Dirofilaria immitis | |
---|---|
A German Shepherd dog heart infested with Dirofilaria immitis | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Nematoda |
Class: | Chromadorea |
Order: | Rhabditida |
Family: | Onchocercidae |
Genus: | Dirofilaria |
Species: | D. immitis |
Binomial name | |
Dirofilaria immitis (Leidy, 1856) | |
Synonyms [1] | |
Filaria immitisLeidy, 1856 |
Dirofilaria immitis, also known as heartworm or dog heartworm, is a parasitic roundworm that is a type of filarial worm, a small thread-like worm, and which causes dirofilariasis. It is spread from host to host through the bites of mosquitoes. Four genera of mosquitoes transmit dirofilariasis, Aedes , Culex , Anopheles , and Mansonia . [2] The definitive host is the dog, but it can also infect cats, wolves, coyotes, jackals, foxes, ferrets, bears, seals, sea lions and, under rare circumstances, humans. [3]
Adult heartworms often reside in the pulmonary arterial system (lung arteries) as well as the heart, and a major health effect in the infected animal host is a manifestation of damage to its lung vessels and tissues. [4] In cases involving advanced worm infestation, adult heartworms may migrate to the right heart and the pulmonary artery. Heartworm infection may result in serious complications for the infected host if left untreated, eventually leading to death, most often as a result of secondary congestive heart failure.
Although at one time confined to the southern United States, heartworm has now spread to nearly all locations where its mosquito vector is found. In the southeast region of the United States, veterinary clinics saw an average of more than 100 cases of heartworm each in 2016. [5] Transmission of the parasite occurs in all of the United States (cases have even been reported in Alaska), and the warmer regions of Canada. The highest infection rates are found within 150 miles (240 km) of the coast from Texas to New Jersey, and along the Mississippi River and its major tributaries. [4] It has also been found in South America, [6] southern Europe, [7] [8] Southeast Asia, [9] the Middle East, [10] Australia, Korea, and Japan. [11] [12]
Heartworms go through several life stages before they become adults infecting the pulmonary artery of the host animal. The worms require the mosquito as an intermediate host to complete their lifecycles. The rate of development in the mosquito is temperature-dependent, requiring about two weeks of temperature at or above 27 °C (80 °F). Below a threshold temperature of 14 °C (57 °F), development cannot occur, and the cycle is halted. [13] As a result, transmission is limited to warm weather, and duration of the transmission season varies geographically. The period between the initial infection when the dog is bitten by a mosquito and the maturation of the worms into adults living in the pulmonary arteries takes six to seven months in dogs and is known as the "prepatent period". [14]
The first larval stage (L1) and second larval stage (L2) of heartworm development occurs within the body of a mosquito. Once the larvae develop into the infective third larval stage (L3), the mosquito locates and bites a host, depositing the larvae under the skin at the site of the bite. After a week or two of further growth, they molt into the fourth larval stage (L4) . Then, they migrate to the muscles of the chest and abdomen, and 45 to 60 days after infection, molt to the fifth stage (L5, immature adult). Between 75 and 120 days after infection, these immature heartworms then enter the bloodstream and are carried through the heart to reside in the pulmonary artery. Over the next three to four months, they increase greatly in size. The female adult worm is about 30 cm in length, and the male is about 23 cm, with a coiled tail. [15] By seven months after infection, the adult worms have mated and the females begin giving birth to live young, called microfilariae. Heartworms can live for 5 to 7 years in a dog. [16]
The microfilariae circulate in the bloodstream for as long as two years, and are ingested by bloodsucking mosquitos, where development occurs and the cycle repeats.[ citation needed ]
Hosts of Dirofilaria immitis include: [3]
Reservoir hosts for D. immitis are coyotes and stray dogs. [19]
Dogs show no indication of heartworm infection during the six-month prepatent period prior to the worms' maturation, and current diagnostic tests for the presence of microfilariae or antigens cannot detect prepatent infections. Rarely, migrating heartworm larvae get "lost" and end up in aberrant sites, such as the eye, brain, or an artery in the leg, which results in unusual symptoms such as blindness, seizures, and lameness, but normally, until the larvae mature and congregate inside the heart, they produce no symptoms or signs of illness. [20]
Many dogs show little or no sign of infection even after the worms become adults. These animals usually have only a light infection and live a fairly sedentary lifestyle. However, active dogs and those with heavier infections may show the classic signs of heartworm disease. Early signs include a cough, especially during or after exercise, and exercise intolerance. In the most advanced cases where many adult worms have built up in the heart without treatment, signs progress to severe weight loss, fainting, coughing up blood, and finally, congestive heart failure.[ citation needed ]
There are four different classes of symptoms:
Wolbachia pipientis is an intracellular bacterium that is an endosymbiont of D. immitis. All heartworms are thought to be infected with Wolbachia to some degree. The inflammation occurring at the die-off of adult heartworms or larvae is in part due to the release of Wolbachia bacteria or protein into the tissues. This may be particularly significant in cats, in which the disease seems to be more related to larval death than living adult heartworms. Treating heartworm-positive animals with an antibiotic such as doxycycline to remove Wolbachia may prove to be beneficial as it does for the filariae that cause elephantiasis, [22] but further studies are necessary. [23]
Microfilarial detection is accomplished by the using one of the following methods:
A blood sample is collected and viewed under the microscope. The direct smear technique allows examination of larval motion, confirming the presence of microfilaria. It also helps in the distinction of D. immitis from Acanthocheilonema reconditum. This distinction is important because the presence of the latter parasite does not pose a health risk to the host. D. immitis usually has stationary body movement, while A. reconditum has progressive movement. However, this method often misses light infections because only a small amount of blood sample is used. [25]
This method uses a microhematocrit (or capillary tube) filled with a blood sample that has been centrifuged, separating the plasma from the red blood cells. These layers are divided by the buffy coat. The buffy coat consists of the leukocytes and platelets that are in the sample. The tube is snapped at the buffy coat and added to a slide for microscopic examination. Adding methylene blue stain to the sample may allow greater visibility of any microfilariae. However, the hematocrit tube method will not allow for species differentiation. [26]
The modified Knott's test is more sensitive because it concentrates microfilariae, improving the chance of diagnosis. [4] A blood sample is mixed with 2% formalin and centrifuged in a tube. The supernatant is removed and methylene blue stain is added to the pellet remaining in the tube for microscopic examination. It allows microfilariae species differentiation based on morphology. Microfilariae can be differentiated between D. immitis and Acanthocheilonema reconditum because of small differences in morphology. The Modified Knott's test is the best method of visual examination when determining presence of microfilaria because it preserves their morphology and size. It is easy to perform, quick, and inexpensive. [27]
The potential for a microfilaremic infection is 5 – 67%. The number of circulating microfilariae does not correlate with the number of adult heartworms, so is not an indicator of disease severity. [4]
In most practices, antigen testing has supplanted or supplemented microfilarial detection.[ citation needed ] Combining the microfilaria and adult antigen test is most useful in dogs receiving diethylcarbamazine or no preventive (macrolides like ivermectin or moxidectin typically render the dog amicrofilaremic). Up to 1% of infected dogs are microfilaria-positive and antigen-negative. [4] Immunodiagnostics (ELISA, lateral flow immunoassay, rapid immunomigration techniques) to detect heartworm antigen in the host's blood are now regularly used. They can detect occult infections, or infections without the presence of circulating microfilariae. However, these tests are limited in that they only detect the antigens released from the sexually mature female worm's reproductive tract. Therefore, false-negative results may occur during the first five to eight months of infection when the worms are not yet sexually mature. [4] The specificity of these tests is close to 100%, and the sensitivity is more than 80%. [28] A recent study demonstrated a sensitivity of only 64% for infections of only one female worm, but improved with increasing female worm burden (85%, 88%, and 89% for two, three, and four female worms, respectively). Specificity in this study was 97%. [4] False-negative test results can be due to low worm counts, immature infections, and all-male infections.
X-rays are used to evaluate the severity of the heartworm infection and develop a prognosis for the animal. Typically, the changes observed are enlargement of the main pulmonary artery, the right side of the heart, and the pulmonary arteries in the lobes of the lung. Inflammation of the lung tissue is also often observed. [29]
If an animal is diagnosed with heartworms, treatment may be indicated. Before the worms can be treated, however, the dog's heart, liver, and kidney function must be evaluated to determine the risks of treatment. Usually, the adult worms are killed with an arsenic-based compound. The currently approved drug in the US, melarsomine, is marketed under the brand name Immiticide. [30] It has a greater efficacy and fewer side effects than the previously used drug thiacetarsamide, sold as Caparsolate, which makes it a safer alternative for dogs with late-stage infections.[ citation needed ]
After treatment, the dog must rest, and exercise is to be heavily reduced for several weeks so as to give its body sufficient time to absorb the dead worms without ill effect. Otherwise, if the dog is under exertion, dead worms may break loose and travel to the lungs, potentially causing respiratory failure and sudden death. According to the American Heartworm Society, the administering of aspirin to dogs infected with heartworms is no longer recommended due to a lack of evidence of clinical benefit, and aspirin may be contraindicated in several cases. Aspirin had previously been recommended for its effects on platelet adhesion and the reduction of vascular damage caused by the heartworms.[ citation needed ]
The course of treatment is not completed until several weeks later, when the microfilariae are dealt with in a separate course of treatment. Once heartworm tests are negative and no surviving worm is detected, the treatment is considered a success, and the patient is effectively cured.[ citation needed ]
Surgical removal of the adult heartworms as a form of treatment may also be indicated, especially in advanced cases with substantial heart involvement and damage. [31]
Prevention of heartworm infection can be obtained through a number of veterinary drugs. The drugs approved for use in the US are ivermectin (sold under the brand names Heartgard, Iverhart, and several other generic versions), milbemycin (Interceptor Flavor Tabs and Sentinel Flavor Tabs) and moxidectin (Simparica Trio) administered as chewable tablets. Moxidectin is also available in both a six-month and 12-month sustained-release injection, ProHeart 6 and ProHeart 12, respectively, administered by veterinarians. This injectable form of moxidectin was taken off the market in the United States due to safety concerns in 2004, but the FDA returned a newly formulated ProHeart 6 to the market in 2008. ProHeart 6 remains on the market in many other countries, including Canada and Japan. Its sister product, ProHeart 12, is used extensively in Australia and Asia as a 12-month injectable preventive. It was approved for use in the United States by the FDA in July 2019. [32] Topical treatments are available, as well. Advantage Multi (imidacloprid plus moxidectin) Topical Solution, uses moxidectin for control and prevention of roundworms, hookworms, heartworms, and whipworms, as well as imidacloprid to kill adult fleas. Selamectin (Revolution) is a topical preventive likewise administered monthly, and can also be used to control fleas, ticks, and mites.[ citation needed ]
Preventive drugs are highly effective, and when regularly administered, have been shown to protect more than 99% of dogs and cats from heartworm. Most compromises in protection result from the failure to properly administer the drugs during seasonal transmission periods. [33] In regions where the temperature is consistently above 14 °C (57 °F) year-round, a continuous prevention schedule is recommended.[ citation needed ]
Due to newly emerging resistant strains of heartworms, which no macrocyclic lactone (heartworm prevention) can protect against, the American Heartworm Society recommends dogs be on a repellent and a heartworm preventive. The repellent, such as Vectra 3-D, keeps mosquitoes from feeding on the dog and transmitting the L3 stage worms. If a dog is bitten, the heartworm preventive takes over when administered. If a mosquito feeds on a heartworm positive dog on a repellent, they do not live long enough for the microfilaria they ingested to molt into the infective L3 larva. Vectra 3-D was tested using thousands of mosquitoes infected with the resistant heartworm strain JYD34. In the control group that was given only a placebo, every dog contracted heartworms. In the experimental group that was given only Vectra 3-D, two of eight dogs contracted heartworms and had an average of 1.5 adult worms each. In the experimental group given both heartworm prevention and Vectra 3-D, one dog was infected with L3 stage larvae that did not mature into adulthood due to the heartworm prevention. Using a repellent and a prevention is at least 95% effective. [34] [35]
Ivermectin, even with lapses up to four months between doses, still provides 95% protection from adult worms. This period is called the reach-back effect. [36] Since dogs are susceptible to heartworms, they should be tested annually before they start preventive treatment. [19] Annual heartworm testing is highly recommended for pet owners who choose to use minimal dosing schedules. Testing a dog annually for heartworms and other internal parasites is a fundamental part of a complete heartworm prevention program, and is also recommended for dogs who are already on a monthly prevention program. [19]
While dogs are a natural host for D. immitis, cats are atypical hosts. Because of this, differences between canine and feline heartworm diseases are significant. The majority of heartworm larvae do not survive in cats, so unlike in dogs, a typical infection in cats is two to five worms. The lifespan of heartworms is considerably shorter in cats, only two to three years, and most infections in cats do not have circulating microfilariae. Cats are also more likely to have aberrant migration of heartworm larvae, resulting in infections in the brain or body cavities. [37]
The infection rate in cats is 1–5% of that in dogs in endemic areas. [38] Both indoor and outdoor cats are infected. The mosquito vector is known to enter homes. [39]
The vascular disease in cats that occurs when the L5 larvae invade the pulmonary arteries is more severe than in dogs. A reaction has been identified in cats: heartworm-associated respiratory disease, which can occur three to four months after the initial infection, and is caused by the presence of the L5 larvae in the vessels. The subsequent inflammation of the pulmonary vasculature and lungs can be easily misdiagnosed as feline asthma or allergic bronchitis. [40]
Obstruction of pulmonary arteries due to emboli from dying worms is more likely to be fatal in cats than dogs because of less collateral circulation and fewer vessels. [41] Heartworms can live for 2 to 3 years in cats. [16]
Acute heartworm disease in cats can result in shock, vomiting, diarrhea, fainting, and sudden death. Chronic infection can cause loss of appetite, weight loss, lethargy, exercise intolerance, coughing, and difficulty breathing. Some cats' immune systems are able to clear a heartworm infection, though the immune system response can cause many of the same symptoms. Also, even if the infection resolves, respiratory damage can cause some symptoms to persist beyond it. [40] [ need quotation to verify ] [42]
Diagnosis of heartworm infection in cats is problematic. Like in dogs, a positive ELISA test for heartworm antigen is a very strong indication of infection. However, the likelihood of a positive antigen test depends on the number of adult female worms present. If only male worms are present, the test will be negative. Even with female worms, an antigen test usually only becomes positive seven to eight months after infection. Therefore, a cat may have significant clinical signs long before the development of a positive test. Heartworm-associated respiratory disease can be found in cats that never develop adult heartworms and therefore never have a positive antigen test.[ citation needed ]
An antibody test is also available for feline heartworm infection. It will be positive in the event of exposure to D. immitis, so a cat that has successfully eliminated an infection may still be positive for up to three months. The antibody test is more sensitive than the antigen test, but it does not provide direct evidence of adult infection. [43] It can, however, be considered specific for diagnosing previous larval infections, and therefore fairly specific for heartworm-associated respiratory disease.
X-rays of the chest of a heartworm-infected cat may show an increased width of the pulmonary arteries and focal or diffuse opacities in the lungs. Echocardiography is a fairly sensitive test in cats. Adult heartworms appear as double-lined hyperechoic structures within the heart or pulmonary arteries. [44]
Heartworm prevention for cats is available as ivermectin (Heartgard for Cats), milbemycin (Interceptor), or the topical selamectin (Revolution for Cats) and Advantage Multi (imidacloprid + moxidectin) topical solution. Ivermectin, milbemycin, and selamectin are approved for use in cats in the US.[ citation needed ]
Arsenic compounds have been used for heartworm adulticide treatment in cats, as well as dogs, but seem more likely to cause pulmonary reactions. A significant number of cats develop pulmonary embolisms a few days after treatment. The effects of melarsomine are poorly studied in cats. Due to a lack of studies showing a clear benefit of treatment and the short lifespan of heartworms in cats, adulticide therapy is not recommended, and no drugs are approved in the US for this purpose in cats. [41]
Treatment typically consists of putting the cat on a monthly heartworm preventive and a short-term corticosteroid. [37] Surgery has also been used successfully to remove adult worms. The prognosis for feline heartworm disease is guarded. [45] [ clarification needed ][ citation needed ]
Dirofilaria are important medical parasites, but diagnosis is unusual and is often only made after an infected person happens to have a chest X-ray following granuloma formation in the lung. The nodule itself may be large enough to resemble lung cancer on the X-ray, and requires a biopsy for a pathologic assessment. [18] This has been shown to be the most significant medical consequence of human infection by the canine heartworm. Patients are infected with the parasite through the bite of an infected mosquito, which is the same mechanism that causes heartworm infection in dogs. [46] [ medical citation needed ]
D. immitis is one of many species that can cause infection in dogs and humans. It was thought to infect the human eye, [18] with most cases reported from the southeastern United States. However, these cases are now thought to be caused by a closely related parasite of raccoons, Dirofilaria tenuis . Several hundred cases of subcutaneous infections in humans have been reported in Europe, but these are almost always caused by another closely related parasite, Dirofilaria repens , rather than the dog heartworm. There are proven D. immitis infections, [18] but humans rarely get infected with heartworms due to the larvae never fully maturing.[ medical citation needed ] When the heartworm infective larvae migrate through the skin, they often die since heartworms cannot survive in a human host, even if they make it into the bloodstream. Once the heartworms die, the immune system in the human body reacts to their tissue with inflammation as it tries to destroy the heartworms.[ medical citation needed ] When this happens, the condition is called pulmonary dirofilariasis. Heartworm infection in humans is not a serious problem unless they are causing pain, discomfort, and other noticeable symptoms.[ medical citation needed ]
Filariasis, is a filarial infection caused by parasitic nematodes (roundworms) spread by different vectors. They are included in the list of neglected tropical diseases.
Wuchereria bancrofti is a filarial (arthropod-borne) nematode (roundworm) that is the major cause of lymphatic filariasis. It is one of the three parasitic worms, together with Brugia malayi and B. timori, that infect the lymphatic system to cause lymphatic filariasis. These filarial worms are spread by a variety of mosquito vector species. W. bancrofti is the most prevalent of the three and affects over 120 million people, primarily in Central Africa and the Nile delta, South and Central America, the tropical regions of Asia including southern China, and the Pacific islands. If left untreated, the infection can develop into lymphatic filariasis. In rare conditions, it also causes tropical pulmonary eosinophilia. No vaccine is commercially available, but high rates of cure have been achieved with various antifilarial regimens, and lymphatic filariasis is the target of the World Health Organization Global Program to Eliminate Lymphatic Filariasis with the aim to eradicate the disease as a public-health problem by 2020. However, this goal was not met by 2020.
Toxocariasis is an illness of humans caused by the dog roundworm and, less frequently, the cat roundworm. These are the most common intestinal roundworms of dogs, coyotes, wolves and foxes and domestic cats, respectively. Humans are among the many "accidental" or paratenic hosts of these roundworms.
Brugia malayi is a filarial (arthropod-borne) nematode (roundworm), one of the three causative agents of lymphatic filariasis in humans. Lymphatic filariasis, also known as elephantiasis, is a condition characterized by swelling of the lower limbs. The two other filarial causes of lymphatic filariasis are Wuchereria bancrofti and Brugia timori, which both differ from B. malayi morphologically, symptomatically, and in geographical extent.
Acanthocheilonema is a genus within the family Onchocercidae which comprises mainly tropical parasitic worms. Cobbold created the genus Acanthocheilonema with only one species, Acanthocheilonema dracunculoides, which was collected from aardwolf in the region of South Africa in the nineteenth century. These parasites have a wide range of mammalian species as hosts, including members of Carnivora, Macroscelidea, Rodentia, Pholidota, Edentata, and Marsupialia. Many species among several genera of filarioids exhibit a high degree of endemicity in studies done on mammalian species in Japan. However, no concrete evidence has confirmed any endemic species in the genus Acanthocheilonema.
Canine parvovirus is a contagious virus mainly affecting dogs and wolves. CPV is highly contagious and is spread from dog to dog by direct or indirect contact with their feces. Vaccines can prevent this infection, but mortality can reach 91% in untreated cases. Treatment often involves veterinary hospitalization. Canine parvovirus often infects other mammals including foxes, wolves, cats, and skunks. Felines (cats) are also susceptible to panleukopenia, a different strain of parvovirus.
Uncinaria stenocephala is a nematode that parasitizes dogs, cats, and foxes as well as humans. It is rare to find in cats in the United States. Uncinaria stenocephala is the most common canine hookworm in cooler regions, such as Canada and the northern regions of the US, where it can be found primarily in foxes (40%). U. stenocephala is also one of the most common hookworms in the UK, called the northern hookworm, however it has a rather low prevalence. U. stenocephala is also considered to be zoonotic hookworms because they live in animals but can be transmitted to humans.
Dirofilariasis is an infection by parasites of the genus Dirofilaria. It is transmitted through a mosquito bite; its main hosts include dogs and wild canids. These can give rise to granulomas in the pulmonary artery. Some common symptoms include cough, fever and pleural effusion. It may also appear on X-rays of the chest.
Toxocara cati, also known as the feline roundworm, is a parasite of cats and other felids. It is one of the most common nematodes of cats, infecting both wild and domestic felids worldwide. Adult worms are localised in the gut of the host. In adult cats, the infection – which is called toxocariasis – is usually asymptomatic. However, massive infection in juvenile cats can be fatal.
The combination milbemycin oxime/lufenuron is a parasite control drug in which the active ingredient, milbemycin oxime, eliminates worms, while a second active ingredient, lufenuron, arrests the development of eggs and larvae, preventing them from maturing and continuing the infestation of an animal. This combination is registered for animal use only. To achieve efficacy, the treatment is administered once monthly, together with food, in a dosage suitable for the weight of the affected animal. The usual ratio is 500 μg milbemycin oxime and 10 mg lufenuron/kg body weight. Novartis indicates the proper dosage by color-coding the packages.
Dirofilaria is a filarial (arthropod-borne) nematode (roundworm), in the family Onchocercidae. Some species cause dirofilariasis, a state of parasitic infection, in humans and other animals.
Dirofilaria repens is a filarial nematode that affects dogs and other carnivores such as cats, wolves, coyotes, foxes, and sea lions, as well as muskrats. It is transmitted by mosquitoes. Although humans may become infected as aberrant hosts, the worms fail to reach adulthood while infecting a human body.
The Filarioidea are a superfamily of highly specialised parasitic nematodes. Species within this superfamily are known as filarial worms or filariae. Infections with parasitic filarial worms cause disease conditions generically known as filariasis. Drugs against these worms are known as filaricides.
Angiostrongylus vasorum, also known as French heartworm, is a species of parasitic nematode in the family Metastrongylidae. It causes the disease canine angiostrongylosis in dogs. It is not zoonotic, that is, it cannot be transmitted to humans.
Dirofilaria tenuis is a species of nematode, a parasitic roundworm that infects the subcutaneous tissue of vertebrates. D. tenuis most commonly infects raccoons, but some human cases have been reported. They are vectored by mosquitoes and follow similar development and transmission patterns as other Dirofilaria.
Brugia is a genus for a group of small roundworms. They are among roundworms that cause the parasitic disease filariasis. Specifically, of the three species known, Brugia malayi and Brugia timori cause lymphatic filariasis in humans; and Brugia pahangi and Brugia patei infect domestic cats, dogs and other animals. They are transmitted by the bite of mosquitos.
Imidacloprid/moxidectin, sold under the brand names Advantage Multi for Dogs and Advantage Multi for Cats among others, is a medicine for dogs and cats to treat heartworm, fleas, sarcoptic mange, intestinal parasites and ear mites.
Sarolaner, sold under the brand name Simparica, is an ectoparasiticide veterinary medication for the treatment of flea and tick infestations in dogs. It is also used off-label to control sarcoptic mange and demodectic mange.
Cat worm infections, the infection of cats (Felidae) with parasitic worms, occur frequently. Most worm species occur worldwide in both domestic and other cats, but there are regional, species and lifestyle differences in the frequency of infestation. According to the classification of the corresponding parasites in the zoological system, infections can be divided into those caused by nematode and flatworms - in the case of the latter, mainly cestoda and trematoda - while other strains are of no veterinary significance. While threadworms usually do not require an intermediate host for their reproduction, the development cycle of flatworms always proceeds via alternate hosts.
Nematode infection in dogs - the infection of dogs with parasitic nemamotodes - are, along with tapeworm infections and infections with protozoa, frequent parasitoses in veterinary practice. Nematodes, as so-called endoparasites, colonize various internal organs - most of them the digestive tract - and the skin. To date, about 30 different species of nematode have been identified in domestic dogs; they are essentially also found in wild dog species. However, the majority of them often cause no or only minor symptoms of disease in adult animals. The infection therefore does not necessarily have to manifest itself in a worm disease (helminthosis). For most nematodes, an infection can be detected by examining the feces for eggs or larvae. Roundworm infection in dogs and the hookworm in dogs is of particular health significance in Central Europe, as they can also be transmitted to humans (zoonosis). Regular deworming can significantly reduce the frequency of infection and thus the risk of infection for humans and dogs.