Ursodiol (Ursodeoxycholic Acid)
Ursodiol, or ursodeoxycholic acid, is a hydrophilic bile acid used as an adjunct in selected hepatobiliary disorders. Its principal veterinary role is support of bile flow and reduction of potentially injurious bile-acid exposure in nonobstructive cholestatic disease. Clinical evidence for individual canine and feline disorders remains less extensive than the biochemical rationale.
Group
Hydrophilic bile acid and choleretic
Mechanism of Action
Ursodiol becomes part of the bile-acid pool and can shift its composition toward less hydrophobic, less cytotoxic bile acids. It promotes bile secretion and may support bicarbonate-rich flow, reducing exposure of hepatocytes and cholangiocytes to damaging bile constituents. Additional cytoprotective and immunomodulatory effects have been proposed. The clinical impact depends on the underlying hepatobiliary disorder.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Hepatobiliary disease | 10–15 mg/kg | PO | Every 24 h | 15 mg/kg once daily is the commonly used reported amount. |
| Hepatobiliary disease | 11–15.4 mg/kg | PO | Every 24 h | |
| Hepatobiliary disease divided daily amount | 5.5–7.7 mg/kg | PO | Every 12 h | Half of explicitly stated total daily 11-15.4 mg/kg; not the full daily amount twice daily. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Hepatobiliary disease | 10–15 mg/kg | PO | Every 24 h | 15 mg/kg once daily is the commonly used reported amount. |
| Hepatobiliary disease | 11–15.4 mg/kg | PO | Every 24 h | |
| Hepatobiliary disease divided daily amount | 5.5–7.7 mg/kg | PO | Every 12 h | Half of explicitly stated total daily 11-15.4 mg/kg; not the full daily amount twice daily. |
| Hepatobiliary disease | 10 mg/kg | PO | Every 24 h |
Birds
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Liver disease adjunct | 10–15 mg/kg | PO | Every 24 h |
Indications
- Adjunctive treatment of selected nonobstructive cholestatic liver disease in dogs and cats.
- Adjunctive treatment of selected cholangitis or chronic inflammatory hepatobiliary disease, with limited disease-specific outcome evidence.
- Specialist medical management of selected cholesterol-containing gallstones where a supported dissolution strategy is appropriate.
Interactions
- No specific veterinary interaction is established in the clinical guidance.
Adverse effects
- Diarrhea or loose stool.
Toxicity
Excess usually causes diarrhea; provide supportive treatment according to exposure and clinical signs.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Ursodiol (Ursodeoxycholic Acid) 250 mg | Tablet | 250 mg / tablet | PO |
| Ursodiol (Ursodeoxycholic Acid) 500 mg | Tablet | 500 mg / tablet | PO |
| Ursodiol capsule 300 mg | Capsule | 300 mg / capsule | PO |
Monitoring and Administration
Give with meals and follow liver enzymes and bile acids. Gradual titration over 1-2 weeks can reduce GI effects; investigate hepatobiliary disease before choleretic therapy.
Reported oral suspension stability varies by vehicle, 35-60 days.