Parasit Review

Which best characterizes the term "epizootic"?

Occurrence of disease in an animal population in excess of the generally accepted number of cases

What best characterizes the term "zoonotic"?

An animal disease transmissible to humans

What is the working definition of a parasite?

An organism that is metabolically dependent and survives at the measurable expense of another organism

What parasite group is most likely associated with eggs like these (90x54um) when they occur on the fecal flotation of a 15-week-old foal?

Unspecified small strongyles

What is the main disease caused by Strongylus vulgaris?

The larvae extra-intestinally migrate through the cranial mesenteric artery.

What worms are depicted in this picture?

Immature small strongyle worms that have recently emerged from the colonic wall

What parasite is the cause of this picture?

Ocular larval migrans

What disease is depicted in this picture?

Cutaneous larval migrans

A 6-year-old rottweiler presents with the eggs depicted in the picture. How was the parasite transmitted?

Hookworms → Ingestion or skin penetration from contaminated backyard

Why is Pyrantel Pamoate commonly used for GI nematodes?

Because it is a broad spectrum anthelmintic and has a wide margin of safety

These eggs were found on the fecal flotation of a 9-week-old Miniature Schnauzer puppy presenting for its vaccinations and an initial physical examination. They measure approximately 85 micrometers in diameter. What is the diagnosis?

Toxocara canis

What is the parasite depicted in this picture?

Parascaris equorum

How does this worm cause desease?

Mass emergence and damage to tissue

A 10 day old puppy comes in and fecal is negative. Listless, anemic, diagnosis is hookworm. How do you treat the patient?

1. Deworm immediately with a broad spectrum anthelmintic

2. Provide supportive care

A patient is diagnosed with Physaloptera. How did they most likely contract?

Patient ate an Orthoptera intermediate host species (grasshopper)

These eggs were found in a scotch tape fecal from the perianal folds of a mare. The eggs are depicted in the picture. What is your diagnosis?

Oxyuris Equi

What does frequent deworming of horses lead to?

It allows "naturally treatment resistant" worms to reproduce with competition from other worms.

What is an intermediate host?

It is an obligate host where the larval stage parasite must undergo development before it becomes infective to the final or definitive host → reaches sexual development

Eggs that look like these were found on the fecal floatation of a 5-year-old mixed breed hound confined in a backyard run. They measure approximately 90x40um. What is the most appropriate therapeutic intervention?

Whipworm → Treat with Fenbendazole at labeled dose, follow up with Milbemycin monthly, and recheck fecal exam for progress

How does 12 week foal get this parasite?

Pastures + Mother’s udder

A 5 year old dog has a high presence of this parasite. What does the presence of so many eggs mean?

Whipworm → Through the ingestion of infectious eggs from contaminated soil, water, food, or feces

10 day old old puppy presents cold, pale mucus membranes as well as black diarrhea. The fecal is negative. What type of disease?

Per-acute disease

5 year old mixed hound dog presents for a wellness exam. PCV is 30% and they are diagnosed with Hookworm (Ancylostoma caninum). What type of the disease does the dog have?

Chronic compensated disease

Why is it recommended to deworm puppies at 2, 4, 6, and 8 weeks of age?

Avoid reinfection and contamination of environment

What is the difference between large and small strongyles?

Large strongyles extra-marginally migrate; small strongyles encyst in intestinal tissues

These eggs were found on the fecal flotation of a 10-day-old puppy. They measure approximately 60 x 40 um. How was the puppy infected?

Lactogenically → ingestion of infective larvae in mother's milk

These eggs were found on the fecal flotation of an 8 week old puppy. They measure approximately 60 * 40 um. What is your diagnosis?

Ancylostoma caninum

These eggs were found on a fecal flotation of a 9 week old puppy. They measure 60x40um. How was puppy infected?

Ingestion of infective larvae in mothers milk

What causes the pot bellied appearance of a dog infected with toxocara canis?

Leak and accumulation of plasma proteins in the abdomen

What species causes "blackhead" and enterohepatitis in turkeys?

Heterakis gallinarum

Why is it recommended that we treat with a heartworm prophylaxis with a positive test before adulticide treatment?

To prevent microfilariae transmission and spread to mosquitos (to prevent larval migration and new infections)

What is the distinguishing factor between Capillaria and Trichuris vulpis?

Capillaria are smaller and in the nasal sinuses and bronchi

What are the clinical signs of Type 1 Ostertagia?

Profuse watery diarrhea caused by the emergence of hypobiotic worms positive fecal exam

Something about osteotagia type 1 and when it would occur?

First season in grazing pasture and October to March

What is the number one most economically significant cattle parasite?

Ostertagia ostertagi

What is this egg?

Ascaris suum

Trichinella is most commonly associated with ingestion of infected pork. Why is there a decreased amount of reported cases of Trichinella in the US?

Decreased risk associated with total confinement breeding

What species cause milk spots on the liver?

Ascaris suum

Why should you put cats on heartworm prevention?

Disease is fatal and there is no treatment

If you have a cat with a single worm. Do you have to worry about the cat spreading the disease?

No cats only infected by single sex worms that don't produce microfilaria

You see these eggs in a goat. What does this FEC represent?

Contributes to high contamination/parasitic load in pasture

Why are anti-parasitic added to HW monthly prevention?

Anti-flea and tick helps with parasite bites - total parasite control

Wolbachia is a gram-negative bacteria. What is the main function of Wolbachia in case HW related disease?

They enhance inflammation and host immune response

Why is doxycycline used along with adulticide treatment of canine heartworm disease?

It mediates the inflammatory immune response caused by Wolbachia

A 12 wk old piglet tested positive for Ascaris suum, what is the most likely way he got this parasite?

From ingestion of larvated eggs that stuck on the sow's teats

How does macrocyclic lactone prevent HW infection in dogs?

It kills the migrating infective larvae from the previous 30 days

A Nubian goat shows signs of anemia and bottled jaw, which of the following parasites causes that disease?

Haemonchus contortus

What is the most important complication that arises after a canine HW adulticidal treatment in?

Pulmonary thromboembolism

What are the benefits of selective deworming in cattle production?

Treat calves and high fecal egg count animals

Something about selective deworming?

Maintaining genetic heterogenous

A goat has Muellerius capillaris sp. what is the most likely symptom of the goat?

In the lungs and respiratory system (coughing, rapid breathing)

A patient is identified as CHW positive with a reputable antigen detection assay. Which population tested is associated with the highest positive prediction value?

Dogs showing clinical signs suggestive of CHWD

What parasites are associated with the nodules in the image of the intestine of this necropsied pig?

Oesophagostomum dentanum

The eggs in the accompanying image were seen on the fecal flotation of a beagle with occasional sneezing. The eggs measured approximately 65 um. What are these eggs?

Capillaria sp

Why are Thelazia spp. not as prominent in horses? How is the species treate?

• Treat with macrocyclic lactones (Ivermectin) for 8 weeks

• Decreased prevalence in horses because they may have historical 8 week treatment regimens against Strongyles

Microfilariae like the one in the image was found in a 6-year- old poodle and measures 265 um in length. The dog was on monthly prevention. What is the significance of finding this parasite?

Acanthocheilonema reconditum - The parasite is a nonpathogenic filarial worm and treatment is not necessary

What role do microfilariae play in the heartworm lifecycle?

They are embryonic stage larvae and must develop in mosquitos before becoming infective to canine hosts

Dog presents with cough, bronchoscopy revealed nodes in trachea and bronchi. What worm would cause this?

Filaroides osleri

In eradication efforts of Dracunculus insignis there were no cases for 10 years. What is the most likely the significance of increased animal and human cases?

New evidence shows that there are new hosts such as raccoons and canines

What is the appropriate diagnostic technique for diagnosing demodectic mange?

Deep skin scrape of the erythematous lesions on the affected area

You see proglottids in stool after treating a cat for tapeworms. Why?

Treatment was focused on the adult worms, but not flea control (intermediate host)

Flies like this were buzzing around the legs of the horse. What was the fly doing? (I think this was the picture)

Laying eggs

These 38x32um eggs were found on a fecal flotation. What is appropriate to put in the medical notes?

Taenia type eggs

What is primary myiasis?

Penetration of normal (healthy) tissue

Why is QuestPlus/Zimecterin combo drugs good for horses and treating parasites?

Helps to eliminate tapeworms and prevent colic by those worms

The tick in this pic causes lyme disease. What type is it?

Ixodes scapularis

These egg packets were found in the fecal sample of a 10 year old Yorkshire Terrier. What parasites are these eggs associated with?

Dipylidium caninum (Flea tapeworm)

These eggs were found in the fecal sample of a 10 year old Yorkshire Terrier. The dog had been treated for the same worms once before, why did the treatment not work?

Because the owners focused primarily on treatment of the dog but not the intermediate host (fleas)

These eggs were found in the fecal sample of a 10 year old Yorkshire Terrier. How was this dog infected?

Ingestion of an infected flea with metacestode

Flies like this were found buzzing around the horses at the DVTC and painfully biting them. What stage of this fly is considered parasitic?

Adult stage

What parasite is responsible for the severe oozing scabs and pruritus that is depicted in this picture?

Sarcoptes sp

What type of louse is this?

Chewing louse

Flies buzzing around the legs of cattle, how do you treat them?

Get rid of the dead/decaying material in the pasture because that's where they lay eggs

What parasite caused this red flaky skin on this dog?

Demodex sp

This tick was found on cows in Virginia. What tick is this?

Haemaphysalis longicornus

What parasite is responsible for this dark waxy cerebrum in the dogs ear pictured?

Otodectes Cynotis

What is the parasite represented in this image?

Dermacentor variabilis

What is the predominant way that disease is transmitted in 1-host-lifecycle ticks?

Trans-ovarial

You are a vet- and a client is not happy because they used the flea product and the animal still has fleas- why is this?

Need to treat the environment or asymptomatic

What parasite is depicted in this image of a two genital pore on the proglottid?

Diplyidium caninum

These proglottids were found in the GI contents of a coyote from the Great Smokey Mountains during necropsy. What parasite is this?

Enchinococcus granulosus

Eggs like the one pictured were found on a horse fecal. The horse was grazing on rocky scrubby pasture. How did the horse become infected?

Ingestion of an infected mite on pasture

Why isn't ivermectin and other macrocyclic lactones a good treatment for tapeworms?

Tapeworms lack glutamate ion channels and GABA receptors

What parasite causes this (cysts on elk)?

Echinococcus granulosum

What are the most common ways humans acquire hydatid disease?

By accidentally ingest eggs that sticked on pet dog fur that they pick up from wild canidae feces

A skin scrape was taken of a dog with oozing scabs and pruritus? What parasite is responsible?

Sarcoptes scabiei

A cattle in Louisiana has bottle jaw and elevated liver enzyme value, a brown oval egg was found in fecal, what is the organism that infected them?

Fasciola hepatica

What is the worm in this picture?

Thorny-headed worm

Blood fluke was found in a dog, how did the dog get it?

Skin penetration by cercarial stage

There is a dog with this parasite that's called Salmon poisoning fluke. What is it?

Nanophyetus salmicola

There is a cat that has Platynosomum fastosum - how did this cat get the disease?

Ingestion of a lizard/amphibian IH

There is a dog that has this parasite. How did it become infected?

Ingestion of a metacercaria in a crayfish IH

What diseases are caused by salmon poisoning fluke in dogs?

Neorickettasia helminthoeca that are vectored by the fluke cause hemorrhagic enteritis

There's a cocker spaniel that has this tick (PICTURE) how does this tick reproduce?

Breeding and something else (laying eggs?)

There is a pig with this worm in its small intestine. Why would you accept/reject this hypothesis?

Reject, pigs don't host any tapeworms in their small intestine

A dog has tapeworm segments in stool. How would you treat it?

Treat the dog with Praziquantal and continuous flea control

A dog has reactive arthritis and Lyme borealis. What stage of the tick responsible transmits this disease?

Nymphal stage

What is this parasite that is found in monkeys? (WORDED DIFFERENT)

Prostenorchis elegans

Tear drop shaped parasite and how does it affect the health of host?

asexual division in cell and causes diarrhea

These pear shaped piroplasms were found in the fecal examination of Pitbull terrier from SW VA comes in the animal shelter. The dog is lethargic and anemic. They measure approximately 3um. What is this parasite?

Babesia Gibsoni