The approach to a health problem is based on training, experience and probability. Some health problems are common, others are rare.
Some problems occur more commonly in young animals, other problems are more common in aged pets.
Some problems are common in one part of the country but rarely occur in other locations. After getting a history of your pet's problem and examining your pet, your veterinarian will go through a mental or written process of listing all the problems from the history and physical examination. Tests are often recommended in stages, beginning with screening tests that are relatively inexpensive and have little potential for causing harm to the animal. Based on the results of the screening tests more sophisticated tests, which often cost more and may have some risks, may be recommended. Although your veterinarian cannot predict what will be found on a specific test, usually the veterinarian will provide some possible outcomes for each of the tests so that you can decide whether the costs and risks are worth the information that may be gained.