Can I Give My Cat generic syrup?

Ask your vet first
Lactulose is used in cats, but dosing decisions belong to your veterinarian. Reference only.
Source: Merck Veterinary Manual
Get the exact range for your cat's weight

Skip it or ask a vet first if

self-directed use

The safe habit

Confirm any medication decision with your veterinarian, who knows your cat's health history and other medications. VetDose shows published reference data, not prescriptions.

See also

Other GI (Rx in practice) questions for cats