Veterinary parasitology
Encyclopedia
Veterinary parasitology is the study of animal parasites, especially relationships between parasites and animal hosts. Parasites of domestic animals, (livestock
and pet
animals), as well as wildlife
animals are considered. Veterinary parasitologists study the genesis and development of parasitoses in animal hosts, as well as the taxonomy
and systematics
of parasites, including the morphology
, life cycles, and living needs of parasites in the environment and in animal hosts. Using a variety of research methods, they diagnose, treat, and prevent animal parasitoses. 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.
, 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.
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
.
, 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.
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.
Veterinary protozoology
Examples of protozoan parasites:
Veterinary helminthology
Examples of helminth parasites:
Veterinary entomology
Examples of arachnid, insect, and crustacean parasites:
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
and pet
Pet
A pet is a household animal kept for companionship and a person's enjoyment, as opposed to wild animals or to livestock, laboratory animals, working animals or sport animals, which are kept for economic or productive reasons. The most popular pets are noted for their loyal or playful...
animals), as well as wildlife
Wildlife
Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative....
animals are considered. Veterinary parasitologists study the genesis and development of parasitoses in animal hosts, as well as the taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
and systematics
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...
of parasites, including the morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
, life cycles, and living needs of parasites in the environment and in animal hosts. Using a variety of research methods, they diagnose, treat, and prevent animal parasitoses. 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.
Diagnostic methods
Various methods are used to identify parasites in animals, using feces, blood, and tissue samples from the host animal.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.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 smearsBlood film
A blood film or peripheral blood smear is a thin layer of blood smeared on a microscope slide and then stained in such a way to allow the various blood cells to be examined microscopically...
, 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
Staining (biology)
Staining is an auxiliary technique used in microscopy to enhance contrast in the microscopic image. Stains and dyes are frequently used in biology and medicine to highlight structures in biological tissues for viewing, often with the aid of different microscopes...
with a dye in order for the cells to be easily distinguished.
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
Mite
Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...
.
Immunological
Immunological examinations, such as indirect immunofluorescenceImmunofluorescence
Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on biological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specific biomolecule targets within a cell, and therefore allows...
, ELISA
ELISA
Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...
, Immunoblotting (Western blot
Western blot
The western blot is a widely used analytical technique used to detect specific proteins in the given sample of tissue homogenate or extract. It uses gel electrophoresis to separate native proteins by 3-D structure or denatured proteins by the length of the polypeptide...
), and Complement fixation test are methods of identifying different kinds of parasites by detecting the presence of their antigens
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
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.
Molecular biological
Molecular biological methods involve studying the DNA of the parasite in order to identify it. PCRPolymerase chain reaction
The polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....
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.
Veterinary protozoologyProtozoologyProtozoology is the study of protozoa, the "animal-like" protists. This term has become dated as our understanding of the evolutionary relationships of the eukaryota has improved....
- focused on veterinary important protozoans
Examples of protozoan parasites:
- Trypanosoma bruceiTrypanosoma bruceiTrypanosoma brucei is a parasitic protist species that causes African trypanosomiasis in humans and nagana in animals in Africa. There are 3 sub-species of T. brucei: T. b. brucei, T. b. gambiense and T. b. rhodesiense.These obligate parasites have two hosts - an insect vector and mammalian host...
- Trypanosoma equiperdumTrypanosoma equiperdumTrypanosoma equiperdum is a protozoan that causes Dourine, or covering sickness, in horses and other animals in the family equidae. The donkey shows no symptoms but is a carrier of this parasite. Unlike other species of Trypanosoma, this parasite can be sexually transmitted, also mother foal...
- Leishmania donovaniLeishmania donovaniLeishmania donovani is a species of Leishmania. It is an important cause of visceral leishmaniasis. The reference genome of L. donovani extracted in the south eastern Nepal was published in 2011...
- Leishmania infantumLeishmania infantumLeishmania infantum is the causative agent of infantile visceral leishmaniasis in the Mediterranean region of the Old World and in Latin America, where it has been called Leishmania chagasi. It is also an unusual cause of cutaneous leishmaniasis. Wild canids and domestic dogs are the natural...
- Giardia duodenalisGiardia lambliaGiardia lamblia is a flagellated protozoan parasite that colonizes and reproduces in the small intestine, causing giardiasis. The giardia parasite attaches to the epithelium by a ventral adhesive disc, and reproduces via binary fission...
- Trichomonas gallinaeTrichomonas gallinaeThe protozoan Trichomonas gallinae is a cosmopolitan parasite of pigeons and doves. Other birds such as domestic and wild turkeys, chickens, raptors may also become infected. The disease in pigeons is commonly called "canker"...
- Tritrichomonas foetusTritrichomonas foetusTritrichomonas foetus is a single celled flagellated protozoan parasite that is known to be a pathogen of the bovine reproductive tract as well as the intestinal tract of cats. In cattle, the organism is transmitted to the female vagina and uterus from the foreskin of the bull where the parasite...
- Histomonas meleagridisHistomonas meleagridisHistomonas meleagridis is species of parasitic protozoan that infects a wide range of birds including chickens, turkeys, peafowl, quail and pheasants, causing blackhead disease, infectious enterohepatitis, or histomoniasis. H. meleagridis can infect many birds but it is most deadly in turkeys...
- Cryptosporidium parvumCryptosporidium parvumCryptosporidium parvum is one of several protozoal species that cause cryptosporidiosis, a parasitic disease of the mammalian intestinal tract....
- Balantidium coliBalantidium coliBalantidium coli is a parasitic species of ciliate protozoan that causes the disease Balantidiasis. It is the only member of the ciliate phylum known to be pathogenic to humans.-Morphology:...
- Eimeria acervulinaEimeria acervulinaEimeria acervulina is a species of Eimeria that causes coccidiosis in older poultry. Lesions are limited to the anterior or first third of the small intestine. Diagnosis is made by on necropsy based on location and the pathognomic white to gray striations that appear on the mucosa or inner surface...
- Eimeria tenellaEimeria tenellaEimeria tenella is a species of Eimeria that causes hemorrhagic cecal coccidiosis in young poultry.This species has a monoxeous life cycle with the definitive host as chickens; it is extremely host-specific...
- Isospora canis
- Toxoplasma gondiiToxoplasma gondiiToxoplasma gondii is a species of parasitic protozoa in the genus Toxoplasma. The definitive host of T. gondii is the cat, but the parasite can be carried by many warm-blooded animals . Toxoplasmosis, the disease of which T...
- Neospora caninumNeospora caninumNeospora 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 is determined by the Wellcome Trust Sanger Institute...
- Hammondia hammondi
- Besnoitia besnoitiBesnoitia besnoitiBesnoitia besnoiti is an important parasite that can afflict livestock. In particular, cattle are vulnerable to B. besnoiti....
- Babesia divergensBabesia divergensBabesia divergens is an intraerythrocytic protozoan parasite, transmitted by the tick Ixodes ricinus. It is the main agent of bovine babesiosis, or "redwater fever", in Europe. Young cattle are less susceptible...
Veterinary helminthologyHelminthologyHelminthology is the study of worms, especially parasitic worms. This field deals with the study of their taxonomy and the effect on their hosts....
- focused on veterinary important helminth parasites
Examples of helminth parasites:
- Fasciola hepaticaFasciola hepaticaFasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic flatworm of the class Trematoda, phylum Platyhelminthes that infects the livers of various mammals, including humans. The disease caused by the fluke is called fascioliasis . F...
- Fascioloides magnaFascioloides magnaFascioloides magna, also known as giant liver fluke, large American liver fluke or deer fluke, is an important parasite of a variety of wild and domestic ruminants in North America and Europe. Adult flukes occur in the liver of the definitive host and feed on blood...
- Dicrocoelium dendriticumDicrocoelium dendriticumThe Lancet liver fluke is a parasite fluke that tends to live in cattle or other grazing mammals.- History of discovery :...
- SchistosomaSchistosomaA genus of trematodes, Schistosoma, commonly known as blood-flukes and bilharzia, includes flatworms which are responsible for a highly significant parasitic infection of humans by causing the disease schistosomiasis, and are considered by the World Health Organization as the second most...
bovis - Trichobilharzia regentiTrichobilharzia regentiTrichobilharzia regenti is a nasal parasite of birds that causes cercarial dermatitis in humans.-Life cycle:The life cycle for avian schistosomes is similar to that of human schistosomiasis. Adult flukes mate and produce eggs which are usually excreted with the bird's feces. Once in the water, the...
- Paragonimus westermaniParagonimus westermaniParagonimus westermani is a lung fluke and is most prominent in Asia and South America. It was discovered from two Bengal tigers that died in zoos in Europe in 1878...
- Dipylidium caninumDipylidium caninumDipylidium caninum, also called the cucumber tapeworm or the double-pore tapeworm, is a cyclophyllid cestode that infects organisms afflicted with fleas, including canids, felids, and pet-owners, especially children. Adult worms are about 18 inches long...
- Taenia pisiformisTaenia pisiformisTaenia pisiformis is a tapeworm. It is related to Taenia solium, the pork tapeworm, and to Taenia saginata, the beef tapeworm.The adult may reach up to 200 cm in length.The definite host is represented by carnivores such as the dog or the cat....
- Taenia saginataTaenia saginataTaenia saginata, also known as Taeniarhynchus saginata or the beef tapeworm, is a parasite of both cattle and humans, causing taeniasis in humans. Taenia saginata occurs where cattle are raised by infected humans maintaining poor hygiene, human feces are improperly disposed of, meat inspection...
- Taenia solium
- Echinococcus granulosusEchinococcus granulosusEchinococcus granulosus, also called the Hydatid worm or Hyper Tape-worm, is a cyclophyllid cestode that parasitizes the small intestine of canids as an adult, but which has important intermediate hosts such as livestock and humans, where it causes hydatid disease...
- Dictyocaulus bovis
- Muellerius capillarisMuellerius capillarisMuellerius capillaris , also known as hair lungworm, is nematode parasite of small ruminants. Adult worms occur in small air passages and in the alveoli, even in the subpleural tissue. In ruminants, parasite causes chronic bronchopneumonia. In case of massive infection or secondary bacterial...
- Haemonchus contortusHaemonchus contortusHaemonchus contortus, also known as red stomach worm, wire worm or Barber's pole worm, is very common parasite and one the most pathogenic nematode of ruminants. Adult worms are attached to abomasal mucosa and feed on the blood...
- Ostertagia ostertagi
- Strongyloides canis
- Ancylostoma duodenaleAncylostoma duodenaleAncylostoma duodenale is a species of the worm genus Ancylostoma. It is a parasitic nematode worm and commonly known as Old World hookworm. It lives in the small intestine of host such as humans, cats and dogs....
- TrichurisTrichurisThe roundworm family Trichuridae includes as type genus Trichuris, often referred to as whipworms...
suis - Syngamus tracheaGapewormA gapeworm is a parasitic nematode worm infecting the tracheas of certain birds. The resulting disease, known as gape or the gapes, occurs when the worms clog and obstruct the airway. The worms are also known as red worms or forked worms due to their red color and the permanent procreative...
- Ascaris suum
- Toxocara canis
- Strongylus vulgarisStrongylus vulgarisStrongylus vulgaris, commonly known as the blood worm, is a common horse parasite in the phylum Nematoda. It generally lives in the large intestine and migrates in the mesenteric arteries. This nematode is considered to be one of the "most pathogenic" of the large strongyles subphylum and is...
- MetastrongylusMetastrongylusMetastrongylus is a genus of nematodes of the family Metastrongylidae, usually found as lungworms in pigs and sometimes causing verminous bronchitis. It causes a disease called metastrongylosis.- Species :...
- Trichinella spiralisTrichinella spiralisTrichinella spiralis is a nematode parasite, occurring in rats, pigs, bears and humans, and is responsible for the disease trichinosis. It is sometimes referred to as the "pork worm" due to it being found commonly in undercooked pork products...
Veterinary entomologyEntomologyEntomology is the scientific study of insects, a branch of arthropodology...
(arachnoentomology)
- focused on veterinary important ArachnidArachnidArachnids are a class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, although in some species the front pair may convert to a sensory function. The term is derived from the Greek words , meaning "spider".Almost all extant arachnids are terrestrial...
s, InsectInsectInsects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, and CrustaceanCrustaceanCrustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s
Examples of arachnid, insect, and crustacean parasites:
- Sarcoptes equiSarcoptes equiA form of scabies, Sarcoptes equi occurs in horses and riders can suffer an itchy skin disorder from these mites....
- Psoroptes ovis
- Ixodes ricinusIxodes ricinusIxodes ricinus, the castor bean tick, is a chiefly European species of hard-bodied tick. It may reach a length of when engorged with a blood meal, and can transmit both bacterial and viral pathogens such as the causative agents of Lyme disease and tick-borne encephalitis.-Description:In common...
- Dermacentor marginatus
- Caligus clemensi
- Caligus cuneifer
- Caligus elongatus
- Caligus rogercresseyi
- Cimex colombarius.
- Cimex lectularius
- Culex pipiensCulex pipiensCulex pipiens is a species of blood-feeding mosquito of the family Culicidae. It is a vector of some diseases, such as Japanese encephalitis, meningitis, Urticaria...
- Culicoides imicolaCulicoides imicolaCulicoides imicola is a midge which transmits the bluetongue virus. Other suspected BTV vectors areCulicoides pulicaris and species in the Culicoides obsoletus complex....
- Demodex bovis
- Gasterophilus intestinalis
- Haematobia irritansHaematobia irritansHaematobia irritans, the horn fly, is a small fly of the genus Haematobia which is the European genus of bloodsucking flies. Haematobia irritans is a native of Europe but has been introduced to North America and is considered a potentially dangerous livestock pest. - Appearance :H...
- Hypoderma bovis
- Knemidocoptes mutans
- Lepeophtheirus salmonis (sea louse)
- Lucilia sericata
- Musca domestica
- Nosema apisNosema apisNosema apis is a microsporidian, a small, unicellular parasite that mainly affects honey bees. It causes nosemosis, also called nosema, which is the most widespread of adult honey bee diseases. The dormant stage of Nosema apis is a long lived spore which is resistant to temperature extremes and...
- Notoedres cati
- Oestrus ovis
- Otodectes cynotis
- PhlebotomusPhlebotomusPhlebotomus is a genus of "sand fly" in the Dipteran family Psychodidae. In the past, they have sometimes been considered to belong in a separate family, Phlebotomidae, but this alternative classification has not gained wide acceptance.-Epidemiology:...
- Pulex irritans
- Rhipicephalus sanguineusRhipicephalus sanguineusThe brown dog tick, Rhipicephalus sanguineus, is a species of tick which is found world-wide, but more commonly in warmer climates. This species is unusual among ticks in that its entire life cycle can be completed indoors.-Hosts:...
- Sarcophaga carnaria
- Tabanus atratus
- TriatomaTriatomaTriatoma is a genus of assassin bug in the subfamily Triatominae The members of Triatoma are blood-sucking insects that can transmit serious diseases, such as Chagas disease....
- Ctenocephalides canis
- Ctenocephalides felis