Feline Diabetes Guide: Symptoms, Remission, and the Best Diet for Cats

Introduction

Diabetes Mellitus is the most frequent endocrine disorder in felines. It is characterized by insufficient insulin production and the inability to use insulin, causing hyperglycemia. Obese and inactive cats have higher risks of developing diabetes mellitus.

In Type 2 Diabetes, the body's cells become resistant to insulin, preventing glucose from being used as energy.

Pathophysiology of Feline Diabetes Mellitus

Diabetes Mellitus in cats is a multi-step process comprising Insulin Resistance and Beta-cell Dysfunction.

1. Insulin Resistance (The Cellular Barrier)

Insulin serves as a "key" to lock onto cell receptors and open the cells up to glucose uptake. In diabetic cats (most commonly obese cats), cells become resistant to insulin.

Role of Obesity: 

Adipose tissue releases inflammatory cytokines and adipokines which disrupt insulin signalling.

Result: 

Despite sufficient amounts of insulin, cells become unable to let glucose in, thus causing hyperglycaemia.

2. Islet Amyloid Polypeptide (IAPP) deposition

What makes the pathology of feline diabetes unique is that there is Amyloid (a starchy protein) build-up within Pancreatic Islets.

As a result of increased pancreatic activity trying to compensate for resistance to insulin, the pancreas starts releasing another hormone called Islet Amyloid Polypeptide along with insulin.

Eventually, these amyloids start depositing in the pancreas and destroy insulin-producing Beta-cells.

3. Glucose Toxicity (The Vicious Cycle)

Persistently elevated blood glucose levels are highly toxic to remaining insulin-producing beta-cells.

This Glucose Toxicity shuts down remaining insulin production.

Prompt administration of exogenous insulin and a restrictive diet may allow us to reverse it and reach Clinical Remission.

Osmotic Diuresis (Reason Behind PU/PD)

As blood glucose rises above the "Renal Threshold," which is about 200 - 280 mg/dL in felines, the kidneys cannot retain all the extra glucose.

Glucose appears in the urine ("glucosuria").

Since glucose molecules are osmotically active, they attract water to themselves, resulting in its movement towards the bladder.

There is huge water loss in the form of polyuria and the cat responds by increasing water intake ("polydipsia").

​"Four Pillars" of Diabetes Symptoms

​Here are some symptoms of diabetes:

​Polyuria: 

The cat urinates too frequently and clumps up their litter box.

​Polydipsia: 

The cat drinks water excessively.

​Polyphagia: 

Cats eat more food than before yet lose weight.

​Plantigrade Stance: 

The cat moves with the plantar aspect of the feet. It is an unusual stance caused by diabetic neuropathy.

​Diagnosis: Beyond Blood Glucose Levels

​It may be hard to diagnose because cats experience "Stress Hyperglycemia" (elevated glucose levels while stressed). However, veterinarians conduct the following:

​Blood Glucose Curve: 

This test measures blood glucose over several hours.

​Fructosamine Test: 

It helps identify the mean value of blood glucose over 2-3 weeks and excludes temporary stress spikes.

​Urinalysis: 

Glucose and ketone bodies in the urine.

​Management & Treatment

​Feline Diabetes mellitus can be effectively managed and even cured, unlike most chronic diseases. These are the management options:

​Insulin Injection

​The vast majority of felines are administered insulin injections twice daily (such as Glargine or PZI). Surprisingly, owners find it relatively easy to inject cats with minuscule needles.

The “Keto” Method (Nutritional Control)

The food is VITAL. Cats are strict carnivores.

Low-Carb, High-Protein: 

Transitioning to a wet diet with high protein and low carbs may send the diabetic cat into "Remission," where no insulin will be necessary anymore.

Dry Food is Forbidden: 

Commercial pet foods tend to contain too much starch for a diabetic feline.

Home Testing

Home glucose monitoring using a glucometer is far less traumatic for the cat and offers precise information for the doctor to tailor medications accordingly.