Feline Diabetes and Weight Loss: Uncover Causes, Spot Symptoms & Master Management!

Diabetes mellitus is a condition affecting a cat's ability to produce or respond to insulin, resulting in elevated blood glucose levels. Like humans, cats need glucose for energy, and insulin is the hormone that allows glucose to enter cells. When this process is disrupted, it can lead to various health issues, including weight loss. Understanding the causes, recognizing the signs, and implementing proper management strategies are crucial for ensuring a good quality of life for your feline companion.

Understanding Feline Diabetes

Diabetes mellitus in cats occurs when the body cannot properly produce or utilize insulin. Insulin, produced by the pancreas, acts as a key, unlocking cells to allow glucose from the blood to enter and provide energy. When insulin is deficient or ineffective, glucose accumulates in the blood, leading to a state of hyperglycemia.

There are two main types of diabetes in cats:

Type I Diabetes: Characterized by a decrease in insulin production.
Type II Diabetes: Characterized by cells not responding appropriately to insulin.

Cats most commonly suffer from Type II diabetes. In both types, cells are unable to access the glucose they need, despite its abundance in the bloodstream. It is estimated that between 1 in 100 and 1 in 500 cats will be diagnosed with diabetes during their lifetime.

Risk Factors for Feline Diabetes

Several factors can increase a cat's risk of developing diabetes:

Read also: Kidney-Friendly Cat Food Explained

Obesity: Obese cats are up to four times more likely to develop diabetes compared to cats with an ideal weight.
Age: Increasing age is a significant risk factor.
Physical Inactivity: Lack of exercise contributes to insulin resistance.
Gender: Male cats are more prone to diabetes.
Glucocorticoid Use: Steroids used to treat other illnesses, such as feline asthma, can increase the risk.
Breed: Burmese cats may have a higher risk in some countries.

Maintaining a healthy weight and encouraging physical activity through daily play are essential steps to reduce the risk of diabetes.

Clinical Signs of Diabetes in Cats

The two most common signs of diabetes noticed by owners are weight loss despite a good appetite and increased thirst and urination.

Weight Loss: In both Type I and Type II diabetes, the cells in the body are unable to absorb glucose from the blood and become starved of energy. To get the energy it needs, the body turns to other sources, breaking down fats and proteins to feed glucose-starved cells. This breakdown results in weight loss, despite an increased appetite.
Increased Thirst and Urination: High levels of sugar in the blood can overwhelm the ability of the kidney to filter glucose, allowing sugar to “spill out” of the blood and into the urine. This high urine glucose concentration can actually pull excessive amounts of water into the urine, resulting in increased urine volume, increased urinary water loss, a propensity for dehydration, and a compensatory increase in thirst. Excessive thirst and frequent urination are often the first signs noticed by cat owners. Diabetic cats may start relieving themselves outside the litter box due to the increased frequency.
Plantigrade Stance: In rare cases of uncontrolled diabetes, cats may experience damage to the nerves in the hind limbs, resulting in a “plantigrade” stance of the hind limbs (walking or standing with their hocks on or close to the ground). This is not painful, and will often resolve with treatment.

Diagnosing Feline Diabetes

A veterinarian will diagnose diabetes mellitus by demonstrating persistently elevated glucose levels in a cat’s blood and urine. This testing, along with consistent clinical signs, will lead to the diagnosis of diabetes.

Blood Glucose Reading: A single blood glucose reading in a veterinary clinic may not be sufficient to diagnose diabetes in all cases. Cats can develop a short-term elevation in blood glucose as a response to stress, known as stress hyperglycemia.
Fructosamine Concentration: In these uncertain cases a lab test known as a fructosamine concentration can be helpful. This test gives a rough average of a cat’s blood glucose concentration over the last two weeks, so would not be affected by stress hyperglycemia.
Additional Tests: Other tests will likely be recommended by the veterinarian to rule out other diseases which might be contributing to a cat’s clinical signs, such as a urinary tract infection, chronic kidney disease, pancreatitis or hyperthyroidism.

Treatment Options for Feline Diabetes

The main goals of treatment for feline diabetes are:

Restoring normal blood glucose concentrations
Stopping or controlling weight loss
Stopping or minimizing signs of increased thirst and urination
Avoiding inappropriately low blood sugar due to treatment (hypoglycemia)

These goals are traditionally achieved through a combination of insulin and dietary therapy, though new oral medications may be a good treatment option for some cats. Treatment options should be discussed with the veterinarian based on each individual cat.

Read also: Guide to Raw Feeding for Cats

Insulin Therapy

Injectable insulin is a mainstay of treatment for feline diabetes and has generally been considered the standard of care for cats with this disease. There are multiple types of insulin preparations that can be used for cats in the treatment of diabetes, such as lente insulin (Vetsulin), ProZinc or glargine insulin. These types of insulin vary in cost, duration of action, and concentration, so it is important for an owner to discuss the pros and cons of each type with their veterinarian when deciding which insulin is best for their cat. It is also important to note that each insulin type has a specific syringe size (U-100 or U-40), so it is vital that a cat owner ensure that they are using the appropriate syringe for their cat’s insulin.

Insulin injections are given under the skin (subcutaneously) approximately every 12 hours. While giving injections may seem daunting, most owners can be taught to administer these injections at home quite easily and due to the very small needle size, cats tend to tolerate these injections very well. Though ideally injections should be spaced 12 hours apart, varying injection times by 1-2 hours when needed will not adversely affect a cats’ treatment.

Dietary Therapy

A diet low in carbohydrates has been shown to improve blood sugar regulation in diabetic cats. There are several prescription food options that are available in both wet and dry food forms, though feeding a wet-food only diet may be beneficial for many cats. For cats who are overweight when diagnosed with diabetes, slow, controlled weight loss under the close monitoring of a veterinarian is very important to achieve better control over blood glucose levels.

The optimal timing of meals for diabetic cats is controversial. Many veterinarians recommend feeding at the time of insulin injection to avoid a dangerous drop in blood glucose levels. However, there is no definitive evidence that the timing or frequency of meals in diabetic cats protects them from insulin-induced hypoglycemia. With a low carbohydrate diet, free choice feeding may be acceptable for cats who prefer to “graze” throughout the day, especially if a longer-acting insulin preparation is used. If food must be withheld for any reason, such as an anesthetic procedure, it is generally recommended to give 50 percent of the usual dose of insulin, with careful follow-up monitoring to ensure good glycemic control.

Oral Medications

In 2023, a new class of medications that are administered by mouth once daily was approved for the treatment of feline diabetes,. These medications, known as SGLT2 (sodium-glucose cotransporter 2) inhibitors, lower the concentration of glucose in the blood by increasing the amount excreted through the kidneys. These medications help improve the clinical signs of diabetes by lowering insulin resistance and reducing damage to the pancreas, allowing the cat to produce more of its own insulin. Because these treatments rely on the cat making at least some insulin on its own, it is not appropriate for every patient, and this treatment should be discussed with a veterinarian before starting. SGLT2 inhibitors are approved for treatment of newly-diagnosed diabetic cats who are otherwise healthy and have not been previously treated with any injectable insulin, and studies have shown these medications to be more than 80% effective at improving blood glucose control in appropriate patients.

Monitoring Your Diabetic Cat

Close monitoring by both the owner and the veterinarian is an essential part of treatment for a diabetic cat. Regular monitoring will help determine the ideal insulin dose for each cat as well as help avoid complications, such as hypoglycemia or uncontrolled diabetes and diabetic ketoacidosis. Regular assessments of weight, water intake, and appetite should be recorded to help determine if treatment goals are being met.

Blood Glucose Curves: Blood glucose curves are the ideal way to monitor blood sugar regulation during treatment. During a blood glucose curve, the cat’s blood sugar will be checked right before receiving an insulin injection, and then every 1-4 hours throughout the day. This helps make sure that the average blood glucose is within an acceptable range, and that the value does not drop dangerously low at any time throughout the day. These assessments may need to be performed every few weeks when a cat is first diagnosed with diabetes in order to determine the appropriate dose of insulin, but can be spaced out further once the diabetes is more well-regulated. Even in a stable cat, blood glucose curves should still be performed every 3-4 months, as insulin needs can change over time.
Home Monitoring: Eventually, many cat owners can learn to perform blood glucose curves at home. This helps avoid stress hyperglycemia and inappetence experienced by many cats in the veterinary clinic, and can therefore give more accurate results. Blood can be collected at home from an ear vein or paw pad, and should be read on a blood glucose monitor that has been tested in cats. Alternatively, some veterinarians may utilize a continuous blood glucose monitoring system to help determine blood sugar concentrations at home. With this approach, a small monitor is implanted on the cat’s skin in the veterinary clinic, which stays in place and records blood glucose readings every few minutes for a few days up to two weeks. Though this can provide a lot of information without repeated needle pricks, not all cats will tolerate the monitor for long so it is not a viable option for all owners. It is very important that owners who monitor blood glucose readings at home do NOT change their cat’s insulin dose without discussing first with their veterinarian.
Fructosamine Concentration: If performing a blood glucose curve is not an option, a fructosamine concentration can be used to get a rough estimate of blood sugar control over the last two weeks with a single blood draw. However, this is not an ideal way of monitoring a diabetic cat as it only measures the average, rather than the blood sugar highs and lows throughout the day, which are often more important in determining the success of their treatment.

For cats being treated with an SGLT2 inhibitor, close monitoring is also important, especially during the beginning of the treatment. Bloodwork, including ketone levels and blood glucose curves, will be regularly monitored, as well as physical examinations and weight measurements.

Prognosis and Remission

Though there is no cure for feline diabetes, the prognosis for a good quality of life is good with adequate management at home. With early, aggressive treatment of diabetes, many cats will enter a state of diabetic remission, meaning they are able to maintain normal blood sugar levels without insulin injections. Older cats, cats who have previously received steroid medications, and cats treated with glargine insulin have been shown to be more likely to go into diabetic remission, but the most important factor is starting insulin therapy early and monitoring closely. If a cat has not entered diabetic remission within the first six months after diagnosis, it will almost certainly require life-long insulin injections. Cats who have achieved diabetic remission should continue to be fed a low-carbohydrate diet and receive close monitoring, as some will eventually require insulin therapy again.

Possible Complications of Feline Diabetes

Hypoglycemia: Insulin therapy and SGLT2 medications lower blood glucose, possibly to dangerously low levels. Signs of low blood sugar (hypoglycemia) include weakness, lethargy, vomiting, lack of coordination, seizures, and coma. Hypoglycemia can be fatal if left untreated, so any diabetic cat that shows any of these signs should be offered its regular food immediately. If the cat does not eat voluntarily, it should be given oral glucose in the form of honey, corn syrup, or proprietary dextrose gels (available at most pharmacies) and brought to a veterinarian immediately. It is important, however, that owners not attempt to force fingers, food, or fluids into the mouth of a convulsing or comatose cat.
Diabetic Ketoacidosis: Diabetic cats with uncontrolled diabetes may develop a condition known as ketoacidosis. This occurs when cells starved for glucose begin to break down fats for energy, a process that creates chemicals called ketones, which make the blood more acidic. Ketoacidosis is considered a medical emergency, and cats diagnosed with this complication require hospitalization for ideal management.

Home Monitoring

Monitoring a diabetic cat at home requires careful attention to a few things. Cats with well-controlled diabetes should maintain a normal activity level and demeanor. Owners should also monitor daily water intake, urine production, appetite, body weight, amount of insulin or medication administered, and possibly blood or urine glucose levels. Monitoring is best coordinated in close collaboration with your veterinarian to achieve optimal control over your cat’s diabetes.

Weight Loss in Diabetic Cats: Additional Considerations

Unintentional weight loss in cats can be a cause for concern. The causes of unintentional weight loss in cats range from simple lifestyle changes to serious illness. Any noticeable weight loss in your cat warrants a visit to your veterinarian to rule out serious health conditions.

Other Potential Causes of Weight Loss

It's important to consider other potential causes of weight loss in cats, as diabetes may not always be the sole factor. Some of these include:

Eating Habits: Sometimes, your cat is eating less than you think. Do you have another cat or dog in the house? Did you recently change brands of food? Is the food dish easy to access?
Parasites: Pregnant mothers can give their kittens parasites, and they can also pass parasites through their milk when they are nursing. Your vet can examine your cat’s feces to determine if they’re carrying parasites that might be causing weight loss.
Hyperthyroidism: The thyroid is a butterfly-shaped organ in the throat. In a hyperthyroid cat, their metabolism goes into overdrive-they lose weight, are ravenously hungry all the time, have a very high heart rate, and often meow at night and have trouble sleeping. Your vet will do blood work to see if this is the cause of the weight loss. Treatment of hyperthyroidism involves controlling the thyroid gland, either with medicine, special food, or inpatient radioactive iodine treatment.
Viral Diseases: FIP, FeLV and FIV are viral diseases in cats. If your vet suspects a virus is the cause of your cat’s weight loss, they may perform tests to determine if one of these viruses is the cause.
Kidney Disease: Feline kidney disease can also lead to weight loss in your cat. To determine if kidney disease is the cause of your cat’s weight loss, your vet will do blood work and a urinalysis.
Cancer: The diagnosis and treatment plan will vary depending on the cancer’s type and stage. Older cats can lose some weight as a normal part of aging as they lose muscle mass. For senior pets, it’s best to be proactive about their care and to screen them for weight loss as well as illness.
Stress or Anxiety: Animals tend to eat less food when they are anxious or stressed out, and your cat could potentially be losing weight because of chronic stress.
Dental Disease: Dental disease, including a fractured tooth, severe gingivitis, and a tooth abscess, can cause oral pain and difficulty chewing. Your cat may lose weight from decreased intake as a result.
Gastrointestinal Issues: Like in people, GI tract issues could cause a reduced appetite in cats.
Infectious Diseases: Viral and bacterial infections can also cause a reduced appetite in cats, and this can cause weight loss if your cat has the illness for a while.
Systemic Disease: Cats can lose weight because of systemic diseases, including kidney, lung, heart, liver and gall bladder disease.

Addressing Weight Loss in Diabetic Cats

If your cat is losing weight despite treatment for diabetes, it's crucial to consult with your veterinarian. Here are some steps to consider:

Insulin Dosage Adjustment: Losing weight while eating a lot are signs of unregulated diabetes. It's possible that your kitty might need a larger dose. Also, insulin needs can fluctuate over time. It's not a "set and forget" thing. The only way to know what the insulin is doing to the blood glucose level is to test BG regularly at home.
Home Blood Glucose Monitoring: Home testing is the only thing that has given me a true picture of what's going on with him and it's a relief not having to bring him to the vet for tests and curves.
Dietary Changes: Diabetic cats do best on a low carb diet and that the symptoms I saw, weight loss, excessive urination and hunger were probably due to TOO MUCH insulin rather than too little. Once I lowered Gandalf's insulin dose and changed over to low carb wet food, such as certain varieties of Fancy Feast, grain free varieties of Wellness or even certain varieties of 9Lives, he got better and gained some of his weight back.
Type of Insulin: Humulin can be a difficult insulin to work with. It tends to lower the blood glucose fairly fast in most cats and then wear off before the 12 hour cycle is up. In most cats, they all offer a smoother curve and last longer.

Obesity and Insulin Resistance

Up to 40% of the domestic feline population is overweight or obese. Obesity in cats leads to insulin resistance via multiple mechanisms, with each excess kilogram of body weight resulting in a 30% decline in insulin sensitivity. In cats that develop diabetes, appropriate treatment includes dietary modification to achieve ideal body condition (for reduction of insulin resistance), and optimization of diet composition and insulin therapy (for glycemic control and the chance of diabetic remission).

Initially, as many obese cats that become diabetic will have lost a significant amount of weight and muscle mass by the time of presentation, some degree of diabetic control should be attempted with insulin before initiating any caloric restriction. Once body weight has stabilized, if further weight loss is needed, a diet with ≤ 12-15% carbohydrate metabolizable energy (ME) and >40% protein ME should be fed at 80% of resting energy requirement for ideal weight, with the goal of 0.5-1% weight loss per week. Other approaches may be necessary in some cats that need either substantial caloric restriction or do not find low carbohydrate diets palatable.

The Role of Insulin Resistance

Under normal circumstances, binding of insulin to its cell surface receptor results in phosphorylation of intracellular proteins known as insulin receptor substrates (IRSs). IRSs are involved in signaling cascades with both metabolic and mitogenic (growth -promoting) effects.

Metabolic effects of insulin signaling in muscle include mobilization of the glucose transporter GLUT-4 to the cell surface, leading to a substantial increase in glucose uptake (muscle is responsible for 75% of peripheral glucose uptake after a meal). The entering glucose is stored as glycogen under the influence of insulin, or used for the production of energy. In the liver, insulin signaling promotes glycogen formation and suppresses endogenous glucose production.

Progression from Insulin Resistance to Diabetes

The progression to diabetes may be similar to what happens in naturally occurring situations, in that there is likely a pre-existing defect in β-cell function of variable etiology in some cats, and the chronic metabolic stress of insulin resistance eventually overcomes insulin secretory capacity. Once diabetes is established, hyperglycemia itself contributes to β -cell dysfunction.

Dietary Management for Obese Diabetic Cats

Feeding canned foods to obese diabetic cats may be preferable for several reasons. Secondly, canned foods are likely to be lower in carbohydrate (although prescription dry diabetic diets may also be low in carbohydrate). The optimal dietary carbohydrate content for management of feline diabetes is not known at this time.

Understanding Diabetic Cat Behavior

If your cat has been diagnosed with diabetes, understanding their behavior changes can be crucial for their well-being. Diabetes in cats can lead to a variety of behavioral shifts that may seem concerning to pet owners. Recognizing and interpreting these changes can help you provide the best care for your feline friend.

Increased Thirst and Urination: One of the most noticeable changes in diabetic cat behavior is increased thirst and urination. Diabetes causes a cat’s blood sugar levels to rise, leading to excessive thirst (polydipsia) and increased urination (polyuria). You may find your cat drinking water more frequently and for longer periods. This behavior can result in more frequent trips to the litter box, and in some cases, accidents outside the box.
Changes in Appetite and Weight: Diabetes can also affect your cat’s appetite and weight. Some diabetic cats may experience increased hunger (polyphagia) while losing weight despite eating more. This paradox occurs because their bodies are unable to use glucose properly for energy. As a result, they may constantly seek food but still appear thin and undernourished. Conversely, some cats might lose their appetite entirely.
Lethargy and Weakness: Hypoglycemia, or low blood sugar, is a serious condition that can occur in diabetic cats, particularly if they receive too much insulin. Lethargy and weakness are common signs of hypoglycemia. A cat experiencing hypoglycemia may appear unusually tired, less responsive, and reluctant to engage in normal activities like playing or grooming. In severe cases, hypoglycemia can lead to seizures and disorientation. These symptoms are alarming and require urgent medical intervention.
Difficulty Walking: Diabetic neuropathy is a condition caused by prolonged high blood sugar levels, leading to nerve damage. One of the primary symptoms is difficulty walking. Cats with diabetic neuropathy may have a wobbly gait, weakness in their hind legs, or an inability to jump. This condition can significantly impact their mobility and quality of life.
Sensitivity to Touch: Cats suffering from diabetic neuropathy may also become sensitive to touch, particularly around their limbs and back. They may react negatively to being petted or handled, even if they previously enjoyed these interactions. This sensitivity can be a sign of discomfort and pain due to nerve damage.
Irritability and Aggression: Diabetic cats can become more irritable or aggressive. The discomfort and stress caused by fluctuating blood sugar levels, frequent vet visits, and changes in their routine can contribute to this behavior.
Changes in Grooming Habits: You might notice changes in your diabetic cat’s grooming habits. Some cats may groom excessively, while others may neglect grooming altogether. Excessive grooming can be a sign of stress or discomfort, whereas a lack of grooming might indicate that your cat is feeling unwell or is too weak to maintain their usual grooming routine.

Understanding and managing diabetic cat behavior can be challenging, but with the right knowledge and support, you can help your cat lead a comfortable and happy life. Regular veterinary check-ups, proper medication, and a stable home environment are key to managing diabetes in cats.

tags: #feline #diabetes #and #weight #loss #causes