How can I understand that my pet is sick? What symptoms or body language should I watch out for?

Signs of illness in dogs vary depending on age of the dog, system affected, type and duration of illness, etc. For example, some dogs with simple fever continue to eat and play while some become lethargic and loose appetite. Therefore regular visit to your vet for monitoring his health is essential for preventing and controlling serious ailments. Here’s a partial list of signs worth reporting to your vet as soon as possible–loss of appetite, weakness or lethargy for longer than 24 hours, loosing body weight, collapse or convulsions, increased thirst and water intake, discharge from nostrils, eyes, ears change in urination or defecation pattern, red eyes, lumps and bumps on skin, lameness or reluctant to walk, itching or shaking his head,

Question by – Shajeeha Mallick, Hyderabad