I have 2 dogs & a cat. My cat is white but shes so dirty she looks brown..

If you have any toys then you should sell them, thats really the only way if your pets are that unhealthy.
After selling the items, feed,water and bathe your pets. When they are healthy you can train and enter them in competitions to earn some money. Hopefully this works for you. You can also try asking your friends to give you things to sell through Bark mode,
And repay them etc. If you have more pets than you can care for then sadly, you should get rid of the ones you can't afford to keep.

Well... Maybe try spawing them around usin'the hotel, idk if this work, due to me only have one pet! :3

If that don't work, then follow what Wolf love Said, sell some toys, train and enter Contests.

-Dark Fire Wolf.

Sell your stuff at the store so that you can
Buy shampoo, water and food, etc.

First, sell everything you have. But if you don't have anything to sell, take your dog on a walk and it might pick up something you can sell- sometime they even pick up shampoo! Then, buy shampoo, food and drink (You'll need to get wet food to get their weight up!) then you can enter them in comps.