If your cat has frequent contact with other cats or kittens, you should be informed about feline leukemia virus. The presence of this virus causes major problems with the cat or kitten's immune system and other organs, and may even cause cancer. Research indicates that feline leukemia virus is highly contagious among cats of all ages. Current research indicates that it does not affect humans or other species. Among cats, it is spread by saliva, urine, and blood. A cat can also pass the virus along to its kittens in a number of ways before they are born.

Some of the symptoms include:

• Anemia, lack of pink or red color in the gums
  
• Weight loss
  
• Recurring or chronic illness
  
• A progressive weakness
  
• Lethargy, fever, diarrhea
  
• Breathing difficulty
  
• Yellow color in the mouth and/or the white of the eyes

Remember, avoiding exposure with infected cats and updating vaccinations are the best tools of preventive medicine. Your veterinarian can determine the best program for your cat.