Many factors can contribute loss of appetite in dogs like pain, all diseases of digestive tract including esophagus, stomach, intestine, pancreas, and liver, other diseases that can affect kidneys, mouth, eyes, nose, skin, brain, throat etc. Depression and anxiety can also cause anorexia.
Treatment depends upon diagnosis first and can be both supportive and specific. But finally, your vet can give better suggestion.
If he has been eating human food, slowly start to feed him by hand. Then, mix some human food-not a lot, and something like bread. Slowly decrease the amount of human food until its just dog food
Loss of appetite in not only golden Retrievers but also in all dogs should be watched closely. If it is for less than 24 hours in adult dogs and 10-12 hours in puppies then no need to worry. Loss of appetite in dogs for more than this period is not good sign and can be indication of underlying cause. Almost all diseases in dogs cause loss of appetite, e.g.
1. Kidneys and liver diseases
2. All diseases of GI tract
3. Diseases of blood
4. Mouth diseases
5. Depression and anxiety
6. Eye diseases
7. Diseases of nose and throat
8. Diseases of brain
9. Skin diseases
It will be better option to take your golden Retriever to vet for diagnosis and treatment of loss of appetite.
I have a 2 year old golden since he was a puppy he could careless about eating I'm getting worried but he will eat human food no problem what should I do to get him to eat