Dog Losing Weight: What you should know

Introduction

Generally, a dog that is underweight means its weight has fallen below the ideal or optimum weight for the dog. Specifically, a dog is considered ‘underweight’, ‘thin’ or ‘malnourished’ if it loses between 10% and 20% of its ideal weight. This is a sign of concern for dog owners.

How do we know if a dog is losing weight? Let’s find out more about what causes weight loss in dogs.  

Photo by Sam Lion from Pexels

Causes of weight loss in dogs

A dog’s weight loss may be normal, sudden or rapid, or even inexplicable. To spot an underweight dog, you could look for these signs: 

• Its ribs, spine and hip are visible or pronounced and can be easily felt. 
• From an overhead view, the dog has a marked hourglass frame. 
• From its side view, there is also a marked abdominal tuck.

If it loses more than 20% of its ideal weight, the dog is then considered ‘very thin’. In this scenario, drastic action is usually needed to restore the dog’s health and well-being. You may check out the symptoms of a very thin dog in the dog weight chart and learn more on How to Help an Underweight Dog Gain Weight.

Here are some common causes of weight loss in dogs.

Parasites

Parasites are organisms that survive by living in or on another organism: the host. Two types of parasites common in dogs are internal and external (fleas, lice, ticks, mites) parasites.

Internal parasites are intestinal worms such as (arranged from ‘potentially deadly’ to ‘the least deadly but most hardy’): tapeworms, heartworms, hookworms, roundworms and whipworms. Intestinal worms can originate from several sources. Pregnant or nursing dogs, for example, can transmit hookworm and roundworm larvae to their puppies during pregnancy or lactation.

Puppies and dogs exposed to contaminated food and water, stagnant water bowls or the environment — where the soil may contain parasite eggs or faeces of infected dogs — might ingest hookworms, roundworms and whipworms. Additionally, dogs may ingest tapeworms during grooming.

These exposures to parasites may contribute to mild symptoms (tiredness, scratching, vomiting, diarrhoea), or bloody stool, weight loss, and death if untreated.

Weight loss by parasitism in healthy dogs can be detected and treated at a veterinary clinic. Although dog owners cannot eliminate their dog’s exposure to parasites completely, they can definitely protect their dogs against parasites via deworming.

Wrong diet, changes in diet or fussy eater

A dog’s diet is important for sufficient nutrition. A diet that is wrong for a particular dog can cause it to lose weight brought on by either malnutrition or other health complications.

Similarly, changes in a dog’s diet or food can result in weight loss. Dog owners need to be mindful that not all pet food have the same nutritional value. To mitigate this, they should compare the ingredient labels of pet food.

A dog could also just be fussy about its food, thus eating less or not at all. This could trigger weight loss if prolonged. Read on more about this, and other reasons for weight loss in dogs plus the suggested solutions, at How to Feed Underweight Dogs. 

Diseases and disorders

Weight loss can be a sign of a disease or disorder in dogs, especially if it happens suddenly, rapidly or inexplicably. This can affect dogs of any age and breed.

The weight loss may take place over a short period of time, and occur even if the dog’s diet and exercise routines are the same. The best way to address this concern is to consult a veterinarian.

The following diseases are a cause of concern and may contribute significantly to your dog’s weight loss:

• Cancer

• Cancer can bring about unexplained weight loss. This is generally more common in older dogs.
• Dogs with mouth cancer usually avoid food due to discomfort or pain while eating and swallowing. Consequently, they will lose weight. However, early detection and treatment of the disease could save your dog’s life.

• Kidney disease

• Weight loss induced by a build-up of a loss of appetite, vomiting and severe diarrhoea could be linked to chronic kidney disease.
• Sometimes, however, a dog suffering from kidney disease will eat normally, and still lose weight. Therein lies the importance of dog owners not to take their dog’s weight loss for granted.
• Consulting the veterinarian early can catch or rule out kidney disease and, in the process, address the dog’s weight loss.  

• Heart disease

• Dogs suffering from heart disease may experience weight loss due to decreased appetite. On the other hand, these dogs may also experience unexplained weight loss.    
• Thus, it is pertinent to consult the veterinarian early, so that heart disease can be diagnosed, or ruled out, and treatment can begin. A treatment plan will help in managing the dog’s condition and ensure that the dog still has some quality in life.

• Dental disease

• Dogs experiencing oral pain, an abscess or other gum problems will have difficulty eating. Dogs with advanced dental diseases will generally be ill.
• Both situations inevitably lead to weight loss. Thus, dog owners need to always check and monitor their dog’s dental hygiene to prevent any diseases.
• Moreover, if a dental disease progresses, it could spread to other parts of the dog’s body, risking painful heart, liver and kidney infections.

• Gastrointestinal disorder

• A gastrointestinal disorder involves the stomach and intestines. It can be caused by a pet dog swallowing an item by mistake, or a variety of other causes.
• When the item gets trapped in the dog’s digestive tract, it prevents nutrient absorption. This problem can gradually trigger weight loss because, despite still eating regularly, the dog may also experience vomiting and diarrhoea.
• The dog could eventually become significantly underweight, despite the type and amount of food it receives.
• Furthermore, it could result in other risks (internal perforation). Hence, the item or obstruction should be removed, before it leads to bigger problems other than weight loss.     

Anxiety, stress or depression

Anxiety, stress and depression can negatively impact a pet’s appetite. A pet dog that is distressed in a household may start being disinterested in its food.

Being abandoned by owners, the addition of a new pet in the house, or being neglected: these are potential stressors that affect weight and cause depression in pet dogs. Chronic stress can weaken the dog’s immune system, increasing its risk of developing an infection.

So, dog owners who notice their dogs appearing anxious or depressed should find out what is causing the distress and address this source.    

Old age and muscle atrophy

Ailments that older dogs are susceptible to go hand in hand with loss of appetite and weight loss. However, weight loss for no apparent reason is also common in aging dogs.

Thus, weight loss can be due to age-related health issues (diabetes, liver disease, kidney disease). Yet, it is also true that older dogs are just more prone to weight loss, and muscle atrophy (wasting away of muscle), as they age.

The best way to determine the real reason for weight loss in senior dogs is to consult a veterinarian. In some cases, veterinarians might suggest a suitable comfort food to restore the senior dog’s appetite and rehydrate it, such as bone broth for senior pets.

Early signs of dying for older dogs

Weight loss in much older dogs can be an early sign of dying. Apart from the loss of weight, other common symptoms to look for are tiredness, decreased appetite and social detachment.

These symptoms may start to become apparent months or weeks prior to death. For some dogs, these signs may even start to show just days before their last breath.

As dog owners, it may be painful to acknowledge these facts. However, being aware and prepared would enable dog owners to provide a comfortable transition during their old dog’s passing.  

Final words

The underweight dog could be suffering from a single factor, or a host of reasons, that causes its weight to plummet. 

Ultimately, dog owners should determine the actual cause(s) for the dog’s weight loss before trying to cure its condition. With information and awareness, they can learn how to help an underweight dog gain weight and how to feed underweight dogs properly.