These aren't necesarily cheats they are more of a note type of thing
BUT THEY HELP!

Go to the dresser in your room and you can change into a different outfit.
The dog, bird, and cat food are in the feed room in the main builing.
Take the dogs out of the kennel and you can play ball.
You can take your horse into town.
If your in town after 20:00, you have extra time until 22:00.

Hope these tips help augustgirl17

I have tried many variations of the currently published cheat codes for Pet Vet and on various screens and could not get any of them to work. So....for those of you who are experiencing the same, I did find a solution.
First, start Pet Vet then save your game. Exit the game and open Notepad. Go to File>Open and, using the drop down box, select All file types.
Go to My Documents>THQ>Pet Vet>save
And open your saved game file.
Save this file to a different location so that you'll have a backup in case you mess something up.
At the top of this file, you'll see text like:
Object type="Composite" pid="25229360" loc="db:Composite:hundehaus" name="Hundehaus" tform="-0.034020 0.000336 -0.999508 0.000000 0.019796 0.999804 -0.000336 0.000000 0.999312 -0.019796 -0.034020 0.000000 -78.352997 -0.060000 -7.573000 1.000000" composite_pid="0" composite_list="0" is_shown="true" is_dismissed="false" start_version="0" end_version="2" cur_version="1"

All of these Object type="Composite".... Entries at the top of the file are for the buildings and upgrades in the game. The above example is for the house. Look at where it says end_version and notice the number beside it. Then look at where it says cur_version and change that number to the same number that end_version has. In the above example, end_version="2" so we would change cur_version="1" to cur_version="2".
If you do this for all of the Object type="Composite" entries, when you load your saved game, you'll have all of the buildings and all of the upgrades.
Toward the middle of this file, you'll see entries that start with Object type="Dispenser"... These are the food and water dishes in each of the buildings, as shown in the example below:
Object type="Dispenser" pid="25100160" loc="db:Dispenser:dogfoodcontainer1" name="HundefutterDose" tform="0.600782 0.000000 -0.799207 0.000000 0.000000 1.000000 0.000000 0.000000 0.799207 0.000000 0.600782 0.000000 -44.151772 0.897000 -32.550117 1.000000" composite_pid="24990296" composite_list="2" is_shown="true" is_dismissed="false" animal_type="Dog" storage="true" capacity="100" food_quality="1" food_count="25" water_count="0"
Notice where it says capacity then use that number (100 in the above example) to change food_count and water_count. So, food_count and water_count in the above example would change to ="100". Food_quality="1" should also be changed to "3" to have the best quality food.
Do this to all of the "Dispenser" entries.
Next, press Ctrl + F and type the word money then press enter. You'll see a paragraph that ends with the money entry, similar to that below:
Object type="Inventory" pid="27294152" loc="" name="" tform="1.000000 0.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 0.000000 1.000000" composite_pid="0" composite_list="0" is_shown="true" is_dismissed="false" entries="Dog:4:2,Any:4:0,:0:0" invisible_entries="AnointDrug:Entzündungshemmende Salbe:50,AnointDrug:Heilsalbe:50,AnointDrug:Antiparasitsalbe:50,InjectDrug:Antiparasit:50,InjectDrug:Impfung:50,InjectDrug:Schmerzmittel:50,InjectDrug:Antibiotikum:50,InjectDrug:Aufbaupräparat:50,SwabDrug:Desinfektion:50,KineDrug:Massageball:50,Money:Money:25972"
This is all of your inventory. You can pretty much change any of these. For example, SwabDrug:Desinfektion:50 can be changed to whatever number you want. In the above example, I changed the number to 50. This gives me 50 disinfecting swabs without having to pay for them. And, of course, you can change the amount of money you have by simply changing the numbers after Money:Money:
Hope this helps!