By Dr Steve Surujbally
Continued from last week
Supportive
treatment
It is logical that the treatment of hookworm infestation should mirror the symptoms of the disease, in addition to concentrating on the eradication of the ‘perp.’ (You see how American-isms can invade even science. Either that or I am seeing too many detective movies. ‘perp’ means ‘perpetrator’ – and, in this case, the agent of destruction is the hookworm.)
You remember me saying in the last article (Pet Corner, May 11, 2008) that hookworms are voracious bloodsuckers. In addition, there is usually massive blood loss during the diarrhoea espisode. This means that if there has been a great haemorrhaging, then a blood transfusion might be indicated. You and your veterinarian will discuss the matter and come to a decision.
As supportive therapy, blood-building foods and special diets containing iron are indicated. Iron injection / tablets may be prescribed.
While all of this is going on, we have got to arrest the bleeding and the diarrhoea. There is not much that you can do at home. Bloody diarrhoea is always a serious matter. Conse-quently, the panic button must be pushed. Call your vet the moment you see blood (even traces) in the animal’s stool.
Last week, we spoke of debilitation and listlessness and emaciation as being symptoms of a hookworm infestation. As part of the supportive treatment, it is imperative that vitamins metabolic and appetite stimulants, appropriate/balanced carbohydrate/fat/protein diets be introduced to counteract the general unthriftiness of the animal.
Your veterinarian will advise on the diet. I personally go for the soft foods that are high in digestible protein and carbohydrates (run the recommended mixture through the blender so that a highly nutritious, homogeneous mass of thin gruel is produced).
If too much fluid has been lost because of the diarrhoea/blood loss, then rehydration is of paramount importance. One can use coconut water or prepare an oral rehydration fluid or purchase the packets of powder/crystals that are commercially available in every drug store. Yes, it is the product for humans that we use. I can’t overemphasise the importance of the fluid replacement therapy!
Vomiting is often associated with a heavy hookworm burden. It is quite amazing how much fluids can be lost via ‘throwing-up.’ In this case, one must attempt to ‘settle the stomach’ by using any of the many preparations (stomach wall coating and anti-vomiting medication, etc) destined for human usage. Your vet will advise you on the drug choice and the dosage rates. I actually prefer the immediate injection of an anti-emetic (against vomiting) drug.
Specific treatment
The support therapy must mirror the symptoms. For example, if the pet was exhibiting the consequences of hookworm related diarrhoea, our main focus would be to treat the haemorrhaging, the dehydration, the emaciation, the loss of appetite, the possible secondary infection, and so on – all attendant consequences of the diarrhoea.
Of course, we must attack the hookworms themselves.
There are several dewormers on the market which claim to be able to kill hookworms. Some of these dewormers are to be obtained over the counter. Let me advise you not to buy and use an over-the-counter anthelmintic without prior counselling by a knowledgeable person. This precludes taking advice from your neighbour, a friend, even a dog handler/breeder – unless you are pretty sure that they know what they are talking about.
Several broad-spectrum dewormers advertise that they can rid the animal of hookworms, but the latter are very resilient. Furthermore, some of these dewormers have been on the market for decades. As a result, the hookworms have built up a pretty good immunity against them. Others are vermifuges which expel the stunned but living worms, with the hope that the hot, sunny environment will kill the worms. That might or might not happen. But of one thing you can be sure: the eggs laid by a dying mother worm are sturdy and will not succumb to the elements so easily. The eggs lie there waiting to enter the mouth of the puppy, later reaching the intestines.
Chemicals like Fenbendazole are very efficient in dealing with the hookworms. In fact this was one of the ingredients in the medicine used on the lion cubs which died in the zoo some time ago. It was the other chemical (Trichlorphon, an organo-phosphate) in the drug that did the damage. Actually, there are many dewormers in the stores which contain different types of organo-phosphates and which are recommended for use in dogs. However, because organophosphates in general are toxic, especially if the recommended dosage rate is not followed, then one should be reluctant to use them internally.
Many veterinarians use Pyrantel Pamoate as the drug of choice. Others swear by Mebendazole. Drug store counter clerks, in their willingness to ‘help’ a customer, often suggest Levamisole, the active ingredient in Ketrax, the old favourite. We have found that some of the dewormers, especially after they have been used excessively for decades, do not possess a great efficacy in getting rid of a hookworm burden. The worms have become immune to them.
I shall also mention that some dewormers (eg Mebendazole) must be given at a very specific dosage rate over a successive period of days – preferably 5 consecutive days.
Some of the dewormers mentioned above (eg Mebendazole and Ketrax) are actually preparations made for humans. The equivalent dosage rate that will ensure potency against the hookworms in dogs is not a straightforward mathematical calculation. For example, if the dosage rate of Ketrax is 5 mls (one teaspoonful) for a five year old (40 pound) child, please do not think that one-fortieth of the dose is what you have to administer to a one pound puppy.
Lastly, I must warn that dewormers come in all shapes and forms: tablets, capsules, granules, liquids, injectables. Choose the type with which you feel most comfortable, and which is easiest for you to administer. Are you able to get a tablet down the animal’s throat into the stomach? Do you have the dexterity in administering a liquid dewormer to a fidgety dog (if the dewormer perchance finds its way into the lung instead – big trouble). And what about those dewormers which are mixed in the food? Are you sure that the animal will consume the total dosage required? Should you starve/purge the dog before/ after treatment?
The message is clear. Deworming is a science. Let the trained scientist advised you – especially since some of the chemicals have a low safety threshold. If the active ingredient is toxic to the worm, it could, to some degree, be toxic to the host (dog/cat), if not used correctly.
Next week, we’ll deal with the prevention and control of the hookworms. Tune in to the final episode of this true-life drama.
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 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.
