ANSWER: For anyone who has battled a flea problem, the old adage about an ounce of prevention rings very true. Once fleas become established they are very difficult to eliminate from the house or environment. Each flea you see on your cat only represents less than 5 percent of the various life stages living on or around your cat. The treatments you describe are absorbed into your pet's skin and typically diffuse along through the oil glands. There are also very effective oral flea preventives.
Fleas can cause terribly itchy skin conditions, and the secondary infections that can develop are difficult to clear. Many of the animals I see are literally chewing or biting themselves raw from the allergic reaction to the flea bites. In cats it can also spread a serious blood parasite that leads to a life-threatening anemia.
You have to be very careful about what treatments you use for fleas. Cats are extremely sensitive to a family of chemicals called permethrins, which are the main component of flea collars and dips. Many over-the-counter topical flea treatments also may have this ingredient. It can cause depression, tremors, or even full-blown seizures that require days in the hospital to control until the chemical is out of your cat's system.
The other common mistake is not treating the pet long enough to eliminate infestation. The eggs the fleas lay in the environment can lie dormant for an extended period of time, depending on environmental conditions. March through November is the bare minimum pets should be on flea prevention in our area. The key word is prevention.
Ask your veterinarian for recommendations on how to clear the flea infestation and have your cat examined if he is intensely itchy and has scabs or hair loss. These may require treatment, and she may prescribe something to help with the itching or infection. The newer generation of flea prevention and treatment is light years ahead of what was available previously.
ANSWER: The process you are describing is typical of what often is involved in accurately diagnosing Cushing's disease, and it sounds like you are in good hands. However, the important point is that if you ever are concerned about the process or disease your pet has been diagnosed with, ask your veterinarian.
If needed, ask for some referrals for a second opinion. Not every veterinarian may have a comfort level with a specific disease, but he or she will gladly give you names of veterinarians who are. If you encounter a veterinarian who is not willing to send you to anyone for a second opinion, that should be cause for alarm. However, in my experience in our area, that is highly unlikely.
Questions for Dr. Thompson can be e-mailed to firstname.lastname@example.org or mailed to The Blade, Attn. Ask the Vet, 541 North Superior St., Toledo, OH 43660. Dr. Thompson regrets that he cannot answer individual letters.