# Ursodiol (Ursodeoxycholic Acid): veterinary dose and monograph

> Ursodiol (Ursodeoxycholic Acid) is a veterinary gastrointestinal drug. A hydrophilic ("good") bile acid used as a hepatoprotective CHOLERETIC in chronic liver and biliary disease — it improves bile flow, displaces toxic hydrophobic bile acids, and has anti-inflammatory, immunomodulatory and anti-apoptotic… Indications include chronic hepatitis / cholangiohepatitis (cats) — hepatoprotection; cholestatic liver disease (improves bile flow); biliary sludge and gallbladder mucocele (medical management of non-obstructive cases). This monograph lists 3 reference doses for dogs, cats and birds, each with route, frequency and source.

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

## At a glance

- **Drug class:** Gastrointestinal
- **Also known as:** UDCA, Actigall, Udiliv, Ursocol
- **Species with doses:** Dogs, Cats and Birds
- **General dose range:** 10–15 mg/kg PO q24h (or divided q12h) with food — check the species tables for the indication
- **Routes:** PO
- **Last reviewed:** 1 October 2026

## Indications

- Chronic hepatitis / cholangiohepatitis (cats) — hepatoprotection
- Cholestatic liver disease (improves bile flow)
- Biliary sludge and gallbladder mucocele (medical management of non-obstructive cases)
- Adjunct in many chronic hepatobiliary disorders

## Ursodiol (Ursodeoxycholic Acid) 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

*Ursodiol (Ursodeoxycholic Acid) doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Chronic/cholestatic liver disease | 10–15 mg/kg | PO | q24h with food | — |

- Chronic/cholestatic liver disease: Papich 5e: 10–15 mg/kg q24h PO (15 mg/kg most often). Plumb’s p.1156: 10–15 mg/kg PO once daily (Webb & Twedt); 11–15.4 mg/kg once daily or divided twice daily (Tams). Give with food; confirm the bile duct is not obstructed.

### Cats

*Ursodiol (Ursodeoxycholic Acid) doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Cholangitis / cholangiohepatitis | 10–15 mg/kg | PO | q24h with food | — |

- Cholangitis / cholangiohepatitis: Papich 5e: 10–15 mg/kg q24h PO. Plumb’s p.1156: 10–15 mg/kg once daily (Webb & Twedt); 10 mg/kg/day (Zoran); about ⅙ of a capsule mixed with food (Tams). Rule out extrahepatic bile duct obstruction first.

### Birds

*Ursodiol (Ursodeoxycholic Acid) doses for birds*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Liver disease (adjunct) | 10–15 mg/kg | PO | q24h | — |

- Liver disease (adjunct): Plumb’s p.1156 (Oglesbee 2009): 10–15 mg/kg PO once daily.

## Contraindications

Complete biliary obstruction (increasing bile flow against an obstruction is harmful — confirm patency first; a developing/ruptured mucocele needs surgery). CONTRAINDICATED in rabbits and other hindgut fermenters — ursodiol is converted to toxic lithocholic acid (Plumb's). Known hypersensitivity. Use with caution where surgical biliary disease is the real problem.

## Species-specific warnings

> **Caution:** Cats: A mainstay for the feline cholangitis/cholangiohepatitis complex — pair with appropriate antibiotic and/or immunosuppressive therapy based on the cholangitis type and biopsy.

## Adverse effects

- Generally very well tolerated
- Occasional diarrhoea / GI upset
- Rare vomiting

## Drug interactions

- Bile-acid sequestrants (cholestyramine), aluminium antacids: bind ursodiol and reduce its absorption — separate dosing
- No major systemic CYP interactions

## Pregnancy and lactation

Limited veterinary data; generally regarded as low-risk (it is a physiological bile acid). Use if clearly indicated.

## Monitoring

- Liver enzymes / bilirubin and bile acids over time (response)
- Imaging of the biliary tree (confirm patency; monitor mucocele/sludge)
- GI tolerance
- Overall hepatobiliary disease response (often part of a multidrug plan)

## Toxicity and overdose

Very wide safety margin — overdose typically causes only diarrhoea/GI upset. The important caution is mechanistic, not toxic: do not push bile flow in a completely obstructed biliary tree.

Management: Supportive; no specific antidote needed. Manage diarrhoea symptomatically. Reduce dose if GI upset.

## Clinical pearls

- A cornerstone hepatoprotectant for chronic/cholestatic liver disease and feline cholangitis — improves bile flow and swaps toxic bile acids for benign ones
- CONFIRM the bile duct is patent first — don't drive bile flow against a complete obstruction (that's a surgical problem)
- Give with food; commonly combined with SAMe/silybin (and antibiotics/immunosuppressants for the underlying disease)
- Very safe and well tolerated — diarrhoea is the only common nuisance

## Mechanism of action

Ursodeoxycholic acid is a non-toxic, hydrophilic bile acid. It (1) promotes bile flow (choleresis), (2) competitively reduces the proportion of toxic, hydrophobic bile acids in the bile-acid pool (cytoprotective to hepatocyte and cholangiocyte membranes), and (3) exerts anti-inflammatory, immunomodulatory and anti-apoptotic effects on liver cells. The net effect is reduced cholestatic hepatocellular injury.

## Formulations and products

- 150 mg tablet
- 300 mg tablet/capsule
- Suspension (compounded) 25–50 mg/mL
- Udiliv — 150 / 300 mg tablet, Tablet (human-label)
- Ursocol — 150 / 300 mg tablet, Tablet (human-label)

## Storage

Tablets/capsules: 15–30 °C, dry. Compounded suspension per pharmacy beyond-use date.

## 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 gastrointestinal drugs

- [Silymarin (Milk Thistle / Silybin)](https://vetmasterji.com/drugs/silymarin)
- [Sucralfate](https://vetmasterji.com/drugs/sucralfate)
- [Sulfasalazine](https://vetmasterji.com/drugs/sulfasalazine)
- [Tylosin](https://vetmasterji.com/drugs/tylosin)

## Frequently asked questions

### What is the dose of Ursodiol (Ursodeoxycholic Acid) for dogs?

Reference doses for Ursodiol (Ursodeoxycholic Acid) in dogs: 10–15 mg/kg PO q24h with food (Chronic/cholestatic liver disease). Confirm against the label and the patient before use.

### What is the dose of Ursodiol (Ursodeoxycholic Acid) for cats?

Reference doses for Ursodiol (Ursodeoxycholic Acid) in cats: 10–15 mg/kg PO q24h with food (Cholangitis / cholangiohepatitis). Confirm against the label and the patient before use.

### What is the dose of Ursodiol (Ursodeoxycholic Acid) for birds?

Reference doses for Ursodiol (Ursodeoxycholic Acid) in birds: 10–15 mg/kg PO q24h (Liver disease (adjunct)). Confirm against the label and the patient before use.

### When should Ursodiol (Ursodeoxycholic Acid) not be used?

Complete biliary obstruction (increasing bile flow against an obstruction is harmful — confirm patency first; a developing/ruptured mucocele needs surgery). CONTRAINDICATED in rabbits and other hindgut fermenters — ursodiol is converted to toxic lithocholic acid (Plumb's). Known hypersensitivity. Use with caution where surgical biliary disease is the real problem.

### What are the side effects of Ursodiol (Ursodeoxycholic Acid) in animals?

Generally very well tolerated; Occasional diarrhoea / GI upset; Rare vomiting.

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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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.