If your dog is behaving in an unusual manner, it is wise to get them checked out by a vet. There is often a cross over in symptoms between depression and sickness, and it is not always easy to tell the difference because both sick and depressed dogs tend to be off their food, and are reluctant to exercise. A healthy dog is unlikely to become depressed for no reason, therefore it is helpful to know if a recent event has impacted your dog's mental well-being. Dogs are routine driven, so the most common trigger for canine depression is a change of routine. Changes in routine that can trigger depression may include:  Stress: In doggy terms stress includes anything that stops him from getting the attention he is used to. A stay-at-home owner who now goes out to work. A new baby, or puppy, in the household. The sudden loss of a companion (human or canine). Moving house. Being re-homed. Major building work or renovations in the home. Go for more walks, play games your dog likes (fetch, tug-of-war), try a canine sport like agility, train your dog to do tricks, head to the dog park. When you watch TV, sit on the floor at your dog’s level instead of in a chair. Whatever you decide to do, make sure it is fun for both you and your dog. Spending enjoyable time with you is the best way to help your dog overcome his depression. If your dog has recently lost a canine companion, consider getting a new one. If your dog is home alone for long hours, try daycare a few days a week or having a walker come by. Also plan trips to the park so that your dog can socialize. The mistake many owners make when dealing with a depressed dog is that they fuss over them when the dog is behaving abnormally.  For example, if you make a fuss out of your dog when they don't eat, you inadvertently send them the message that they are doing a clever thing by not eating. A much better way of handling the situation is to put the food bowl down and ignore the dog until they decide to eat. Then once they take a mouthful, heap them with praise. This...

TL;DR in Indonesian:
Pastikan anjing Anda tidak sakit. Pahamilah apa yang bisa memicu depresi ini. Luangkan lebih banyak waktu dengan anjing Anda. Ajak dia lebih sering besosialisasi. Beri imbalan untuk perilaku positif anjing Anda. Buat anjing merasa lebih aman dengan menjaga rutinitas seperti biasanya. Jika depresi terus berlanjut, bawa anjing Anda untuk menemui dokter hewan yang memiliki spesialisasi dalam masalah perilaku.