Heart-worm control

Well, we have surely exhausted this topic – and perhaps even supersaturated you with facts about Canine Heart-worm Disease.

We have dealt with the transmission, the life cycle, the symptoms, laboratory diagnosis and the treatment.  This last episode – the series finale, so to speak – should deal with the control of this dreaded disease.

Notice I referred to ‘control’ and not ‘prevention’. To prevent this disease is truly ambitious. Today, we will instead offer suggestions, which will go a long way in putting a halt to the possibility of your dog contracting this heartworm disease.

In fact, a truly effective control of Canine Heartworm is doubtful, for the simple reason that so many of our canine wards hardly ever (if at all) see the veterinarian.

Consequently, these untreated dogs could be harbouring the disease (heartworms) as a reservoir, from which the transmission could have its origin.

You may recall me writing that the lowly (but deadly) mosquito is the courier of Canine Heartworm Disease. The microscopic microfilaria (immature stages of the heartworm) are in the mosquito’s mouth parts and are deposited on the animal’s skin, from which they actively enter the animal, growing all the time until they reach the right-side heart chambers where they become sexually mature and produce an abundance of new microfilaria.

Obviously, therefore, our first line of attack, within the context of control, would be to reduce the mosquito population in the area surrounding the dog (the premises at which the dog lives). This would not always be possible in a country where hygiene and sanitation of our living environments leave much to be desired.

Also, I dare say that our Malaria Prevention Units with their Vector (Mosquito) Control personnel must be strapped for cash, like so many other agencies.  As a result, we cannot hope to have a mosquito-free coast (and elsewhere) where untreated stagnant waters (the breeding ground for mosquitoes) abound.

On top of all of this, the fact is that mosquitoes are true survivors. It seems that they were around together with the dinosaurs and, over the millions of years they have not even found it necessary to change their shape.  Mosquitoes, we have been informed, can survive in high (cold) altitudes, as well as in tropical (hot) zones.

Waiting patiently for a new home: This female dog has been spayed.

The point being made is that mosquito proliferation is difficult to control.  Yet, we must try not only because of human health problems (eg Malaria), but because of diseases like heartworm, which attack our canine wards.  Of course, I have not even mentioned the nuisance factor.  We must use all the weapons at our disposal, including:

i. Getting rid of all stagnant pools of water in the immediate environment of our habitations.

ii. Treating – eg with kerosene oil – areas where pools of water tend to accumulate

iii. Fogging the area with chemicals that would kill mosquitoes and their immature forms.

iv. Influencing Municipal Councils and the Ministry of Health to improve their respective Vector Control Programmes.

The logic, of course, is that once the mosquitoes can’t reproduce, then the disease cannot be transmitted.

The second method of control of Canine Heartworm is to ensure that the microfilaria (once they enter the dog’s body) do not reach adulthood, where they would be able to reproduce. This means that we must kill these microfilaria when they are circulating in your pet’s blood. This can be done as a routine once every month.

Here we are lucky. The drug manufacturers have accommodated us by manufacturing several products containing an active microfilaricide, one of which we mentioned last week. They have even made different strengths of tablets according to the dog’s weight. This means that after we have checked the blood on two occasions in the space of four weeks, and found that there are no immature stages of the heartworm circulating, then we can begin to administer, once a month, the tablets/oral liquid/ subcutaneous injections. The advantage of the tablet/oral suspension is that you can administer it at home.  For the injection, you have to visit the vet.

There is also the possibility of giving the dog the four-course injections of Arsenic twice yearly. I would advise against this method. It really is not a true control at all. What we would be doing is allowing the animal to be infected, allowing the microfilaria to grow into adult heartworms, and then killing them.  That does not seem to be good idea to me, especially since Arsenic in itself is a rough drug and has some side effects on the body’s cells/tissues.

Lastly, mosquitoes tend to feed mostly in the late afternoons and during the evenings.  One could therefore keep the dogs in a mosquito-proof kennel during these periods, especially in those areas where we know the Canine Heartworm disease to be endemic (eg the lower East Coast Demerara), or where there is a high incidence. The truth is that Canine Heartworm Disease is all over Guyana, and mosquitoes seem to bite throughout the entire day.

So, enough is enough! By now, you may not want to hear the word heartworm.  Sorry, but it was necessary.  The last words: (1) Introduce the chosen prophylactic drug as soon as your dog has reached 6 months of age. (2) Listen for the soft, deep cough, which might indicate a Canine Heartworm infection.

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 spaying 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.