|Cluster of adult worms|
Toxocara mystax(Zeder, 1800)
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.
Feline roundworms are brownish-yellow to cream-colored to pink and may be up to 10 cm in length. Adults have short, wide cervical alae giving their anterior ends the distinct appearance of an arrow (hence their name, toxo, meaning arrow, and cara, meaning head). Eggs are pitted ovals with a width of 65 μm and a length of about 75 μm making them invisible to the human eye. The larvae are so small that they are easily transmitted from an adult female to her nursing kittens through her milk.
Wild felids can become infected from a variety of sources; the primary source is infected fecal matter. The eggs of the roundworm become infective in three to four weeks after being passed out in fecal matter.Contact with the soil, licking fur near feet, and eating a host animal (such as rodents) can also lead to infection of the felines. The consumption of infected carrion also leads to contraction of the parasites, which is some of the food that members of Felidae consume. The eggs hatch in the intestines and the larvae are then released into the cat's digestive tract. The larvae are capable of migrating through the tissues and are found in the liver, lungs, tracheal washings and muscles as well as in the digestive tract. From there, they move up to the trachea where they are swallowed, causing hacking and other problems. The larvae can also move throughout the body and cause more damage to the infected individuals. The worms can even go into the mother's milk and infect the young.
There are numerous clinical signs when dealing with feline roundworm. Some clinical signs that can be detected easily are vomiting, decreased appetite, and poor growth.Like many diseases, changes in behavior can also be attributed to toxocariasis. Decreased appetite will result in a scrawny, mangy, and sickly appearance. Toxocariasis is exceptionally detrimental to kittens, as appetite loss and poor growth can ultimately lead to mortality. Additional clinical signs that can be identified include a pot bellied appearance, abdominal discomfort, and diarrhea. Those with a small worm burden, however, may not show the clinical signs of being infected with worms, and not receive treatment.
Treatment for Toxocara cati infections in cats is rather simple. There are a number of anthelmintics that will kill the adult worms, including emodepside, fenbendazole, milbemycin, and moxidectin. However, most drugs are ineffective against the immature parasites. Consequently, infected cats will usually need multiple doses administered in two or three week intervals in order to fully eradicate the worms.
It is possible for Toxocara cati to be transmitted to humans, usually as a consequence of humans consuming the larval stage of the parasite, resulting in a condition known as toxocariasis.Typically, this happens when an individual pets an infected cat, picks up the parasite off of the fur and touches their face before washing their hands. The larvae migrate through the viscera in humans. Depending on the location and number of the larva in the human host, the disease can either be asymptomatic or cause conditions such as fever, cough, pneumonia, and vision loss.
The two more severe forms of the disease are visceral toxocariasis and ocular toxocariasis. Visceral toxocariasis typically occurs in children, but can infect persons of any age. Signs and symptoms can include fever, wheezing, hepatomegaly, abdominal pain, anorexia, or skin reaction. Rarely, the migrating larvae can cause eosinophilic meningitis or encephalitis, myelitis, optic neuritis, radiculitis, cranial nerve palsy, or myocarditis. In lab findings, there is almost always a marked peripheral eosinophilia and often, anemia and a hypergammaglobulinemia.
Ocular toxocariasis typically occurs in 5 to 10-year-olds resulting in significant damage to the eye.Usually only one eye is affected, and manifestations can include strabismus, decreased vision, and leukocoria. Eye exam may show a subretinal granulomatous mass or posterior pole granuloma. Even in relatively healthy people, the roundworm larvae infect organs such as the liver, lungs, eyes or brain and cause severe symptoms, such as:
Loa loa is the filarial nematode (roundworm) species that causes Loa loa filariasis. Loa loa actually means "worm worm", but is commonly known as the "eye worm", as it localizes to the conjunctiva of the eye. Loa loa is commonly found in Africa. It mainly inhabits rain forests in West Africa and has native origins in Ethiopia. The disease caused by Loa loa is called loiasis and belongs to the so-called neglected diseases.
Praziquantel (PZQ), sold under the brandname Biltricide among others, is a medication used to treat a number of types of parasitic worm infections. Specifically it is used for schistosomiasis, clonorchiasis, opisthorchiasis, tapeworm infections, cysticercosis, hydatid disease, and other fluke infections. It should not be used for worm infections of the eye. It is taken by mouth.
Toxocariasis is an illness of humans caused by larvae of either the dog roundworm, the cat roundworm or the fox roundworm. Toxocariasis is often called visceral larva migrans (VLM). Depending on geographic location, degree of eosinophilia, eye and/or pulmonary signs, the terms ocular larva migrans (OLM), Weingarten's disease, Frimodt-Møller's syndrome, and eosinophilic pseudoleukemia are applied to toxocariasis. Other terms sometimes or rarely used include nematode ophthalmitis, toxocaral disease, toxocarose, and covert toxocariasis. This zoonotic, helminthic infection is a rare cause of blindness and may provoke rheumatic, neurologic, or asthmatic symptoms. Humans normally become infected by ingestion of embryonated eggs from contaminated sources
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Dipylidium caninum, also called the flea tapeworm, double-pored tapeworm, or cucumber tapeworm, is a cyclophyllid cestode that infects organisms afflicted with fleas and canine chewing lice, including dogs, cats, and sometimes human pet-owners, especially children.
The Toxocaridae are a zoonotic family of parasitic nematodes that infect canids and felids and which cause toxocariasis in humans. The worms are unable to reproduce in humans.
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, that causes dirofilariasis. It is spread from host to host through the bites of mosquitoes. The definitive host is the dog, but it can also infect cats, wolves, coyotes, jackals, foxes, and other animals, such as ferrets, bears, seals, sea lions and, under rare circumstances, humans.
Feline panleukopenia virus (FPLV) is a species of parvovirus that can infect all wild and domestic members of the felid (cat) family worldwide. It is a highly contagious, severe infection that causes gastrointestinal, immune system, and nervous system disease.
Visceral larva migrans (VLM) is a condition in humans caused by the migratory larvae of certain nematodes, humans being a dead-end host, and was first reported in 1952. Nematodes causing such zoonotic infections are Baylisascaris procyonis, Toxocara canis, Toxocara cati, and Ascaris suum. These nematodes can infect but not mature in humans and after migrating through the intestinal wall, travel with the blood stream to various organs where they cause inflammation and damage. Affected organs can include the liver, heart and the CNS. A special variant is ocular larva migrans where usually T. canis larvae travel to the eye.
Feline viral rhinotracheitis (FVR) is an upper respiratory or pulmonary infection of cats caused by Felid alphaherpesvirus 1 (FeHV-1), of the family Herpesviridae. It is also commonly referred to as feline influenza, feline coryza, and feline pneumonia but, as these terms describe other very distinct collections of respiratory symptoms, they are misnomers for the condition. Viral respiratory diseases in cats can be serious, especially in catteries and kennels. Causing one-half of the respiratory diseases in cats, FVR is the most important of these diseases and is found worldwide. The other important cause of feline respiratory disease is feline calicivirus.
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Mansonella streptocerca,, is the scientific name of a human parasitic roundworm causing the disease streptocerciasis. It is a common parasite in the skin of humans in the rain forests of Africa, where it is thought to be a parasite of chimpanzees, as well.
Baylisascaris procyonis, common name raccoon roundworm, is a roundworm nematode, found ubiquitously in raccoons, the definitive hosts. It is named after H. A. Baylis, who studied them in the 1920s–30s, and Greek askaris. Baylisascaris larvae in paratenic hosts can migrate, causing visceral larva migrans (VLM). Baylisascariasis as the zoonotic infection of humans is rare, though extremely dangerous due to the ability of the parasite's larvae to migrate into brain tissue and cause damage. Concern for human infection has been increasing over the years due to urbanization of rural areas resulting in the increase in proximity and potential human interaction with raccoons.
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Toxocara malayasiensis is a species of feline roundworm, a parasite which infects the intestine of cats. Feline roundworms are passed in the fecal matter of cats, and can be transmitted to humans, causing toxocariasis, a potentially serious disease.
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