There are many different worms that can affect dogs and other pets. However, not all worms occur in Germany. In this country, dogs are most often infected with roundworms or tapeworms.
Roundworms are common around the world and not only affect the intestines of dogs, but can also damage other organs. Dogs get infected through oral ingestion of roundworm eggs. There is a high risk of infection with roundworms wherever there are many animals, for example on dog walks. Dogs pick up the worm eggs by licking the area or eating feces. The roundworm’s eggs then penetrate the dog’s intestinal wall and travel with the blood first to the liver, then via the heart to the lungs, before they are transported to the throat via the trachea and swallowed. In the dog’s intestine, they then develop into sexually mature roundworms up to 20 cm long.
Since some of the roundworm larvae get from the lungs back into the bloodstream and other parts of the dog’s body such as the muscles or the teats, puppies can become infected in the uterus or through breast milk.
The most common tapeworm with which dogs become infected in Germany is the cucumber core tapeworm. Unlike other tapeworms that attack dogs through prey such as mice (e.g. fox tapeworm) or raw meat, the cucumber tapeworm uses fleas and lice as intermediate hosts. The infectious tapeworm stages enter the dog’s intestines via infected fleas or lice that are swallowed by the dog during grooming, where they develop into adult worms, which can be up to a meter long. At the rear end, the tapeworm then constricts individual limbs in which the infectious worm eggs are located. The infected dog then excretes these with the faeces. Some of these tapeworm limbs burst in the dog’s intestinal tract, and the infectious eggs are released in the intestinal tract.
The risk of infection is high on the dog meadow. © stock.adobe.com / theendup
In principle, it is possible for roundworms and certain tapeworms to pass from dogs to humans. In the case of roundworms, infection occurs through the ingestion of the infectious worm eggs from the environment, in which, however, they first have to develop into infectious stages. It is therefore important to prevent environmental contamination from roundworm eggs by, for example, collecting dog droppings and throwing them away with household waste. With certain tapeworms such as Eg the small dog tapeworm (Echinococcus granulosus) or the dangerous fox tapeworm (Echinococcus multilocularis) the eggs excreted with the feces of infected dogs are directly contagious. Therefore, especially in dogs that eat rodents or are fed raw meat, an intensive worm control or control should be carried out.
As a rule, a worm infestation is difficult to detect for dog owners. Especially for the tapeworms and roundworms mentioned, visible symptoms often only occur if the infection is severe or the infection has existed for a long time.
In general, roundworm infestation rarely causes symptoms in adult dogs, but puppies can get seriously ill from them. The symptoms of severe dishworm infestation include:
The excretion of roundworm eggs and thus infection with roundworms can be detected by a fecal examination.
If you discover flat, whitish, sometimes movable structures in the dog’s feces, it can be tapeworm limbs. The tapeworm eggs released from this can also be detected by a fecal examination. However, in principle, the faecal examination does not offer absolute certainty of detection, since on the one hand only adult worms produce eggs and thus early infections cannot be detected. On the other hand, the eggs are not released continuously, which often leads to false-negative results.
Healthy dogs often show no symptoms despite worm infestation. © stock.adobe.com / Martin Bad
There is a wide range of preparations that differ, among other things, in the range of worms against which they are effective. In addition, there are antiparasitic drugs that act simultaneously against a number of other pathogens such as B. ticks and fleas are effective. The vet can therefore recommend a suitable means of de-worming depending on the infestation.
The worming preparations usually work for about a day after use and kill existing worms during this period. There is then no protection against a new infection with worms. It is therefore important that the dog is regularly examined for worms and dewormed in accordance with the risk assessment and after consultation with the veterinarian.
How often a dog needs to be dewormed depends on many risk factors. ESCCAP (European Scientific Counsel Companion Animal Parasites) divides dogs into risk groups from A to D, with group A being the least at risk and group D being the most at risk. In order to find out which risk group a dog belongs to, the following questions must be answered, among others:
For dogs in risk group A, it is usually sufficient to deworm tapeworms and roundworms once or twice a year or to have faeces examinations carried out. If your dog belongs to risk group D and there is a high risk of infection through close contact with the family (especially with small children), a monthly deworming or faecal examination can be useful. However, the individual risk for each animal must be determined individually in consultation with the veterinarian, so that monthly deworming cannot be recommended across the board.