Unexplained Weight Loss in Dogs: Why Is My Dog Losing Weight?

It does make sense to take a close look a the diet, especially if you recently changed your dog’s food. Don’t think that only inferior foods can cause problems—even an expensive brand can cause trouble.

For example, at one time, we experimented with various freeze-dried foods. One of them we tried contained turkey and chickpeas as main ingredients—sounds great, doesn’t it?

The chickpeas were ground into relatively fine grit visible after adding water. What I noticed, however, that my dog’s poop was full of identical particles. However, nutritional chickpeas might be, they went through my dog untouched by the digestive process.

No matter how wonderful the ingredients in your dogs food sound, they are useless of the body cannot use them.

If your dog isn’t eating, naturally, they’ll start losing weight. Food is essential to survival, though, and dogs instinctively know that. Generally, dogs won’t begin to refuse food unless they are seriously stressed, ill, or in pain.

It is imperative that you figure out the reason behind your dog’s anorexia. Some potential causes include:

• severe stress or anxiety
• serious illness
• pain
• fever
• severe dental disease

Further information: Loss of Appetite in Dogs: Why Did My Dog Stop Eating?

If your dog regurgitates, it means the food doesn’t even reach their stomach. While different from vomiting, regurgitation can lead to starvation.

Further information: Regurgitation in Dogs: Is It Different from Vomiting?

Anything that interferes with chewing or swallowing results in reduced interest in eating. Dental disease is one example but other conditions, such as masticatory myositis can have the same outcome.

Any condition that causes nausea will reduce the desire to eat, and it can lead to weight loss.

If your dog is throwing up, they are likely to be nauseous and not eating—which would technically fall into the earlier category. However, even if your dog is eating, diarrhea or vomiting leads to a severe loss of water and nutrients. Depending on the severity, though, dehydration can be the more imminent threat.

It is essential to identify and resolve the reason your dog is having diarrhea or throwing up.

One situation is particularly of note—when your dog’s poop is greasy, slimy, and clay-colored. You might be looking at insufficiency pancreatic deficiency, which is a condition when your dog is unable to digest their food. Your dog will eat ravenously but still starve.

Further information: Excessive Hunger in Dogs: What If Your Dog Acts Like They’re Starving?

Intestinal parasites can literally steal the nutrients your dog eats. While this problem is not as common as it used to be in the past, it can happen. Whipworms, in particular might be to blame.

Since whipworm infestation can also lead to loss of appetite, vomiting, and diarrhea, it is a double-whammy.

Some cancers have high metabolic demand and will rob the rest of the body of calories. Further, associated pain can make your dog lose interest in eating.

The kidneys process blood by filtering out wastes and toxins, while preserving nutrients and water and sending back into the body. When the kidneys don’t function properly, it leads to accumulation of toxins in the blood and/or loss of nutrients through urine.

Further information: Kidney Disease in Dogs – Say What? Canine Kidneys and the Associated Verbiage

Sometimes, nutrients, such as protein, can be lost in the strangest ways. In PLE, protein is lost be excessively leaking back into the GI tract after already being digested and absorbed.

Despite initially mild symptoms, PLE can become a life-threatening situation fast. This problem goes far beyond the nutrient loss itself.

Along with weight loss, signs include ambiguous things such as:

• loss of appetite
• vomiting
• diarrhea
• blood in the stool
• lethargy
• lethargy

Potential causes include GI disease, lymphatic disease, or heart disease.

Further information: Protein-Losing Enteropathy (PLE) in Dogs

Gastrointestinal disorders can lead to vomiting or diarrhea, resulting in nutrient loss. However, a diseased gut can also lead to malabsorption or maldigestion. What is the difference?

Maldigestion means that the GI tract cannot break nutrients down to their basic building blocks. Unless the food is taken apart into usable bits, it cannot get absorbed and passes through the digestive tract without the body being able to benefit.

Once the food is broken down/digested, the individual, broken-down nutrients pass through the intestinal walls for distribution through the body. If the intestinal wall is diseased, it is unable to perform this important part, which is referred o as malabsorption.

While the end result is pretty much the same, the causes are not.

After nutrients are digested, absorbed, and sent into the bloodstream, they still need to make their way to where they’re needed—the cells.

For example, a condition such as diabetes means that glucose accumulates in the blood while the cells starve for it.