There are a very large number of different factors that can lead to weight loss in cats and it often takes investigative work to find out exactly what is going on. There is no doubt that weight loss in cats, regardless of age or breed, is an important discovery. Except in specific cases, such as when an owner has tried to make his cat lose weight by giving him fewer calories or increasing his physical exercise, weight loss is a sign that something is going on.
Some owners may notice that their cat (especially if it is an outdoor cat that likes to hunt) can sometimes lose some weight in the summer and pick it up again in the winter. As long as weight loss is not substantial and the animal still has a normal body condition score, this may be acceptable. Veterinarians usually have a register that allows them to know what weight cats have weighed in previous years and, as long as the pace is steady, this slight weight loss can be ‘normal’. This is probably due to the fact that they are more sedentary in winter and spend much more time indoors, lazing around. In general, weight loss of 10% or more is a concern.
When trying to determine the cause of weight loss, it is important to look for any other clues that might help us determine what is going on. Owners should pay close attention to their cat; eating habits, litter habits and general activity. They should report any vomiting or coughing and inform the veterinarian. If a cat normally does its “needs” outdoors, it may be helpful to bring it in for a few days to make sure that it is urinating normally and that it has no diarrhea or constipation. Similarly, homeowners should watch their cat eating: does he leave hard cookies behind or does he have trouble swallowing?
Owners are encouraged to take a closer look at their cat’s diet and routine. Have they changed their brand of food or has another family member started feeding the cat? Has an overly friendly neighbour who spoiled the kitten with food recently moved? Did he forget to buy these delicious treats last month? It may be a good idea to rate a cat’s caloric intake over a few days to make sure it receives a sufficient amount of food. All treats or human food they eat must be included. Calorie requirements depend on factors such as the cat’s age, size and breed, and a veterinarian can help determine them.
One of the most obvious causes of weight loss in cats, especially in young adults and active hunters, would be parasites. Cats that have worms (such as tapeworm and ascarid) can continue to eat well, but they lose weight because worms consume all the nutrients from food. Owners may also notice that the cat has a swollen belly, poor quality coat and raised third eyelids. Although it is possible to see worms in a cat’s poo or on the fur around its buttocks, this is not always the case. The general recommendation is that all cats should be dewormed every 3 to 6 months with a good quality product. Those who hunt or eat raw foods may need to be treated more regularly than that.
Having a large external parasitic load, such as many lice or fleas, can also lead to weight loss because not only do they transmit worm infections, but they can also lead to excessive scraping and over-treatment that burns a lot of calories. It is important to eliminate these itchings by using effective and complete control of parasites.
.Another common cause of weight loss is an oral disease. In a young cat, it can be gingivitis, while older cats are prone to oral abscesses and rotten teeth. Cats generally don’t like someone looking in their mouth, but if an owner does, they may notice red gums, a build-up of brown tartar, and a foul smell. It is wrongly believed that cats stop eating when they have a toothache, but this is not the case. In the wild, if a cat stopped eating, it would not be taken to the vet, it would simply die. As cats continue to eat, many homeowners will neglect dental disease, assuming everything is fine. However, savvy owners may notice that a cat eats slowly or chews its food quickly (to avoid pain when chewing). They may also prefer wet food to dry food and may eat less than they normally would. Veterinarians can quickly diagnose if there is a problem with the mouth and often a dental cleaning is enough to solve the problem.
When a veterinarian is confronted with a cat who is losing weight, he or she always performs a thorough physical examination. This review can help determine where the problem lies. He will look for telltale signs of an underlying condition, such as pale gums, goiter (thyroid swelling), rapid heartbeat, enlarged or narrowed organs, thickening of the intestines, or fever. Through their experience, they may be able to clearly guess the nature of the problem, but they usually perform basic blood and urine tests to accurately diagnose the problem.
Many (but not all) causes of weight loss in a cat can be detected through simple and relatively inexpensive internal testing. Many clinics are able to provide same-day results. Chronic conditions such as kidney disease, diabetes, liver failure, viral infections (such as IVF or FELV), and hyperthyroidism are easily detected from just a few ml of blood.
If a cat loses weight and its blood and urine tests return to normal, this does not rule out an underlying problem and simply means digging deeper. Some causes of weight loss, such as inflammatory bowel disease or intestinal lymphoma, may not be detected by urine and blood tests. For animals whose disease is not diagnosed from basic tests, further investigation is required. Many of them will undergo more specific blood tests, which will evaluate organs such as the pancreas and determine the extent to which the intestine absorbs nutrients. A stool examination can also be ordered to eliminate any strange or rare parasite or infection in the intestine. Similarly, imaging studies such as chest x-rays and abdominal scanners are often recommended to look for items such as cancer.
It is frustrating to note that some conditions are difficult to distinguish and that it is sometimes difficult to tell, from an abdominal scan, whether a cat has inflammatory bowel disease or bowel cancer. For this reason, it may be suggested that bowel biopsies be done in order to diagnose and begin treatment.
It is important to mention that rapid weight loss, especially in overweight cats, can lead to a dangerous condition called ‘foie gras’, or liver lipidosis. If left untreated, this infiltration of fat into the liver can lead to liver failure and even death. Owners may notice that their kitten has suddenly developed a yellow tint on the skin and eyes (yellowing), vomiting, drooling, and hiding. When offered food, he is unlikely to accept it. Fortunately, cats that are treated quickly and effectively have an excellent prognosis and tend to recover completely. Time is an essential factor and the faster the cat is admitted to the hospital, the sooner it can recover. Treatment consists of supportive care, nutritional support, intravenous fluids, and management of the underlying condition that led to a lack of nutrition and weight loss in the first place.
Although a veterinarian may initially treat your cat symptomatically, perhaps by giving it appetite stimulants, fluid therapy and a high-calorie diet, the important thing is to find out why a cat loses weight in order to put in place an appropriate course of action. Not all diagnoses can be cured and some cats may need life-to-life therapy. Many cats will need frequent checks and weight checks in the future to ensure that their condition is well managed.