Diabetes mellitus in cats
Diabetes mellitus in cats: causes, treatment with insulin and low-carbohydrate diet, remission chances and when to see a vet immediately.
Short & honest
Feline diabetes is treatable; strong evidence (RCTs and guidelines) shows insulin plus a low-carbohydrate diet offers the best remission chances — up to 78% with early, strict management.
Veterinary review not yet completed
This page is awaiting review by a registered veterinary surgeon. Until then, treat the text as education based on the sources listed — not as a verified veterinary judgement.
What is diabetes mellitus in cats?
Diabetes mellitus in cats is almost always type 2: the pancreas still produces insulin, but the body cells respond insufficiently to it. Obesity and lack of exercise are the main risk factors. Neutered male cats are overrepresented. Classic symptoms are extreme thirst, excessive urination, weight loss despite a good appetite and sometimes weakness in the hind legs.
What the evidence says
Insulin therapy — indispensable
Insulin is almost always necessary as initial treatment. Long-acting insulin types such as insulin glargine or protamine zinc insulin provide the best blood glucose regulation in cats [2][4]. The 2025 iCatCare guidelines emphasise that the type of insulin and the dosage must be individually adjusted [2]. Replacing insulin with something else is not responsible and not supported by evidence.
Low-carbohydrate diet — strong evidence
A low-carbohydrate diet (less than 25% carbohydrates on a dry matter basis) significantly increases the chance of remission. In a comparative study, 68% of cats on a low-carbohydrate diet achieved remission, compared to 41% on a higher-carbohydrate diet [1]. Remission means that the cat becomes insulin-free — a real and desirable treatment goal in cats with type 2 diabetes.
Early and strict treatment — better prognosis
The earlier and more strictly blood glucose is regulated, the greater the chance of remission. In an optimal treatment paradigm with long-acting insulin and a low-carbohydrate diet, the chance of remission increased to 78% [3]. Timely diagnosis is therefore crucial.
Diabetic neuropathy
Long-term poorly regulated diabetes can lead to weakness or a plantigrade stance of the hind legs (the cat walks on its hocks). This is partially reversible with good blood glucose regulation [2].
Natural and supplementary options — an honest assessment
| Option | Evidence | Assessment |
|---|---|---|
| Low-carbohydrate diet | Strong [1][4] | Recommended, part of standard treatment |
| Weight reduction | Strong [2] | Recommended in case of obesity |
| Herbal preparations | None | Not supported as a replacement for insulin |
| Supplements | None | No evidence for blood glucose control in cats |
There are no herbal preparations or supplements proven to be able to replace insulin in cats with diabetes mellitus. Supplementary agents must never replace or delay conventional treatment.
When to see the vet?
If diabetes is suspected — excessive drinking, urination and weight loss — a visit to the veterinary surgeon is necessary for blood testing and urine analysis. After diagnosis, regular check-ups are essential to adjust the insulin dosage and to monitor for remission. See the red flags below for situations that require immediate medical attention.
Key points
Diabetes in cats is treatable and remission is possible. The combination of insulin and a low-carbohydrate diet, initiated as early as possible, yields the best outcomes [1][2][3]. Herbal remedies and supplements have no proven role in the treatment.
Why this verdict?
The evidence for treating diabetes mellitus in cats is strong (grade A): several randomised controlled studies are available, including an RCT with 63 cats comparing dietary effects [1][3], supplemented by the iCatCare 2025 consensus guideline based on the full available literature [2]. Limitations include relatively small study populations and variations in insulin protocols between studies.
Interactions with medication
- Corticosteroids raise blood sugar and can significantly increase insulin requirements — always report to the veterinary surgeon
- Some dietary changes can rapidly alter insulin requirements — never adjust the diet without consultation in a diabetic cat
Legal status (Netherlands)
Insulin for cats is prescription-only; always use the product and dosage prescribed by the veterinary surgeon.
Sources
- [1] Comparison of a low carbohydrate–low fiber diet and a moderate carbohydrate–high fiber diet in the management of feline diabetes mellitus. Journal of Feline Medicine and Surgery (JFMS), 2006. Narrative review source ↗
- [2] iCatCare 2025 consensus guidelines on the diagnosis and management of diabetes mellitus in cats. Journal of Feline Medicine and Surgery (JFMS), 2025. Guideline doi:10.1177/1098612X251399103
- [3] In cats with newly diagnosed diabetes mellitus, use of a near-euglycemic management paradigm improves remission rate over a traditional paradigm. Journal of Veterinary Internal Medicine (PubMed), 2014. RCT source ↗
- [4] Effects of diet on glucose control in cats with diabetes mellitus treated with twice daily insulin glargine. Journal of Feline Medicine and Surgery (PMC), 2008. Narrative review source ↗