The koala, sometimes called the koala bear, is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae and its closest living relatives are the wombats. The koala is found in coastal areas of the mainland's eastern and southern regions, inhabiting Queensland, New South Wales, Victoria, and South Australia. It is easily recognisable by its stout, tailless body and large head with round, fluffy ears and large, dark nose. The koala has a body length of 60–85 cm (24–33 in) and weighs 4–15 kg (9–33 lb). Fur colour ranges from silver grey to chocolate brown. Koalas from the northern populations are typically smaller and lighter in colour than their counterparts further south. These populations possibly are separate subspecies, but this is disputed.
The Pythonidae, commonly known as pythons, are a family of nonvenomous snakes found in Africa, Asia, and Australia. Among its members are some of the largest snakes in the world. Ten genera and 39 species are currently recognized. Being naturally non-venomous, pythons must constrict their prey to suffocate it prior to consumption. Pythons will typically strike at and bite their prey of choice to gain hold of it; they then must use physical strength to constrict their prey, by coiling their muscular bodies around the animal, effectively suffocating it before swallowing whole. This is in stark contrast to venomous snakes such as the rattlesnake, for example, which delivers a swift, venomous bite but releases, waiting as the prey succumbs to envenomation before being consumed. Collectively, the pythons are well-documented and -studied as constrictors, much like other non-venomous snakes, including the boas and even kingsnakes of the New World.
Ascaris lumbricoides is a large parasitic worm that causes ascariasis in humans. A roundworm of genus Ascaris, it is the most common parasitic worm in humans. An estimated 807 million–1.2 billion people are infected with A. lumbricoides worldwide. People living in tropical and subtropical countries are at greater risk of infection.
The Phascolarctidae is a family of marsupials of the order Diprotodontia, consisting of only one extant species, the koala, and six well-known fossil species, with another six less well known fossil species, and two fossil species of the genus Koobor, whose taxonomy is debatable but are placed in this group. The closest relatives of the Phascolarctidae are the wombats, which comprise the family Vombatidae.
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.
Morelia spilota, commonly known as the carpet python, is a large snake of the family Pythonidae found in Australia, New Guinea, Bismarck Archipelago, and the northern Solomon Islands. Many subspecies are recognised; ITIS lists six, the Reptile Database six, and the IUCN eight.
Parelaphostrongylus tenuis is a neurotropic nematode parasite common to white-tailed deer, Odocoileus virginianus, which causes damage to the central nervous system. Moose, elk, caribou, mule deer, and others are also susceptible to the parasite, but are aberrant hosts and are infected in neurological instead of meningeal tissue. The frequency of infection in these species increases dramatically when their ranges overlap high densities of white-tailed deer.
Sparganosis is a parasitic infection caused by the plerocercoid larvae of the genus Spirometra including S. mansoni, S. ranarum, S. mansonoides and S. erinacei. It was first described by Patrick Manson in 1882, and the first human case was reported by Charles Wardell Stiles from Florida in 1908. The infection is transmitted by ingestion of contaminated water, ingestion of a second intermediate host such as a frog or snake, or contact between a second intermediate host and an open wound or mucous membrane. Humans are the accidental hosts in the life cycle, while dogs, cats, and other mammals are definitive hosts. Copepods are the first intermediate hosts, and various amphibians and reptiles are second intermediate hosts.
Chlamydia pecorum, also known as Chlamydophila pecorum is a species of Chlamydiaceae that originated from ruminants, such as cattle, sheep and goats. It has also infected koalas and swine. C. pecorum strains are serologically and pathogenically diverse.
Mammomonogamus is a genus of parasitic nematodes of the family Syngamidae that parasitise the respiratory tracts of cattle, sheep, goats, deer, cats, orangutans, and elephants. The nematodes can also infect humans and cause the disease called mammomonogamiasis. Several known species fall under the genus Mammomonogamus, but the most common species found to infest humans is M. laryngeus. Infection in humans is very rare, with only about 100 reported cases worldwide, and is assumed to be largely accidental. Cases have been reported from the Caribbean, China, Korea, Thailand, and Philippines.
Dioctophyme renale, commonly referred to as the giant kidney worm, is a parasitic nematode (roundworm) whose mature form is found in the kidneys of mammals. D. renale is distributed worldwide, but is less common in Africa and Oceania. It affects fish-eating mammals, particularly mink and dogs. Human infestation is rare, but results in kidney destruction, usually of one kidney and hence not fatal. A 2019 review listed a total of 37 known human cases of dioctophymiasis in 10 countries with the highest number (22) in China. Upon diagnosis through tissue sampling, the only treatment is surgical excision.
Toxocara canis is a worldwide-distributed helminth parasite that primarily infects dogs and other canids, but can also infect other animals including humans. The name is derived from the Greek word "toxon," meaning bow or quiver, and the Latin word "caro," meaning flesh. T. canis live in the small intestine of the definitive host. This parasite is very common in puppies and somewhat less common in adult dogs. In adult dogs, infection is usually asymptomatic but may be characterized by diarrhea. By contrast, untreated infection with Toxocara canis can be fatal in puppies, causing diarrhea, vomiting, pneumonia, enlarged abdomen, flatulence, poor growth rate, and other complications.
Angiostrongyliasis is an infection by a roundworm of the Angiostrongylus type. Symptoms may vary from none, to mild, to meningitis.
Morelia spilota spilota is a subspecies of carpet python, popularly known as the diamond python. It is a medium to large snake, found in coastal areas and adjacent ranges of south-eastern Australia. It is the most southerly occurring python in the world and is found at higher altitudes than any other species of Australian python.
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.
Morelia imbricata is a large snake found in southern regions of Western Australia and western South Australia. A member of the python family, it is commonly known as the southwestern carpet python.
Angiostrongylus cantonensis is a nematode (roundworm) parasite that causes angiostrongyliasis, an infection that is the most common cause of eosinophilic meningitis in Southeast Asia and the Pacific Basin. The nematode commonly resides in the pulmonary arteries of rats, giving it the common name rat lungworm. Snails are the primary intermediate hosts, where larvae develop until they are infectious.
Toxascaris leonina is a common parasitic roundworm found in dogs, cats, foxes, and related host species. T. leonina is an ascarid nematode, a worldwide distributed helminth parasite which is in a division of eukaryotic parasites that, unlike external parasites such as lice and fleas, live inside their host. The definitive hosts of T. leonina include canids and felines (cats), while the intermediate hosts are usually rodents, such as mice or rats. Infection occurs in the definitive host when the animal eats an infected rodent. While T. leonina can occur in either dogs or cats, it is far more frequent in cats.
Baylisascaris procyonis, also known by the 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 larva migrans. 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 the urbanization of rural areas, resulting in the increase in proximity and potential human interaction with raccoons.
Trypanosoma irwini is a blood parasite of koalas. First discovered in 2009 by Linda M. McInnes and her peers, it was named in honor of Steve Irwin, "The Crocodile Hunter". The study done by McInnes et al. was the first to describe a Trypanosoma species from koalas.
