After three treatments, the dog had 14 * 2 = <<14*2=28>>28 fleas.
After two treatments, the dog had 28 * 2 = <<28*2=56>>56 fleas.
After one treatment, the dog had 56 * 2 = <<56*2=112>>112 fleas.
Before any treatments, the dog had 112 * 2 = <<112*2=224>>224 fleas.
Thus, the dog had 224 - 14 = <<224-14=210>>210 more fleas before the treatments than after.
#### 210