Dog Hook Worms
Hookworms. Hookworms are minute leeches living on blood that they suck from the intestine, to which they cling with a set of hooks or teeth about the mouth.
The dog hookworm is not the same worm that causes so much hookworm anemia in humans. Female dog hookworms are over five-eighths of an inch long and males are slightly shorter. Three types are found distributed in different sections. Lancelot cranium has a very wide distribution, while A. Brazilians are more or less confined to the South and tropical regions. Unitarian stance is a northern hookworm found in wild foxes and dogs kept in northerly climates.
Life history of the hookworm. In the body the larvae behave much like the roundworm larvae, spending their early days in the dog’s blood and lungs. The yare coughed up and swallowed. They then attach themselves to the small intestine by their hooks. Above left, mature worm (life-size). Above right, egg, magnified four hundred times.
The life history of the hookworm is interesting. The eggs, passed out of the host in the feces, need warmth to develop. Therefore the warm months are the hookworm months in the North, whereas the whole year is hookworm time in the deep South. After the eggs have been incubated for three to six days, larvae emerge. These are called the first-stage larvae. Three days later the larvae molt and become second-stage larvae. Eight days later they molt again to become third-stage or infective larvae and then lie waiting for a host. Hookworms can bore through the skin to reach the bloodstream. More often they are ingested through the mouth and are sometimes inhaled with dust kicked up in a place where stools have disintegrated and become mixed with soil.
If the larvae have reached the bloodstream by boring through the skin or internal tissues, they eventually reach the lungs, bore into the air sacs, are finally coughed up, swallowed, reach the intestine, and molt two more times. By three weeks after they first entered the body as larvae, hookworms are large enough to lay eggs. Sometimes hundreds cling to a dog’s intestinal lining. They are very debilitating. Hookworms can suck half a teaspoonful of blood in a week. A thousand can suck one and a half drinking glasses in a day. No wonder hookworms cause anemia!
With these facts in mind, two questions can now be answered: How can mother dog lick their offspring clean of feces without becoming infested with intestinal parasites? The answer is that all the eggs of parasites have to undergo several days of incubation to be infective. The eggs that the mother cleans from her offspring pass through her digestive tract and lie in her feces, unharmed, to become infective later.
How can two-week-old puppies be passing eggs of hookworms, for instance, when about three weeks are required for the eggs to develop into worms old enough to lay eggs? The answer is that the puppies were infected while they were embryos. Since several species of parasites spend some time in the blood, these larvae manage to penetrate through the placenta and into the blood of the embryos, whence they find the intestinal tract.
The principal damage done by hookworms is the anemia they produce in young dogs and puppies. As dogs grow older and are subject to repeated infestations, they develop partial immunity.
Infested puppies first suffer from lung damage similar to that caused by roundworms. The next result is anemia. One glance at the gums will reveal the puppy’s condition. There are many other variable symptoms. The puppy may have seizures; diarrhea may become persistent and the appetite picky; sometimes the legs will swell. It may moan; usually, it remains to lie down as if even standing up were an effort. It will lose weight, breathe more rapidly than a normal pup, and there is usually an acrid odor due to the discharge from diarrhea that coats its anus and the surrounding hair together with part of its tail.
Older dogs often have fits when first heavily infested. They, too, lose their appetites, develop anemia, become sluggish, have a hangdog appearance, and develop a generally unthrifty look. If proper food is not provided, even older dogs may die – because the best efforts of their red blood-cell-building mechanism are insufficient to make up for the loss caused by the hookworm infestation.
- PREVENTION: Prevention is the same as that indicated for roundworms, but in the case of hookworms, diet is more important. Iron and copper are essential and the protein fed to the dog must be of good quality.
- TREATMENT: There are several excellent treatments for hookworm and preventive drugs, all of which veterinarians keep on hand. But supportive treatment is advisable. Food of high quality helps the dog to recover quickly. Transfusions often work wonders, once the worms are gone, or even before, in very anemic dogs.
Dog breeders often say it is better to build up an infested dog before it is de-wormed. This seems to us to be a great mistake, because a dog can’t be built up as fast as its blood is being thinned by the worms, except by transfusion. The promptest possible action in getting rid of the worms is best if the dog is to be saved. Having rid the dog of its pests, a diet rich in iron and copper should be provided. Some liver is excellent. Meat has iron. Good-quality dog foods all have sufficient amounts for ordinary requirements, but if a mall pinch of ferrous sulfate or ferric and ammonium citrate is added to the diet daily, the redness will come back into the gums and the dog’s energy returns more rapidly.
One treatment is not sufficient to completely rid a dog of hookworms any more than it is enough to eliminate all roundworms. A second treatment two weeks after the first will kill the worms which were blood-living larvae when the first treatment was given. If the dog picks up another infestation, it will go much less severe than the first, and each subsequent infestation will build up a degree of immunity.
See more: Dog Hydro Thorax
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