I have a 4 months+ old labrador retriever puppy. I used to feed him Nurtiedge Lamb and rice for like 2 weeks after i got him. He liked the food very much and i have no problem feeding him. When the kibble was almost finished, I switched to a brand called Blackwood Lamb since I couldnt get the Nutriedge kibble at the Petstore near my house. At first my lab seemed to like it and was able to finish the whole portion that i fed him. But starting on the next day, he barked like usual when he saw me preparing his food, but after he sniffed it when i put down the bowl, he would just walk away without eating any. At first i tot he had no appetite due to teething so i left him alone. But the whole process repeated for 2 days and that means he didnt eat anything for 3 days. So the next day i bought a 1kg packet of Nutriedge lamb and rice for him, and still he didnt want to eat the Nutriedge kibble. Immediately, i took him to the vet. The vet told me that he is fine and he is just being picky over food. The vet also advised me to either switch brand again to identify the brand that he likes or to starve him by not giving him any treats. So i tried the 2nd approach which is to stop giving him treats. I also tried to extend the usual walk before his meal in the morning and in the evening and this approach seemed to work, my lab started to eat abit before walking away. I told myself to be patient and not to force him to eat more than he wants. Yesterday, i wanted to try the other approach the vet advised me to do which is to try another brand so I bought a 2.5kg Orijen puppy. I was happy to see that he liked the food and finished the portion i fed him and begged for more and i tot the problem is solved once and for all. This morning, after his usual walk, he walked away like usual after sniffing the food and now i feel so sad. Could any experienced owner give me some advice?