Introduction:
Heart Disease in Dogs and Cats,
by Roger Ross, DVM
It surprises some owners that heart disease is common in cats and dogs...just like in humans. And just like in humans, the heart is a mechanical-electrical pump made out of living tissue and is prone to not only to all the biological hazards affecting cells, but also to all kinds of mechanical, stretching, leaking, and electrical mishaps, pressure problems, clogs, and disasters that affect non living tissue.
Unlike with diarrhea or skin problems, most pet owners don't know or even suspect their pet has heart disease, but veterinarians often detect the problem during routine physical exams early enough to make a wonderful difference to the longevity and well being of the pet.
This is one of several major reasons for making sure your pet has a good check up at least once a year.
Your veterinarians will also suspect or detect heart disease when your pet is brought in for
coughing or hacking
wheezing
decreased energy or stamina
edema
abdominal bloat
signs of poor cirulation
fainting
Sometimes your vet will pick up on early heart disease even when there are no obvious symptoms yet because you're the wonderful type of pet owner that allowed your vet to spend a little extra for pre-anesthetic blood work and/or EKG monitoring prior to and during a surgery or dental cleaning procedure that was needed.
And, of course, heartworm disease ... the most common type of heart disease... is frequently detected long before obvious symptoms occur because of the routine testing done in just about every clinic in those parts of the country where heartworm is prevalent.
One last introductory comment: Just like in humans, heart disease is associated with genetic factors but also with
Obesity
Lack of Exercise
Poor Diet
What To Expect When You Take Your Dog To The Vet
For Heart Disease
(of course, your vet may do things differently)
Exam and History:
There are lots of clues when taking a patient's history such as being tired after a little bit of exercise, coughing after exercise and so forth.
We will be giving your pet a good general exam that will include listening carefully to your pet's heart and lungs, feeling the quality of the pulse, checking the color and nature of the mucus membranes, checking the tiny vessels in the eyes, palpating the abdomen, and maybe rechecking everything after exercise.
We will also be asking a lot of questions that will help us with the diagnoisis and hopefully prevent us from going down some expensive false trails. (such as mistaking indigestion for heart disease and vice versa)
It's interesting that certain breeds are more likely to have certain types of heart disease:
Murmers: Cockers, Poodles, Schnauzers, Dachshunds, Chihuahuas, Pomeranians, and Min. Pinschers
Myocarditis: Boxers, St Bernards, and German Shorthair Pointers
Cardiomyopathy: large breeds of dogs
Heart base tumors: Boston Terriers, Boxers, and English Bulldogs
Various Congential Heart Problems: Poodle, Collies, Poms, Sheperds, Eng. Bulldogs, Schnauzers, Pointers, Keeshonds, Fox Terriers, Irish Setters, and Weimaraners.
Cardiomeagly (thickened heart): common in many breeds but especially in CATS
Once heart disease is suspected, your vet will discuss and offer and least some of the following laboratory and imaging choices:
A. Rule out heartworm disease with a simple in house screening test.
B. CBC and Chemistry; this is important because so often heart disease is seen in association with other diseases...especially kidney and liver diseases.
C. Radiographs; to see if the heart is enlarged typical of certain types of heart disease, to see if there are tumors, to see if the lungs are very congested, and to see if there is fluid around the heart.
D. Urinalysis: This test is not likely to tell us anything specific about the heart, but it's included in the work up of pets suspected of serious disease.
Why? Because most serious diseases also involve other organ systems and this fairly inexpensive test of urine gives us a good feel for the heatlh of the kidneys and bladder as well as hints about pancreatic, liver, and gall bladder health. It helps with our asscessment of tissue hydration too.
E. EKG: EKG's help us rule out cardiac blocks and arrthymias, electrical conduction problems of the heart, and also are pretty good at indicating cardiac enlargement.
Note: If your vet, like me, is not expert at reading EKG's...or chest x-rays, for that matter, with the modern miracle of the digital age, we can have an expert read your pet's EKG or X-ray from a remote location through the phone lines!
F. Echo, Ultra Sound, Angiograms, MRI's, Cat Scans, and other types of Imaging: All this is now available in veterinary medicine, although usually a trip to a specialist facility is necessary.
As you might suspect, while many heart problems can be greatly improved with inexpensive medicine and nutritional support, the best available testing and treatment for heart disease can be quite expensive.
I mention this for three reasons:
One: To prepare you to think realistically. Heart disease is farily common and often stikes without much warning.
Two: To motivate you to take the trouble and relatively minor expense of providing a good lean diet, lots of exercise, and heartworm preventive.
Three: To consider Pet Health Insurance. It sure is
nice to have when your beloved pet needs it.
Once a Tentative Diagnosis is Made, your vet will discuss these treatment options:
1. Consider referral to a specialist for heart disease...Your vet will give you an honest accessment of his or her skill level in treating any serious disease. Don't expect your general practioner to be an expert in everything...especially a complex disease like heart disease where highly specialized equipment is often needed and where new, potentially dangerous, medications are frequently being introduced.
2. At our clinic, if you elect to let me treat your dog after making a tentative diagnosis of heart disease, here's what we'll consider trying:
B. Weight Loss if appropriate...Many heart disease patients are way too fat.
C. Furosimide tablets as needed to control coughing and congestion. This is a diuretic and will make your dog urinate and drink more but often works well in relieving the fluid load in the lungs associated with heart disease.
D. Digoxin tablets: this poison, given in tiny amounts helps improve cardiac function. This medication is not tolerated by many pets (causes nausea etc), so we will start out with a small dose and work up. Update, 2001: Now that Vetmedin is available, we don't use Digoxin much anymore.
E. Vetmedin: Vetmedin not only improves cardiac function, but it usually does it without side effects common with digoxin, AND Vetmedin opens up the blood vessels taking blood away from the heart, so reducing the work the heart has to do to pump blood around your dog's body. At the same time, Vetmedin opens up the blood vessels returning blood to the heart which reduces pressure on the heart.
This is a great medication and for some dogs (not available for cats at this time), it's like a miracle.
F. Blood Pressure tablets: Ace Inhibitors (Enalapril or Captopril) greatly reduce the work load of the heart by causing dilation of the blood vessels. Possibly dangerous if your pet also has kidney disease. Another reason to do blood work and an urinalysis to check other organ systems.
G. Potassium or Multivitamins; loss of potassium is a problem with both heart disease and the medications used to treat heart disease.
H. Aspirin; small amounts help prevent secondary problems such as blood clots that are sometimes part of the cardiac disease syndrome.
The aspirin dose we will be recommending is small enough that problems such as GI inflammation is not likely.
I. Beta Blockers decrease outflow obstruction common in heart disease and are often recommended by cardiac specialists, especially for cardiomyopathy.
J. CoEnzyme Q10: a neutriceutical highly touted by the people that sell it for improving cardiac and vascular health. CoEnzyme Q10 does seem to be helpful, but beware that it hasn't been accepted yet as safe and effective by cardiac specialists, the FDA, etc.
It's hard to get approval in the medical industry for neuticeuticals and despite lots of testimonials for these medications it's very hard to get honest information about them. I'm presently a believer in the usefulness of CoEnzyme Q10 but based on pretty flimsy medical evidence. (See my comments on the neutriceutial business in the medication section of this site.)
Despite these warnings, supplementation with coenzyme Q10 has resulted in dramatic increases in cardiac contractility in humans with cardiomyopathy. Coenzyme Q10 is a member of the electron transport chain essential in myocardial energy production. Clinical trials examining the efficacy of coenzyme Q10 in the dog are underway.
K. Frequent rechecks. Heart disease and the medications used to treat heart disease both merit frequent rechecking and adjusting.
K. Again...consider referral. Especially if initial treatment results are poor.
Heart Failure
One major threat to your dog's health is heart failure. Of the dogs in the United States examined annually by a veterinarian, approximately 3.2 million have some form of acquired heart disease and may be in heart failure.
Heart failure results from the heart's inability to pump blood at a rate required to meet the body's needs. While continuing to work harder to pump blood, further heart damage can occur.
Although some of the early stages of heart failure in dogs have no visible signs, heart failure can be diagnosed through a clinical evaluation by a veterinarian. Dogs with mild to moderate heart failure typically experience heart enlargement, coughing, lethargy and difficulty breathing.
Severe heart failure is characterized by difficulty breathing (even at rest), fainting, profound intolerance to exercise, loss of appetite and weight loss.
"Too often, dog owners do not take their dogs to visit the veterinarian until they are displaying severe signs of heart failure, and by then it may be too late," says Dr. Bicknese.
"When heart disease is detected in your dog, your veterinarian can recommend a schedule of regular visits and discuss a treatment plan that can help."
Overall Good Health
In addition to safeguarding your dog's heart, there's a lot you can do to keep your dog happy and in top shape. Ensure that your dog gets a moderate amount of exercise on a regular basis and has a balanced diet. An obese dog may have a harder time staying healthy.
Avoid the heartbreak of seeing your family's best friend fall ill. Proper care and veterinary supervision can help you watch your dog grow to a "hearty" old age.