Ms. Giancoli cited possible side effects of fasting, like the risk of
developing gallstones, hair loss, headaches, fatigue, volume depletion,
electrolyte imbalances, muscle cramping, and constipation, although many of these can be managed with the guidance of a health professional.
Any cat may
develop gastroenteritis, which may be mild and self limiting or, in some cases, result in severe vomiting and diarrhea, (occasionally with blood) leading to decreased appetite, dehydration and an
electrolyte imbalance.