I'm not a veterinarian, but the symptoms you've described—including weakness, reduced appetite, stomach problems, and mouth dryness—can indicate a range of health issues in animals. It's crucial to consult a veterinarian for a proper diagnosis and treatment plan.
In some cases, these symptoms could be related to dehydration, gastrointestinal issues, infections, or other systemic problems. Veterinarians may recommend supportive care, fluid therapy, dietary changes, or specific medications based on the underlying cause.
If you're unable to see a vet immediately, you can try to ensure the animal remains hydrated by providing fresh water and possibly a bland diet (like boiled chicken and rice for dogs) until you can get professional advice. However, these are just general suggestions and should not replace professional veterinary care.