Here is something we've learned with our dog.
When it comes to the diets of animals, their stomachs can be just as sensitive as human's.
A dog can be sensitive to certain dyes, additives or chemicals that are in specific brands of dog food. Sometimes this sensitivity can come in the form of unexplainable weight loss. Although you're providing more and more food to try and put weight back onto your canine friend, he or she could still be losing weight. Before you assume that your dog is dying, take a look at the food you're providing.
One of the first things you should do is monitor your dog's bowel movements. A problem with your dog's food can reflect in the stools.
If the feces is softer than expected, funny looking or downright liquid in nature, take it seriously. Diarrhea will rob the body of water and needed nutrition in order to develop or maintain itself. If the food is passing through your dog too quickly, the poor animal doesn't have a chance to digest and absorb the nutrients from the food. This can actually be quite common if you feed your canine cheap brands of kibble.
Jana's note: If your dog does have diarrhea which lasts longer than couple of days, do visit your veterinarian. With a young puppy, visit your veterinarian right away. You can read more about diarrhea types and causes here.
Not all dogs can eat popular brands of food and remain healthy. Sometimes even the expensive labels can cause digestive problems. If your dog doesn't have an actual sickness, it could take quite a while before you can find the right food that he or she can eat without causing an upset stomach. It could take anywhere from three days to a week in order for a new food to be positively identified.
Similarities Between Species
Many people don't put a great deal of consideration about how animals and humans are similar when it comes to proper digestion. A lot of individuals are deeply affected by spicy foods in a similar fashion. However, humans have the capacity to refuse those certain foods and find alternatives. Your canine, on the other hand, is only provided with what you give him or her. Think of the most rancid meal you've ever had and then think about how you would feel if that was the only food available day-in and out.
Sometimes a neighbor may be inclined to feed your dog if they believe the animal is starving. Until you find what is causing the weight loss, your neighbor could be inadvertently making the matters worse by feeding the dog food that he or she can't digest properly. If you suspect your neighbor of treating your dog in this manner, speak to him or her and explain how the animal is having digestive problems and that the food is making it worse.
Don't Forget Your Veterinarian
Severe illnesses share the same symptoms. But if you ruled those out, it could be as simple as a problem with the food.
Jana's note: If my dog had unexplained weight loss, seeing a veterinarian would be my first course of action in order to make sure nothing sinister is going on medically. Food, could be behind many problems and symptoms. However, ruling out a medical reason is crucial. Food-related causes of unexplained weight loss are first four causes listed on petMD, but then there is a long list of other causes.
Note from VetChangesWorld: I have had several owners "convinced" their pet was losing weight due to their pet food when in fact the pet "did" have cancer, liver disease, or heart disease. They delayed their pet's care for months, putting their pet's life at risk because they were trying to switch between different foods. Even if your pet does not have diarrhea - if your pet is losing enough weight that you can tell, I would highly recommend checking with your vet FIRST so they can both rule out any more concerning conditions and help you pick an appropriate and healthy pet food. More expensive does not necessarily mean better quality.
If you're unsure about the proper look of your dog's breed, consult your veterinarian or research the breed type online. Some breeds naturally look anorexic without actually being sick. In fact, some breeds are considered overweight if you can't see the silhouette of a ribcage such as a Greyhound or the Rhodesian Ridgeback.
@KenneyMyers on Twitter.