Hydrochlorothiazide for Cats

Cats, like humans, can develop conditions such as hypertension or high blood pressure, suffer from different forms of edema or fluid retention and suffer from congestive heart failure. One type of medication used to treat these conditions is hydrochlorothiazide (HCTZ), which is a prescription diuretic drug. HCTZ helps to treat the symptoms associated with these disorders, but does not treat hypertension directly.

  1. Hypertension in Cats

    • Many cats with hypertension or high blood pressure do not have any symptoms of the condition. In cats that do show symptoms of high blood pressure, the most common is vision problems or blindness. Often high blood pressure is found to be present in conjunction with hyperthyroidism and kidney disease. Hypertension may also be discovered during a physical exam with your veterinarian. This condition is quite common in older cats.

    Function of Hydrochlorothiazide

    • HCTZ is a thiazide diuretic. A regular diuretic simply helps to rid the body of excess water; a thiazide diuretic rids the body of excess salt and water. Removing the excess salt from the bloodstream will help to lower blood pressure. Since hypertension in cats is often related to congestive heart failure and kidney disease, HCTZ is also beneficial in reducing the fluid that can accumulate in the lungs and abdomen as a result of these conditions.

    Side Effects

    • As with any medication, it is important to look for possible side effects in your cat. According to Drs. Foster and Smith Pharmacy, some of these side effects include dehydration and excessive thirst, lack of energy, vomiting and diarrhea. Signs of an allergic reaction include swelling of the face, itching and seizures. If you suspect an allergic reaction to the medication, or in the case of an overdose, contact your veterinarian immediately.

    Warning

    • According to the information sheet provided by Drs. Foster and Smith Pharmacy, this medication should not be used in cats that are pregnant or lactating, cats with Cushing's disease, or in combination with the drug mitotane. In addition, they indicate that you should use caution in cats with diabetes mellitus, lupus and gout. For a complete list of warnings, visit the Drs. Foster and Smith Pharmacy website. (See References.)

    Other Information

    • HCTZ is typically given to a cat orally in a dose of 2 to 4 mg per kg of body weight, two times per day. According to Dr. Andrew H. Sparkes in his article, "Feline Systemic Hypertension-A Hidden Killer," HCTZ is not, by itself, an effective treatment of high blood pressure in cats. He does note, however, that it is "possibly helpful acutely with retinal detachment," one of the eye and vision problems associated with hypertension.