Taking care of your dog starts with making sure they are properly fed and given plenty of water. However, if you don't know what to look for you may confuse a slender dog with malnutrition. There are several signs of malnourishment:
If your pet's ribs, pelvic bone and lumbar are prominent, with a waist tuck, they're too skinny. If you feel their rib cage they are also too skinny. There should be a slight layer of fat on the ribs while their abdomen is tucked up.
Is your dog constantly sick? A malnourished dog is more likely to become sick due to a weakened, strained immune system. Additionally, if your pet has regularly smelly gas problems, does not have regular bowel movements or the movements are extremely hard or extremely runny, it's likely a dietary issue.
Of course, not having enough food results in not having energy to play.
What Can You Do About It?
If they are eating all their food and are not putting on any weight, gradually increase their food intake.
If you recently adopted a malnourished dog, don't overdo it. If you feed them too much too soon it can cause further stomach problems. Monitor their food intake. As they become used to you, they will eat more and put on weight.
If your dog is not eating, it could be a sign of a serious health problem. See your vet immediately.