A TSH test measures the amount of thyroid stimulating hormone (TSH) in your blood. TSH is produced by the pituitary gland and tells the thyroid gland to make and release the hormones thyroxine (T4) and triiodothyronine (T3). See also: 1  T3 test.  T4 test.
Best Answer: Female cats typically have their first heat around the age of six months, which usually lasts for 5 to 7 days. Cat's heat cycles are light dependent and they usually have heat cycles every 9 to 13 days from January through October, though some indoor cats exposed to constant light times will cycle all year. I advise unless you want kittens to keep her in at these times.
Quick Answer. WebMD states that female cats go into heat several times during the year unless they are being bred. The heat cycle is influenced by the seasons, and is activated when there are 12 hours of daylight. Other factors include the temperature of the environment and the presence of other cats.