Good question. While I'm not aware of walker animals, I can't claim any particular familiarity with the comic universe upon which this TV show is based.

However, within the show itself, there are a few indicators and oddities to contemplate

1. According to what they learned at the CDC, this all seems specifically aimed at humans, and we know that certain ailments affect different organisms differently. Some animals carry diseases that don't hurt them but kill us; meanwhile, we love chocolate, but dare not share it with our dogs. It seems, therefore, that this did not infect animals.

2. Forget the CDC. Fact is, by this stage, had animals been affected, we'd have seen them; their utter absence through seven seasons rather simply asserts that there are none.

3. There didn't seem to be a lot of domestic raising of animals at any of the communities (Hilltop, Terminus, Alexandria, Oceanside) that I can recall. But I could be wrong on that. Do let me know.

4. In fact, there are not a lot of animals in TWD at all. For all the animals that do live in America - from pets to farms to zoos to the wild - we haven't seen a cow, or a goose, or a cougar, or a bear, or a wolf, or a raccoon... for effect, the show has tossed in the odd rabbit, squirrel, possum (seems rodents are a-ok) and the group were even fattening a pig at the prison but, by and large, significantly few animals have managed to survive.

5. One more note - it seems that, most chances the group has had to catch animals (the aforementioned rodents, for example, or even a dog), they ate it without hesitation, with apparently no fear of any additional contamination.

TL;dr - all indications from the TV show are that animals are not infected by whatever is reanimating humans.

@Raymondoz2007 said:

In season4 after the prison is gone Rick and the gang encounter a bunch of dogs.....they looked so dirty I thought they may be walkers. Question: in TWD universe are there zombie animals??

No, the showrunners have said there are no zombie animals.