Call Us! Button

Request an Appointment Button

Heart Disease
May 26, 2017

A heart attack in people is a condition where one or more of the blood vessels supplying the heart become occluded so that part of the heart muscle dies leading to sudden and potentially fatal heart failure.  This condition very rarely happens in dogs and cats.

In dogs and cats there are three common conditions that can lead to heart failure and death.

A. The valves start to leak making the heart inefficient leading to “failure”.

The dog and cat heart consists of four chambers – two smaller atria (the top of the heart) and two larger ventricles (the chambers which serve to pump blood out to the lung and body) that are separated by valves (see Figure 1).  When the valves become leaky, the one-way flow of the blood through the heart gets disrupted so that the heart pumps less blood out to the body with each beat because some blood gets pumped backwards through the leaky valve.  This ultimately causes the heart to enlarge and fail.

B. The coordinated beating of the heart gets disrupted so that it beats irregularly causing the heart to fail.

The “nervous system” of the heart that allows the heart to have a coordinated heart beat is called the conduction system of the heart.  This system begins at the pacemaker that is located in the wall of the right atrium.  When the pacemaker fires, electricity emitted from the pacemaker follows a specific path causing the heart muscle to contract.  Initially the electricity follows a path causing the atria to contract which fills the ventricles.  From there, the path goes through the area between the atria and the ventricles called the atrioventricular node.  Here the electricity is slowed to allow time for the ventricles to fill as the atria contract.  The electrical impulse then moves out through the muscular septum between the ventricles to the ventricular walls causing them to contract pushing blood out to the body.  When the conduction system becomes diseased, the heart beats irregularly in an uncoordinated fashion that is too fast or too slow causing the heart to fail.

 C. The heart muscle is unable to relax or contract properly causing it to fail.

The heart muscle must be able to relax to fill, and to contract to push blood out to the body.  Different diseases occur that prevent the heart muscle from being able to relax properly so that the ventricles can completely fill.  When a smaller than normal volume of blood fills the ventricle, the heart has to beat twice as fast to push out the correct volume of blood, eventually leading to heart failure.

When the heart can properly fill, but the heart muscle is so weak that it cannot push out the proper volume of blood from the ventricles, then heart failure occurs.  In either circumstance, being unable to fill, or being unable to contract, heart failure occurs.

  • All
  • Birds
  • Cat Care
  • Cat Health
  • Dog Care
  • Dog News
  • Dog Training
  • General
  • General Care
  • General News
  • Illness & Disease
  • News
  • Pocket Pets
  • Uncategorized

National Catio Day

March 15th is National Catio Day! This is one holiday we know our feline patients…
Read More

How Do You Know If Your Dog Is Allergic to Spring?

Spring is a time of rebirth and renewal. Your lawn will be green and lush,…
Read More

Is It Better to Adopt or Buy a Dog?

Some people have strong feelings about whether it’s better to adopt or buy a dog.…
Read More

Canine Flu

Did you know that your canine companion can get the flu? In fact, there’s an…
Read More

Blepping In Cats

Have you ever spotted your cat just sitting there with her tongue sticking out? This…
Read More
Cat looking up and to the left

Fluffy’s Year In Review

Happy New Year! As we say goodbye to 2022, many people will be looking back…
Read More

National Cat Lovers Month

If you’re a cat lover, this is the month for you! From December 1st to…
Read More
Bird on a Perch

Are Christmas Trees Safe for Pet Birds?

If you’re thinking about buying a Christmas tree this holiday season, you might be wondering…
Read More
Big dog lying down

Tips on Keeping Your Dog Safe During Thanksgiving

Thanksgiving is a time for families to come together and eat lots of food, but…
Read More
1 2 3 8