Signs of Diabetes in Cats: Symptoms Every Owner Should Know

Cats are quietly stoic, which makes illness easy to miss — so if you've noticed something and gone looking, you're already doing well. The main signs of feline diabetes are drinking noticeably more, larger or more frequent clumps in the litter tray, weight loss despite a healthy appetite, and a duller coat or lower energy.

The water bowl and the litter tray

As with dogs, when insulin isn't working properly, excess glucose spills into the urine and drags water with it — more urination, more drinking to compensate. The tells are practical: the bowl going down faster, heavier clumps, more tray visits. A sustained change here is one of the clearest early clues you'll get.

The walk that changes

Here's a sign specific to cats worth knowing: some diabetic cats develop nerve trouble (diabetic neuropathy) that makes them walk flat on their hocks — the "ankles" of the back legs — instead of up on their toes, giving a distinctive crouched stance. If you see it, mention diabetes to your vet; it often improves with good glucose control.

Is my cat at higher risk?

Weight is the biggest modifiable risk factor — overweight cats are considerably more likely to develop diabetes — and males are over-represented, at roughly twice the odds of females in UK data. Age matters more than the word "middle-aged" suggests: incidence peaks between ten and thirteen years. Neutering is often named as a risk factor too, but the evidence there is weaker than for sex and age, and the current AAHA position is that its role is unclear. The hopeful flip side: weight management and low-carb feeding are powerful tools, and some cats achieve remission with early, good control.

Symptom overview

| Sign | What owners notice | Cat-specific clue | Vet urgency | |---|---|---|---| | Drinking more | The bowl goes down faster | Changes may be subtle | Promptly | | Larger litter clumps | Heavier or more frequent clumps | A useful measurable change | Promptly | | Weight loss despite appetite | Getting thinner while eating | Often missed under a coat | Promptly | | Dull coat | Less grooming or a greasy coat | Cats hide illness well | Promptly | | Low energy | Less movement or interaction | Quiet withdrawal can be the clue | Promptly | | Flat-footed hind-leg walk | Walking on the hocks | Can indicate diabetic neuropathy | Promptly | | Vomiting or food refusal | Not eating or being sick | Cats should not go without food | Urgent |

Could it be something else?

Kidney disease, thyroid disease, urinary tract problems and other conditions can cause overlapping signs. That is exactly why testing matters rather than assuming the cause is diabetes.

When to see the vet

Promptly, for any of the above — diagnosis is a straightforward blood and urine test. If your cat stops eating, becomes very lethargic or is vomiting, treat it as urgent.

If the diagnosis comes, start with our Just Diagnosed guide — and let Mello keep the whole routine calm and organised.

If your vet is discussing newer oral treatment options, read our guide to SGLT2 inhibitors for diabetic cats, including the warning signs that need urgent attention.

For a concise route through symptoms, treatment, diet and remission, start with cat diabetes: symptoms, treatment, diet and remission.

Sources

The pages below were each opened and checked before being listed here, and anything that could not be opened was left off rather than guessed at.

• Recognizing DM in Cats (Section 2) — 2026 AAHA Diabetes Management Guidelines for Cats, 2026. The signs owners report — drinking, urinating and eating more, weight loss, lethargy — an unkempt coat on examination, and the plantigrade stance; also that most diabetic cats are over seven.
• 2025 iCatCare consensus guidelines on the diagnosis and management of diabetes mellitus in cats — Journal of Feline Medicine and Surgery 27:1–37, 2025. That prolonged high glucose can cause the neuropathy behind the flat-footed walk, seen in about one cat in ten, and that increasing age is the most important risk factor.
• ISFM Consensus Guidelines on the Practical Management of Diabetes Mellitus in Cats — Journal of Feline Medicine and Surgery 17(3):235–250, 2015. That obese cats are up to four times more likely to develop diabetes than cats at an optimal weight.
• Frequency, Risk Factors and Mortality for Diabetes Mellitus in 1,225,130 Cats Under Primary Veterinary Care in the UK — Journal of Veterinary Internal Medicine 39(4), 2025. The UK figures used here: male cats at roughly twice the odds of females, and a sharp rise in risk from nine years of age.