I do agree with him, they really know how to foul up a water bowl! I do recommend that you get the toad dewormed, which is not hard to do with such a large frog. My only experience with cane toads were ones that were heavily parasitized.
I sure would like to know where the use of cat and dog food got started from. I can only assume that since they had been observed eating this in the "wild", that people thought it was okay to feed it to them. If you look and Dr. Frye's book (can remember exact title, but costs $175 per volume) you'll see horrible pictures of reptiles that had been fed cat or dog food. Most of these animals suffer while going through some type of organ failure. I've never seen dog or cat food being recommended for an amphibian in any credible literature I have come across. I say as long as they are perfectly safe alternatives, stay away from it.
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*Humans aren't the only species on earth... we just act like it.
".the oldest task in human history: to live on a piece of land without
spoiling it."
Aldo Leopold (1938)