Veterinary Parasitology Flashcards

Question

Where is the predilection site of Strongylus vulgaris? a Renal vein b Cranial mesenteric artery c Coeliac artery d Thigh vein

Answer 1

b ## Footnote S. vulgaris is the most pathogenic nematode parasite of horses. It is known for extensive migration in the cranial mesenteric artery which can lead to life threatening intestinal infarctions.

Answer 2

a ## Footnote Hyalomma truncatum, also known as the shiny hyalomma or small smooth bont-legged tick, is a species of hard tick in the family Ixodidae. It is found in Africa. Sweating sickness is a tick-borne, toxic condition that affects the skin and visible mucous membranes of cattle. The cause is a toxin attracted to skin, which is secreted by females of certain strains of the tick Hyalomma truncatum.

Answer 3

c ## Footnote Bursa is a lobular modification of the male posterior end in some groups of nematodes which is highly elaborated in strongylid nematodes.

Answer 4

b ## Footnote Pentastonids parasitizes the respiratory tract of reptiles. Man can be infected by ingestion of lizards. Lizards are ingested in a belief that it can cure asthma.

Answer 5

b ## Footnote Basis capitulum is the base of the head of ticks onto which mouthparts are attached. Basis capitulum is the distinguishing part of Rhipicephalus as it is the only tick species with hexagonal-shaped capitulum.

Answer 6

a ## Footnote Fasciola hepatica is one of the most important flukes of domestic ruminants worldwide, causing liver fluke disease (liver rot, fascioliasis). Chronic liver fluke disease is more common in cattle and rarely fatal. Acute and subacute disease is more common in sheep and camelids and is often fatal. The lesion in the bile ducts is thought to be due, in part, to the secretion of large amounts of proline by the parasites.

Answer 7

a ## Footnote Knemidocoptes pilae commonly causes crusty legs and face in budgerigars

Answer 8

c ## Footnote Parafilaria multipapilosa is a nematode that infects horses. It causes the disease known as ""summer bleeding"" due to the pathognomonic clinical signs such bleeding and the skin nodules.

Answer 9

a ## Footnote Aelurostrongylus abstrusus is common in cats around the world. The cat appears to be the only definitive host; wild mice and other rodents, along with frogs, toads, snakes, lizards, and small birds, can serve as transport hosts. Crenosoma vulpis is a lung parasite of foxes. Ollulanus tricuspis nematodes are worms found in the gastric mucosa of the cat. Physaloptera praeputialis are pink worms found in the stomach of cat, usually with their anterior end attached to the mucosa. First-stage larvae are passed in the feces. The larvae are about 400 μm long, have “kinky” tail with a dorsal spine. Nematodes and eggs may cause chronic coughing, dyspnea, open-mouth breathing, sneezing, wheezing or no clinical signs.

Answer 10

a ## Footnote By description, the one saw in fecalysis is an egg of Trichuris spp (whipworms) which is actually related to the manifesting clinical sign which is intermittent bloody diarrhea. Among the choices, fenbendazole is the most recommended drug as it is a broad spectrum benzimidazole anthelmintic used against gastrointestinal parasites including whipworms.

Answer 11

b ## Footnote Coccidiosis is a protozoal disease causing diarrhea, weight loss, and decreased production in poultry. Diagnosis is by fecal flotation to detect oocysts, often in combination with characteristic necropsy findings. E tenella infections are found only in the ceca and can be recognized by accumulation of blood in the ceca. This is the most pathogenic among poulty Eimeria spp. E necatrix produces major lesions in the proximal and mid portions of the small intestine. They produce the characteristic “salt and pepper" lesion. E acervulina is the most common cause of infection. Lesions include numerous whitish, oval or transverse patches in the upper half of the small intestine, which may be easily distinguished on gross examination. E brunetti is found in the lower small intestine, rectum, ceca, and cloaca.

Answer 12

a ## Footnote Haematopinus eurysternus is known as the short-nosed cattle louse; H. asini is the horse-sucking louse; and H. suis is also known as the pig louse.

Answer 13

d ## Footnote Eucoleus aerophilus (with a direct life cycle) is transmitted through contaminated sputum and feces. Aelurostrongylus abstrusus have an indirect life cycle

Answer 14

a ## Footnote Toxoplasmosis is a disease caused by the single-celled parasite Toxoplasma gondii. Although cats are a necessary part of the life cycle of T. gondii, the parasite rarely causes clinical disease in them. Immunodeficient people and pregnant women were advised to avoid cats in the past; however, the CDC now advises that this is not necessary.

Answer 15

d ## Footnote Decoquinate, a 4-hydroxyquinoline, is a synthetic coccidiostat used for poultry and cattle as a feed additive against Eimeria species. This drug interfere with sporozoite development by inhibiting electron transport in protozoal mitochondria.

Answer 16

c ## Footnote Under Nitroimidazoles, (Ronidazole, carnidazole and metronidazole) are the most common drug against trichomonas gallinae.

Answer 17

b ## Footnote Mehli's gland, also known as Shell gland, is a component of the female reproductive system of Platyhelminthes and is mainly found surrounding the ootype. It plays a significant part in directing the eggs toward the channel that leads to the uterus of flat worms as a component of the female reproductive system. As a result, its secretion lubricates the uterine tube through which ovaries travel. It might have an impact on how eggshells form.

Answer 18

b ## Footnote Ascaridia spp. are one of the most common nematodes in birds. The location in the small intestine and the large size can be used to differentiate Ascaridia from Heterakis. Ascaridia galli is a nematode parasite occurring in all parts of the small intestine, while H. gallinarum is in the cecum. However, these different roundworms do have very similar egg and life cycles and are widely distributed in different parts of the world.

Answer 19

c ## Footnote Exposure to feces from infected cats can cause toxoplasmosis in people.

Answer 20

d ## Footnote Apart from humans, a number of mammals serve as reservoir hosts for T. cruzi, e.g. armadillos, opossums, raccoons, woodrats, some other rodents, and domestic dogs.

Answer 21

b ## Footnote McMaster is a fecal egg counting slide.

Answer 22

b ## Footnote Ostertagia ostertagi (brown stomach worm) is the most pathogenic and most costly of the cattle nematodes. Worms can readily be seen and identified in the abomasum, and small petechiae (blood spots) may be visible where the worms have been feeding. Heavy infections they tend to coalesce and give rise to a ""cobblestone"" or ""morocco leather"" appearance.

Answer 23

c ## Footnote Sparganosis is parasitic infection caused by the larva of the tapeworm in the genus Spirometra. Humans are the definitive host of the disease and can be infected by drinking water contamined with copepods which acts as the intermediate hosts.

Answer 24

a ## Footnote Neural toxin is paralytic agent secreted through the saliva of ticks that causes rapidly progressive motor paralysis or tick paralysis. Tick paralysis is a noninfectious and neurologic disease caused by several species of ticks.

Answer 25

a ## Footnote Mechanical vectors transmit diseases by transporting the causative agent from contaminated material (e.g. feces) on their feet or mouth parts and then spreading the pathogens or parasites onto food, drink, faces or eyes. Biological vectors may carry pathogens that can multiply within their bodies and be delivered to new hosts, usually by biting.

Answer 26

c ## Footnote There are 5 filarial stages of the D. immitis. Female worms release the microfilaria or the L1 which can be ingested by a vector (mosquito) during blood meal. L1 will mature within the vector until it reach the L2 and L3. Once it matured into L3 it will migrate to the probocis of the mosquito which can be transfer to another host as the mosquito feeding. L4 remains in the subcutaneous tissue and then the young adult or L5 will then migrate to pulmonary arteries.

Answer 27

b ## Footnote The small intestine (middle segment) is where E. maximum develops. It results in petechial bleeding, a reddish, orange, or pink sticky mucous exudate, and dilatation and thickening of the intestinal wall.

Answer 28

a ## Footnote The predilection site of S. lupi is the esophagus. Many dogs who have S. lupi infection doesn't typically have any clinical symptoms, but when it does, the most common symptoms are weight loss, coughing, and dyspnea. The dog may have trouble swallowing and may repeatedly vomit after trying to eat if the esophageal lesion is very large (which typically happens when it has developed into a neoplasm).

Answer 29

c ## Footnote This is a case of Trichomoniasis caused by Trichomonas gallinae and is extremely common in domestic pigeons. It causes necrotic ulcerations in the esophagus, crop, and proventriculus.

Answer 30

b ## Footnote Equine protozoal myeloencephalitis (EPM) is caused by CNS infection of equids with either of the apicomplexan protozoa Sarcocystis neurona or Neospora hughesi. Among the choices, the approved treatment of choice for EPM is ponazuril. Ponazuril is given by mouth in the form of a paste.

Answer 31

b ## Footnote P. gallinaceum is the most pathogenic species affecting chickens.

Answer 32

c ## Footnote Because of their bilateral genital pores, Dipylidium caninum is in often referred to as the ""double pored tapeworm."" Eggs accumulate within each proglottid until the proglottid becomes packed like a ripe seed pod. Gravid proglottids are creamy white, 10 to 12 mm in length and resemble cucumber seeds.

Answer 33

c ## Footnote A dog can develop sarcocystosis after eating undercooked beef or pork containing sporocysts or after eating food infected with sporocysts from another animal's feces. Infected dogs often have no signs, although a mild diarrhea may be seen.

Answer 34

b ## Footnote Oxyspirura mansoni is a species of roundworm which infects the chicken's eye. Thelazia is also an eyeworm but it infects mammals like dogs and ruminants. Ascaridia galli is a nematode present in the small intestine while Menopon gallinae is a louse and not a worm.

Answer 35

c ## Footnote Tegument is outer body covering of members of tapeworms and flukes which serves as protective cover and also serves secretory and absorbtive functions for nutrients.

Answer 36

c ## Footnote E. necatrix affects the entire small intestine characterized by hemorrhagic mucosa; E. maxima affects the middle to lower SI characterized by salmon pink exudate; E. brunetti occurs in the lower SI characterized by boody enteritis.

Answer 37

b ## Footnote Flea larvae that feed on undigested blood passed in the feces of the adult fleas and detritus (organic matter produced by the decomposition of organisms) in the environment are attracted to the egg balls of D. caninum that are passed in the feces of dogs and cats. Tapeworm larvae in the larval, pupal, and adult fleas do not become infective until adult fleas have been on the mammalian host for a couple of days.

Answer 38

b ## Footnote Ancylostoma braziliense causes only mild digestive disturbance and diarrhea in affected animals, but is regarded as the main cause of cutaneous larva migrans in humans. Bayliascaris procyonis mainly affects racoons and skunks, but a range of animals including small mammals, poultry, and rabbits serve as intermediate hosts and may be affected by visceral larval migration where the nervous system is invaded by the parasite. Toxocara canis mainly parasitizes the small intestines of dogs and foxes, and is also the most widely recognised form of VLM in humans. Kalicephalus spp. affects the small intestines of snakes, but may undergo VLM and cause respiratory problems.

Answer 39

a ## Footnote Male horse flies (Tabanus, Chrysops, Haematopota spp.) do not have the paired mandibles, hence cannot feed on blood. They feed on honeydew or nectars instead.

Answer 40

a ## Footnote Notoedric mange, also referred to as Feline scabies, is a highly contagious skin infestation caused by an ectoparasitic and skin burrowing mite Notoedres cati. The disease is characterized by severe itching and a crusty appearance of the skin, particularly around the head, ears, and neck.

Answer 41

c ## Footnote The eggs of other choices are unembryonated when laid and passed out in fresh feces.

Answer 42

d ## Footnote Quinine is used for the treatment of malaria in humans and is associated with a triad of dose-related toxicities when given at full therapeutic or excessive doses, e.g. hypoglycemia, cinchonism, and hypotension. It may also cause blindness due to retinopathy. All the other choices are generally well-tolerated.

Answer 43

b ## Footnote Hydatid cyst is a parasitic feature of the larval stage of Echinococcus. Hydatid cyst are commonly found in the liver and lungs, it may also occur in other organs like bones and muscle.

Answer 44

c ## Footnote Gilt Only Scheme is one of the identified measures to control Stephanurus dentatus. The infection has long long prepatent period and this scheme prevents infection from developing. Older boars are replaced with young boars from clean herds, and only gilts are bred and then sold after weaning.

Answer 45

d ## Footnote People can be infected by accidental ingestion of oocysts after cleaning a cat's litter box when the cat has shed Toxoplasma in its feces. Leishmaniasis can be transmitted to humans and animals by the bite of phlebotomine sand flies. Histomoniasis is caused by the protozoa Histomonas meleagridis (HM) that are laterally transmitted among birds leading to high mortality in commercial flocks. This is not zoonotic. Anaplasmosis is a bacterial disease transmitted to humans by Ixodes scapularis (blacklegged tick or deer tick).

Answer 46

a ## Footnote A holometabolous insect that has a four-stage life cycle that includes eggs, larvae, pupae, and adults. They are wingless, dark brown in color, and feature piercing-sucking mouthparts that help them feast on the blood of their hosts. The adult flea lacks genal and pronotal combs and has a rounded head.

Answer 47

c ## Footnote Puppies born to mothers with patent infections of the heartworm Dirofilaria immitis will often have circulating microfilariae in their blood at birth. It is one of the top transplacental parasitic Infections in dogs.

Answer 48

a ## Footnote Ostertagia ostertagi (brown stomach worm) is the most pathogenic and most costly of the cattle nematodes. Worms can readily be seen and identified in the abomasum, and small petechiae (blood spots) may be visible where the worms have been feeding. Heavy infections they tend to coalesce and give rise to a ""cobblestone"" or ""morocco leather"" appearance.

Answer 49

b ## Footnote M. benedeni primarily affects cattle. The egg of this parasite is characteristically quadrangular in apperance.

Answer 50

c ## Footnote Babesia is an apicomplexan parasite that infects red blood cells and is transmitted by ticks.

Answer 51

b ## Footnote The parasite being described is Hemoproteus columbae. It is a major protozoan infection reported in pigeons and appeared in the erythrocyte of the peripheral circulation. H. columbae is a species of blood parasite related to Plasmodium and other malaria parasites.

Answer 52

a ## Footnote Pediculus spp. is an example of a sucking louse or Anoplura. Anoplura is only present in mammalian hosts so this is not present in chickens.

Answer 53

b ## Footnote Trypanosoma equinum affects horses and causes an infectious disease marked by fast emaciation, anemia, blood-colored urine, paresis, and edema. This disease is called Mal de Caderas or Derrengadera

Answer 54

b ## Footnote Culicoides Hypersensitivity, also known as Sweet Itch, is a condition caused by an allergic reaction to the saliva of Culicoides species known as "No See Ums." Horses with this hypersensitivity are extremely pruritic or itchy. They will rub their manes, ears, faces, and tails to the point of self-mutilation.

Answer 55

a ## Footnote Infestations typically begin in the area around the ears before spreading to the lower body. The inside of the legs, the neck, the skin folds, and the ears are among the predilection sites

Answer 56

b ## Footnote Leishmania adleri is a lizard parasite.

Answer 57

b ## Footnote A significant number of hookworms can cause inflammation in the dog's intestine, as well as a life-threatening decrease of red blood cells (anemia). Anemia is most common in puppies but can occur in adult dogs.

Answer 58

d ## Footnote Acanthocheilonema (formerly Dipetalonema) reconditum is a non-pathogenic nematode that lives in the body cavity and subcutaneous tissues of dogs. Its importance lies in the fact that its imicrofilariae can be easily confused with those of Dirofilaria immitis (heartworm). Among the choices, flea is the most commonly reported vector although lice were also considered.

Answer 59

b ## Footnote Adult hookworms can be identified based on their teeth. Their buccal capsule contain either three pairs of teeth (A. caninum), two pairs of teeth (A. braziliense), or cutting plates (U. stenocephala).

Answer 60

c ## Footnote Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors and is found only in the Americas. Chagas disease is also referred to as American trypanosomiasis. The insect vectors are called triatomine bugs. These blood-sucking bugs get infected with T. cruzi by biting an infected animal or person. Because they tend to bite people’s faces, triatomine bugs are also known as “kissing bugs”. After they bite and ingest blood, they defecate (poop) on the person. The person can become infected if T. cruzi parasites in the bug feces enter the body through mucous membranes or breaks in the skin. The unsuspecting, sleeping person may accidentally scratch or rub the feces into the bite wound, eyes, or mouth. Inside the host, the trypomastigotes invade cells near the site of inoculation, where they differentiate into intracellular amastigotes . The amastigotes multiply by binary fission and differentiate into trypomastigotes, and then are released into the circulation as bloodstream trypomastigotes

Answer 61

a ## Footnote Sarcoptes is a burrowing mite.

Answer 62

b ## Footnote Cryptobia iubilans is a flagellate that can be dangerous and can cause frequent fish deaths in the aquarium due to the said clinical signs. Cryptobia iubilans, an endoparasite that lives in the intestines and causes granulomatous inflammation of the abdominal organs, resulting in weight loss and death. Cryptobia salmositica, C. borreli, and C. bullocki, blood parasites that lead to anaemia and lesions in the haematopoietic tissues.

Answer 63

b ## Footnote Acanthocephala (also known as spiny- or thorny-headed worms) are common parasites of wildlife and some domestic animal species, but they rarely infect humans. Natural definitive hosts include rats (Moniliformis moniliformis), swine (Macracanthorynchus hirudinaceus), and raccoons (Macracanthorynchus ingens). The insect intermediate host varies by species but is usually beetles for M. hirudinaceus and M. ingens. In can be beetles or cockroaches for M. moniliformis.

Answer 64

d ## Footnote Otobius megnini ( Spinose Ear Tick) affects cattle, sheep, goat, horse, deer, wild ruminants, dogs, and humans. The ear tick species affecting rabbits and hares is O. lagophilus.

Answer 65

b ## Footnote Tetrahymena spp. is a cilliated protozoa that causes Guppy killer disease as it commonly affects the guppies, although other tropical aquarium fish can be affected as well. It is usually a commensal of the fish, only becoming a pathogen when there is a build up of bacteria in the water. The lesions are similar to those of the white spot disease caused by Ichthyophthirius multifiliis.

Answer 66

b ## Footnote Macracanthorhynchus hirudinaceus has an indirect life cycle that requires scarabaeoid or hydrophilid beetle larvae as intermediate hosts. Dogs infected with M. hirudinaceus shed eggs in their feces, which contain the larval (acanthor) stage. Dung beetle is the only intermediate host of this specific parasite

Answer 67

c ## Footnote Only menthol crystal can be used safely without affecting the honey bee colonies and it is also registered as a pesticide for tracheal mite control in honey bees.

Answer 68

b ## Footnote Stephanurus dentatus is also known as kidney worm of swine. Pigs can be infected by ingestion of the larvae but earthworm can serve as transport host. Earthworms can also ingest the larva and once the pig ingests the earthworm it will also be infected.

Answer 69

c ## Footnote Platynosomum fastosum is a trematode that infects the biliary ducts and gallbladder of cats. Intermediate hosts include lizards, marine toads, and various arthropods. Lizard is an intermediate host and not a final host.

Answer 70

b ## Footnote The most readily recognized protozoan fish parasite is Ichthyophthirius multifiliis, commonly referred to as ""Ich"" or ""white spot disease"". It causes multiple small raised, white lesions that develop as a result of the parasite residing in the skin, fins and gill tissue of the host. It can be identified by the presence of a relatively large horseshoe-shaped macronucleus.

Answer 71

b ## Footnote Lice are divided into two general categories: Anoplura or known as the blood sucking/sucking lice; and the Mallophaga or the chewing/biting lice.

Answer 72

b ## Footnote All of the other choices are medications used for external parasites. Only ivermectin can be used to control internal parasites such as pulmonary acariasis.

Answer 73

a ## Footnote Arista is the last segment of the antenna in the Sub Order Cyclorrapha.

Answer 74

b ## Footnote A typical and widespread protozoal disease affecting rabbits is coccidiosis. Carriers are often recovering rabbits. There are two anatomic forms: the hepatic form, which is caused by Eimeria stiedae, and the intestinal form, which is caused by E. magna, E. irresidua, E. media, E. perforans, E. flavescens, E. intestinalis, or other Eimeria spp.

Answer 75

b ## Footnote Males of roundworms usually possess cuticular copulatory organs (spicules) that are inserted in the female's vulva to attach the male to the female and to widen the vulva against the inner body pressure for sperm transfer. The male of Trichinella species do not have a spicule and the tail terminates with two lateral lobes that give it a characteristic appearance

Answer 76

b ## Footnote Surra is a disease caused by protozoan Trypanosoma evansi which infects the blood of the vertebrate host, causing fever, weakness, and lethargy which lead to weight loss and anemia. It is transmitted mechanically by hematophagous biting flies of the species Tabanus and Stomoxys. Surra is most severe and most frequently diagnosed in horses and camels. It may also affect cattle, buffalo, llamas, dogs, cats, sheep, goats, pigs, and elephants.

Answer 77

c ## Footnote Only Prosthenorchis (Acanthocephalan) and Bertiella (Tapeworm) affects monkey in the choices given. Prosthenorchis spp. infestation is influenced by diet with an increased risk of exposure from ingesting invertebrate intermediate hosts.

Answer 78

c ## Footnote Ophionyssus natricis is a snake mite that feeds on blood of its host. Heavy infestation, when left untreated, causes anemia and death. Bacterial or viral infection may also occur secondarily.

Answer 79

d ## Footnote Among the following choices, only Trichomonas gallinae produces yellow button lesions on the crop surface.

Answer 80

d ## Footnote Salmon poisoning disease (SPD), a lethal condition that affects dogs, is brought on by the obligate intracellular endosymbiotic bacterium Neorickettsia helminthoeca, which is carried by the trematode Nanophyetus salmincola.

Answer 81

c ## Footnote Ancylostoma spp. and other hookworms typically occur in the small intestine of their definitive host.

Answer 82

c ## Footnote Arthropods are invertebrates with jointed legs. The main arthropod assemblages include crustaceans (crabs, lobsters, crayfish, shrimp), arachnids (spiders, scorpions, ticks, mites) and insects (beetles, bugs, earwigs, ants, bees, termites, butterflies, moths, crickets, roaches, fleas, flies, mosquitoes, lice). Lungworms are nematodes. Anchor worms are technically not a worm at all but a Lernaea species, a type of copepod crustacean of the arthropod family

Answer 83

d ## Footnote Dicrocelium dendriticum has two intermediate hosts in its life cycle, namely the land snail, and ant (Formica sp.). The land snail ingests the embryonated egg, which later on forms into sporocyts, and further into cercaria. The land snail shed a mass of mucus, known as slime ball, which contains the cercaria. The ants then ingests the slime ball.

Answer 84

a ## Footnote As the fly moves onto its next feeding station, it will rid itself of excess water in its crop by a process known as “bubbling” or regurgitating the water out. This is commonly known as fly vomit or vomit drops. When a fly’s feeling hungry, it will land on its food and vomit out a mix of saliva and stomach acids. These liquids have digestive proteins that help to break down the food before it even enters the fly’s mouth, turning a solid meal into a soup. Like using a straw, the fly uses its long-sucking mouthpart to slurp up its liquefied meal. Their mouthparts even have sponges at the end so they fly can suck up every last drop.

Answer 85

a ## Footnote This mite's larvae can cause redness and itching on the cat's skin. The adults reside in the soil and leaf litter; only the larvae form are parasitic.

Answer 86

b ## Footnote Trichomonas gallinae thrives in moist environments leading to infection due to contaminated waterer in pigeons.

Answer 87

b ## Footnote Among the pairing, only the Haemonchus and Bunostomun are more likely can be seen by the naked eye.

Answer 88

a ## Footnote Coenurosis is caused by Coenurus cerebralis, the larval stage of Taenia multiceps. Its life cycle includes a canid as the definitive host and the sheep as the natural intermediate host.

Answer 89

d ## Footnote Icthyophthirius multifiliis- causes white spot disese or"ich" in freshwater fish; Cryptocaryon irritans causes ich in marine fish; Brooklynella hostilis causes subcutaneous and respiratory problems in groupers.

Answer 90

c ## Footnote Libyostrongylus douglassi, also known as ostrich wireworm, is the most significant GI parasite of ostriches economically. The crypts of the glandular section of the stomach are home to adult worms and late larval stages causing severe lesions and high mortalities in young ostriches.

Answer 91

a ## Footnote Dirofilaria is normally transmitted by mosquitoes.

Answer 92

b ## Footnote Ancylostoma caninum infections can be acquired by vertical (transmammary) transmission, percutaneous invasion, or ingestion of infective third-stage larvae or paratenic hosts. In mature dogs with some acquired immunity, infective larvae may not develop directly into adults, but rather migrate to somatic tissues such as kidney and skeletal muscle, where they undergo prolonged arrested development. These arrested larvae are most commonly reactivated by the hormones of pregnancy and lactation, and larvae are transmitted to suckling pups in the bitch’s milk.

Answer 93

c ## Footnote A dry cough, shortness of breath, tiredness, sluggishness, and lack of stamina are the most noticeable clinical symptoms of D. immitis infection. All of these symptoms are most obvious after exercise, when some dogs may even pass out or become confused. When listening to the chest using a stethoscope, you might hear unusual heart and lung sounds.

Answer 94

a ## Footnote Fluke eggs do not float; sedimentation is applicable for fluke egg recovery.

Answer 95

d ## Footnote Adults of Macracanthorhynchus hirudinaceus are large pseudocoelomates that vary in color from milky-white to pinkish to reddish. The body typically has a wrinkled appearance, giving the illusion of segmentation (pseudosegmentation). Adult females measure 18–65 cm long by 4–10 mm wide; adult males measure 5–10 cm long by 3–5 mm wide.

Answer 96

b ## Footnote Fischoederius spp are amphistomes present in the rumen.

Answer 97

d ## Footnote Rhipicephalus sanguineus is a three-host tick, all hosts being dogs, with each stage of the tick life cycle coming off the canine host to moult in the environment. The entire life-cycle can be completed in as little as 2 months but normally takes longer (4-5 months) if ticks of all stages are not able to find an appropriate host

Answer 98

a ## Footnote Taenia saginata lesions are found in different muscles of cattle, including the heart, tongue, masseter, and intercostal muscles. In humans, the small intestine is affected. Taenia multiceps, the cause of gid in sheep, affects the CNS of its intermediate hosts through the cyst form, Coenurus cerebralis. Bayliascaris procyonis signs in its hosts may resemble that of rabies as it damages the CNS. Parelaphosytongylus tenuis, also known as cerebrospinal nematodosis, meningeal worm, or moose disease, is a parasite of the veins and venous sinuses of cranial meninges, as well as the CNS.

Answer 99

d ## Footnote The eyeworm of birds, Oxyspirura, is acquired by ingestion of an infected cockroach.

Answer 100

d ## Footnote Macracanthorhynchus hirudinaceus is an intestinal, acanthocephalan parasite also known as the “Giant Thorny-Headed Worm of Swine,” as its primary definitive host is swine. The intermediate host for is usually a scarabaeoid or hydrophilid beetle. In pigs, the prepatent period is 8–12 weeks, and the incubation period takes only 10 days; then the following symptoms of the disease may be seen: enteritis, peritonitis, diarrhea, malnutrition, and abdominal pain.

Answer 101

c ## Footnote Eimeria necatrix and Eimeria tenella are the most pathogenic in chickens, because schizogony occurs in the lamina propria and crypts of Lieberkühn of the small intestine and ceca, respectively, and causes extensive hemorrhage

Answer 102

d ## Footnote The lesions described are those of Chabertia ovina, affecting the large intestine of sheep and goat, and occasionally cattle. The presence of a large bell-shaped buccal capsule makes it distinct. The prepatent period is around 6-7 weeks.

Answer 103

a ## Footnote Thysanosoma actinioides, also known as the fringed tapeworm, is a worm infecting the bile ducts, pancreatic ducts, and small intestines of sheep and goats.

Answer 104

b ## Footnote At the larval stage, fleas feed on organic debris from the environment. This is the stage where they may ingest Dipylidium caninum eggs from the environment. The egg and pupal stages do not feed. Adults feed on blood. Learn more about fleas and their life cycle here: https://www.youtube.com/watch?v=va-ce4iDup8

Answer 105

d ## Footnote The major branches of the cranial mesenteric artery can be damaged by the migrating forms of Strongylus vulgaris.

Answer 106

c ## Footnote The infective stage of T. vulpis is the egg-containing first-stage larva (L1).

Answer 107

b ## Footnote Dermanyssus gallinae (the common red mite) maintains the majority of the population in the environment so it is important to monitor and treat the environment including the cracks and crevices where mites tend to reside. Ornithonyssus sylviarum mites (northern fowl mites) spend their entire life cycle on the bird. This allows them to multiply more rapidly and makes it essential to treat the birds themselves to control the problem.

Answer 108

b ## Footnote Furcocercous cercariae are characterized by having a forked tail. Schistosoma japonicum has a Furcocercous-type of cercaria.

Answer 109

a ## Footnote T. saginata is commonly known as the "beef tapeworm". Human serves as the final host and cattle is the intermediate host. Human infection can be due to the consumption of raw or undercooked beef.

Answer 110

b ## Footnote Psoroptes is one of the mange mites that affects ruminants and camelids including llamas.

Answer 111

c ## Footnote Anoplocephala sp. is cestode which needs oribatid mites as intermediate hosts. It is found in grasses or forages, thus making it impossible to control.

Answer 112

b ## Footnote Lyme disease is cause by Borrelia burgdorferi which is transmitted by Ixodes scapularis.

Answer 113

d ## Footnote Babesia spp. is naturally spread by ticks, though it can also happen mechanically. The principal vector for B. caballi, which can be transmitted transovariously through tick generations, is Dermacentor nitens, a tick that has been firmly established in regions where the temperature consistently rises beyond 16°C (60°F).

Answer 114

c ## Footnote Pilobolus is a type of fungi in which the L3 larvae of Dictyocaulus attaches to its sporangia. Upon their consumption by the suitable host, the larvae move from the digestive tract to infect the respiratory tract of the animal.

Answer 115

c ## Footnote The bird's esophagus serves as the predeliction site for this worm, where it buries its anterior end and causes inflammation. High concentrations can be deadly and cause a noticeable thickening of the esophageal wall.

Answer 116

a ## Footnote Iodine is readily available and can provide good contrast.

Answer 117

d ## Footnote The Spirurida are a group of nematodes that use an IH (usually an arthropod) and live in the upper digestive system, primarily in the stomach.

Answer 118

d ## Footnote Hepatozoon canis is acquired when the vector tick is ingested by the dog.

Answer 119

c ## Footnote Corridor fever, East Coast fever, or Theileriosis, is caused by Theileria parva affecting cattle and buffalo. The hosts are infected when the intermediate host, Rhipicephalus appendiculaus., sucks their blood.

Answer 120

d ## Footnote Three types of arthropods can affect ratites: lice, ticks, and quill mites. Lice can be a problem, especially in ostriches. Biting lice (Struthioliperurus struthionis) cause skin and feather damage. Treatment with permethrin spray (poultry concentration) is effective.

Answer 121

c ## Footnote Wet feather is a condition that occurs when a duck's feathers become water-logged, and lose their ability to repel water. Loss of waterproofing on their feathers also affects a duck's ability to float The Amblycera is a large clade of chewing lice. Holomenopon leucoxanthum causes "wet feathers" of ducks.

Answer 122

b ## Footnote Pearsonema plica (Capillaria plica) is a nematode commonly seen in urinary bladder and kidneys of dogs, foxes and other mammals. Animals can be infected by ingestion of earthworm containing first-stage larvae.

Answer 123

d ## Footnote A.perfoliata and A. magna can be diffentiated through the lappets, predilection site and size. A. perfoliata has four ear-shaped lappets while A. magna has none and is usually larger in size. The ileocecal valve of horses is the predilection site of A. perfoliata while small intestines of the horse’s digestive tract for A. magna.

Answer 124

b ## Footnote The stomach hair worm, Trichostrongylus axei, is a trichostrongylid parasite that affects a wide range of hosts, including sheep, goats, cattle, and horses. The third stage larva, which is the infectious stage, is comparable to the cyathostomin life cycle. The larvae enter the stomach, pass through the mucosa, grow into adult worms, and then come out into the gastric lumen.

Answer 125

d ## Footnote Strongyloides eggs can be recognized using fecal flotation or fecal egg counts. They resemble ovoid strongyle eggs but are shorter and have thinner walls. They frequently have larvae inside.

Answer 126

a ## Footnote Simulium (black fly) is a genus of insect that prefers fast-running (highly oxygenated) waters. Running water is required for their egg deposition and larval/pupal development.

Answer 127

a ## Footnote The eyes, comb, and wattle of hens are prime targets for Echidnophaga spp. since they lack hair and fur in those places.

Answer 128

c ## Footnote A metacestode is the larval stage of a tapeworm, found in an intermediate host. In pseudotapeworms, the first metacestode is called procercoid. The second metacestode is plerocercoid.

Answer 129

d ## Footnote Quinapyramine dimethylsulfate can be used for prophylaxis only.

Answer 130

b ## Footnote One of the honey bees' most devastating enemies is the Varroa mite. The brood cells of bee hives are where adult female varroa mites lay their eggs. The mites feed on bee larvae and pupae, which causes the bees' wings and bodies to become deformed when they grow up and become adults. They consume adult bees as well.

Answer 131

a ## Footnote FAMACHA (FAffa MAlan CHArt) is a selective treatment method for controlling the level of parasitic barber's pole worm (Haemonchus contortus, also known as twisted wireworm) among domesticated small ruminant populations.

Answer 132

a ## Footnote The wirewormLibostrongylus douglassii is the most economically important GI parasite of ostriches. Mature worms and late larval stages live in the crypts of the glandular portion of the stomach. Diagnosis is based on finding trichostrongyloid-type eggs in the feces. The recommended treatment for the ostrich wireworm is administration of ivermectin at 0.2 mg/kg or fenbendazole at 15 mg/kg.

Answer 133

a ## Footnote The large roundworm of pigs (Ascaris suum) is the most common and widespread parasite of swine. Larval migration through the liver results in focal hepatitis (milk spots) and condemnation of the liver at slaughter but no clinical signs.

Answer 134

b ## Footnote Unlike other flukes, the infective stage of Schistosoma spp is only at the level of cercaria. In the entire lifecycle, it lacks redia and metacercariae.

Answer 135

a ## Footnote A unique test called a fecal Baermann can identify specific parasite species. Some parasites, however, secrete free larvae rather than eggs in the stool. A special procedure known as a ""fecal Baermann"" is required to diagnose infection because these larvae cannot be found using standard fecal flotation.

Answer 136

d ## Footnote Dermacentor andersoni, or also known as the Rocky Mountain Wood tick is said to transmit Rocky mountain spotted fever, Colorado tick fever, and Tularemia.

Answer 137

b ## Footnote Species of the family Prosthogonimidae are considered the most pathogenic poultry trematodes worldwide, affecting particularly low intensity farming in rural areas. Adults of Prosthogonimus occur mainly in the bursa of Fabricius, oviduct and cloaca of ducks, geese, fowl and other birds feeding at least occasionally on dragonflies .

Answer 138

b ## Footnote Histomonas meleagridis infects a wide range of gallinaceous birds and causes histomoniasis (blackhead disease). H meleagridis is primarily transmitted in the egg of the cecal nematode, Heterakis gallinarum. Chickens and other gallinaceous birds act as a reservoir for H. gallinarum. Chickens are typically asymptomatic carriers, but mortality in turkeys is commonly 80%-100%.

Answer 139

b ## Footnote In the majority of European nations, fenbendazole (50 mg/kg per day, for 3–10 days) is approved for the treatment of dogs, and it may also be suggested for cats. It is suitable for pregnant and nursing animals and is said to halt the shedding of Giardia cysts in dogs. There have been no known adverse effects. As a result, fenbendazole is regarded as the first line of treatment; nevertheless, should clinical indications persist, metronidazole may also be considered, either by itself or in combination with fenbendazole.

Answer 140

b ## Footnote Equine aural plaques, also known as papillary acanthoma or ear papillomas, are caused by papillomavirus. Black flies (Simulium spp) are likely the mechanical vector. The flies are active at dawn and dusk when they attack the head, ears, and ventral abdomen of horses. Dourine is a chronic or acute contagious disease of equids that is primarily transmitted directly from animal to animal during coitus. Fasciolosis is caused by Fasciola hepatica, requires a snail intermediate host, and can be transmitted through ingestion of metacercaria. Equine Piroplasmosis is a blood-borne protozoal infection of horses caused by Theileria (Babesia) equi and/or Babesia caballi. The protozoa are transmitted by ticks.

Answer 141

b ## Footnote A gapeworm (Syngamus trachea), also known as a red worm and forked worm, is a parasitic nematode worm that infects the tracheas of certain birds. The resulting disease, known as ""gape"" occurs when the worms clog and obstruct the airway.

Answer 142

b ## Footnote Trichomonas tenax is a flagellated protozoan parasite found in the oral cavities of humans and animals and has been associated with periodontal disease.

Answer 143

c ## Footnote Pneumonyssus simicola, the monkey lung mite is the most common arachnid mite of primates, infesting the lungs.

Answer 144

d ## Footnote Toxoplasmosis is a disease that results from infection with the Toxoplasma gondii parasite, one of the world's most common parasites. Infection usually occurs by eating undercooked contaminated meat, exposure from infected cat feces, or mother-to-child transmission during pregnancy.

Answer 145

b ## Footnote Triangular eggs are distinct characteristics of the Moniezia expansa eggs which are approximately 55 x 65 micrometers. It can infect sheep and goat. Quadrangular eggs are eggs of Moniezia benedini and ellipsoidal eggs are usually fluke eggs.

Answer 146

c ## Footnote From the name itself, Eimeria aurati is a parasite of goldfish. (Au means gold).

Answer 147

b ## Footnote Haematobia irritans takes advantage of the opportunity to lay eggs while the dung is still at body temperature. The temperature is essential for further development of the eggs of H. irritans.

Answer 148

a ## Footnote Syngamus trachea (gapeworm) can cause considerable losses in pheasants and turkeys. Gasping for breath or 'gaping' as it is known is the biggest sign of gapeworm. 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. Stephanurus dentatus (swine kidney worm) is a nematode that parasitizes the urinary tract of domestic and wild pigs, especially in tropical areas. Ancylostoma caninum is a species of nematode known as a hookworm, which principally infects the small intestine of dogs.

Answer 149

a ## Footnote The bigger size of this worm's eggs can also help to distinguish them from Ancylostoma's. When present in mixed infections, the eggs of U. stenocephala are notably simple to distinguish from the eggs of Ancylostoma because they are roughly 70 to 90 um length by 40 to 50 um wide.

Answer 150

a ## Footnote The morphology of these host-specific, blood-sucking insects is designed for living on mammals: they lack wings, are dorso-ventrally flattened, have tibio-tarsal claws for attaching to host hair, and have feeding mouthparts that pierce the host's skin.

Answer 151

b ## Footnote Muscomorpha and in most lower Diptera with vestigial maxillae and mandibles, the hypopharynx closes ventrally to the lumen of the food canal.

Answer 152

a ## Footnote Acanthor is the first larva of Acanthocephala

Answer 153

c ## Footnote Babesia, Theileria and Cytauxzoon are all tick-transmitted.

Answer 154

b ## Footnote Syngamy, or sexual fusion, is a permanent form of sexual reproduction whereby two protozoan cells fuse together to create a fertilized cell, also known as a zygote. More specifically, the nuclei of both parent cells fuse together to form the zygote, which grows into an adult through one of many types of fission. Schizogony is an asexual type of reproductive process by protozoans by multiple fission. In protozoa, a trophozoite increases in cell size while the nucleus, together with other organelles, divides repeatedly. The organism in that condition is referred to as schizont. Endopylogeny is a form of internal budding resembling schizogony, except that daughter cells (endozoites) form new organelle sets within their own plasma membranes anywhere in the cytoplasm of the parent cell (as opposed to at the periphery, as in schizogony). Binary fission is an asexual mode of reproduction in which a cell splits into two daughter cells.

Answer 155

a ## Footnote Carnivores are the final host and rabbits serve as intermeddiate host of Taenia pisiformis. Taenia saginata is commonly known as the beef tapeworm and Taenia solium is porktapeworm which both of can infect human.

Answer 156

b ## Footnote Lucilia cuprina is a primary facultative myiasis fly.

Answer 157

d ## Footnote Metagonimus yokogawai is a minute intestinal fluke and considered as the smallest human fluke. The diagnosis is based on the microscopic identification of eggs in the stool. However, the eggs are indistinguishable from those of Heterophyes heterophyes and resemble those of Clonorchis and Opisthorchis. Microscpically, the ceca is described to be simple.

Answer 158

a ## Footnote Hypoderma lineatum migrates to the submucosal connective tissue of the esophageal wall; Gasterophilus pecorum occurs in the GIT and mainly affects horses.

Answer 159

b ## Footnote Mosquitoes use their labella that act as sensory probes to find the most suitable area to feed on, which is usually that of closest to capillaries.

Answer 160

c ## Footnote Eurytrema pancreaticum is one of the most common flukes, which mainly infects ruminants. Snails act as the first intermediate host and grasshoppers the second intermediate hosts.

Answer 161

d ## Footnote Trichomoniasis is a venereal disease of cattle characterized primarily by early fetal death and infertility, resulting in extended calving intervals. Bulls of all ages can remain infected indefinitely, but this is less likely in younger males. By contrast, most cows are free of infection within 3 months after breeding. However, immunity is not longlasting and reinfection does occur.

Answer 162

c ## Footnote Hyostrongylus rubidus is the red stomach worm of pig. It is approximately 6 mm long, red in color and quite slender.

Answer 163

c ## Footnote Pathogenic Entamoeba species must be differentiated from other intestinal protozoa such as the nonpathogenic amebae (Entamoeba coli, E. hartmanni, E. gingivalis, Endolimax nana, Iodamoeba buetschlii). Mature Entamoeba histolytica cysts have 4 nuclei that characteristically have centrally-located karyosomes and fine, uniformly distributed peripheral chromatin.

Answer 164

a ## Footnote Cattle grubs (Hypoderma lineatum and Hypoderma bovis) are obligate parasites that cause myiasis in cattle in the Northern Hemisphere. Larval stages, migrating within the host body and in subdermal warbles, cause marked economic losses and increased susceptibility to other diseases. Xenopsylla cheopis, the Oriental rat flea, also known as the tropical rat flea or the rat flea, is a parasite of rodents, primarily of the genus Rattus, and is a primary vector for bubonic plague and murine typhus. Cordylobia anthropophaga, the mango fly, tumbu fly, tumba fly, putzi fly, or skin maggot fly, is a species of blow-fly common in East and Central Africa. The parasite produces a painful boil-like (furuncular) swelling in the skin in both man and animals. Dermatobia hominis is the primary human bot fly.

Answer 165

b ## Footnote Cymothoa exigua is also known as the fish tongue-eating louse.

Answer 166

a ## Footnote Cyathostomes or small strongyles are intestinal parasites of horses and donkeys. The parasitic larvae develop intraluminally in the mucosa of cecum and colon, and no migration occurs. The L3 may further develop into L4 without interruption, or may undergo hypobiosis in the mucosa where development into L4 proceeds only after a period of dormancy. When the L4 emerges from the intestinal wall, they feed on the mucosa superficially and may rupture capillaries.

Answer 167

b ## Footnote Fecal sedimentation is a procedure used to recover eggs of trematodes, which normally do not float in standard flotation technique. Among the choices, the only trematode is the Fasciola hepatica.

Answer 168

b ## Footnote Ticks in reptiles are frequently hidden in areas with the thinnest scaling because these areas are least likely to be nibbled or brushed off. These areas include the area behind the legs and the area close to the eyes, nostrils, and vent. The belly is rubbed at the floor so it is least likely to locate ticks at that region.

Answer 169

c ## Footnote The esophagus is a muscular organ that pumps food into the intestines. It can be used for identification of roundworms. The common types are filarial, double-bulb, trichuroid, bulb and rhabditiform. For ascarid esophagus are bulb type which can be described as simple and slightly thickened posterior.

Answer 170

c ## Footnote Capillaria species usually have direct lifecycle except for C. hepatica. The life cycle of C. hepatica may be completed in a single host species. However, the eggs, which are laid in the liver, must mature outside of the host body (in the environment) prior to infecting a new host. The death of the host in which the adults reach sexual maturity, either by being eaten or dying and decomposing, is necessary for completion of the life cycle.

Answer 171

c ## Footnote Scaly face mites also known as Budgie mites typically affects bugerigars and canaries. Symptoms include crusty thickening of the skin on the cere and on and surrounding the beak. This crustiness also can be around the vent and on the legs and feet. Budgie mites can be detected through microscopic examination of the crusted material.

Answer 172

d ## Footnote Sarcoptic mange occurs in all age groups but is inapparent in neonatal pigs until signs and lesions have had time to develop. The mite Sarcoptes scabiei var suis causes most mange in swine. Scrapings from the inner surface of the ear usually reveal more mites than do other sites. Scrapings are usually wetted with 10% potassium hydroxide, cover-slipped, and examined under a microscope using a low-power objective

Answer 173

d ## Footnote Acute parasitic bronchitis is caused by the nematode, Dictyocaulus viviparus. Common treatment used against it are imidothiazoles (ivermectin), benzimidazoles (fenbendazole), and imidathiazole (levamisole). The action of praziquantel is limited only to cestodes and trematodes.

Answer 174

c ## Footnote All of the following symptoms described is called Caval syndrome (Class IV) There are four stages to heartworm disease. Stage 1 — This is when a dog is infected but does not yet show symptoms. The heartworms are present in the heart even if there are no detectable antigens. Stage 2 — In stage 2, a dog will start to have less exercise tolerance and be more lethargic. A dog may also develop a dry cough. Heartworms are usually producing microfilariae to create more heartworms. Stage 3 — In this stage, you can detect definite signs of adult heartworms in the heart and vessels. They are like long strands of spaghetti growing in the heart. A dog will become increasingly lethargic and start coughing more with the possibility of coughing up blood. Stage 4 — In the most advanced stage, the heart and lungs will show significant damage. The liver will also be enlarged. Dogs at this stage are very ill and are at risk of death.

Answer 175

b ## Footnote Davainea proglottina, also called the minute tapeworm or the small chicken tapeworm, is a parasitic worm that has chicken, turkey, guineafowl, grouse, other domestic and wild gallinaceous birds but also pigeons as final hosts. Terrestrial slugs and snails act as intermediate hosts. Fasciola is a fluke and not a tapeworm.

Answer 176

d ## Footnote Size is the major difference between the two Fasciola spp. However, all of the choices can be used to differentiate the two.

Answer 177

a ## Footnote Acanthocephala or the spiny- or thorny-headed worms are common parasites of wildlife and some domestic animal species. The most common is the Macracanthorynchus hirudinaceus. In the definitive host, juvenile acanthocephalans attach to the wall of the small intestine, where they mature.

Answer 178

a ## Footnote Cutaneous habronemiasis is a skin disease of horses caused in part by the larvae of the spirurid stomach worms in the genera Draschia and Habronema. When the larvae emerge from flies feeding on preexisting wounds or on the moisture of the genitalia or eyes, they migrate into and irritate the tissue, which causes a granulomatous reaction. The lesion becomes chronic, and healing is protracted. Diagnosis is based on finding nonhealing, reddish brown, greasy skin granulomas that contain yellow, calcified material the size of rice grains. Larvae, recognized by spiny knobs on their tails, can sometimes be demonstrated in scrapings of the lesions. Fortunately, the lesions respond very well to ivermectin therapy.

Answer 179

d ## Footnote Moniezia benedeni is a cestode which infests the small intestine of ruminants, such as cattle. M. expansa is for small ruminants like sheep and goats. The parasite needs an intermediate host, the oribatid mite, to complete its lifecycle.

Answer 180

d ## Footnote A common mistake for students is to answer C. Horse because that is the animal veterinarians directly work with. The correct answer, however, is D. Oppossum because this is where the sexual stages of S. neurona occur. The horse is an aberrant, dead-end host (although some references say intermediate host). Learn more about Equine Protozoal Myeloencephalitis (the disease caused by S. neurona) here: https://www.youtube.com/watch?v=Fq_8zuPmTXM

Answer 181

b ## Footnote West nile virus is a single stranded RNA virus. It causes the disease called West Nile fever, a mosquito-borne disease that is commonly transmitted by culex mosquitoes to human and horses.

Answer 182

d ## Footnote Macracanthorhynchus hirudinaceus is commonly known as the thorny-headed worm of pigs. Pigs can become infected by ingesting of grubs or adult beetles containing cystacanth stage.

Answer 183

c ## Footnote The adults and larvae of P. praeputialis are found in the stomach of dogs and cats normally with their anterior end attached to the mucosa.

Answer 184

a ## Footnote Frog or snake flesh are usually used as dressing for wounds in traditional medicine. This is one of route of having Spirometrosis or Sparganosis because Fishes, reptiles, and amphibians are recognized as second intermediate hosts of Spirometra spp.

Answer 185

a ## Footnote Platynosomum fastosum is a hepatic trematode which causes 'lizard poisoning' in cats. “Lizard Poisoning” refers to disease as a result to ingesting lizards containing the P. fastosum infective stage (metacercariae) and subsequent infection with the fluke – not as a result of ingesting the lizard itself.

Answer 186

b ## Footnote Eimeria spp can be identified based on the location of the liver. Among the choices, only the E. brunetti localizes in the distal segment of the intestinal tract.

Answer 187

b ## Footnote Demodex canis and Demodex cati are considered normal commensal fauna ubiquitous on dogs and cats, respectively, live in the hair follicles and sebaceous glands, and are transmitted early in life by direct contact from dams to nursing neonates. As normal skin inhabitants, the mites reside in hair follicles without causing cutaneous changes in most dogs.

Answer 188

a ## Footnote In less than 50% of people bitten by a triatomine bug, the characteristic first visible signs can be a skin lesion or a purplish swelling of the lids of one eye. Additionally, they can present fever, headache, enlarged lymph glands, pallor, muscle pain, difficulty in breathing, swelling, and abdominal or chest pain.

Answer 189

a ## Footnote The common ear mite of rabbits, Psoroptes cuniculi, results in external ear canal ulcers and crusting. Despite being barely visible to the naked eye, the mites are big and active. They are surface-dwelling creatures that, in large populations, can be extremely irritating.

Answer 190

b ## Footnote Cattle is infected with the brown stomach worm or Ostertagia ostertagi through the ingestion of the third larval stage

Answer 191

b ## Footnote Visceral larva migrans (VLM) and ocular larva migrans (OLM) are the two main clinical manifestations of toxocariasis, however the majority of infections remain asymptomatic. In VLM, the larvae infect numerous tissues (often the heart, liver, lung, and skeletal muscle).

Answer 192

c ## Footnote One method of identifictaion of parasite is through the eggs. Some eggs can be describered as pitted or cannis, operculated or with lid or operculum for flukes and rippled surface or mamilatted as for Ascaris.

Answer 193

b ## Footnote Moniezia expansa's egg is triangular in shape and ~55 x 65 micrometers in size. Its egg also has a thick envelope. Sheep is a known host.

Answer 194

b ## Footnote The West African Shorthorn, along with N'Dama, are cattle breeds of Bos taurus type that have shown trypanotolerant characteristics. Other known trypanotolerant animals include Djallonke sheep, and the West African sheep and goat.

Answer 195

d ## Footnote The larvae, nymphs and adults of Ixodes can all be recognized by the pre-anal groove. This structure is not present in any other ticks. Due to the public awareness of Lyme disease, of which Ixodes are primary vectors, this characteristic is useful in identifying a tick as a possible vector when it is brought to the clinic for identification.

Answer 196

a ## Footnote In the Philippines, the reported snail second intermediate host of Echinostoma ilocanum is Pila luzonica.

Answer 197

b ## Footnote Chagas disease is a vector-borne disease commonly transmitted through contact with contaminated feces/urine of the reduviid bug, also known as the kissing bug or triatomine bug. Chagoma is a swelling resembling a tumor that appears at the site of infection in Chagas disease. There is an intense local inflammation and/or 2 months of uniocular conjunctivitis. Chagoma is also known as Romana's sign.

Answer 198

b ## Footnote Sarcocystosis is a disease caused by a parasite called Sarcocystis. There are numerous species of Sarcocystis. This disease usually affects animals but also can also cause disease in humans. Two types of the disease can occur, one type causes diarrhea, mild fever, and vomiting (intestinal type, for example infection caused by S. hominis and S. suihominis), and the other type causes muscle pain, transitory edema, and fever (muscular type). Most people infected with Sarcocystis do not have symptoms. Sarcocystis hominis and S. suihominis use humans as definitive hosts and are responsible for intestinal sarcocystosis in the human host. Humans may also become dead-end hosts for non-human Sarcocystis spp. after the accidental ingestion of oocysts. In the intestinal type of sarcosystosis, people become infected when they eat undercooked meat containing the parasite.

Answer 199

b ## Footnote Hepatozoon canis is a protozoal agent that is known to be transmitted by oral uptake of H. canis-infected Rhipicephalus sanguineus sensu lato ticks in dogs This mode of transmission of hepatozoonosis is not typical in the classical sense of a tickborne disease; like other species in the genus, H canis and H americanum infections occur when infected ticks, the definitive host, are ingested by canine hosts. Sporozoites released from the mature oocysts in the ticks' hemocoel enter canine hosts via the gut.

Answer 200

a ## Footnote Ichthyobodo spp. are ectoparasitic flagellates of fish that may cause disease (Ichthyobodosis) causing this kind of steel gray discoloration. Poor water quality and other stresses (especially crowding) may allow this mutualistic parasite to reproduce rapidly and overwhelm the fish host. The skin of affected fish may appear "cloudy" or covered with a thin mucus layer. Infected fish commonly have clamped fins, gulp at the surface for air, and "shimmy" or "shake" back and forth in the water column.

Answer 201

c ## Footnote Bacillus thuringiensis israelensis is a naturally occuring soil bacterium that targets the larvae of blackflies in rivers and streams. It is a gram positive, aerobic, spore-forming bacterium that produces protoxins in the form of parasporal protein crystals. In the alkaline digestive tract of black flies and mosquitoes, the protoxins become activated into highly toxic delta-endotoxins.

Answer 202

a ## Footnote Histomoniasis (blackhead) is a protozoal disease caused by Histomonas meleagridis that primarily affects the liver and ceca of turkeys. Gross lesions are characterized by pathognomonic, necrotic target lesions in the liver and caseous cecal cores.

Answer 203

b ## Footnote Larvae of Hypoderma spp cause myiasis characterized by the presence of subcutaneous warbles on the dorsal and lumbar regions of domestic and wild ruminants. Two species—Hypoderma bovis and Hypoderma lineatum—are economically important and primary parasites affecting cattle and water buffalo. L1 larvae (~15 mm long) of Hypodermis leave their respective resting sites and arrive in the subdermal tissue of the host's back, where they make breathing holes (central puncta) through the skin. A granulomatous reaction, referred to as a warble, forms around the larvae. Carcasses and hides of cattle infested with cattle grubs show marked evidence of the infestation and have decreased value.

Answer 204

b ## Footnote When the temperature drops below 15 degrees Celsius, cercaria may be concentrated in the ant's sub-esophageal ganglion (brain-worm) and induce a cataleptic cramp. This blocks the ant from crawling up the ends of grass and plants, making it easier for grazing animals to eat.

Answer 205

a ## Footnote The Malpighian tubule system is a type of excretory and osmoregulatory system in insects. The system consists of branching tubules extending from the alimentary canal that absorbs solutes, water, and wastes from the surrounding hemolymph. Coxal gland is a gland found in some arthropods, for collecting and excreting urine. The nephridium is an invertebrate organ, found in pairs and performing a function similar to the vertebrate kidneys. It is present in annelids. Flame cell is a specialized excretory cell found in the simplest freshwater invertebrates, including flatworms.

Answer 206

c ## Footnote An immunologic condition known as flea allergy dermatitis is brought on by the injection of flea salivary gland antigens into the host animal. Pruritis and papulocrustous lesions that are dispersed across the lower back, tailhead, caudal, and inner thighs of dogs are the main clinical signs.

Answer 207

a ## Footnote The most marked clinical signs of Anaplasmosis are anemia and jaundice, the latter occurring late in the disease. Haemoglobinemia and hemoglobinuria are not present, and this may assist in the differential diagnosis of anaplasmosis from babesiosis, which is often endemic in the same regions.

Answer 208

a ## Footnote Sacrocystis neurona is protozoan parasite of horses that causes equine protozoal encephalomyelitis. Horses can be infected by ingestion of sporocysts from opossum feces in contaminated feed or water.

Answer 209

c ## Footnote Trichuris vulpis occurs in dogs, cats, foxes, and coyotes. Eggs are unembryonated when passed in feces and are highly resistant to desiccation, extremes in temperature, and ultraviolet radiation. Eggs embryonate in 9 to 21 days (or longer) depending on the temperature and moisture content of the soil. Infective whipworm eggs can remain viable for many years. Hosts are infected by ingesting embryonated eggs from the soil or other substrates in which eggs are found. Each female T. vulpis can produce more than 2,000 eggs per day. Larvae hatch from eggs (generally in the small intestine) and penetrate the mucosa. They develop for 2 to 10 days in the mucosa, move to the cecum (occasionally the terminal small intestine or colon), and mature into adult worms. The prepatent period of T. vulpis is 74 to 90 days or 3 months.

Answer 210

c ## Footnote Adult fleas of cats usually prefer to be on the host because fleas prefer to wait and jump onto a passing animal.

Answer 211

d ## Footnote Otobius sp. is exceedingly specialized biologically and structurally, infests the ear canals of cattle, horses, goats, sheep, dogs, and people.

Answer 212

c ## Footnote Merozoite is a small amoeboid sporozoan trophozoite produced by schizogony that is capable of initiating a new sexual or asexual cycle of development. Schizogony is an asexual reproduction by multiple fission. Gametogony is a stage in the sexual cycle of sporozoans in which gametes are formed.

Answer 213

b ## Footnote Hyostrongylus rubidus (red stomach worm of pigs) is a gastric parasite that causes a thickening of the mucosa, with mucus accumulation and mucous cell hyperplasia and inflammation of the lamina propria by lymphocytes, plasma cells, and eosinophils.

Answer 214

b ## Footnote Cryptobia occurs in the blood of fishes.

Answer 215

d ## Footnote Cyclophyllidea and Pseudophyllidea are both tapeworms and not flukes. Both of them have vittelairum/vitellaria which are also know as vitteline glands or yolk glands. The cells from the vitellaria are used in the formation of yolk and eggshell.

Answer 216

c ## Footnote Fasciola spp pass through phases in their life cycle in the following order: egg, miracidium, sporocyst, redia, cercaria, metacercaria, and adult fluke.

Answer 217

b ## Footnote Halteres are modified hind wings and are used for balance when in flight.

Answer 218

d ## Footnote Mallophaga (biting or chewing lice) is a group of obligatory ectoparasites mainly of birds and to a lesser extent (only 12%) of mammals. Orthoptera is an order of insects that comprises the grasshoppers, locusts, and crickets, including closely related insects. Hemiptera is an order of insects, commonly called true bugs. Anoplura is a suborder of Phthiraptera. They are the sucking lice.

Answer 219

a ## Footnote Twelve Eimeria spp have been identified in the feces of cattle worldwide, but only three (E zuernii, E bovis, and E auburnensis) are most often associated with clinical disease. Coccidiosis in cattle is usually a self limiting but drugs such as Sulfaquinoxaline and amprolium can be used as treatment and prevention.

Answer 220

c ## Footnote The other nematodes are not transmitted by transmammary route.

Answer 221

d ## Footnote Geographical distribution of Babesia spp. is worldwide but it is normally prevalent in warm locations.

Answer 222

d ## Footnote Fleas are laterally compressed, wingless insects; the head is shield or helmet-shaped, compound eyes are absent, and mouthparts are specialized for piercing and sucking.

Answer 223

b ## Footnote Fasciola jacksoni is a significant contributor to the health and mortality of Asian elephants.

Answer 224

d ## Footnote Setaria labiatopapillosa utilizes mosquitoes as an intermediate host.

Answer 225

b ## Footnote All of the following choices are hard ticks. Hyalomma aegyptium (Tortoise tick) is more prevalent in hermann's tortoises but not in gopher tortoises. Dermacentor variabilis is also known as american dog tick. Ixodes daminii is also known as deer tick.

Answer 226

a ## Footnote The area most commonly involved in flea allergy dermatitis is over the rump, just in front of the tail. Many flea-allergic cats chew or lick the hair off their legs. Itching and hair loss around the tail base, neck, and head should be considered suspicious for flea allergy dermatitis.

Answer 227

b ## Footnote Free-living oribatid mites act as intermediate hosts of A. perfoliata. The final hosts are horse and donkey.

Answer 228

c ## Footnote Although adult tapeworm infections are uncommon in domestic rabbits, cysts of the larval form are frequently found on the serosal peritoneum. Rabbits are intermediate hosts for two species of canine tapeworm, Taenia serialis and T. pisiformis.

Answer 229

b ## Footnote Anoplocephala sp. is a tapeworm of horses that infects the caudal part of the small intestine and cranial part of the cecum (ileo-cecal junction). The horses get infected through the ingestion of the oribatid mites in the grasses.

Answer 230

c ## Footnote The scaly leg mite caused by Knemidocoptes mutans, is a small, spherical, sarcoptic mite that usually tunnels into the tissue under the scales of the legs of poultry birds.

Answer 231

a ## Footnote Acarapis woodi is an internal parasite commonly known as tracheal mite of honey bees capable of infecting queen bees, drones, and worker bees affecting their respiratory system.

Answer 232

a ## Footnote The largest tapeworms that may infect humans are Diphyllobothrium latum. Fish eaten uncooked or undercooked might cause infection. Fish that has been properly frozen or cooked will kill the parasite.

Answer 233

a ## Footnote C. quiscali is exposed to emus after a bite from Culicoides crepuscularis. Birds with C. quiscali infection experience severe torticollis and incoordination, which cause emaciation, scoliosis, and eventual death. The preferred treatment for C. quiscali infection in emus is ivermectin.

Answer 234

c ## Footnote Haemaphysalis leachi leachi is also known as the yellow dog tick. it is attached in to three hosts to complete its life cycle. When the host such as a dog starts to scratch, female dog tick starts to produce a dog-repelling allomone, which enable tick to survive on the hosts further time

Answer 235

c ## Footnote In puppies, the most common mode of infection is transplacental transfer. If pups < 3 months old ingest embryonated infective eggs, the hatched larvae penetrate the intestinal mucosa and reach the lungs via the liver and bloodstream. Then they are coughed up and swallowed, maturing to egg-producing adults in the small intestine. However, when infective eggs of T canis are swallowed by older dogs, the larvae hatch, penetrate the intestinal mucosa, and migrate to the liver, lungs, muscles, connective tissue, kidneys, and many other tissues, where development is arrested.

Answer 236

a ## Footnote Sphaerospora auratus is a parasite that causes renal dropsy. It attacks the kidneys of pond-raised goldfish and can lead to severely enlarged kidneys.

Answer 237

b ## Footnote By consuming earthworms that contain the first-stage larvae, dogs and cats catch the infection. Most cats and dogs exhibit no symptoms.

Answer 238

a ## Footnote Sarcocystis spp cysts appear as small, white foci in skeletal muscle. Diaphragm is a skeletal muscle.

Answer 239

b ## Footnote Studies reported the occurrence of liver cancer in humans infected with Opisthorchis sinensis.

Answer 240

a ## Footnote Freshwater snails serve as the initial intermediate hosts, where the flukes go through a number of phases of development (sporocyst, mother and daughter rediae, and cercariae).

Answer 241

b ## Footnote Female pinworms deposit their eggs near the anus on the perianal skin. Some of these eggs are detached from the perianal region and lodge on clothing, bedding, and other surfaces. Infection takes place through ingestion or inhalation of infective eggs or retrograde migration of hatched juveniles from the anus to the intestines.

Answer 242

d ## Footnote Most biting midges can pass through 16-mesh insect wire screen and netting, so a smaller mesh size is required. Larval habitats are not targeted in control efforts because of the extensive amount of area that the habitats may cover, some negative environmental impacts. Applications of insecticides directly to the animal is impractical and not efficient.