Dexamethasone: veterinary dose and monograph

At a glance

Drug class

Anti-inflammatory

Also known as

Azium, Dexasone, Dexamethasone Sodium Phosphate, Dexa

Species with doses

Dogs, Cats, Cattle, Horses, Sheep, Pigs, Birds, Guinea pigs, Chinchillas, Hamsters, Rats, Mice, Gerbils, Hedgehogs, Sugar gliders and Primates

General dose range

0.05–0.5 mg/kg IV q12–24h — check the species tables for the indication

Routes

IV, PO, IM

Last reviewed

1 October 2026

Indications

• Anti-inflammatory / anti-allergic (acute allergic reactions, urticaria)
• Bovine ketosis (gluconeogenic)
• Bovine pregnancy termination / induction of parturition (term)
• Equine recurrent airway obstruction (heaves)
• Adjunctive therapy for shock / endotoxaemia (controversial)
• Adrenal crisis (Addisonian) — initial parenteral glucocorticoid (does not interfere with cortisol assay)
• Immune-mediated disease (immunosuppressive doses)
• Diagnostic — low/high-dose dexamethasone suppression test

Dexamethasone dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Anti-inflammatory: Papich 5e: dogs and cats 0.07–0.15 mg/kg q12–24h IV, IM or PO; immunosuppressive 0.125–0.25 mg/kg q24h initially. Plumb’s p.369 (Azium label): 0.5–1 mg TOTAL per dog IV/IM for 3–5 days. Switch to oral prednisolone for ongoing therapy where possible.
• Addisonian crisis (initial): Plumb’s p.369: dexamethasone sodium phosphate 0.1–0.2 mg/kg IV initially, then 0.05–0.1 mg/kg q12h until oral prednisone (Wilson); 0.2–0.5 mg/kg IV once (Jutkowitz); 0.5–2 mg/kg in shock (Scott-Moncrieff). It does not interfere with the cortisol assay, so the ACTH stimulation test stays valid. Provides no mineralocorticoid — correct fluids and electrolytes.
• Low-dose dexamethasone suppression test (LDDST): Papich 5e (Dexamethasone, Instructions for Use): low-dose suppression test dogs 0.01 mg/kg IV (0.015 in some references) and cats 0.1 mg/kg IV, sampling at 0, 4 and 8 hours; high-dose test dogs 0.1 mg/kg (1.0 in some references) and cats 1.0 mg/kg. DIAGNOSTIC dose - not the anti-inflammatory dose. Use dexamethasone sodium phosphate for IV administration.
• High-dose dexamethasone suppression test (HDDST): Papich 5e (Dexamethasone, Instructions for Use): low-dose suppression test dogs 0.01 mg/kg IV (0.015 in some references) and cats 0.1 mg/kg IV, sampling at 0, 4 and 8 hours; high-dose test dogs 0.1 mg/kg (1.0 in some references) and cats 1.0 mg/kg. DIAGNOSTIC dose - not the anti-inflammatory dose. Use dexamethasone sodium phosphate for IV administration.

Cats

• Anti-inflammatory: Papich 5e: cats 0.1–0.2 mg/kg q24h PO added to food, then maintenance 0.05 mg/kg q48–72h PO; injectable anti-inflammatory 0.07–0.15 mg/kg q12–24h IV/IM. Plumb’s: dose as 10–20% of the prednisolone dose (0.75 mg dexamethasone ≈ 5 mg prednisone).
• Low-dose dexamethasone suppression test (LDDST): Cats need 10x the canine LDDST dose. Papich 5e (Dexamethasone, Instructions for Use): low-dose suppression test dogs 0.01 mg/kg IV (0.015 in some references) and cats 0.1 mg/kg IV, sampling at 0, 4 and 8 hours; high-dose test dogs 0.1 mg/kg (1.0 in some references) and cats 1.0 mg/kg. DIAGNOSTIC dose - not the anti-inflammatory dose. Use dexamethasone sodium phosphate for IV administration.
• High-dose dexamethasone suppression test (HDDST): Cats need 10x the canine HDDST dose. Papich 5e (Dexamethasone, Instructions for Use): low-dose suppression test dogs 0.01 mg/kg IV (0.015 in some references) and cats 0.1 mg/kg IV, sampling at 0, 4 and 8 hours; high-dose test dogs 0.1 mg/kg (1.0 in some references) and cats 1.0 mg/kg. DIAGNOSTIC dose - not the anti-inflammatory dose. Use dexamethasone sodium phosphate for IV administration.

Cattle

• Primary ketosis: Label dose: 5–20 mg per cow IM/IV (Azium). Glucocorticoid-induced gluconeogenesis. CAUTION: any dose may cause abortion in pregnant animals.
• Induction of parturition / abortion: Papich 5e: induction of parturition 0.05 mg/kg (25 mg per animal) as a single dose in the last 1–2 weeks of pregnancy, optionally with PGF2α 0.5 mg. Confirm gestational stage — premature induction gives weak or non-viable calves and increases retained placenta. Follow the product-label withdrawal.
• Pregnancy CONTRAINDICATION: AVOID in pregnant cattle unless intentional induction — strongly abortifacient. Withdrawal: not established for milk; consult product label / FARAD.

Horses

• Anti-inflammatory (label): Plumb’s p.370 (Azium label): 2.5–5 mg TOTAL IV or IM per adult horse (≈0.005–0.01 mg/kg). Papich 5e: cattle and horses 0.04–0.15 mg/kg/day IV or IM for conditions needing more. ARCI Class 4 — observe competition withdrawal; caution in laminitis-prone horses.
• Recurrent airway obstruction (heaves): Papich 5e: 0.05–0.1 mg/kg IV or IM q24h (or 0.165 mg/kg PO q24h) usually for 2–3 days, then half the dose for 7 days. Plumb’s p.370: 0.1 mg/kg IM daily for 4 days, 0.075 for 4 days, 0.05 for 4 days (Courouce-Malblanc); 40 mg IM every other day tapering by 5 mg every 3 treatments for a 500 kg horse (Ainsworth). Avoid in laminitis-prone horses or those with endocrinopathy.

Goats

• No reference dose for this species: The previous 0.05–0.1 mg/kg IM anti-inflammatory row for goats had no source; neither Papich 5e nor Plumb’s gives a goat dose. Dexamethasone is abortifacient in pregnant ruminants.

Sheep

• No reference dose for this species: The previous 0.05–0.1 mg/kg IM anti-inflammatory row for sheep had no source. The only sheep dose in Papich 5e is for induction of parturition (0.15 mg/kg/day IM for 1–5 days in the last week of gestation). Abortifacient in pregnant ewes.
• Induction of parturition (last week of gestation): Papich 5e: sheep 0.15 mg/kg/day IM for 1–5 days during the last week of gestation. Confirm gestational age — earlier use produces non-viable lambs.

Pigs

• Glucocorticoid therapy: Plumb’s p.370 (Howard 1986): 1–10 mg total IV or IM per pig. Observe slaughter withdrawal for the product used (FARAD).

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Primary ketosis: Label dose: 5–20 mg per cow IM/IV (Azium). Glucocorticoid-induced gluconeogenesis. CAUTION: any dose may cause abortion in pregnant animals.
• Induction of parturition / abortion: Papich 5e: induction of parturition 0.05 mg/kg (25 mg per animal) as a single dose in the last 1–2 weeks of pregnancy, optionally with PGF2α 0.5 mg. Confirm gestational stage — premature induction gives weak or non-viable calves and increases retained placenta. Follow the product-label withdrawal.
• Pregnancy CONTRAINDICATION: AVOID in pregnant cattle unless intentional induction — strongly abortifacient. Withdrawal: not established for milk; consult product label / FARAD.

Birds

• Shock / trauma / endotoxaemia: Plumb’s p.370 (Clubb 1986): 2–4 mg/kg IM or IV once to three times daily for shock, trauma or Gram-negative endotoxaemia; taper when used long term. Birds are prone to immunosuppression and secondary aspergillosis.

Guinea pigs

• Anti-inflammatory: Plumb's p.370 (Adamcak & Otten 2000): Mice/Rats/Gerbils/Hamsters/Guinea pigs/Chinchillas 0.6 mg/kg IM as an anti-inflammatory. Use corticosteroids very cautiously in small mammals — immunosuppression and GI ulceration risk.

Chinchillas

• Anti-inflammatory: Plumb's p.370 (Adamcak & Otten 2000): 0.6 mg/kg IM.

Hamsters

• Anti-inflammatory: Plumb's p.370 (Adamcak & Otten 2000): 0.6 mg/kg IM.

Rats

• Anti-inflammatory: Plumb's p.370 (Adamcak & Otten 2000): 0.6 mg/kg IM.

Mice

• Anti-inflammatory: Plumb's p.370 (Adamcak & Otten 2000): 0.6 mg/kg IM.

Gerbils

• Anti-inflammatory: Plumb's p.370 (Adamcak & Otten 2000): 0.6 mg/kg IM.

Hedgehogs

• Anti-inflammatory / shock: Carpenter Exotic Animal Formulary 6th ed, Table 8-6 (p.518): hedgehogs 0.1–1.5 mg/kg IM (glucocorticoid for inflammation; higher end for shock).

Sugar gliders

• Anti-inflammatory / allergy: Carpenter Exotic Animal Formulary 6th ed, Table 7-5 (p.501): sugar gliders 0.1–0.6 mg/kg SC/IM/IV; 0.2 mg/kg SC/IM/IV q12–24h.

Primates

• Anti-inflammatory / cerebral oedema (monkeys): Carpenter Exotic Animal Formulary 6th ed, Table 13-7 (p.705): monkeys 0.25–1 mg/kg PO/IM q24h; cerebral oedema 0.5–2 mg/kg SC/IM/IV once.

Contraindications

ABORTIFACIENT IN PREGNANT CATTLE — high doses (≥20–25 mg total) commonly induce parturition / abortion in cattle in late gestation. CAUTION in pregnant ruminants generally. Systemic fungal infections (unless replacement therapy). IM use in immune-mediated thrombocytopenia. Hypersensitivity. Diabetes mellitus / impaired glucose tolerance (dexamethasone is markedly hyperglycaemic, especially in cats). Do NOT combine with NSAIDs — additive GI ulceration / colonic perforation (well documented in dogs at high doses). Live attenuated vaccines should not be given to animals on immunosuppressive doses. Horses predisposed to laminitis — dexamethasone has been implicated in steroid-induced laminitis. Severe corneal ulceration (topical / systemic). Rapid IV propylene-glycol-based product → haemolysis. Taper after chronic use to avoid iatrogenic Addisonian crisis.

Species-specific warnings

Dogs: Watch for iatrogenic Cushing's on prolonged use. NEVER concurrent with NSAID. Taper after >2 weeks of therapy.

Cats: Less prone to side effects than dogs but precipitates DIABETES MELLITUS at >0.5 mg/kg/day. Monitor blood glucose.

Cattle: INDUCES PARTURITION / ABORTION at 20–25 mg IM late gestation — used intentionally; avoid otherwise in pregnant cows. Used for ketosis at 5–20 mg IV.

Horses: Laminitis risk — extra caution in obese, PPID, or insulin-resistant horses. Single dose for inflammation usually safe; chronic = high risk.

Birds: EXTREME caution — birds (especially raptors) are very sensitive to steroid immunosuppression; aspergillosis often develops on systemic steroids.

Adverse effects

• Polyuria/polydipsia/polyphagia (esp. dogs)
• GI ulceration / colonic perforation (high-dose, esp. neurosurgical patients)
• Iatrogenic hyperadrenocorticism with chronic use
• Hyperglycaemia / diabetogenic effect (especially in cats)
• Steroid hepatopathy (elevated ALP/ALT)
• Muscle wasting, alopecia, thin skin, poor wound healing
• Immunosuppression — masking of infection
• Cattle: parturition / abortion in late gestation
• Horses: laminitis (especially predisposed individuals)

Drug interactions

• NSAIDs (meloxicam, carprofen, flunixin): synergistic GI ulceration / perforation — DO NOT combine; washout NSAID 5–7 days before starting steroid
• Phenobarbital / phenytoin / rifampicin: induce hepatic metabolism — reduce dexamethasone effect
• Insulin / hypoglycaemics: dexamethasone induces hyperglycaemia — antagonises glucose control
• Digoxin: dexamethasone-induced hypokalaemia potentiates digoxin toxicity
• Furosemide / thiazides: additive hypokalaemia
• Anti-cholinesterase drugs (pyridostigmine in myasthenia): reduce response
• Vaccines (live attenuated): immunosuppression may impair response — postpone
• KCl-sparing drugs (ACE-I, spironolactone): protective against steroid hypokalaemia

Pregnancy and lactation

AVOID in pregnant animals — induces parturition / abortion in cattle and other species (used INTENTIONALLY to induce calving). Teratogenic at high doses (cleft palate, fetal growth restriction). Suppresses fetal HPA axis. Use alternatives or accept induction effect when used near term.

Monitoring

• Blood glucose at baseline and serially in diabetic / pre-diabetic patients
• Body weight, BCS, abdominal distension (Cushing's signs)
• CBC, biochemistry (ALT, ALP, BUN, electrolytes) at 2–4 weeks then every 3 months on chronic use
• Urine specific gravity, urinalysis (USG <1.020 expected; check for UTI)
• Blood pressure — hypertension risk
• Concurrent NSAID review — never co-administer
• Mineralocorticoid effect: dexamethasone has minimal Na retention vs. prednisolone — better choice for CHF, hypertension

Toxicity and overdose

Acute: rapid IV push can cause anaphylactoid reaction (rare). Chronic: iatrogenic Cushing's (PU/PD/polyphagia, muscle wasting, alopecia, calcinosis cutis, hepatopathy, diabetes mellitus). GI ulceration / perforation — risk increases with: high dose, prolonged use, concurrent NSAID, hypoperfusion. Immunosuppression — opportunistic infections (UTI, demodicosis, fungal pneumonia). Behaviour changes (agitation). Cats: relatively resistant to steroid side effects; high doses (>0.5 mg/kg/day) can precipitate diabetes mellitus.

Management: No specific antidote. Discontinue. GI protection: omeprazole 1 mg/kg PO q12h + sucralfate 0.5–1 g PO q6–8h. Aggressive IV fluids + electrolyte correction (K supplementation). Insulin for severe hyperglycaemia. Monitor for adrenal suppression on withdrawal — taper rather than stop abruptly (taper duration depends on length of therapy: >2 weeks = mandatory taper).

Clinical pearls

• Anti-inflammatory (allergy, immune-mediated): 0.1–0.2 mg/kg IV/IM/PO q12–24h, then taper to lowest effective every-other-day dose
• Immunosuppressive (IMHA, IMT, IBD): 0.25–0.5 mg/kg IV/IM/PO q12–24h × 2–4 weeks, then taper
• Bovine ketosis: 5–20 mg IV/IM single dose — gluconeogenesis boost
• Bovine pregnancy termination / induction of parturition: 20–25 mg IM single dose late gestation
• Anaphylactic shock: 0.25–1 mg/kg IV slow (adjunct only — epinephrine is first-line)
• Spinal cord trauma: NO longer recommended (MASCIS trial — no benefit, increased complications)
• NSAID + steroid combo = GI perforation risk — washout NSAID 5–7 days before starting
• Taper, never stop suddenly after >2 weeks of therapy — iatrogenic Addisonian crisis risk
• Cats less sensitive to side effects than dogs but precipitates DM at >0.5 mg/kg/day

Mechanism of action

Long-acting synthetic glucocorticoid with high anti-inflammatory potency (~25× cortisol) and prolonged biological half-life (36–54 h). Binds intracellular glucocorticoid receptor → translocates to nucleus → modulates transcription of >1000 genes: suppresses pro-inflammatory cytokines (IL-1, IL-6, TNF-α), induces anti-inflammatory mediators (lipocortin-1), reduces leukocyte trafficking and phagocytosis. Negligible mineralocorticoid (sodium-retaining) effect — preferred for inflammation/allergy/oncology over prednisolone when mineralocorticoid effect is unwanted.

Formulations and products

• Azium injection 2 mg/mL
• Dexamethasone sodium phosphate 4 mg/mL
• Tablet 0.25 mg
• Tablet 0.5 mg
• Tablet 1.5 mg

Storage

Tablets: 15–30 °C, dry, protected from light. Injection: 15–25 °C, do NOT freeze. Multidose vial: discard 28 days after broaching. Ophthalmic: per label.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Other anti-inflammatory drugs

• Carprofen
• Deracoxib
• Diclofenac
• Dimethyl Sulfoxide (DMSO)
• Firocoxib
• Flunixin Meglumine
• Grapiprant
• Isoflupredone Acetate

Frequently asked questions