Potassium depletion can be controlled with potassium supplementation. Oral Ulcers Mouth and tongue ulcers, common in CRF cats, can cause discomfort and may prevent a cat from eating, thus causing substantial weight loss. In some cases, ulcers may extend into the esophagus. There may be an indicative odor from the cat's mouth. The mouth should be checked frequently by you and your veterinarian.
Vomiting causes dehydration and loss of potassium.
The cat may lick its lips frequently as if trying to get rid of a bad taste. Some CRF cats tend to vomit clear liquid on a regular basis. Anti-ulcer drugs and protective agents may alleviate the nausea enough so that the cat regains its appetite.