Did you know that there are cheats in Nintendogs even without cheating devices?Here are a few:
Unlimited walks:
1 Plan your route on your walk, and at the end, go to a park.
2. When you are in that park, change accessories.
3. When you go back, it saves.
4. When the saving message disappears, switch it off .
5. When you switch your DS back on, you will have your items from your previous walk, and you are able to go on another walk!
Note: You will not get trainer points for this. And your dog's stamina will not increase.

Unlimited contests: Wanna enter in more than 3 contests a day?Do the maximum number of contests. save it so you keep all the money. Then turn off the power. Then turn your ds back on and change your date to two days prior to the current one, and change the time to 23:59. Go and turn your ds back on and go to play nintendogs. You can now do the three contests and learn 3 tricks all over!

Easy trainer points: Put the correct brush on your dog and for every 1 minute the brush stays there 1 trainer point increases. Leave the DS on with charger all day or night, and you'll see a bunch of trainer points!
Note: This also raises the time spent with your dog. Having a high amount time spent will affect your dog's personality.

Fireman's Hat (Unlock Dalmatian breed) : If you have any version (besides Dalmatian and Friends) here's a tip on increasing your luck to find the fireman's hat: When you hear a firetruck siren, immediately take your dog out for a walk. (Be prepared, have the dog with the longest stamina, be clean and happy and well fed. The happier the luckier :) (To increase chances {just in case} put on something red on the dog.) Note: This won't be guaranteed to work, so don't worry when you don't find it the first time!
Or, you can try going to bark mode with someone who has a dalmatian. Make sure its the first time you went onto Bark Mode with that person.



Nintendogs Cheats
Unlockables!

Lab and Friends Version
Pug -2,000 Trainer Points
German Shepherd Dog -4,000 Trainer Points
Desktop(Interior Decorator)- 6,000 Trainer Points
Shih Tzu- 8,000 Trainer Points
Boxer- 10,000 Trainer Points
Seaside(Interior Decorator) -12,000 Trainer Points
Beagle -14,000 Trainer Points
Shetland Sheepdog- 16,000 Trainer Points
Outer Space(Interior Decorator) -18,000 Trainer Points
Golden Retriever -20,000 Trainer Points
Cavalier K.C.Spaniel- 22,000 Trainer Points
Ranch House (Interior Decorator)- 25,000 Trainer Points
Husky -30,000 Trainer Points
Yorkshire Terrier -35,000 Trainer Points
Northern European- ( house rennovation) 40,000 Trainer Points
Dachshund (dog) -45,000 Trainer Points
Chihuahua (dog)- 50,000 Trainer Points


Dachshund and friends

Collect 2,000 Trainer Points - Yorkshire Terrier
Collect 4,000 Trainer Points - Shiba Inu
Collect 8,000 Trainer Points - Cavalier K.C. Spaniel
Collect 10,000 Trainer Points - Pembroke Welsh Corgi
Collect 14,000 Trainer Points - Shetland Sheepdog
Collect 16,000 Trainer Points - Miniature Schnauzer
Collect 20,000 Trainer Points - Boxer
Collect 22,000 Trainer Points - Toy Poodle
Collect 30,000 Trainer Points - German Shepherd
Collect 35,000 Trainer Points - Miniture Pinscher
Collect 45,000 Trainer Points - Chihuahua
Collect 50,000 Trainer Points - Labrador Retrieiver
Find the Fireman Hat item - Dalmatian
Find the Jack Russell Book - Jack Russell Terrier

Unlock Houses & Items
Once you accumulate the proper amount of Trainer Points, new houses will
appear in the interior decorator.

Collect 6,000 Trainer Points - Desktop Interior ($20,000)
Collect 12,000 Trainer Points - Seaside Room ($50,000)
Collect 18,000 Trainer Points - Outer Space ($100,000)
Collect 25,000 Trainer Points - Northern European ($5,000)
Collect 40,000 Trainer Points - Urban Living ....
Chihuahua and Friends
Collect 2,000 Trainer Points - Miniature Pinscher
Collect 4,000 Trainer Points - Siberian Husky
Collect 8,000 Trainer Points - Toy Poodle
Collect 10,000 Trainer Points - Golden Retriever
Collect 14,000 Trainer Points - Miniature Schnauzer
Collect 16,000 Trainer Points - Beagle
Collect 20,000 Trainer Points - Pembroke Welsh Corgi
Collect 22,000 Trainer Points - Shih Tzu
Collect 30,000 Trainer Points - Shiba Inu
Collect 35,000 Trainer Points - Pug
Collect 45,000 Trainer Points - Labrador Retriever
Collect 50,000 Trainer Points - Dachshund
Find the Fireman Hat item - Dalmatian
Find the "Jack Russell Book"- Jack Russell Terrier

Unlock Houses & Items
Once you accumulate the proper amount of Trainer Points, new houses will
appear in the interior decorator.

Collect 6,000 Trainer Points - Desktop Interior ($20,000)
Collect 12,000 Trainer Points - Seaside House
Collect 18,000 Trainer Points - Outer Space
Collect 25,000 Trainer Points - Urban Living
Collect 40,000 Trainer Points - Northern European
....

.
Best Friends
Shih Tzu Collect 2,000 trainer points
Desktop Interior Design 6000TP
Toy Poodle 8000TP
Shetland Sheepdog Puppy 4000TP
Boxer Puppy 10,000 Trainer Points
Seaside 12,000 Trainer Points
Pug 14,000 Trainer Points
Miniature Schnauzer 16,000 Trainer Points
Siberian Husky 20,000
Outer Space Interior Design 18,000
Urban Living Interior Design 25,000 TP
Welsh Corgi 22,000 Trainer Points
Miniature Pinscher 30,000 TP
Dalmation Obtain Firemans Hat on Walk or Via Bark Mode
Jack Russel Terrier Obtain Jack Russel Book on Walk or Via Bark Mode
Cavalier K.C. Spaniel 35,000 TP
Ranch House Interior Design 40,000 TP
Shiba Inu 45,000 TP
Chihuahua 50,000 TP....
Dalmatian and Friends
2000 -- Cavalier King Charles Spaniel
4000 -- Shetland Sheepdog
8000 -- Chihuahua
10,000 -- Pembroke Welsh Corgi
14,000 -- Toy Poodle
16,000 -- Pug
20,000 -- Miniature Schnauzer
22,000 -- Husky
30,000 -- Miniature Pinscher-Doberman
35,000 -- Shih Tzu
45,000 -- Labrador
50,000 -- Daschund
68,000 -- Jack Russel; but you must take your dog for a walk. If your dog finds a "Jack Russell book" then a Jack Russell will be available in your kennel. If your dog doesn't find the book item, you need to do another walk. The item will eventually show up
If you have any more cheats, tell me on the homepage and I'll add it!