Dear Christopher Cat:  Astro, our 11-year-old cat, has chronic kidney disease. His veterinarian prescribed an appetite stimulant, fish oil and vitamins, but Astro still isn’t himself. We heard about subcutaneous fluids. Will they help him feel better

Christopher Responds: Most cats like Astro feel better with subcutaneous fluid therapy, which is cost-effective and easy to administer at home. If your veterinarian recommends it for him, try it and see how he responds.

Cats with chronic kidney disease lose their ability to conserve water and filter toxins from the blood. As the toxins build up and the cat becomes dehydrated, he loses his appetite and energy.

These problems can be addressed by feeding canned food, which is about 80 percent water, and giving fluids under the skin.

These subcutaneous or “sub-Q” fluids are identical to the sterile electrolyte fluids given intravenously. However, it’s much easier to administer fluids into the large subcutaneous space between the cat’s skin and underlying musculature, especially after a lesson by a veterinary technician.

Most cats with chronic kidney disease feel best when sub-Q fluid administration is repeated every one to three days.

If the sub-Q fluids improve Astro’s quality of life, talk with your veterinarian about making a gradual transition to a prescription diet for cats with chronic kidney disease. These diets help cats feel better and live longer.