How do I fatten up an underweight cat?
Now to answer the question, firstly of course if there is an underlying sickness contributing to a loss of appetite that needs to be addressed (we will look at that further down the article). If that is fixed, the appetite should return. Basically, you want to stimulate your cat's appetite (if he's stopped eating) and/or increase calories. Below are some ways to help fatten up a cat.
Why is my cat losing weight?
Cats lose weight for a number of reasons and diet alone is just one small cause. Before we go into ways to help fatten up your cat, it is important to determine if there is an underlying cause. Weight loss can be loosely divided into the following categories:
- Sickness resulting in a loss of appetite
- Loss of appetite due to other factors (fussiness, stress etc)
- Weight loss despite a healthy appetite and no underlying sickness (not enough food, nursing queen, age-related it is common for cats to lose muscle mass as they age)
- Weight loss due to a medical condition but not related to loss of appetite (hyperthyroidism, IBD to name two)
Medical causes are seen most commonly in middle-aged to senior cats, the majority of which cause your cat to lose weight due to a poor appetite. Hyperthyroidism, on the other hand, speeds up your cat's metabolism, so despite a normal to increased appetite, your cat continues to lose weight.
The most common causes in middle-aged to senior cats include:
- Hyperthyroidism - Caused by a benign tumour of the thyroid gland which causes the metabolism to speed up.
- Diabetes -
- Kidney disease - Senior cats are very prone to developing kidney disease. As the kidneys fail, toxins begin to build up in the cat's system, causing him to feel unwell and lose his appetite.
- Cancer - There are many types of cancer which can develop in cats, most cancers will cause your cat to feel unwell, which in turn leads to anorexia and weight loss. Cancers can develop in the cat's mouth, creating discomfort when he eats.
Other causes of weight loss include:
- Parasitic worms - Cats are prone to several types of parasitic worms, tapeworm is the most common cause of weight loss in cats due to the worm competing with the cat for food.
- Nursing kittens - A lactating queen (mother cat) uses enormous resources to provide nourishment to her kittens, which over time can lead to her losing weight.
- Mouth ulcers
- Cryptosporidium and giardia - Parasitic infections caused by single-celled protozoa resulting in vomiting and diarrhea.
- Ecoli - A bacterial infection of the intestinal tract leading to vomiting and diarrhea.
- Inflammatory bowel disease - A leading cause of vomiting and diarrhea in cats, IBD is a group of disorders caused by the infiltration of inflammatory cells in the intestinal tract resulting in poor digestion and absorption of food.
- Cat flu - There are several types of pathogen which can cause flu in cats, symptoms typically affect the upper respiratory tract which can result in a loss of appetite as they lose their sense of smell.
- Stress - Cats are very sensitive to changes in routine, household, bullying from other cats.
This list is by no means extensive, there are many other medical causes. Read here for more causes of weight loss in cats.
How is the cause of weight loss diagnosed?
Many of the above conditions will also have additional side effects, which can give your veterinarian an indicator as to what the problem is.
Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you. He will want to perform some baseline tests to check the overall health of your cat. These will include a biochemical profile, urinalysis and a complete blood count. Depending on his index of suspicion, he may want to perform additional tests such as x-rays, ultrasound, and additional bloodwork.