Last week, we documented that the Heartworms live mostly in the right-side heart chambers. That alone could compromise the heart function immensely. The heart is unable to efficiently pump an adequate volume of blood for circulation. This means that many organs are starved of blood and oxygen (the blood carries the oxygen) to sustain their optimal functionalities.
Apart from occupying space in the heart (space needed for specific volumes of blood), these bundles of worms can entangle themselves in the heart valves and impede the mechanical aspects of the heart’s function.
Of course, all of this becomes worse, if the worms are actually and physically constraining the flow of blood from the heart to the lungs. You can imagine how the animal would be panting (increase in the breathing rate) while trying to get more oxygen into the system. During the dry, hot weather season, the respiratory distress becomes even more disastrous.
But not only is the lung function messed up. Some of these worms can actually get into the large blood vessels related to the liver! The liver’s functions begin to collapse. Jaundice (yellowing) develops. The abdomen swells due to increased fluid there. The animal can become anaemic especially if it is losing blood via diarrhoea. Once the liver is compromised, the prognosis looks very bleak. In fact, the animal will most likely die in a couple of days. The disturbing consideration here is that the veterinarian seeing the symptoms might logically be tempted to focus on the liver, since the symptoms are associated with liver damage.
So, let this be a lesson to us all: If the abdomen swells with fluid (ascites), check for Heartworm. It may not be a case of Heartworm, but have it checked nevertheless. Better safe than sorry. The test is completed in minutes. It is better to go this route than to berate ourselves (owner and vet) for not having recognized Heartworm as a possible cause in the differential diagnosis.
Anyway, enough lecturing. This story I was developing with the liver is actually not the norm. Acute (sudden) ailment with an obvious set of symptoms is not usually the way the heartworm infection progresses.
Q: WHAT ARE THE HEARTWORM SYMPTOMS
A: As I said last week, this is an insidious (gradual, proceeding secretly, subtly, and slowly) disease. It sneakily invades the dog (cat), and it treacherously progresses into a full-blown malady.
The first signs sometimes do not appear until many months, even a year (even years, according to some cases cited in the literature) after the infection by the mosquito has taken place. No wonder the veterinarian could mistake if for another ailment.
Relative to this ailment, I will share with you the things that impact upon me the most; those things that make me think of Heartworm!
(i) Any dog that comes from the Lower East Coast and immediate environs. Actually, nowadays I advise that patients be routinely checked for Heartworm, irrespective of where they live.
(ii) Emaciation – especially when I know that the dog is being well fed and is dewormed regularly. The weight loss is often accompanied by an abdomen, that is, at first, bit (almost imperceptibly) swollen; and where you can actually see the ribs of the ribcage.
(iii) A cough! Not a rasping, gasping, throaty spasmic cough. It is soft yet deep cough. Not as if something is stuck in the throat. Rather, it may best be compared with the cough that might be emitted if one has a slight sore throat.
(iv) Fatigue and tiredness, even after minimal exertion. Apathy and listlessness are usually present in heartworm cases.
(v) These other symptoms, which develop later:
– Vomiting blood
– Severely laboured breathing
– Swollen abdomen
(vi) Of course, the clincher is the laboratory examination of the blood. There can be no dispute as to the presence of Heartworm if the test is conducted correctly.
Next week we will discuss the lab test, because it is not as straightforward as it sounds.
