One dose, one number: 1 mg/kg once a day
Velagliflozin is sold as Senvelgo, a 15 mg/mL oral solution given at 1 mg/kg (0.45 mg per pound) every 24 hours. A 4 kg cat gets 4 mg, or 0.27 mL from the supplied syringe. It is licensed only for cats never treated with insulin, and the US label treats prior insulin therapy as a contraindication rather than a caution.
Why a liquid can replace a needle
Insulin replaces a hormone the pancreas no longer makes in sufficient quantity. An SGLT2 inhibitor works downstream: it blocks the transporter that pulls filtered glucose back into the blood at the kidney, so surplus glucose leaves in urine. The effect does not depend on how much insulin the pancreas can still produce, and it does not drive glucose below normal the way an insulin overdose can. In the 252-cat field study behind the approval, no cat had clinical hypoglycemia. The same mechanism is the danger: glucose is dumped rather than used, so ketoacidosis can develop while the meter reads 150 mg/dL.
Who qualifies, and the four tests that come first
The label says otherwise healthy cats with newly diagnosed diabetes not previously treated with insulin, which in practice means a cat eating, drinking and not dehydrated at diagnosis. Before the first dose the veterinarian should run a complete blood count, serum chemistry, fructosamine and urinalysis with a ketone check, plus a urine culture: silent urinary infections are common in diabetic cats and this drug class raises that risk. Cats with IRIS stage 3 or 4 kidney disease were not evaluated, and anorexia, vomiting or lethargy at diagnosis is a reason to start insulin instead.
Dose to millilitres: the arithmetic behind the bill
The bottle is 15 mg/mL, so daily volumes are small and one bottle lasts weeks. The table converts weight into milligrams, millilitres and monthly cost at 2026 US retail: $10.6/mL for a 30 mL bottle, $12.8/mL for a 12 mL bottle.
| Cat weight | Daily dose | Volume per day | 30 mL bottle lasts | Drug cost per month |
|---|---|---|---|---|
| 3 kg | 3 mg | 0.20 mL | 150 days | $64 to $77 |
| 4 kg | 4 mg | 0.27 mL | 113 days | $85 to $102 |
| 5 kg | 5 mg | 0.33 mL | 90 days | $106 to $128 |
| 6 kg | 6 mg | 0.40 mL | 75 days | $128 to $153 |
| 8 kg | 8 mg | 0.53 mL | 56 days | $170 to $204 |
An opened bottle keeps 6 months at or below 25 C, so a small cat will finish 12 mL comfortably while a large cat needs the 30 mL size to avoid the small-bottle premium.
Days 1 to 14: where 86% of ketone episodes happen
In the field study, 85.7% of all ketosis or ketoacidosis episodes occurred within the first 14 days. The label therefore asks for a urine ketone check 2 to 3 days after the first dose and again at about 7 days, plus any time the cat looks unwell. The trap is the glucose reading: 77.8% of the cats that developed ketoacidosis were euglycemic at diagnosis, with blood glucose under 250 mg/dL. A normal meter reading does not clear a cat that has stopped eating.
Stop the drug and call the clinic the same day for any of these:
- Refusing food for more than 12 hours
- Vomiting, diarrhea or drooling
- Hiding, weakness, or reluctance to jump
- Fast or deep breathing, or a sweet smell on the breath
Established ketoacidosis is treated with insulin and dextrose regardless of the glucose value, plus fluids and nutritional support. Waiting for the next scheduled visit turns a survivable episode into a fatal one.
What the trials measured, including the deaths
The SENSATION field study enrolled 252 cats: 214 insulin-naive and 38 previously treated with insulin. Median glucose fell from 436 mg/dL at screening to 125 mg/dL at day 180, and fructosamine from 538 to 263 micromol/L. Of the 158 cats still enrolled at day 180, 81% had glucose, fructosamine or both inside the reference range. Ketonuria appeared in 13.9% and ketoacidosis in 7.1%, but only 5.1% of naive cats against 18.4% of cats switched off insulin.
A randomized trial of 116 cats compared velagliflozin with twice-daily Caninsulin: composite success at day 45 was 54% against 42%, inside the pre-set 15% noninferiority margin, and by day 91 owner-rated quality of life had improved in 81% of the oral group. Nineteen cats in the 180-day field study died or were euthanized, 13 possibly related to the drug or to failing control. Those figures belong in the conversation with your vet.
Cost against insulin, line by line
US retail in 2026 is about $150 to $155 for 12 mL and $318 to $345 for 30 mL, which produces the monthly range above for cats from 4 kg to 8 kg. A full insulin regimen, including vial or pens, 30 needle tips, 30 to 60 glucose strips and a share of rechecks, costs $100 to $300 a month in the US, as our insulin cost breakdown and full monthly basket show. Add the first month of monitoring: an exam with a glucose curve is $80 to $150, and urine ketone strips $20 to $45. The oral drug is roughly cost-neutral. It buys fewer needles and no clinical hypoglycemia, not a cheaper pharmacy bill.
The monitoring calendar
| When | What is checked | Decision rule |
|---|---|---|
| Before the first dose | CBC, chemistry, fructosamine, urinalysis with ketones, urine culture | Ketones or active infection: treat first, do not start |
| Day 2 to 3 | Urine ketones | Any ketone: stop the drug, start insulin |
| Day 7 | Urine ketones, weight, appetite | Same rule; weight loss triggers a call |
| Week 1 | Exam, glucose curve, fructosamine, weight | Mean glucose 300 mg/dL or higher: consider insulin |
| Week 4 | Same panel | Fructosamine above 450 micromol/L: switch |
| Every 3 months | Chemistry, urinalysis, weight, fructosamine | Rising triglycerides or fPL: reassess |
Two rules are easy to forget. Glucosuria is not a monitoring tool here, because glucose keeps spilling into urine for 2 to 3 days after the last dose. The drug should also be paused during any period of reduced food intake, including surgery and dental work, because fasting plus an SGLT2 inhibitor is the combination that produces ketoacidosis.
Senvelgo or Bexacat
Bexacat (bexagliflozin) is the other approved oral option in the US: a 15 mg tablet, one daily for cats of 3 kg or more, at a fixed dose rather than by weight. Its decision point is 8 weeks, with a mean glucose threshold of 250 mg/dL and serum beta-hydroxybutyrate monitoring. Senvelgo is weight-based, with a 4-week decision point. Both carry the same boxed warning and neither is for a cat already receiving insulin. Bexacat is also contraindicated in liver disease or reduced kidney function, and long-term use may raise urothelial carcinoma risk.
This article is not a substitute for veterinary diagnosis or a prescription. Velagliflozin and bexagliflozin are prescription drugs with a boxed warning for ketoacidosis; starting, stopping or switching treatment is a decision for the veterinarian who has examined the cat and seen its bloodwork.
Frequently asked
Can my cat switch from insulin to Senvelgo?
Not under the US label. Prior insulin treatment is a contraindication, and the field study bears that out: ketoacidosis occurred in 18.4% of cats switched off insulin (7 of 38) against 5.1% of insulin-naive cats (11 of 214). A cat that has been on insulin is treated as insulin-dependent until a veterinarian proves otherwise with lab work, and any switch needs a washout period and ketone monitoring.
Does velagliflozin cause low blood sugar?
No clinical hypoglycemia occurred in the 252-cat field study, because the drug lowers glucose by dumping it in urine rather than by adding insulin. The emergency to watch for is the opposite: ketoacidosis with a normal glucose. In the same study 77.8% of the cats diagnosed with ketoacidosis had blood glucose below 250 mg/dL, so a normal reading does not rule it out.
How much does Senvelgo cost per month?
At 2026 US retail prices a 30 mL bottle costs $318 to $345 and a 12 mL bottle $150 to $155. A 4 kg cat uses 0.27 mL a day, which works out to $85 to $102 a month; a 6 kg cat uses 0.40 mL a day, or $128 to $153. Add $80 to $150 for the first recheck with a glucose curve and $20 to $45 for ketone strips.