation with the modified Knott’s technique of confirmed single filarial infections in 377 dogs.
IT, Italy; ES, Spain; GR, Greece; PT, Portugal; RO, Romania; HU, Hungary; BG, Bulgaria; TR, Turkey; FR, France; Unknown Origin: UO.
^a PCR confirmation for 6 samples positive for D. immitis, 4 for D. repens, 7 for A. dracunculoides and 6 for A. reconditum infections.

ISSN: 1756-3305