There are **no cheat codes** for infinite money in Nintendogs (DS). Action Replay codes exist but corrupt saves / break contests. The game rewards consistent care and smart competition entry. Here's the optimal legitimate grind:
| Item | Sell Price | Source |
|---|---|---|
| Gold Bar | $2,000 | Rare present (walk) |
| Diamond | $1,500 | Rare present |
| Ruby / Sapphire / Emerald | $800–$1,000 | Rare present |
| Metallic Collar / Leash | $500–$800 | Contest prizes / Presents |
| Unneeded Toys (RC Helicopter, etc.) | $50–$200 | Presents |
Target: 50,000 $ unlocks everything (all interiors, breeds, contests). Achievable in ~2–3 weeks of daily play. No cheating needed.