My dog, who usually has a very healthy appetite, has suddenly stopped eating his regular meals for the past day. He's also showing a bit less energy than usual, though not critically so. This sudden change is quite concerning, and I'm wondering what the common reasons might be for a dog to completely stop eating. What are the signs or accompanying symptoms that indicate this is an emergency requiring immediate veterinary attention versus something that might resolve on its own with time? Beyond an urgent vet visit, what are some safe first steps or observations I should make at home when my dog refuses to eat? I'm looking for advice on identifying potential causes and knowing when it's absolutely crucial to rush to the vet, especially given the availability of vet services here in Bangladesh.

1. Mild Illness or Upset Stomach – Just like humans, dogs can have an off day from minor digestive issues or nausea.

2. Changes in Routine or Environment – New people, stress, loud noises (storms, fireworks), or changes at home can reduce appetite.

3. Dental Problems – Pain from a broken tooth, inflamed gums, or oral infection might make chewing uncomfortable.

4. Food Issues – Spoiled food, a change in food brand, or boredom with the same food over time can affect interest.