Let
be the length of a cat's stride, and
their stride per time unit ratio.
So, in a time unit, the cat will cover a distance of

Dogs strides are 30% longer, do a dog's stride is

But its stride per time unit is 30% less:

So, in a unit of time, the dog will cover a distance of

So, in the same amount of time, the dog covers 91% of the distance of the cat.