Diabetes mellitus (dogs and cats)

Symptoms an owner can spot at home

• Increased thirst and urination
• Increased appetite with weight loss
• Lethargy or reduced activity
• Sweet or acetone-smelling breath (advanced cases)
• Cataracts and sudden blindness (dogs, often within months of diagnosis)
• Plantigrade stance, walking on hocks (cats with diabetic neuropathy)

When to see a vet

• Vomiting, profound lethargy, or collapse in any diabetic pet, possible diabetic ketoacidosis (DKA), an emergency
• Sudden vision loss or cloudy eyes in a dog
• Hypoglycemia signs in a treated diabetic, wobbliness, confusion, seizures, give a small amount of corn syrup on the gums and go to the vet immediately
• New polyuria/polydipsia in an unspayed female dog, diabetes plus diestrus is a surgical-spay indication

Dogs and cats are different diseases

Canine diabetes is almost always insulin-dependent, the pancreatic beta cells are destroyed and the dog needs lifelong exogenous insulin. It is most common in middle-aged to senior dogs, and intact female dogs are at elevated risk due to progesterone interference with insulin signaling (spaying is part of management).

Feline diabetes more closely resembles human type 2 diabetes, insulin resistance plus eventual beta-cell exhaustion, strongly linked to obesity. With early aggressive insulin therapy and a low-carbohydrate canned diet, a meaningful fraction of cats, published estimates range broadly but a fraction commonly cited around 30-50% with prompt treatment, achieve diabetic remission and can come off insulin.

How vets diagnose it

Persistent fasting hyperglycemia plus glucosuria confirms diabetes. In cats, stress hyperglycemia is common at the clinic, so vets confirm with a fructosamine test (reflects average glucose over the past 1-3 weeks) before starting insulin. A full diagnostic workup also screens for concurrent conditions, Cushing's, pancreatitis, urinary tract infection, hyperthyroidism, that affect prognosis and dosing.

Treatment overview

Editorial overview, not a treatment plan. The mainstay is twice-daily subcutaneous insulin, with the insulin type and dose individualized to the patient. Diet matters: dogs typically do best on a moderate-carbohydrate diet with consistent meal timing; cats benefit from a low-carbohydrate (often canned) diet. Continuous glucose monitors are increasingly used at home in place of curve days at the clinic. Owners run a real risk of hypoglycemia, knowing the signs and keeping corn syrup or honey at hand is part of basic ownership.

What owners can do

• Prevention starts at the food bowl. Obesity is the single biggest modifiable risk factor for feline diabetes.
• Feed measured meals on a consistent schedule. Free-feeding makes insulin dosing impossible.
• Spay female dogs at the appropriate age, diestrus progesterone is a known diabetogenic factor.
• If diagnosed, never adjust insulin doses without veterinary guidance. Hypoglycemia kills faster than hyperglycemia.
• Track water intake, urine volume, appetite, and weight weekly, these are your between-visit signals.