1. Small: Singapore cats have fever, depression, body temperature begins to gradually decrease, weakness, dehydration, anorexia, vomiting and diarrhea.

2. Rhinotracheitis: Singaporean cats have fever, produce a lot of mucus in the nose, sneeze profusely, conjunctivitis, corneal ulcers, and shed a lot of tears.

3. Calcium virus: Singapore cats have fever, mouth breathing, excessive salivation, loss of appetite, cough, runny nose, ulcers and blisters on the mouth.

4. Feline leukemia: Singapore cats have loss of appetite, weight loss, skin damage, fever, gastrointestinal disorders, etc.

5. Pneumonia: Singaporean cats suffer from excessive scratching, rhinitis, red eyes, loss of appetite, increased nose and eye secretions, accelerated breathing frequency, and even difficulty breathing.