# Itraconazole: veterinary dose and monograph

> Itraconazole is a veterinary antifungal. Triazole antifungal — inhibits fungal CYP-dependent ergosterol synthesis. Indications include dermatophytosis (Microsporum canis) — cats and dogs; systemic mycoses — blastomycosis, histoplasmosis, cryptococcosis; aspergillosis (nasal / disseminated). This monograph lists 10 reference doses for dogs, cats, horses, birds, hedgehogs and sugar gliders and 1 more species, each with route, frequency and source.

Source: https://vetmasterji.com/drugs/itraconazole · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Antifungal
- **Also known as:** Itrafungol, Sporanox
- **Species with doses:** Dogs, Cats, Horses, Birds, Hedgehogs, Sugar gliders and Primates
- **General dose range:** 5–10 mg/kg PO q24h — check the species tables for the indication
- **Routes:** PO
- **Last reviewed:** 1 October 2026

## Indications

- Dermatophytosis (Microsporum canis) — cats and dogs
- Systemic mycoses — blastomycosis, histoplasmosis, cryptococcosis
- Aspergillosis (nasal / disseminated)
- Malassezia dermatitis

## Itraconazole 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

*Itraconazole doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Blastomycosis / histoplasmosis | 5 mg/kg | PO | q12h × 3 d then q24h | minimum 60 d / until 1 month past remission |
| Aspergillosis / cryptococcosis | 5–10 mg/kg | PO | q12–24h | — |
| Malassezia dermatitis | 5 mg/kg | PO | q24h (or 2 consecutive days per week) | 3 weeks |

- Blastomycosis / histoplasmosis: Papich 5e: loading dose 20 mg/kg, then 10 mg/kg q24h (or 5 mg/kg q12h); highly susceptible Blastomyces may respond to 5 mg/kg once daily. Plumb’s p.682: blastomycosis 5 mg/kg PO once daily (or divided twice) for 2–3 months, with an optional 10 mg/kg/day loading dose for 3 days (Taboada 2000); histoplasmosis 10 mg/kg daily. Treat ≥30 days beyond resolution. Give with food; monitor ALT monthly.
- Aspergillosis / cryptococcosis: Papich 5e: cryptococcosis 5 mg/kg q12h PO. Plumb’s p.682: nasal aspergillosis 5 mg/kg PO q12h for 3–6 months (Kuehn 2010); coccidioidomycosis and sporotrichosis 5–10 mg/kg once daily. Give with food; monitor liver enzymes.
- Malassezia dermatitis: Plumb’s p.682: 5 mg/kg PO once daily for 3 weeks (Negre 2009), or pulse 5 mg/kg on 2 consecutive days each week for 3 weeks (Foil 2003). Papich 5e: 5 mg/kg q24h for 2 days, repeated weekly for 3 weeks. Dermatophytes (Papich): 3 mg/kg/day for 15 days.

### Cats

*Itraconazole doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Dermatophytosis (pulse therapy) | 5 mg/kg | PO | q24h, 1 week on / 1 week off × 3 cycles | — |
| Systemic mycoses (histoplasmosis, blastomycosis, cryptococcosis) | 5–10 mg/kg | PO | q24h (or divided q12h) | months — until antigen/clinical resolution |

- Dermatophytosis (pulse therapy): Papich 5e: 5 mg/kg PO once daily on alternating weeks for 3 cycles (weeks 1, 3 and 5); some cats need a further course. Plumb’s (DeBoer 2006): 5 mg/kg once daily every other week for three pulses — toxicity is rare with this protocol. Matches the licensed feline oral-solution protocol.
- Systemic mycoses (histoplasmosis, blastomycosis, cryptococcosis): Papich 5e: 5 mg/kg PO once daily, or 50 mg per cat daily / 100 mg per cat every other day. Plumb’s p.682: histoplasmosis and blastomycosis 10 mg/kg once daily or divided twice daily for 2–4 months or longer; cryptococcosis 50 mg/day (cats ≤3.5 kg) or 100 mg/day for 3–12 months (Malik 2006). Monitor ALT; hepatotoxicity is reversible.

### Horses

*Itraconazole doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Guttural pouch mycosis / mycotic rhinitis | 5 mg/kg | PO | q24h (or 2.5 mg/kg q12h) | — |

- Guttural pouch mycosis / mycotic rhinitis: Papich 5e: 5 mg/kg/day (2.5 mg/kg q12h) PO — use the oral solution; capsules are poorly and inconsistently absorbed in horses. Plumb’s p.682 (Davis 2007): oral solution 5 mg/kg PO q24h.

### Birds

*Itraconazole doses for birds*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Aspergillosis / candidiasis | 5–10 mg/kg | PO | q12–24h | — |

- Aspergillosis / candidiasis: Plumb’s p.682: 5–10 mg/kg PO q12–24h (Tully 2008); aspergillosis 5–10 mg/kg once daily in Amazon parrots, 2.5–5 mg/kg once daily in African grey parrots (Oglesbee 2009) — greys are especially sensitive. Ratites 6–10 mg/kg once daily.

### Hedgehogs

*Itraconazole doses for hedgehogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Dermatophytosis / systemic mycosis | 5–10 mg/kg | PO | q12–24h | — |

- Dermatophytosis / systemic mycosis: Carpenter Exotic Animal Formulary 6th ed, Table 8-2 (p.514): hedgehogs 5–10 mg/kg PO q12–24h; European hedgehogs 10 mg/kg PO q12h in food (dermatophytosis). Dermatophytosis is the commonest skin disease of pet hedgehogs.

### Sugar gliders

*Itraconazole doses for sugar gliders*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Dermatophytosis | 5–10 mg/kg | PO | q12–24h | — |

- Dermatophytosis: Carpenter Exotic Animal Formulary 6th ed, Table 7-1 (p.497): sugar gliders 5–10 mg/kg PO q12h or q24h for dermatophytes.

### Primates

*Itraconazole doses for primates*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Dermatophytosis / yeast infection (marmosets) | 5–10 mg/kg | PO | q12–24h | — |

- Dermatophytosis / yeast infection (marmosets): Carpenter Exotic Animal Formulary 6th ed, Table 13-2 (p.684): common marmosets 5–10 mg/kg PO q12h for dermatophytosis; marmosets/capuchins/lemurs 10 mg/kg PO q24h for fungal (yeast) gastroenteritis.

## Contraindications

Hepatic impairment. Ventricular dysfunction / CHF (negative inotrope at high dose). Pregnancy (teratogenic). Numerous CYP3A drug interactions.

## Adverse effects

- Anorexia and hepatotoxicity (monitor liver enzymes)
- Cutaneous vasculitis / ulcerative dermatitis at >10 mg/kg (dogs)
- GI upset

## Drug interactions

- Amphotericin B: lab-animal studies suggest ANTAGONISM against Aspergillus and Candida when used concomitantly — clinical importance not yet clear
- Antacids: reduce oral absorption — give itraconazole at least 1 hour before or 2 hours after
- Benzodiazepines (alprazolam, diazepam, midazolam, triazolam): itraconazole raises their levels
- Buspirone: plasma concentrations may be elevated
- Busulfan: levels may be increased
- Calcium-channel blockers (amlodipine, verapamil): levels may be increased
- Cisapride: raised levels and toxicity risk — the combination is contraindicated in humans
- Clomipramine: reduced metabolism, increased levels
- Corticosteroids: itraconazole inhibits their metabolism — potential for increased steroid adverse effects

## Pregnancy and lactation

Teratogenic / embryotoxic in laboratory animals — avoid in pregnancy.

## Monitoring

- Liver enzymes (ALT) at baseline then monthly
- Appetite — anorexia is an early hepatotoxicity sign
- Inspect skin for vasculitis at higher doses

## Toxicity and overdose

Plumb's p.681: information on acute itraconazole toxicity is very limited. Oral antacids may help reduce absorption; after a large overdose consider gut emptying and give supportive care. Itraconazole is NOT removed by dialysis. Reassuringly, in chronic toxicity studies dogs given 40 mg/kg PO daily for 3 months showed no overt toxicity. The practical clinical concerns on long courses are hepatotoxicity (monitor liver enzymes) and, at higher doses, cutaneous vasculitis/ulceration in dogs.

## Clinical pearls

- The oral solution has roughly twice the bioavailability of the capsule — do not substitute mg-for-mg
- Stop the drug and recheck if appetite drops — hepatotoxicity is the main reason for discontinuation
- Potent CYP3A inhibitor — raises levels of cyclosporine, digoxin and many sedatives

## Mechanism of action

Plumb's p.680: itraconazole is a fungistatic TRIAZOLE. Like the imidazoles (clotrimazole, ketoconazole) it alters the fungal cell membrane — increasing permeability, allowing leakage of cellular contents and impairing uptake of purine and pyrimidine precursors — by interfering with ergosterol synthesis. Fungistatic activity is documented against many strains of Candida, Aspergillus, Cryptococcus, Histoplasma, Blastomyces and Trypanosoma cruzi, and it is effective against dermatophytes. Note it also has immune-SUPPRESSING activity, probably via suppression of T-lymphocyte proliferation. Compared with ketoconazole it is more potent, better tolerated, and does not meaningfully suppress mammalian steroid synthesis.

## Formulations and products

- Itraconazole 100 mg capsule
- Itraconazole oral solution 10 mg/mL (Itrafungol)

## Before you use this dose

> **Caution:** 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 antifungals

- [Clotrimazole](https://vetmasterji.com/drugs/clotrimazole)
- [Enilconazole](https://vetmasterji.com/drugs/enilconazole)
- [Fluconazole](https://vetmasterji.com/drugs/fluconazole)
- [Griseofulvin](https://vetmasterji.com/drugs/griseofulvin)
- [Ketoconazole](https://vetmasterji.com/drugs/ketoconazole)
- [Lime Sulfur (Lime Sulphur Dip)](https://vetmasterji.com/drugs/lime-sulfur)
- [Miconazole](https://vetmasterji.com/drugs/miconazole)
- [Nystatin](https://vetmasterji.com/drugs/nystatin)

## Frequently asked questions

### What is the dose of Itraconazole for dogs?

Reference doses for Itraconazole in dogs: 5 mg/kg PO q12h × 3 d then q24h for minimum 60 d / until 1 month past remission (Blastomycosis / histoplasmosis); 5–10 mg/kg PO q12–24h (Aspergillosis / cryptococcosis); 5 mg/kg PO q24h (or 2 consecutive days per week) for 3 weeks (Malassezia dermatitis). Confirm against the label and the patient before use.

### What is the dose of Itraconazole for cats?

Reference doses for Itraconazole in cats: 5 mg/kg PO q24h, 1 week on / 1 week off × 3 cycles (Dermatophytosis (pulse therapy)); 5–10 mg/kg PO q24h (or divided q12h) for months — until antigen/clinical resolution (Systemic mycoses (histoplasmosis, blastomycosis, cryptococcosis)). Confirm against the label and the patient before use.

### What is the dose of Itraconazole for horses?

Reference doses for Itraconazole in horses: 5 mg/kg PO q24h (or 2.5 mg/kg q12h) (Guttural pouch mycosis / mycotic rhinitis). Confirm against the label and the patient before use.

### When should Itraconazole not be used?

Hepatic impairment. Ventricular dysfunction / CHF (negative inotrope at high dose). Pregnancy (teratogenic). Numerous CYP3A drug interactions.

### What are the side effects of Itraconazole in animals?

Anorexia and hepatotoxicity (monitor liver enzymes); Cutaneous vasculitis / ulcerative dermatitis at >10 mg/kg (dogs); GI upset.

## Sources

- Plumb's Veterinary Drug Handbook
- Papich, Papich Handbook of Veterinary Drugs, 5th edition
- Carpenter, Exotic Animal Formulary

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.