Ailments of the circulatory system

Continued from last week

Heart failure

Heart failure can be defined as a condition whereby the ability of the heart muscle to contract is compromised. The heart muscle has become weak. This, of course, would result in the inability of the heart to provide adequate circulation to meet the body’s needs. The output of blood from the heart is not enough to supply organs and tissues with enough blood (oxygen). This means that the organs cannot function adequately – not even during rest periods, and surely not when the animal’s body is under stress (eg, physical exercise).

So, in the end, what we are confronted with is a multiple organ malfunction. The kidneys, liver, the lungs and other systems begin to deteriorate. Heart failure is clearly a serious condition.

If the heart can’t push the blood through the vessels (arteries and veins) and organs, then we are faced with a condition in which the blood begins to dam up in the vessels and organs. (The lungs are the first organs that are affected by this inefficient heart pumping.) We have a congestion of blood in the organs, therefore, the organs cannot function optimally. We speak then of a congestive heart failure.

The scientists have bothered to define different levels of heart failure, Class I, Class II and Class III. In Class I, the signs of difficult breathing, coughing and collapse exhibit themselves only after the most vigorous exercise. In Class II, those symptoms appear with minimal exercise, while in Class III, the animal shows the signs even when at rest.

So, what are the causes of heart failure? To be honest, the jury is still out on this matter, since many salient questions about the ailment are still unanswered; nevertheless, we do know of some of the causes:

(i)   The heart may become injured (eg, valve disease, nerve damage causing arrhythmia, etc). If the valves are not functioning well, then blood begins to leak backward; thus the ‘pump‘ works less forcefully. This situation occurs more often in the older dog.

(ii)  The arteries that supply blood to the muscles of the heart itself are hardened, congested with cholesterol plaques, etc. The muscles of an area that is not being supplied with enough oxygenated blood will die.

(iii) Birth defects (for example, heart valve problem, or even a hole in the heart wall – which allows oxygen-filled blood to mix with carbondioxide-filled blood) are associated with heart failure. We experience this very often in dogs which are the products of incest.

(iv) Heartworm: As you can imagine, if balls of heartworms are concentrated  in the heart chamber like spaghetti, there will be not enough space for an adequate quantity of blood to arrive in the chamber and be pumped out. The space is taken over by the heartworms.

(v)   Infectious disease. If the heart muscle or the thin membrane surrounding the heart becomes infected and inflamed, the heart would not be able to function properly.

When the ailing heart begins to weaken, signs of a ‘right side‘ or ‘left side‘ heart failure occur. We will discuss this next week.

Please implement disease preventative measures (vaccinations, routine dewormings, monthly anti-heartworm medication, etc) and adopt-a-pet from the GSPCA’s Animal Clinic and Shelter at Robb Street and Orange Walk, if you have the wherewithal to care well for the animals.  Do not stray your unwanted pets, take them to the GSPCA’s Clinic and Shelter instead. If you do not wish your pet to have puppies or kittens, you may exploit the GSPCA’s free spay and neutering programme. If you see anyone being cruel to an animal, or if you need any technical information, please get in touch with the Clinic and Shelter by calling 226-4237.