The dogs have 16 total legs because 4 times 4 equals <<4*4=16>>16.
The cats have 12 total legs because 4 times 3 equals <<4*3=12>>12.
There are 28 total legs because 16 plus 12 equals <<16+12=28>>28.
She needs to buy 14 pairs because 28 divided by two equals <<28/2=14>>14.
#### 14