VETINUITY
How much prednisolone is dexamethasone equivalent to?
Dexamethasone has roughly 7 to 10 times the glucocorticoid potency of prednisolone, so 0.1 mg/kg of dexamethasone is in the range of 0.7-1 mg/kg of prednisolone.
● ANSWER
Sourced & dated
What is the dexamethasone dose for dogs and cats?
Dexamethasone is dosed at 0.05-0.1 mg/kg IV, IM or SC once daily for inflammation, 0.2-0.4 mg/kg/day for temporary immunosuppression and 0.1-0.2 mg/kg IV in an Addisonian crisis, in dogs and cats alike.
● VETINUITY DEXAMETHASONE DOSE CALCULATOR
Vetinuity dexamethasone dose calculator
Volumes use dexamethasone sodium phosphate 4 mg/mL. For the 2 mg/mL dexamethasone solution, double the volume.
● WHAT'S DOCUMENTED
Vetinuity’s dexamethasone dose table gives 0.05-0.1 mg/kg IV, IM or SC once daily for inflammation, 0.2-0.4 mg/kg/day IV as a stopgap for immunosuppression when a dog cannot take oral prednisolone, and 0.1-0.2 mg/kg IV for an Addisonian crisis, with the same per-kilogram doses in cats. The Vetinuity dexamethasone dose calculator above returns milligrams and the volume of 4 mg/mL dexamethasone sodium phosphate. The page is part of the reference behind Vetinuity, the clinical assistant from Brian Toncray, DVM, who practices emergency medicine.
Dexamethasone doses by indication
| Indication | Dog | Cat | Route and frequency |
|---|---|---|---|
| Anti-inflammatory | 0.05-0.1 mg/kg | 0.05-0.1 mg/kg | IV, IM or SC q24h |
| Immunosuppressive bridge | 0.2-0.4 mg/kg/day | 0.2-0.4 mg/kg/day | IV q24h until oral therapy is possible |
| Hypoadrenocorticism crisis | 0.1-0.2 mg/kg | 0.1-0.2 mg/kg | IV, then q12-24h until oral steroids |
| Anaphylaxis, adjunct after epinephrine | 0.1-0.2 mg/kg | 0.1-0.2 mg/kg | IV once |
| Suppression test | 0.01 mg/kg (low dose) | 0.1 mg/kg | IV, cortisol at 0, 4 and 8 h |
Read the vial: two strengths, two ways of labeling
Two products sit side by side on most emergency shelves. Dexamethasone sodium phosphate (often called Dex SP) is typically 4 mg/mL, and depending on the manufacturer that figure may describe the phosphate salt or dexamethasone phosphate rather than dexamethasone base, so the base content can be a little lower than the number printed. Plain dexamethasone solution in a polyethylene glycol vehicle is usually 2 mg/mL. Pulling 1 mL “because it is dex” from the wrong vial halves or doubles the dose. The calculator assumes 4 mg/mL; change the concentration in your head or in the app before drawing up the 2 mg/mL product.
Cautions
A single anti-inflammatory dose is usually well tolerated, but dexamethasone is long acting (36 to 72 hours of adrenal suppression per dose), so repeated doses suppress the axis faster than prednisolone. Avoid pairing with NSAIDs because of gastrointestinal ulceration risk. It can precipitate congestive heart failure in cats with subclinical cardiomyopathy and destabilize diabetic patients. It is not a substitute for epinephrine in anaphylaxis and adds nothing in the first minutes.
Related: Addisonian crisis, anaphylaxis, IMHA and prednisolone dosing.
● SOURCES
- 1. Swann JW, Garden OA, Fellman CL, et al. ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs. J Vet Intern Med. 2019;33(3):1141-1172. PMID 30847984. Recommendation 7, IV dexamethasone 0.2-0.4 mg/kg/day. Checked 2026-10-26.
- 2. DailyMed: dexamethasone sodium phosphate injection label search. Description, strength expressed as dexamethasone phosphate. Checked 2026-10-26.
● RELATED ANSWERS
- Addisonian Crisis in Dogs: Emergency Treatment
Addisonian crisis requires emergency stabilization with IV fluids, close monitoring and replacement of deficient glucocorticoid support, tailored to the dog’s abnormalities.
- IMHA Treatment Protocol in Dogs
Evidence-based canine IMHA treatment protocol from the 2019 ACVIM consensus, with antithrombotics per the ACVECC CURATIVE guidelines.
- Anaphylaxis in Dogs and Cats: Epinephrine Dose
Vetinuity's anaphylaxis table: epinephrine 0.01 mg/kg IM (0.01 mL/kg of 1 mg/mL), repeated every 5 to 15 minutes, then a 0.05 mcg/kg/min CRI if shock persists, with fluids.
- Prednisolone Dose for Dogs and Cats
Prednisolone is dosed at 0.5-1 mg/kg/day for inflammation and 2 mg/kg/day for immunosuppression in dogs, and 1-2 mg/kg/day and 2-4 mg/kg/day in cats, which should get prednisolone rather than prednisone.
- Diphenhydramine (Benadryl) Dose for Dogs and Cats
Diphenhydramine is dosed at 2 mg/kg IM or SC (or 2-4 mg/kg PO q8-12h) in dogs and 1-2 mg/kg IM or PO q8-12h in cats, using plain products without decongestants or xylitol.
● FAQ
Does dexamethasone interfere with an ACTH stimulation test?
Dexamethasone is not measured by cortisol assays, which is why it is the glucocorticoid of choice in a suspected Addisonian crisis before the stimulation test is finished.
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