Table 2.
Age-adjusted and multivariate odds ratios for the association between exposure to flea/tick control products and canine malignant lymphoma, N=744
| Exposure | Cases (N=266) | Controls (pooled) (N=478) | Age-Adjusted ORa (95% CI) | Multivariate ORa (95% CI) |
|---|---|---|---|---|
| Use of any flea/tick control products | ||||
| No | 41 (15.9%) | 74 (15.9%) | 1.0 (0.7–1.5) | 1.1 (0.7–1.7) |
| Yes | 217 (84.1%) | 391 (84.1%) | ||
| Number of flea/tick control products used | ||||
| None | 71 (26.7%) | 154 (32.2%) | 1 | 1 |
| 1 | 161 (60.5%) | 261 (54.6%) | 1.3 (0.9–1.9) | 1.3 (0.9–1.9) |
| 2 | 27 (10.2%) | 50 (10.5%) | 1.2 (0.7–2.0) | 1.2 (0.7–2.1) |
| ≥3 | 7 (2.6%) | 13 (2.7%) | 1.2 (0.4–3.1) | 0.8 (0.4–3.0) |
| Ptrend | 0.36 | 0.41 | ||
| Type of Flea/Tick control product | ||||
| Collar | ||||
| No | 238 (89.5%) | 432 (90.4%) | 1.1 (0.7–1.8) | 1.2 (0.7–2.0) |
| Yes | 28 (10.5%) | 46 (9.6%) | ||
| Powder/Spray | ||||
| No | 256 (96.2%) | 465 (97.3%) | 1.4 (0.6–3.2) | 1.5 (0.6–3.6) |
| Yes | 10 (3.8%) | 13 (2.7%) | ||
| Shampoo | ||||
| No | 241 (90.6%) | 435 (91.0%) | 1.1 (0.6–1.8) | 1.0 (0.6–1.8) |
| Yes | 25 (9.4%) | 43 (9.0%) | ||
| Dip | ||||
| No | 260 (97.7%) | 466 (97.5%) | 0.9 (0.3–2.4) | 0.9 (0.3–2.6) |
| Yes | 6 (2.3%) | 12 (2.5%) | ||
| Pills | ||||
| No | 250 (94.0%) | 450 (94.1%) | 1.0 (0.5–1.9) | 1.1 (0.6–2.0) |
| Yes | 16 (6.0%) | 28 (5.9%) | ||
| Drops | ||||
| No | 115 (43.2%) | 220 (46.0%) | 1.1 (0.8–1.5) | 1.1 (0.8–1.5) |
| Yes | 151 (56.8%) | 258 (54.0%) | ||
| Brand of Drops | ||||
| Frontline, Frontline Plus, or Frontline TopSpot | 138 (78.4%) | 252 (78.0%) | 1 | 1 |
| Advantage, K9 Advantix, or Biospot | 31 (17.6%) | 54 (16.7%) | 1.0 (0.6–1.7) | 1.1 (0.6–1.7) |
| Revolution | 3 (1.7%) | 9 (2.8%) | 0.6 (0.2–2.3) | 0.6 (0.2–2.4) |
| Other | 4 (2.3%) | 8 (2.5%) | 1.0 (0.7–1.5) | 0.9 (0.3–3.0) |
a
OR, odds ratio. CI, confidence interval. Multivariate relative risks were adjusted for age, reference year, weight, history of cancer, and use of cosequin, chondroitin and prednisone.