Major Uses

Lactulose is primarily used to reduce ammonia blood levels to treat and prevent hepatic encephalopathy in birds and other small animals. It has also been proven effective as a laxative for small animals.

Common Precautions

Lactulose should be used cautiously in diabetic patients, as it contains some free lactose and galactose, which can alter insulin requirements. Should lactulose cause diarrhea, it may exacerbate conditions involving fluid and electrolyte imbalances. Patients with these conditions should exercise caution when taking this drug.

Some negative side effects associated with lactulose include flatulence, gastric distention, and crampi

Lactulose should not be used in animals with a known allergy or hypersensitivity to the drug. A veterinarian should be contacted immediately if an overdose is suspected, the symptoms of which include diarrhea, dehydration, cramping, and flatulence.


Lactulose should be kept at room temperature and stored in a childproof container. It should be kept away from conditions that can cause freezing. The solution is known for darkening or clouding when exposed to heat and light, but this will not affect the drug's potency. Lactulose should be kept out of reach from pets and children


For treating hepatic encephalopathy in dogs, a typical dose of lactulose is .5-30 mL up to 4 times a day. Should a hepatic encephalopathy crisis occur, doses can go up to 20-60 mL every 4-6 hours. When treating cats, a typical dose is between .25-10 mL two or three times a day. For birds, a typical dose ranges from .03-.1 mL two or three times a day. Should a dose be forgotten, it should be given as soon as possible. If it is almost time for the next scheduled dose, the missed dose should be skipped. Two doses of lactulose should never be given at the same time.

Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.