1 Cats: Cats normally have their first estrous cycle between 4 and 6 months of age, with the average age around 5 months. 2  The female cat has 2-4 estrous periods every year, each lasting 15-22 days. 3  If she is bred, estrus seldom lasts more than 4 days.
Lactate dehydrogenase (LD or LDH) is an enzyme involved in energy production that is found in almost all of the body's cells, with the highest levels found in the cells of the heart, liver, muscles, kidneys, lungs, and in blood cells; bacteria also produce LD.actate dehydrogenase (LD or LDH) is an enzyme involved in energy production that is found in almost all of the body's cells, with the highest levels found in the cells of the heart, liver, muscles, kidneys, lungs, and in blood cells; bacteria also produce LD.
You may also have a lactate dehydrogenase isoenzyme test. Your total LDH is made up of 5 isoenzymes numbered LDH-1 through LDH-5. The concentration of each isoenzyme depends on the tissue.For example, LDH-1 and LDH-2 are found mainly in heart tissue. LDH-5 is found mostly in the liver.A higher than normal total LDH means possible tissue damage. Your healthcare provider might order a lactate dehydrogenase isoenzyme test to find out which tissue is damaged or diseased.or example, LDH-1 and LDH-2 are found mainly in heart tissue. LDH-5 is found mostly in the liver. A higher than normal total LDH means possible tissue damage. Your healthcare provider might order a lactate dehydrogenase isoenzyme test to find out which tissue is damaged or diseased.