Malnutrition in dogs occurs when there is a deficiency or imbalance in a nutrient or nutrients in the body. Over time the dog can lose weight, body fat and become emaciated. This condition is typically seen in homeless dogs or animals which have been mistreated or abused by their owner, who may restrict their feedings. The causes of malnutrition are quite broad. Though diet can be one of the main reasons for malnutrition, other health issues can be responsible for the symptoms [ 1].

Causes of malnutrition

Some causes of malnutrition include:

  1. Underfeeding
    Underfeeding is the leading cause of malnutrition. An animal that is underfed won’t have all the nutrients, vitamins, minerals and energy needed to perform its basic metabolic and day to day functions. The dog’s body will then start to feed off itself, breaking down body fats and muscle tissues in order to survive. The dog will become skinny, lethargic and more prone to other health issues. As mentioned earlier, this type of malnutrition is typically seen in homeless dogs that don’t have access to food on a regular basis and those that are abused by their owner (severe food restrictions). You can also underfeed your dog if you do not know how much to feed it. Following the feeding instructions or guidelines on dog food labels as is one way to reduce the risk of such a problem.
  2. Overfeeding
    Dogs can suffer from malnutrition if they are overfed. The extra energy or calories can cause weight gain and build-up of excess nutrients such as minerals and vitamins in the body, which can cause harm. It is important to find out the recommended energy requirement for your dog’s breed, age and activity level. See a veterinary professional for further advice.
  3. Unbalanced and/or low-quality diet
    Some low-quality food products may contain little to no beneficial nutrients, harmful ingredients or preservatives and chemicals that may restrict the absorption of vitamins and minerals by your dog. Many veterinary and behavioural experts are questioning the overall impact that processed chemical- toxin-heavy or dyed commercial dog foods have on the health and behaviour of animals. The continued use of inexpensive and unusual protein sources is thought to be directly and indirectly involved in the disruption of pathological pathways, which can lead to decreased immunity, health and allergic diseases, cancer, as well as behaviour and or stress related problems [ 2 ] “Some of the biggest dog food companies can have the worst ingredients” [ 2 ].
  4. Parasites
    Parasitic infections or infestations can cause nutrient deficiencies in your dog’s body. Tick infestations can cause anaemia, resulting in reduction in blood and iron in the body. It can also lead to various tick borne diseases such as dog tick fever (Canine Anaplasmosis), Lyme disease, Canine Ehrlichiosis, which can all lead to malnutrition and even death. Tapeworms can absorb most of the nutrients from your dog’s digested meals and cause your dog to suffer from nutrient deficiencies. Routine deworming of your dog’s can help with this issue.
  5. Underlying health issues
    Many dogs can become malnourished due to medical disorders. Diseases such as intestinal cancers, chronic inflammation and irritable bowel disease can still cause malnutrition in dog’s that are fed a healthy, balance diet. A trip to the vet could help to determine any underlying disorders such as these.


Signs and symptoms of malnutrition may include:

  1. Rapid weight loss
  2. Dull coat
  3. Hair loss
  4. Flaky skin
  5. Gastrointestinal problems (diarrhoea, gas)
  6. Visibility of dog’s bones (hip bones, rib bones etc.)
  7. Disease prone (compromised immune system)
  8. Lethargy
  9. Refraining from running or any activity [CITATION Can18\l 9225]

Caring for a malnourished dog

It is important that you take your dog to the vet if you believe that they might be displaying signs and symptoms of malnutrition. Your vet can run various tests to find out the cause of any problem that your dog may have.


Emaciated dog

Emaciated dogs need immediate medical attention. Some might require intravenous fluids and other supportive treatments due to the severity of their condition. People often feed emaciated dogs with large amounts of food because they believe that it will help them gain weight faster. In some cases this has caused the death of the dog and should not be practiced. When the emaciated dog’s body is suddenly inundated with food after it has gone a long time with so little, it creates a sudden rise in body fluids, vitamins and minerals which may cause imbalances in the organs and brains. This could then can lead to sudden deaf [3]. This condition is known as “refeeding syndrome”.


The solution is to feed small quantities of higher energy foods. Veterinarians may have different feeding strategies to avoid refeeding syndrome. One such strategy entails feeding the dog one-third of its normal maintenance requirement and then slowly increasing the amount as the dog begins to recover [ 3]. For example, if the dog’s healthy adult weight was supposed to be 11 pounds and its energy requirement for that weight was 456 Kilocalories, then it would be fed a balanced, high quality food with a total of 152 Kilocalories (1/3) for its first meal. Another strategy is to feed less but doing so more frequently such as three to four times a day. Always have water available. Malnutrition is a serious health issue that needs to be addressed as quickly as possible because it can produce irreversible damages to the dog’s body [ 3 ].

Malnutrition can be a very serious threat to dogs, especially if left untreated for an extended period. It is important to see a vet if you notice any signs and symptoms of the disease such as dull coat, rapid weight gain or weight loss and lethargy. See your veterinarian as soon as possible for an exam.


[1] Canna-Pet, “Signs of Malnutrition in Dogs,” 24 April 2018. [Online]. Available: [Accessed 19 January 2019].

[2] V. JP, “Does diet contribute to abnormal dog behaviour?,” Veterinary Record, vol. 180, pp. 16-17, 2017.

[3] J. Coates, “feeding the Starving Dog,” PET MD, [Online]. Available: [Accessed 19 January 2019].


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