Veterinary parasitology

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Veterinary parasitology is a branch of veterinary medicine that deals with the study of morphology, life-cycle, pathogenesis, diagnosis, treatment, and control of eukaryotic invertebrates of the kingdom Animalia and the taxon Protozoa that depend upon other invertebrates and higher vertebrates for their propagation, nutrition, and metabolism without necessarily causing the death of their hosts. Modern parasitology focuses on responses of animal hosts to parasitic invasion. Parasites of domestic animals, (livestock and pet animals), as well as wildlife animals are considered. Data obtained from parasitological research in animals helps in veterinary practice and improves animal breeding. The major goal of veterinary parasitology is to protect animals and improve their health, but because a number of animal parasites are transmitted to humans, veterinary parasitology is also important for public health. [1] [2] [3]

Contents

Diagnostic methods

Various methods are used to identify parasites in animals, using feces, blood, and tissue samples from the host animal. [2]

Coprological

Coprological examinations involve examining the feces of animals to identify and count parasite eggs. Some common methods include fecal flotation and sedimentation to separate eggs from fecal matter. Others include the McMaster method, which uses a special two-chamber slide that allows parasite eggs to be more clearly visible and easily counted. It is most commonly used to monitor parasites in horses and other grazing and livestock animals. The Baermann method is similar but requires more specialized equipment and more time and is typically used to diagnose lungworm and threadworm. [4]

Haematological

Haematological examinations involve examining the blood of animals to determine the presence of parasites. Blood parasites tend to inhabit the erythrocytes or white blood cells and are most likely to be detected during the acute phase of infection. Veterinary parasitologists use blood smears, which involve placing a drop of blood onto a slide and spreading it over the surface in a thin film in order to examine it under a microscope. The blood is stained with a dye in order for the cells to be easily distinguished. [5]

Histopathological

Histopathological examinations involve examining tissue samples from animals. A small slice of the organ suspected of being infected by parasites is mounted on a slide, stained, and examined under a microscope.

Though not technically considered a histopathological technique, skin scraping – which involves taking a small sample of the epidermal cells of a dog, cat, or other household pet – is commonly used to detect the presence of mites. [4]

Immunological

Immunological examinations, such as indirect immunofluorescence, ELISA, Immunoblotting (Western blot), and Complement fixation test are methods of identifying different kinds of parasites by detecting the presence of their antigens on or within the parasite itself. These diagnostic methods are used in conjunction with coprological examinations for more specific identification of different parasite species in fecal samples. [5]

Molecular biological

Molecular biological methods involve studying the DNA of the parasite in order to identify it. PCR and RFLP are used to detect and amplify parasite DNA found in the feces, blood, or tissue of the host. These techniques are very sensitive, which is useful for diagnosing parasites even when they are present in very low numbers; they are also useful for identifying parasites not only in large animal hosts but smaller insect vectors. [6]

Divisions of veterinary parasitology

Veterinary protozoology

Veterinary protozoology is focused on protozoas with veterinary relevance. Examples of protozoan parasites:

Veterinary helminthology

Veterinary helminthology is focused on veterinary important helminth parasites, for example:

Veterinary entomology (arachnoentomology)

Veterinary entomology is focused on important arachnids, insects, and crustaceans. Some examples include:

Related Research Articles

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.

<span class="mw-page-title-main">Parasite load</span> Number and virulence of the parasites that a host organism harbours

Parasite load is a measure of the number and virulence of the parasites that a host organism harbours. Quantitative parasitology deals with measures to quantify parasite loads in samples of hosts and to make statistical comparisons of parasitism across host samples.

Coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa. The disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue. Diarrhea, which may become bloody in severe cases, is the primary symptom. Most animals infected with coccidia are asymptomatic, but young or immunocompromised animals may suffer severe symptoms and death.

<i>Eimeria</i> Genus of single-celled organisms

Eimeria is a genus of apicomplexan parasites that includes various species capable of causing the disease coccidiosis in animals such as cattle, poultry and smaller ruminants including sheep and goats. Eimeria species are considered to be monoxenous because the life cycle is completed within a single host, and stenoxenous because they tend to be host specific, although a number of exceptions have been identified. Species of this genus infect a wide variety of hosts. Thirty-one species are known to occur in bats (Chiroptera), two in turtles, and 130 named species infect fish. Two species infect seals. Five species infect llamas and alpacas: E. alpacae, E. ivitaensis, E. lamae, E. macusaniensis, and E. punonensis. A number of species infect rodents, including E. couesii, E. kinsellai, E. palustris, E. ojastii and E. oryzomysi. Others infect poultry, rabbits and cattle. For full species list, see below.

<i>Neospora caninum</i> Species of Conoidasida in the apicomplex phylum

Neospora caninum is a coccidian parasite that was identified as a species in 1988. Prior to this, it was misclassified as Toxoplasma gondii due to structural similarities. The genome sequence of Neospora caninum has been determined by the Wellcome Trust Sanger Institute and the University of Liverpool. Neospora caninum is an important cause of spontaneous abortion in infected livestock.

<span class="mw-page-title-main">Cat flea</span> Species of flea

The cat flea is an extremely common parasitic insect whose principal host is the domestic cat, although a high proportion of the fleas found on dogs also belong to this species. This is despite the widespread existence of a separate and well-established "dog" flea, Ctenocephalides canis. Cat fleas originated in Africa but can now be found globally. As humans began domesticating cats, the prevalence of the cat flea increased and it spread throughout the world.

<i>Trichuris</i> Genus of roundworms

Trichuris, often referred to as whipworms, is a genus of parasitic worms from the roundworm family Trichuridae, which are helminths. The name whipworm refers to the shape of the worm; they look like whips with wider "handles" at the posterior end. The name Trichocephalus is sometimes used for this genus.

<i>Toxascaris leonina</i> Species of roundworm

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.

<i>Ancylostoma braziliense</i> Species of worm

Ancylostoma braziliense is a species of hookworm belonging to the genus Ancylostoma. It is an intestinal parasite of domestic cats and dogs. Severe infection is often fatal to these pets, especially in puppies and kittens. The infection is particularly endemic in the southern United States. It is most often confused with the zoonotic hookworm species Ancylostoma ceylanicum because of their uncanny resemblance.

<i>Ancylostoma caninum</i> Species of roundworm

Ancylostoma caninum is a species of nematode known as a hookworm, which principally infects the small intestine of dogs. The result of A. caninum infection ranges from asymptomatic cases to death of the dog; better nourishment, increasing age, prior A. caninum exposure, or vaccination are all linked to improved survival. Other hosts include carnivores such as wolves, foxes, and cats, with a small number of cases having been reported in humans.

Trichuris vulpis is a whipworm that lives in the large intestine of canines in its adult stages. Out of different types of worms, Trichuris vulpis is one of the smaller worms with a size ranging from 30–50 mm in length. As the name suggests, the worm has a whip-like shape with distinct features including a small, narrow anterior head, which is the digestive part of the worm, and a larger posterior tail, which is the reproductive part of the worm. Eggs from T. vulpis are oval shaped with bipolar plugs and contain a thick outer shell. Their sizes range from 72–90 μm in length and 32–40 μm in width. Because of their thick outer shell, T. vulpis eggs are very resistant to environmental extremes such as freezing or hot temperatures, thus allowing for their long viability in the outside world.

<i>Taenia taeniaeformis</i> Species of flatworm

Taenia taeniaeformis is a parasitic tapeworm, with cats as the primary definitive hosts. Sometime dogs can also be the definitive host. The intermediate hosts are rodents and less frequently lagomorphs (rabbits). The definitive host must ingest the liver of the intermediate host in order to acquire infection. The worm tends to be white, thick bodied, and around 15 to 60 cm in length. This species of tape worm is much less frequently encountered than Dipylidium caninum, which has fleas as its intermediate host rather than rodents but exhibits most of the same physical characteristics and is treated with the same medications.

<span class="mw-page-title-main">Nitroscanate</span> Chemical compound

Nitroscanate is an anthelmintic drug used in veterinary medicine to treat Toxocara canis, Toxascaris leonina, Ancylostoma caninum, Uncinaria stenocephala, Taenia, and Dipylidium caninum.

<span class="mw-page-title-main">Hookworm</span> Intestinal, blood-feeding, parasitic roundworms that cause types of infection known as helminthiases

Hookworms are intestinal, blood-feeding, parasitic roundworms that cause types of infection known as helminthiases. Hookworm infection is found in many parts of the world, and is common in areas with poor access to adequate water, sanitation, and hygiene. In humans, infections are caused by two main species of roundworm, belonging to the genera Ancylostoma and Necator. In other animals the main parasites are species of Ancylostoma. Hookworm is closely associated with poverty because it is most often found in impoverished areas, and its symptoms promote poverty through the educational and health effects it has on children. It is the leading cause of anemia and undernutrition in developing countries, while being one of the most commonly occurring diseases among poor people. Hookworm thrives in areas where rainfall is sufficient and keeps the soil from drying out, and where temperatures are higher, making rural, coastal areas prime conditions for the parasite to breed.

Eimeria bovis is a parasite belonging to the genus Eimeria and is found globally. The pathogen can cause a diarrheic disease in cattle referred to as either eimeriosis or coccidiosis. The infection predominantly cause disease in younger animals.

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.

Wolves may suffer from various pathogens, both viral and bacterial, and parasite, both external and internal. Parasitic infection in wolves is of particular concern to people. Wolves can spread them to dogs, which in turn can carry the parasites to humans. In areas where wolves inhabit pastoral areas, the parasites can be spread to livestock.

<span class="mw-page-title-main">Cat worm infections</span> Worm infections in cats

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.

<span class="mw-page-title-main">Nematode infection in dogs</span> Threadworm infections of dogs are frequent

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.

References

  1. ↑ Jurášek, V., Dubinský, P., 1993. Veterinárna parazitológia. Príroda a.s., Bratislava, 382 pp.
  2. 1 2 Kaufmann, J., 1996. Parasitic infections of domestic animals: a diagnostic manual. Birkhauser, Berlin, 423 pp.
  3. ↑ Elsheikha, HM; Khan, NA (2011). Essentials of Veterinary Parasitology. Caister Academic Press. ISBN   978-1-904455-79-0.{{cite book}}: CS1 maint: multiple names: authors list (link)
  4. 1 2 Leland S. Shapiro; Patricia Mandel (22 May 2009). Pathology & Parasitology for Veterinary Technicians. Cengage Learning. pp. 237–239. ISBN   978-1-4354-3855-2 . Retrieved 11 September 2011.
  5. 1 2 A. Zajac; Gary A. Conboy; American Association of Veterinary Parasitologists (24 March 2006). Veterinary clinical parasitology. Wiley-Blackwell. p. 162. ISBN   978-0-8138-1734-7 . Retrieved 11 September 2011.
  6. ↑ John E. Hyde (1993). Protocols in molecular parasitology. Humana Press. pp. 213–214. ISBN   978-0-89603-239-2 . Retrieved 11 September 2011.
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