Can I Give My Cat Metamucil?

Yes, with care
Psyllium husk is commonly referenced for cats at published doses. Published guidance for cats: 1/4 - 1/2 tsp in wet food, every 12-24h. Ensure water intake; fiber without water worsens constipation.
Source: Veterinary Partner (VIN)
Get the exact range for your cat's weight

Skip it or ask a vet first if

xylitol-sweetened productsintestinal obstruction

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 fiber / GI questions for cats