Due to strays breeding freely, the fact that dog owners are mixed with cat owners, and many owners not registering their dogs, there are no accurate ways to tell the excact number. However, based on those who do register their pets, there are roughly 3 million owned cats and dogs, with it being almost divided evenly between the animals, and a little over a million of free-roaming dogs and cats.
Again, it's hard to tell, and those are rough estimates made by the Wasington State Federation of Animal Care and Controll Agencies Spay/Neuter Task Force, assuming your talking about the state and no DC.
5,980
90,700
58,900
78,600
283,390
37,939
23,700
388,821
127,330
41,881
88,445
69,820