Skip to main content

Table 1 Numbers of Dirofilaria immitis recovered at necropsy, antigen test results, antibody test results, and significant histopathologic lesions consistent with heartworm infection in cats inoculated with D. immitis

From: Moxidectin steady state prior to inoculation protects cats from subsequent, repeated infection with Dirofilaria immitis

    Pulmonary artery lesion score Pulmonic trunk lesion score
Non-treated cats (No. D. immitis recovered) Antigen* Antibody* Intima, thickening and villous proliferation Intima, leukocyte infiltration Media, thickening Intima, thickening Intima and adventitia, leukocyte infiltration
1 (0)** NEG POS 4 3 4 2 3
2 (6) POS POS 4 3 1 2 2
3 (1) NEG POS 4 4 4 4 3
4 (2) NEG POS 2 2 0 0 0
5 (1) NEG POS 4 4 3 0 0
6 (2) NEG POS 4 3 2 2 3
7 (0) NEG NEG 0 0 0 0 0
8 (0) NEG NEG 0 0 0 0 0
9 (0) NEG NEG 0 0 0 0 0
Treated   
11 (0) NEG NEG 0 0 0 0 0
12 (0) NEG NEG 0 0 0 0 0
13 (0) NEG NEG 0 0 0 0 0
14 (0) NEG NEG 0 0 0 0 0
15 (0) NEG NEG 0 0 0 0 0
16 (0) NEG NEG 0 0 0 0 0
17 (0) NEG NEG 0 1 0 0 0
18 (0) NEG NEG 0 0 0 0 0
19 (0) NEG NEG 0 0 0 0 0
20 (0) NEG NEG 0 0 0 0 0
  1. *Antigen and antibody results from cats 1–6 were published previously; 5/6 cats converted to antigen positive following heat treatment of serum to disrupt immune complexes [13]. None of the non-infected cats (cats 7–9, 11–20) converted to antigen positive with heat treatment (data not shown). **No worms were recovered but severe gross and histologic pulmonary lesions were present.
  2. Treated cats received four monthly topical treatments with 10% imidacloprid-1% moxidectin prior to, but not after, inoculations; data provided were collected on study day 224. (Positive or significant results in bold).