Dog/Catfish aren't permanent.

[cromignon]

I thought that the Dogfish and Catfish were meant to permanently change my pet. I used a Dogfish to change my cat into a dog, but when I used a Bog Perch to change my dog into a Thorned Strider, it changed back into a cat at the end of the Bog Perch's spell.

[Atech66]

Any "Permanant" fish will change back to your original pet if you feed it another fish. Same way in TL2 :)

[cromignon]

Then it should say so. Not 'Warning: Permanent Effect!'. It's a bug and needs to be fixed. Doubly so if it carries over into TL2.