The Aging Pet and Their Internal Organs

Your pet’s internal organs have been running for years and at some point may be slowing down. The most common organ to fail in cats is their kidneys.  For the dog, it could be the heart or the liver depending on breed.  If the symptoms are detected early enough they may be managed by reducing stress on the affected organ either through medications or diet.
It can be really hard for a pet owner to tell if there is a problem with an internal organ.  Clinical signs can be very subtle or non-existent for months to years before the pet shows any sign of disease.  Usually signs of a problem on the inside start with slowing down or not playing as much, eating less, losing weight, or drinking more water than normal.   It can even be hard for a veterinarian to detect internal organ problems, especially if they are not showing any outward signs of disease.  Blood work, urinalysis, x-rays, and sometimes ultrasounds are needed to find internal problems.
If a cat lives long enough, most go into chronic kidney failure.  There are no signs of this disease at first; as they gradually lose function and the kidneys are unable to perform their job of filtering the blood and making urine the cat may start drinking more water and urinating more often and/or in larger amounts.  They start urinating so much that they get dehydrated and this makes them drink more water.  They lose so much water through their urine that they can’t possibly drink enough water to keep up and they become chronically dehydrated. The kidneys also cannot filter the toxins out of the blood so it builds up in the bloodstream and makes them feel really bad.  Diet, supplements, and fluids can all be given by the owner under the direction of their veterinarian to help replace what they are losing and decrease the work the kidneys have to do.  There is no cure for kidney failure but hopefully these things will help the kidneys and increase the cat’s quality and quantity of life.
Certain breeds of dogs can inherit heart problems that may be present for years before they start to cause any problems.  Usually the first sign you will see is breathing a little faster than normal while sleeping at night. Coughing is usually the next sign that shows up.  As the disease progresses they will start to cough more often and will not be able to do their normal amount of activity level.  They can even collapse if they exert themselves too much.  A cardiac work-up is needed to find out what type of heart disease is present and that will dictate what type of treatment is needed.
Liver disease is also very difficult to detect if it comes on slowly.  As the liver ages it may not work as well and you can see a gradual increase in liver enzymes in the blood.  This could be a normal process of an aging liver or it could be early signs of disease like hepatitis or cancer.  Usually blood work, x-rays, and an abdominal ultrasound with biopsy are needed to find out what is causing the problem.
The moral of the story is that just like with people, internal organ problems can be hard to detect and usually require many tests to find the answer to the problem.  Talk with your veterinarian to voice your concerns about your aging pet and to put together a plan on how proceed given their species, age, and breed.