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Cats are beautiful in all sizes. However, you may very well be concerned about your cat being too skinny, especially when she seems to be eating normally.
Just like being overweight can be an alarming issue, being too skinny can also be a red flag for various underlying health problems in cats.
Several factors may be causing your cat to lose weight or prevent her from gaining weight. These factors can vary based on her age or breed, her activity levels, the food she eats, or any health issues she may be experiencing such as diabetes, hyperthyroidism, intestinal parasites, and so on.
Below you’ll find all these factors explained, as well as information about how to tell if your cat can be considered too skinny and how a healthy-weight cat should look like.
Factors That Inhibit Weight Gain in Cats
The factors listed below depend on your cat’s particular circumstances and her natural traits such as her age, breed, and temperaments.
Senior and geriatric cats are most prone to losing weight even when they maintain their usual appetite. This is because old age inevitably brings with it metabolic changes and deteriorates their digestive functions.
Senior cats are also more likely to experience medical problems such as diabetes, hyperthyroidism, and organ failures like kidney disease. These are all health problems that cause weight loss due to symptoms such as diarrhea, vomiting, excessive activity, excessive urination, and muscle loss.
High Activity Levels
Simple math tells us that burning more calories than consumed will lead to weight loss. This usually happens when a cat starts eating less than usual due to physical or psychological distress. However, when a cat eats normally but keeps losing weight, it may have something to do with how active she is.
Activity levels usually depend on a cat’s breed, age, particular temperament, and living situation.
Kittens and junior cats tend to be more active than older, mature cats. They also need almost twice as many calories that an adult cat requires to grow properly. It can vary from cat to cat, but generally, as younger cats mature, they become calmer. Contrary to popular belief, this isn’t a result of neutering, but a natural course of aging.
If you have a young cat that doesn’t seem to be putting on the weight she needs to as she grows, visit your vet to eliminate any health issues such as intestinal parasites.
Some cat breeds are more active than others by default. Breeds such as the Abyssinian, Bengal, Savannah, and Siamese are usually very athletic and active. You may have noticed that these cats appear more slim and fit, like a leopard or a cheetah.
When compared to these, breeds such as the Persian, Ragdoll, and Maine Coon are more sedentary. They are what we usually call “lap cats” and their physical appearance is quite distinct from the more active breeds mentioned above.
Cats that have a chance to go outdoors are also likely to be more active because of their particular living circumstances. When a cat goes outside, she is more alert for danger and has a lot more stimuli to keep her busy and moving.
Depending on the circumstances of her outdoor environment, your cat may be running after a bird or sleeping in a sunny patch. So not all outdoor visits necessarily mean that your cat will be more active than usual.
Although these factors affect a cat’s activity levels and the extent of their daily calorie burn, it is still an important issue if she keeps on losing weight. Even when a cat is very active, she should at least be maintaining her weight if she eats well. So if you are sure that your cat gets all the calories she needs and she’s still losing weight, take her to the vet for conclusive results.
Choice of Food
Even though you may have been feeding your cat the same food for years with no problem, it is possible that she may need a dietary change.
Your cat’s current food may not be fulfilling her caloric or nutritional needs as well as you thought. Or, your cat may be allergic to an ingredient in the food – many cat foods contain a small number of whole foods such as cranberries, tomatoes, and apples.
This is why it’s important to read cat food labels carefully and compare nutrient ratios to facilitate a healthy weight gain.
Go for foods that have high amounts of quality protein. Although they should not be eliminated, fiber and carbs should be at a minimum (no more than 2%) because they upset your cat’s digestion.
The best hack for having your cat eat high amounts of nutritious calories is to go for very tasty food with high calories of protein and fat. The most recommended method to achieve this kind of food is to mix dry and wet food.
Wet food is often recommended for cats that have issues of weight and appetite loss. This is because wet foods usually have more protein than dry foods. Plus, they have more moisture which helps with proper hydration.
Mixing wet and dry food is also a smart idea if your cat refuses to give up her beloved kibble. You may also consider adding delicious, nutritious toppers to your cat’s usual food.
Please consult your vet when going for a change in your cat’s diet. Your vet will do the best job recommending the most fitting food for your cat.
Health Problems That Cause Weight Loss in Cats
When a cat is losing weight even though she eats normally, it is most likely due to the health issues listed below.
Gastrointestinal problems in cats affect their digestive tract and can range from mild to severe. They can be acute (set on by a virus, bacteria, parasite, toxin, etc) or chronic (set on by allergies, cancer, or recurrent infections – especially in older kitties.)
Weight loss as a symptom is especially common in senior cats that suffer from gastrointestinal disorders.
Other symptoms such as diarrhea, vomiting, and lethargy are common in cats that are experiencing digestive problems. Unfortunately, these symptoms can be signifying a number of issues, so it’s best to take your cat to the vet for a definitive diagnosis and a fitting treatment.
Some chronic gastrointestinal problems include pancreatic insufficiency, feline inflammatory bowel disease, and gastrointestinal lymphoma (cancer). These chronic ailments can be diagnosed through a variety of methods such as fecal testing, T4 hormone count, abdominal ultrasound, and chemistry panel testing performed on a blood sample.
Depending on the diagnosis, your vet can recommend treatments ranging from a simple dietary change to a more specialized medication or even surgery.
Acute gastrointestinal conditions usually include food allergies or infections caused by foreign bodies in your cat’s digestive tract such as parasites, viruses, bacteria, toxins, etc.
Out of these, intestinal parasites are the most common reason for sudden weight loss in cats.
Intestinal parasites are also considered a gastrointestinal problem because they cause a disorder in a cat’s digestive tract. I wanted to put them under a separate heading because several types of internal parasites may cause unwanted weight loss for a cat.
Roundworms are the most common intestinal parasite that can cause unwanted weight loss in cats.
When a cat has roundworms in her intestines, the symptoms include weight loss, vomiting, diarrhea, a dull-looking coat, and a slightly enlarged belly.
Cats usually get roundworms from contact with rodents and other small animals. Cats have a high chance of ingesting the larvae that are carried by these animals. So, if your cat likes to go outdoors and has a habit of bringing you gifts like mice, she may be at risk of getting roundworms.
Kittens can also get roundworms from their mother’s milk, if their mother has roundworms.
You can easily spot roundworms in your cat’s feces. They appear as little stringy worms that are quite easy to distinguish. Just keep in mind that humans can also be affected by roundworms – so be very careful when examining your cat’s stool and take measures to keep your hands clean and out of your face.
There is no need to worry if your cat has roundworms because it is an easily treatable condition. There are several medications that eradicate roundworms that your vet can recommend to you.
The important thing is to keep in mind that these medications don’t work on the dormant roundworm eggs, but only on mature roundworms. So your vet will probably prescribe a treatment of a few rounds 2-4 weeks apart to get rid of all the larvae that may still be in your cat’s intestines.
To prevent your cat from getting roundworms in the future, you should adhere to her regular monthly internal parasite medication. It can also help to schedule routine stool checks even if you don’t suspect any problems.
Just like roundworms, hookworms also live in a cat’s intestines. They latch onto the intestinal walls and feed on the blood in the intestinal tissue.
Hookworms are often introduced to a cat’s system when she congests the larvae without noticing. Hookworms are usually found in moist and warm environments. Cats that go outdoors in such environments are prone to ingesting hookworm eggs by way of contact with other animals or surfaces.
Just like roundworm infections, kittens can also get hookworms from their mother’s milk if she has them.
The most common symptoms of hookworms in a cat is weight loss and an unhealthy looking coat. Since hookworms feed on the blood of a cat’s intestinal tissue, the most distinct result of hookworm infection is anemia. The digested blood in a cat’s intestines will cause the feces of an infected cat to appear almost black.
Just like roundworms, the diagnosis and treatment of hookworms are also easy. Your vet can easily recognize roundworm eggs in your cat’s feces under a microscope. The treatment takes at least two rounds of administering a medicine named anthelmintic to destroy newly hatched eggs.
Giardia are one-celled organisms that reside in a cat’s small intestine as a parasite. They cause giardiasis, an ailment that results in weight loss, diarrhea, dehydration, and lethargy in cats.
Fortunately, giardiasis is not very common. It usually spreads in poor, overcrowded environments such as shelters and kennels. Cats can pick up the parasite from each other’s infected feces by sharing a litter box or from contaminated water sources.
The diagnosis and treatment of giardiasis are relatively more difficult when compared to worms. Not all cats that have giardia develop giardiasis, but they can still spread it to other cats.
Giardia can be observed in a cat’s feces under a microscope or by testing for antibodies in the feces. Spotting giardia cysts in the feces is harder than spotting worms and several samples may be needed to be conclusive.
Once diagnosed, the treatment usually involves an antibiotic medication called metronidazole. A cat may need several rounds of this treatment because giardia can be resistant.
If your cat has giardia, make sure to keep her litter box clean to avoid reinfection. It is also important to separate litter boxes if you have multiple cats so that it doesn’t spread.
Hyperthyroidism is a glandular disorder that can affect any cat but is more common in older cats past the age of 10. Its most distinctive symptom is weight loss accompanied by an increase in appetite.
Other symptoms of hyperthyroidism include excessive thirst and urination, an increase in activity levels, vomiting, panting, and diarrhea.
Since hyperthyroidism causes elevated levels of the T4 hormone in the bloodstream, the diagnosis technique is a blood test.
Fortunately, hyperthyroidism is treatable – and it may even be curable if diagnosed early on. Some treatment options include antithyroid medication, thyroid gland removal surgery, and radioactive iodine therapy.
Diabetes means that a cat’s body cannot produce the necessary amount of insulin to regulate her blood sugar. Diabetes in cats can cause weight loss even though another one of its symptoms is that they eat a lot. This is because their body cannot make use of the nutrients they consume, so they crave more.
Other symptoms of diabetes include excessive thirst and urination (which cause dehydration) and vomiting. In some cases, there may also be a loss of appetite.
While the medical treatment of feline diabetes is insulin therapy, adjusting their diet will also help with the situation. Diabetic cats need to be on a high protein and low carb diet.
Psychological distress usually has appetite loss as a cause for weight loss. However, I still wanted to mention this possibility because it may sometimes be hard to tell if your cat is eating normally, especially if you look after multiple cats. If one of your cats is not eating enough, it may be difficult to notice because keeping track of how much each cat eats can be quite a task.
Stress and anxiety in cats can lead to eating disorders like anorexia. Anorexia in cats means a noticeable loss in their appetite that is caused by psychological rather than physical reasons.
There is also pseudo-anorexia, which is when a cat wants to eat but can’t, due to physical difficulties.
To avoid any psychological distress as a cause for appetite loss, you should make sure that your cat’s eating arrangement is ideal. Set her food in a clean, calm corner of your house that is away from her litter box. There shouldn’t be a lot of foot traffic or distractions near her food.
Evaluate your cat’s environment for causes like a big recent change (arrival of a new pet, moving to a new house, change in her usual food) or other constant factors such as too much noise, poor hygiene, stale air, etc. Keep in mind, cats are extremely empathic and may even mirror their owner’s mood.
If you don’t see any behavioral changes other than a loss of appetite, it may still be indicative of underlying stress-related issues. You should take appetite and weight loss very seriously.
Ideal Weight for Cats
There is no set ideal number for a cat’s weight. However, keeping in mind your cat’s age, breed, and health conditions, you may determine a healthy weight range for your cat and make sure she stays in there.
You don’t need a scale in order to determine if your cat is in her ideal range. On the contrary, a scale may even give you the wrong impression.
You can usually tell if a cat is under or overweight by her appearance, especially if she’s a shorthair breed.
How to Tell if Your Cat Is Underweight
With underweight cats, you can easily see their ribs, spine, and hipbones because they have very little or no fat. Underweight cats have a very deep abdominal tuck, which means that their belly area appears almost hollow. (Although as I’ve mentioned earlier, roundworm infection can make a cat’s tummy enlarged.) Underweight cats will also have little muscle so their legs will appear skinny rather than athletic and muscly.
If you have a long hair breed and can’t distinguish these features easily, you can also try inspecting your cat with your hands. This can be more difficult because unless you have an extremely overweight cat, you can feel their ribs, spine, and hipbones easily. Simply feeling these bones does not mean that your cat is underweight.
So here’s a trick: if their ribs feel like a very hard bone (like what you feel when you touch your knuckles), then it means there’s no fat around them. If the ribs feel a lot more cushioned (like the inside of your palm), then it may indicate excessive fat. The ideal hardness you feel should be like the back of your hand, slightly padded but not to the point of being squishy.
How to Tell if Your Cat Is Overweight
Unless she is severely obese, distinguishing an overweight cat can be more difficult because they obviously won’t have their ribs sticking out.
Perhaps the most distinguishing visual feature in an overweight cat is that she doesn’t have an abdominal tuck, which means that you can’t see her waist. She will also have a visible belly that may be drooping down depending on how overweight she is. Besides the torso, an overweight cat’s limbs will also appear chunky.
Look at your cat not just from the side but also from above. With overweight cats, you’ll see obvious protrusions to the sides (in the lumbar area). Although, this may also be the case with pregnant cats, so make sure you’ve eliminated that possibility before declaring your cat overweight.
For longhaired breeds, simply try to feel your cat’s ribs. If you can hardly feel them, or if they feel highly padded (like your palm instead of your knuckles), then there may be excessive fat around them.
The Healthy Weight
So, what should a healthy, ideal-sized cat look like? Again, I can’t offer you a scale number because an ideal weight number will vary depending on breed, sex, and age.
Just like I’ve explained with under and overweight cats, you can also tell when a cat is at her ideal weight by her appearance and through touch.
A healthy cat will appear well-proportioned. Whether you look at her from the sides or above, she will not show any abnormalities like a belly sweeping the floor or love handles extending to her either side. The limbs will not be too skinny or too chunky.
You will be able to see the waist of a healthy-weight cat, although her abdomen will not appear tucked or hollow. In fact, there can be a little bit of fat in the abdomen area.
A healthy-weight cat’s ribs can be felt, but with a bit of padding, like the back of your hand. They will still feel firm but not too boney like your knuckles.
Remember, weight loss is more or less a gradual process. It may be hard to notice, especially if your cat seems to be eating normally. This is why you should make sure to regularly check your cat’s stool, keep up with her routine parasite medications, and try to track any physical changes like the appearance of her coat, the condition of her teeth, her movement, and so on.
It is also important to keep an eye on any behavioral changes for signs of lethargy, stress, poor self-hygiene, unusual sleeping patterns, etc.
If you spot any irregularities in your cat’s appearance or behavior, the first thing to do is to visit your vet and get a full check up on your cat. This will reveal any existing problems and allow you to take action in treating your cat.