Even though cats, cattle, dogs, and horses were also infected with the virus, they still exist in world just like humans. It's just very expensive to able to have a male born in those species.
Only the very rich are able to own cats, dogs, and horses. Cow's milk and cheese are still available in upscale groceries. Beef was only found in the most expensive of restaurants for the longest time.
However recently, the price of beef has dropped significantly. The Beef Industry announced that they had adopted new and improved animal husbandry methods which increased livestock production by using better breeders.
Now for the readers that like to read esoterically or to find the subtext by reading between the lines, whatever speculations you come up with will be a reflection on how depraved and twisted your mind is.