Dog Tape Worms

Tapeworm infestation, also called tacniasis, is a diseasejust as is any one of the ailments caused by bacteria, though its effectsneed not be serious.

In small numbers tapeworms produce few ill effects, but when largenumbers infest a dog they can make it a sick dog showing symptomsof nervousness, restlessness, and sometimes irritability. Because humanbeings are thought to have an increased appetite when they harbortapeworms (it is doubtful if they really do), dogs also are generallyexpected to be hungrier. But they are not. Actually dogs usually losetheir desire for food to some extent when they are infested with manytapeworms. Owners constantly bring their pets to veterinarians and tellus that the dogs must have tapeworms because their appetites are soenormous. Usually these prove to be healthy puppies, not sick dogs.

LARVAE EATSP ROGLOMD

Life history of the flea-host tapeworm. Above left, mature worm (life size); itoften grows to be eighteen inches long. Above right, capsule with eggs, magni-fied one hundred and fifty times.

There are a dozen segments, you may have an examination made and receive anegative report. Your veterinarian studies the stool for eggs, and if thetapeworm has lost no segment in the specimen being examined, he orshe won't find any. Finding segments is the only effective way to deter-mine the presence of this worm.

Fleas and biting lice are the intermediate hosts of the common tape-worm. When fleas are in their larval stage, they feed on tapewormsegments among other foods. The eggs from these segments developinto tapeworm larvae as the flea matures. If an dog ingests the flea,the tapeworm larva is released and attaches itself to the intestinal wall,where it remains and grows.

THE RABBIT-HOST TAPEWORM (TAENIA PISIFORMIS): The rabbit-host tapeworm is a coarser worm than the flea-host tapeworm. Sometimesfive to six feet long, its segments arc larger and more active. The inter-mediate host is the rabbit or hare. This tapeworm lays many eggs thatpass out of the dog in the stool and cling to vegetation. Rabbits eatingthe vegetation become infested. The larvae work into the liver of therabbits to develop, and from there into the abdominal cavity, wherethey attach themselves to intestines in small cysts. When a dog eats aninfested rabbit, it too soon becomes infested.

Tapeworms can cause such loss of condition that the dog has convul-sions; its coat may become thin, its digestion be disturbed. There isoften a marked tendency to vomit small amounts enough to be asource of worry as well as a nuisance in a house dog. Occasionallysegments of the worms lodge in the anal glands and cause irritation, sothat the dog pulls itself along on its rear quarters.

Detection of segments of tapeworms on the dog's stool is the mostcertain method of determining the presence of the pest. A fecal exami-nation may be made, but in the case of the flea-host worm it is notconclusive even when done by a thoroughly competent technician.They tend to retain their eggs, and the examination of any particularstool may not show evidence of infestation even when the worms arepresent in the dog.

There are two general kinds of tapeworms the armed and the un-armed. The armed have suckers and hooks with which they cling, whilethe unarmed arc equipped with only a pair of grooves which hold to theintestinal lining. A large armed tapeworm has powerful devices thatenable the worm to hold fast despite all of the pull exerted on it by thepassing food. It seems almost impossible that the little head can holdall of the worm, yet that is what it does. Besides the host in which theyspend most of their existence, all tapeworms require an intermediatehost and, in some cases, two such hosts. All are composed of a head towhich are added a series of flat segments, joined one to another.

THE FLEA-HOST TAPEWORM (DIPYLIDIUM CANINUM): The most common tapeworm of our pets, the flea-host tapeworm occurs in dogs,foxes, and cats. It is about a foot long. The head is smaller than a small pinhead and the segments close to the head are stretched to the thin-ness of a thread. This section is called the neck. As the worm grows,the segments become wider and shorter. The last few segments are again longer and contain eggs. When ripe, these segments are shed and passed out with the stool. If no stool is present, the segment is moved downward and out of the anus, where it may cling until it dries into as mall, brownish, seed like grain that drops from the pet.

The eggs are not extruded without considerable pressure to the segment; then they appear in capsules and look, under a microscope, like bunches of grapes. When your veterinarian makes a fecal examination and tells you that your dog is free of worms, do not blame him or her for not detecting the presence of tapeworms.

It is rare to find the pork, beef, and sheep tapeworms in city pets. These tapeworms have been reported as long as fifteen feet. In country dog, whirls may feast on carcasses of dead dog, infestations may occur. Hogs, cattle, or sheep that have fed in pastures where human excreta has been deposited can eat grass to which tapeworm eggs cling. The dog eats flesh from these dog and becomes infested from the cysts containing the tapeworm heads.In the North a tapeworm, Tania Rabbi, infests dogs that eat infested reindeer muscle.

THE RODENT-HOST TAPEWORM (TAENIA TAENIAFORMIS): Widely distributed, the rodent-host tapeworm probably does its worst damage tomcats. Rats, mice, squirrels, muskrats, and other rodents may act as inter-mediate hosts. The heads in the cysts develop in their livers and remain dormant until eaten by an dog. Cats are the most likely pets to suffer from this parasite and indirectly spread it to dogs.

THE HYDATID TAPEWORM (ECHINOCOCCUS GRANULOSIS): This unique parasite, the hydrated tapeworm, is dangerous because it does damage torso many species of dog. It infests many pets that eat meat. As intermediate hosts, most dog, including man, can be infested if by any chance the eggs are ingested.

The embryos bore through the intestines to the bloodstream and are transported to various organs where they become cysts which may mea-sure three inches in diameter. The lining of the cyst produces numerous brood capsules in which heads are formed. A brood capsule may contain as many as forty heads six months after infestation. If a dog eats an organ infested with the hydrated he eats many heads, and in less than two months the worms that develop from the heads are laying more eggs to infest other dog which inadvertently consume them.here are three unarmed tapeworms that are important to dog own-ers.

A human harboring the tapeworm passes the eggs in feces which are dumped via sewers into a lake. Small crustaceans cat the eggs. In the first type, fish eat the crustaceans; in the latter two types, amphibians,such as frogs, or mammals that swallow the crustaceans can be the second host. Of course dogs that eat the fish or frogs or infested mammals become infested in turn. Raw whitefish, trout, salmon, pike, and perch have all been responsible for passing the cysts of these huge worms to pets.

Some of these worms have three to four thousand segments and at their widest may be half an inch or even more across.