Heartworm
control
Well, we have surely exhausted this topic – and perhaps even supersaturated you with facts about canine heartworm.
We have dealt with the transmission, the life-cycle, the symptoms, laboratory diagnosis and the treatment. The 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 would be truly too ambitious. We will instead offer suggestions today, which will go a long way in putting a halt to the possibility of your dog contracting this disease.
In fact, even a truly effective control of Canine Heartworm Disease 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 agents as a reservoir, from which future transmission could have its origin.
Secondly, you will recall me writing earlier that the lowly (but deadly) mosquito is the courier. The microscopic microfilariae (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 microfilariae.
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.
This would not always be possible in a country where the 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 where untreated stagnant waters (the breeding grounds for mosquitoes) abound.
On top of all of this is the fact that mosquitoes are true survivors.
They might have been 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 (ergo cold) altitudes as well as in tropical (hot) zones.
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:
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.
The logic, of course, is that once the mosquitoes can’t reproduce (if they are dead) then the disease cannot be transmitted.
The second method of control of canine heartworm is to ensure that the microfilariae (once they are in the dog’s body) do not reach adulthood, where they would be able to reproduce. This means that we must kill these microfilariae while they are circulating in your pet. This can be done on a routine daily or monthly basis – according to which drug you choose.
Here we are in luck. The drug manufacturers have accommodated us by producing a tablet containing the active microfilaricide (Iver-mectin) 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 at least 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 – for the rest of the dog’s life.
The other faithful drug is DEC Salt. Yes, the same medication used as a preventative against filariasis. The only problem is that you will have to place the DEC salt daily in the animal’s food – forever. Thirdly, there is 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 microfilariae to grow into adult heartworms, then killing the heartworms. That does not seem to be a 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 evening. One can 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.
So, enough is enough! By now, you may not want to hear the word heartworm again. Sorry, but it was necessary. The last word: listen for the soft, deep cough which may 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 Clinic and Shelter instead. If you see anyone being cruel to an animal, get in touch with the Clinic and Shelter by calling 226-4237.
