parasitic infections
Parasites are organisms that feed on another organism or reproduce with its help. The animal (or human) infected by the parasite is referred to as the host. Dog parasites are therefore parasites that derive one-sided benefits from living with our dogs.
Parasites can be divided into two groups: Endoparasites and Ectoparasites. Endoparasites live inside the dog, for example in the intestines, lungs or heart. Ectoparasites live on the surface of the dog's body, for example on the skin or in the coat.
Parasitic infections can be very unpleasant and even dangerous for your dog. They can cause various symptoms that vary depending on the type and severity of the infection. In addition, some parasites can also be transmitted to humans and cause illness there. It is therefore important to regularly check your dog for parasites and treat them.
In this article you will learn more about the most common parasites in dogs, how to recognize and prevent them and how they are treated.
Endoparasites
Endoparasites are worms and protozoa that live in internal organs such as the intestines, lungs or heart. They are usually ingested orally, for example through contact with infected feces, soil or water, by eating raw meat or by biting intermediate hosts such as fleas or mosquitoes.
Worms
Worms are the best-known endoparasites in dogs. There are different types of worms that can infest different organs. The most common are
- Roundworms: They live in the small intestine and can grow up to 18 cm long. They look like spaghetti and can sometimes be visible in the dog's vomit or feces. Roundworms can cause diarrhea, vomiting, abdominal pain, flatulence, loss of appetite, emaciation and a bloated stomach, especially in puppies. They can also weaken the immune system and impair growth. Roundworms are zoonotic, which means that they can also spread to humans and cause eye or liver damage, among other things.
- Hookworms: They also live in the small intestine and are much smaller than roundworms. They have hook-shaped mouthparts, which they use to attach themselves to the intestinal mucosa and suck blood. Hookworms can lead to anemia, diarrhea, vomiting, weight loss and weakness. They can even be fatal in puppies. Hookworms are also zoonotic and can cause skin inflammation or intestinal damage in humans.
- Tapeworms: They live in the small intestine or large intestine and consist of many flat segments, each containing eggs. The segments are excreted with the feces and look like grains of rice. Tapeworms are usually transmitted by eating intermediate hosts such as fleas or rodents. Tapeworms do not usually cause severe symptoms, but can lead to itching in the anus, diarrhea, vomiting or reduced performance. Some tapeworm species are zoonotic and can form cysts in various organs in humans.
- Heartworms: They live in the large blood vessels of the heart and lungs and can grow up to 30 cm long. They are transmitted by the bite of mosquitoes that carry the larvae of the worm. Heartworms can lead to heart failure, coughing, shortness of breath, liver damage, kidney failure and even death. Heartworms are still rare in Germany, but are found in southern and eastern Europe as well as in tropical and subtropical regions. Heartworms are not zoonotic, but can occur in cats and ferrets.
The diagnosis of worms is usually made by examining a fecal sample for worm eggs or segments. Treatment consists of the administration of special worming medication, which must be individually adapted depending on the type of worm and the dog. Preventing worms is very important to protect the health of your dog and your family. This includes:
- Regularly worming your dog according to an individualized schedule set by your veterinarian. The frequency of worming depends on various factors, such as your dog's age, health, lifestyle and travel behavior. Generally, deworming is recommended every three to six months, more frequently for puppies.
- Avoiding contact with infected feces, soil or water. This also includes regularly removing dog excrement from the garden or public places.
- Avoiding raw meat or offal that may be contaminated with worm larvae. If you want to feed your dog raw meat, you should freeze or boil it first to kill the larvae.
- Control intermediate hosts such as fleas or mosquitoes with suitable products such as spot-ons, collars or sprays.
Protozoa
In addition to worms, various protozoa are typical endoparasites in dogs. As with worms, young animals are particularly at risk. In adult dogs, an infection often progresses without further symptoms. The most common protozoa are
- Giardia: These are flagellates that are ingested orally and multiply in the small intestine. They usually cause watery to slimy diarrhea, which may also contain blood. Giardia can also lead to vomiting, loss of appetite, weight loss and dehydration. Giardia are zoonotic and can also cause diarrhea in humans.
- Coccidia: These are spore animals that are ingested orally and multiply in the small intestine. They usually cause bloody diarrhea, which may also contain mucus. Coccidia can also lead to vomiting, fever, exhaustion and dehydration. Coccidia are not zoonotic, but can occur in cats.
- Leishmania: These are single-celled parasites that are transmitted by the bite of sand flies. They infect various organs such as the skin, lymph nodes, bone marrow or internal organs. Leishmania can lead to skin changes such as hair loss, dandruff, ulcers or nodules. They can also lead to fever, weight loss, anemia, kidney failure or joint inflammation. Leishmania are still rare in Germany, but are found in southern and eastern Europe as well as in tropical and subtropical regions. Leishmania are zoonotic and can cause skin or organ diseases in humans.
The diagnosis of protozoa is usually made by examining a fecal sample for parasites or their antigens. Treatment consists of the administration of special medication, which must be individually adapted depending on the parasite and the dog. The prevention of protozoa is similar to that of worms:
- Regular examination of the feces for parasites or their antigens.
- Avoiding contact with infected feces, soil or water.
The authors assume that a veterinarian should be consulted if an animal is ill and that medication should only be taken after consultation with a doctor or pharmacist. Only an individual examination can lead to a diagnosis and treatment decision.
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