Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Infectious study
All current information
| Question | Answer |
|---|---|
| What is an infectious disease? | A disease caused by an infectious agent. |
| What are infectious agents? | Microorganisms found in nature that are harmful to animals or plants; termed pathogenic. |
| Why should we understand infectious diseases? | Protect patients Educate clients Understand prevention and treatment Stop the spread Protect humans |
| What are the four main types of infectious agents? | Bacteria, viruses, fungi, and parasites. |
| What are bacteria? | Unicellular prokaryotes with various shapes that reproduce via binary fission. |
| What are some characteristics of bacteria? | Some contain plasmids, leading to antimicrobial resistance Shapes include coccus, bacillus, curved rods, pleomorphic Some are motile with flagella |
| What are viruses? | Non-living, small genetic material collections surrounded by a capsid that infect living cells to replicate. |
| How do viruses reproduce? | They infect living cells and use them to replicate. |
| What are fungi? | Non-photosynthesizing eukaryotes, including yeasts, molds, and mushrooms. |
| What are the two forms of fungi? | Unicellular (Yeasts) Multicellular (Molds and Mushrooms) |
| Why are some fungi pathogenic? | They secrete mycotoxins that cause disease. |
| What are parasites? | Organisms that live in/on another organism and depend on the host for survival. |
| What are the two types of parasites? | Endoparasites: Live inside the body Ectoparasites: Live outside the body |
| How do parasites impact their host? | They benefit at the host’s expense, with varying degrees of damage. |
| What is epidemiology? | The study of disease incidence, distribution, and control. |
| What is zoonosis? | Infectious diseases that can be transmitted between animals and humans (e.g., rabies, Lyme disease). |
| What three factors influence infectious disease outcomes? | Agent, host, and environment. |
| What are agent-dependent factors? | Infectivity Pathogenicity Virulence |
| What are host-dependent factors? | Genetics Immunity (exposure/vaccination) Age Stress Pregnancy Nutritional status Underlying disease |
| What are environmental factors? | Physical/social factors Dog parks increase exposure Hoarding/neglect situations increase vulnerability |
| What are the stages of disease transmission? | Incubation period: Period of critical illness: Latent/pre-infectious period: Infectious period: Disease duration: |
| What are the five main transmission methods? | Direct Transmission Fomite Transmission Aerosol Transmission Oral Transmission Vector-borne Transmission |
| What is the definition of Incubation period? | Time from exposure to first symptoms |
| What is the definition of Period of critical illness? | Duration between first and last symptoms |
| What is the definition of Latent/pre-infectious period? | Time between exposure and infectiousness |
| What is the definition of infection period? | Time when the host can spread the disease |
| What is the definition of disease duration? | Varies based on host, environment, and agent |
| What is the definition of Direct transmission? | Physical transfer via mucous membranes, wounds, bites/scratches |
| What is the definition of Fomite transmission? | Contaminated objects (exam tables, kennels, equipment) |
| What is the definition of Aerosol transmission? | Airborne particles (coughing, sneezing, medical procedures) |
| What is the definition of Oral transmission? | Ingesting contaminated food, water, objects (fecal-oral route most common) |
| What is the definition of Vector-borne transmission? | Carried by living organisms (mosquitoes, fleas, ticks, rats) |
| What is SENSITIVITY in diagnostic testing? | The ability of a test to correctly identify infected individuals. |
| What happens if a test has high sensitivity? | Fewer false negatives More individuals with the disease are correctly identified |
| What is SPECIFITY in diagnostic testing? | The ability of a test to correctly identify uninfected individuals. |
| What happens if a test has high specificity? | Fewer false positives More accurate identification of uninfected individuals |
| What is the difference between screening and confirmatory tests? | Screening tests are highly sensitive (to catch most cases). Confirmatory tests are highly specific (to rule out false positives). |
| What are the main ways to diagnose infectious diseases? | Direct examination of specimens Culture of samples to isolate the agent Antibody testing (immune response) Antigen testing (microorganism molecules) Genetic material testing (e.g., PCR) |
| What is the benchmark pathogen for disinfection? | Parvovirus – If a product can kill parvovirus, it can kill most other pathogens. |
| What factors are necessary for proper disinfection? | Using effective products Proper dilution of chemicals Adequate contact time |
| What are key strategies for handling infectious patients? | Identifying infectious cases Isolation protocols Proper testing Disposal of contaminated waste |
| What measures protect veterinary staff? | Use of PPE Proper handwashing Avoiding injuries (open wounds) |
| Why are vaccinations important in disease control? | They provide immunity and prevent the spread of infectious diseases. |
| What is parasitology? | The study of parasites. |
| What is a host? | An organism in which a parasite exists on or in. |
| What is a final (definitive) host? | The host in which the parasite reaches its adult reproductive stage. |
| What is an intermediate host? | A host required for the development of the parasite’s intermediate or larval stage. |
| What is a paratenic (transport) host? | A host not required for the parasite’s life cycle but helps transport it to its final host. |
| What is an aberrant host? | A host that a parasite does not normally inhabit, which can be harmful to both host and parasite. |
| What is a parasite life cycle? | A series of developmental stages culminating in an adult capable of reproduction. |
| What is a direct life cycle? | A cycle where the parasite moves from one final host to another without an intermediate host. |
| What is an indirect life cycle? | A cycle requiring one or more intermediate hosts before reaching the final host. |
| What are endoparasites? | Parasites that live inside the host. |
| What do we call the presence of endoparasites in a host? | Infection. |
| What are ectoparasites? | Parasites that live on the outside of the host. |
| What do we call the presence of ectoparasites on a host? | Infestation. |
| What are parasiticides? | Drugs used to treat parasites. |
| What are anthelmintics? | Drugs used to treat worms. |
| What are insecticides? | Drugs used to treat ectoparasites. |
| What are immiticides? | Drugs used to kill heartworms. |
| How do parasites vary in host preference? | Some are species-specific, while others can infect multiple species. |
| What is a site-specific parasite? | A parasite that only affects a particular part of the body. |
| How can parasites harm their host? | By robbing nutrients, causing obstruction, transmitting disease, inducing anemia, damaging tissues, interfering with organs, and secreting toxins. |
| What are the methods of parasite transmission? | Direct contact, fecal-oral route, stalking/biting, indirect contact (fomites, vectors), and intermediate hosts. |
| What is a fomite? | An inanimate object that transmits parasites (e.g., blankets, bowls, shoes). |
| What is a vector? | A living organism that transmits parasites (e.g., mosquitoes, ticks). |
| What is the most common route of parasitic transmission? | Fecal-oral route. |
| How does the immune system react to parasites? | It detects parasites via antigens, but immunity to parasites is weaker compared to viruses and bacteria. |
| What is eosinophilia? | An increase in eosinophils, often indicating a parasitic infection. |
| Do maternal antibodies protect against parasites? | No, young animals often have the heaviest parasitic infections. |
| What is taxonomy? | The classification system for living organisms. |
| What are the key taxonomy levels used for parasites? | Class, Genus, Species. |
| How do you correctly write a parasite’s scientific name? | Genus is capitalized and underlined/italicized; species is lowercase and underlined/italicized (e.g., Toxocara canis). |
| What are nematodes? | Roundworms, including ascarids, hookworms, whipworms, lungworms, heartworms, pinworms, and threadworms. |
| What are cestodes? | Tapeworms. |
| What are trematodes? | Flukes. |
| What are protozoa? | Single-celled microscopic organisms, some of which are parasites. |
| What are rickettsia? | One-celled, intracellular parasites. |
| What phylum do roundworms belong to? | Phylum Helminths. |
| What class do roundworms belong to? | Class Nematodes. |
| What order do roundworms belong to? | Order Ascarids. |
| Which animals are most commonly affected by roundworms? | Puppies and kittens. |
| What is the most common roundworm in domestic dogs? | Toxocara canis. |
| What percentage of puppies are infected with Toxocara canis? | Up to 98%. |
| What does Toxocara canis look like? | Spaghetti-like, up to 8 inches long, white when cleaned, brown otherwise. |
| Where do adult roundworms live in the host? | The small intestine |
| How many eggs can a female roundworm lay per day? | Up to 85,000. |
| How long can roundworm eggs survive in soil? | 3-5 years. |
| What type of life cycle does Toxocara canis have? | Direct (no intermediate host required). |
| What are the steps in the Toxocara canis life cycle? | Adult worms mate in small intestine, eggs pass in feces. Eggs enter the environment, embryonate in 2-4 weeks. Infectious eggs are ingested by a new host. Eggs hatch, larvae develop into adult worms in the new host. |
| What is a paratenic host for Toxocara canis? | Rodents and rabbits. |
| How can a dog get infected besides fecal-oral transmission? | By eating an infected rodent or rabbit. |
| What is the pre-patent period for Toxocara canis? | 4-5 weeks. |
| What is the generation time (total time from egg ingestion to egg production)? | About 6 weeks. |
| What are the two migration pathways for Toxocara canis larvae? | Hepatotracheal migration and somatic migration. |
| Which migration pathway is most common in puppies? | Hepatotracheal migration. |
| Describe the hepatotracheal migration pathway. | Larvae burrow through the SI into the portal vein. Travel to the liver, then hepatic vein, then vena cava. Enter the heart, then the lungs. Burrow into alveoli, get coughed up and swallowed. Return to the small intestine and mature into adults. |
| Which migration pathway is most common in adult dogs? | Somatic migration. |
| What happens during somatic migration? | Larvae migrate to other areas (e.g., muscles, kidneys). They encyst and go dormant, waiting for a new host. |
| How can Toxocara canis infect offspring? | Transplacental transmission (larvae cross the placenta to infect fetuses). Transmammary transmission (larvae excreted in milk). |
| Why is pregnancy a high-risk period for Toxocara canis transmission? | Dormant larvae reactivate and infect the mother’s offspring. |
| What are the four ways Toxocara canis can be transmitted? | Fecal-oral route. Paratenic hosts (rodents, rabbits). Transplacental transmission. Transmammary transmission. |
| How do adult dogs typically respond to Toxocara canis infection? | They are usually asymptomatic due to immune suppression of adult worm development. |
| How do puppies respond to Toxocara canis infection? | It depends on worm burden: Low burden = asymptomatic. Higher burden = symptoms such as soft stool, coughing, pot belly, poor coat condition, vomiting, abdominal discomfort, anorexia. Very high burden = bowel obstruction (can be life-threatening). |
| How is Toxocara canis diagnosed? | Seeing adult worms in feces or vomit. Fecal flotation (examining eggs under a microscope). |
| What is the primary treatment for Toxocara canis? | Anthelmintics, such as pyrantel (Strongid). |
| Do heartworm preventatives also kill roundworms? | Yes, most heartworm preventions are effective against roundworms. |
| What is the key to preventing Toxocara canis infection? | Sanitation. |
| What are important sanitation and prevention measures? | Clean up feces regularly. Disinfect surfaces when possible. Prevent dogs from eating feces (coprophagy). Avoid taking puppies to contaminated areas. Routine deworming, especially in the first 4 months of life. Monthly heartworm prevention. |
| How often should puppies be dewormed? | Every two weeks for 3-4 dewormings. |
| Why is it difficult to eliminate encysted larvae? | They require very high doses of dewormer, which can be dangerous. |
| Can Toxocara canis infect humans? | Yes, humans are considered an aberrant host. |
| What age group is most at risk for Toxocara canis infection? | Children. |
| What percentage of children test positive for Toxocara canis antibodies? | A: About 10%. |
| What are visceral larval migrans? | Larvae migrate throughout the human body, damaging organs like the liver, lungs, and brain. |
| How dangerous is visceral larval migrans? | The immune system can usually fight off a few larvae, but a heavy infection can cause permanent damage or even death. |
| What are ocular larval migrans? | Larvae migrate to the eye, potentially causing blindness. |
| How common is ocular larval migrans in the U.S.? | About 1,000 cases per year. |
| What is the most common way humans get infected with Toxocara canis? | Fecal-oral transmission. |
| How can people prevent Toxocara canis infection? | Keep pets on routine antiparasitic treatments. Remove dog feces from the environment. Prevent children from playing in areas contaminated with dog feces. Teach good hygiene habits. Avoid letting dogs lick faces. |
| What is the feline equivalent of Toxocara canis? | Toxocara cati |
| What are the final hosts of Toxocara cati? | Domestic cats and non-domestic felids (e.g., cougars, lions, leopards). |
| What do adult Toxocara cati worms look like? | Spaghetti-like appearance; they live in the small intestine. |
| How do Toxocara cati eggs compare to Toxocara canis eggs? | They are slightly smaller but just as tough and can remain in the environment for years. |
| What type of lifecycle does Toxocara cati have, and what is its prepatent period? | Direct lifecycle; prepatent period is 8 weeks. |
| What are the modes of transmission for Toxocara cati? | Fecal-oral route: In the environment for 2-4 weeks before becoming infectious. Paratenic host transmission: via rodents and birds. Transmammary transmission: Major mode for kittens. No transplacental transmission: Unlike Toxocara canis in dogs. |
| What are the larval migration patterns of Toxocara cati? | Hepatotracheal migration – Occurs in both kittens and adults. Somatic migration – Larvae encyst in tissues. |
| Is Toxocara cati zoonotic? If so, how does it affect humans? | Yes, especially in young children who may ingest eggs from contaminated environments, such as sandboxes. |
| What are the clinical signs of Toxocara cati infection? | Potbelly appearance in kittens Vomiting and diarrhea Poor growth and weight loss coughing poor coat condition abdominal discomfort anorexia. |
| What species does Toxascaris leonine affect? | Dogs, cats, and non-domestic counterparts. |
| What do adult Toxascaris leonine worms look like, and where do they live? | They have a spaghetti-like appearance and live in the small intestine. |
| How do Toxascaris leonine eggs compare to other roundworm eggs? | They look similar but only require 1 week to embryonate. |
| What is the lifecycle type and prepatent period of Toxascaris leonine? | Direct lifecycle with an 8-week prepatent period. |
| Are paratenic hosts involved in the Toxascaris leonine lifecycle? | Yes, paratenic hosts are often involved. |
| How is Toxascaris leonine migration different from Toxocara species? | Migration is simpler Infectious eggs are ingested and hatch in the stomach. Larvae move to the small intestine and burrow into the wall. They mature and re-emerge as adults. No migration throughout the body (No transplacental or transmammary) |
| How is Toxascaris leonine transmitted? | Fecal-oral route Paratenic hosts |
| What are the clinical signs of Toxascaris leonine infection? | Mild infections: No clinical signs. Severe infections: Vomiting, diarrhea, abdominal pain. No coughing (unlike Toxocara species). |
| How is Toxascaris leonine diagnosed and treated? | Anthelmintics like pyrantel and fenbendazole |
| What is the lifecycle of Baylisascaris spp. similar to? | Toxocara canis: Adult worms mate in small intestine, eggs pass in feces. Eggs enter the environment, embryonate in 2-4 weeks. Infectious eggs are ingested by a new host. Eggs hatch, larvae develop into adult worms in the new host. |
| What types of animals are affected by Baylisascaris spp.? | Smaller wildlife species, including skunks, bears, and raccoons. |
| Where do Baylisascaris spp. roundworms live? | In the small intestine (SI). |
| What types of larval migration are seen with Baylisascaris spp.? | Hepatotracheal migration Somatic migration Visceral larval migration (travels to the brain) |
| Why is Baylisascaris spp. especially dangerous? | The larvae can travel to the brain, and as few as 3 larvae can be fatal. |
| In what type of areas is Baylisascaris spp. of particular concern? | Areas where wildlife, especially raccoons, congregate. |
| Can Baylisascaris spp. affect aberrant hosts? | Yes, including rabbits, rodents, groundhogs, songbirds, poultry, pigeons, parrots, and humans. |
| What precautions should wildlife rescuers take when handling raccoons or their nesting sites? | They should take appropriate precautions to avoid inhaling eggs, especially while cleaning out raccoon housing. |
| What is the common name for Ancylostoma caninum? | Hookworm. |
| What is the final host for Ancylostoma caninum? | Dogs. |
| What is the lifecycle of Ancylostoma caninum? | Direct lifecycle. |
| How long are adult Ancylostoma caninum worms? | 12-15 mm long. |
| Where do adult Ancylostoma caninum worms live? | In the small intestine, where they feed on blood. |
| What does the egg of Ancylostoma caninum look like? | Elliptical with a smooth cell wall and a rough morula visible in the center. |
| How long does it take for Ancylostoma caninum eggs to hatch in the environment? | Eggs hatch in 24-72 hours on warm, moist soil. |
| How do animals become infected with Ancylostoma caninum? | Fecal-oral, transplacental, transmammary, skin penetration, and paratenic hosts. |
| What is hypobiosis in hookworms? | Larvae enter a state of arrested development and encyst in muscle tissues. |
| What are the clinical signs of hookworm infections in very young animals? | Rapid, sudden death, severe anemia, listlessness, pale mucous membranes. |
| What clinical signs do weaned puppies with acute hookworm infections show? | Anemia, bloody stool, diarrhea. |
| What are the clinical signs in adult dogs with chronic hookworm infections? | Anemia, bloody diarrhea, malnutrition. |
| How do you diagnose a hookworm infection? | Fecal flotation for ova. |
| What treatment is used for hookworm infections? | Pyrantel (Strongid), fenbendazole (Panacur), heartworm preventions, blood transfusions in severe cases, and vitamin/mineral supplements. |
| How can you prevent hookworm infections in pets? | Preventing coprophagy, sanitation, deworming young animals. |
| Can hookworms be transmitted to humans? | Yes, humans can get cutaneous larval migrans (skin infections), usually self-limiting but can cause severe skin reactions. |
| What other strongylids affect small animals? | Ancylostoma tubaeforme (cats), Ancylostoma braziliense (dogs and cats), Aelurostrongylus abstrusus (lungworm of cats). |
| What is the lifecycle of Aelurostrongylus abstrusus (lungworm of cats)? | Indirect lifecycle, involving snails or slugs as intermediate hosts and birds or rodents as paratenic hosts. |
| What clinical signs are associated with Aelurostrongylus abstrusus infections in cats? | Coughing, dyspnea (difficulty breathing), and death in severe cases. |
| How do you diagnose Aelurostrongylus abstrusus infections? | Direct fecal smear for larvae or fecal sedimentation for larvae. |
| What treatment is used for Aelurostrongylus abstrusus? | Fenbendazole (Panacur) or ivermectin. |
| Does Aelurostrongylus abstrusus have zoonotic potential? | No zoonotic potential |
| What is the final host for Trichuris vulpis (canine whipworm)? | Dogs, foxes, and other wild canines. |
| Does Trichuris vulpis have intermediate hosts? | No intermediate hosts. |
| Where do adult Trichuris vulpis worms live in the host? | In the large intestine and cecum. |
| What is the distinctive shape of Trichuris vulpis? | They have a long, thin end and a short thick end, resembling a "whip." |
| What does the egg of Trichuris vulpis look like? | Elliptical-shaped with a “polar cap” (operculum) at each end. |
| How long can Trichuris vulpis eggs survive in the environment? | 3-4 years. |
| What is the lifecycle of Trichuris vulpis? | Direct lifecycle: eggs pass in feces, become infective in 2-4 weeks, host ingests, larvae migrate to the cecum and large intestine, where they mature into adults and lay eggs. Prepatent period is about 90 days. |
| What are the clinical signs of Trichuris vulpis infections? | Bowel irritation (colitis), diarrhea with fresh blood and mucus (hematochezia), tenesmus (straining), and increased defecation frequency. |
| How is Trichuris vulpis diagnosed? | Fecal flotation, though it is difficult due to intermittent egg shedding. |
| How is Trichuris vulpis treated? | Pentazole (Panacur), and reinfection may require rechecking at 3-month intervals. |
| What is the zoonotic potential of Trichuris vulpis? | Questionable; some reports in Russia, but documentation in the US is unclear. |
| What are Trichuris campanula and Trichuris serrata? | They are whipworms similar to T. vulpis, but they are found in cats, and whipworm infections are rare in cats. |
| What is the final host for Capillaria plica (bladderworm)? | Dogs, foxes, and cats. |
| What is the intermediate host for Capillaria plica? | Earthworms. |
| Where do adult Capillaria plica worms live? | In the urinary bladder. |
| What do Capillaria plica eggs look like? | Similar to Trichuris vulpis eggs, but Capillaria eggs are asymmetrical. |
| What is the lifecycle of Capillaria plica? | Final host ingests an earthworm, larvae migrate to the urinary bladder, develop into adults, lay eggs, and the eggs are passed in urine. |
| Does Capillaria plica have zoonotic potential? | No zoonotic potential. |
| What is the common name for Dioctophyma renale? | Giant kidney worm. |
| What is the final host for Dioctophyma renale? | Dogs, foxes, and minks. |
| What is the intermediate host for Dioctophyma renale? | Earthworms. |
| How large can adult Dioctophyma renale worms grow? | Adult females can be up to 40 inches long. |
| Where do adult Dioctophyma renale worms live? | In the kidneys, usually the right kidney. |
| What do Dioctophyma renale eggs look like? | Barrel (oval)-shaped with a thick, pitted shell and operculum at each end. |
| What is the lifecycle of Dioctophyma renale? | Indirect lifecycle: final host ingests an earthworm, larvae migrate to the kidney or peritoneal cavity, and adults lay eggs that are passed in urine. |
| What are the clinical signs of Dioctophyma renale infections? | Urine retention, emaciation, and hydronephrosis (enlargement and destruction of the kidney). |
| How is Dioctophyma renale diagnosed? | Ova are found in urine (fecal flotation is not useful). |
| What is the treatment for Dioctophyma renale? | Surgical removal of the kidney or worms. |
| Does Dioctophyma renale have zoonotic potential? | Yes, larvae can be found in subcutaneous nodules in humans (as an aberrant host). |
| What is the modern name for Capillaria plica? | Pearsonema plica. |
| What is the final host of Strongyloides stercoralis? | Dogs, cats, primates, and humans. |
| Does Strongyloides stercoralis have an intermediate host? | No, it has a direct lifecycle. |
| Where do adult Strongyloides stercoralis worms live? | In the small intestines of the final host. |
| How is Strongyloides stercoralis typically transmitted? | Through cutaneous migration and transmammary transmission. |
| What is the lifecycle of Strongyloides stercoralis? | Ova hatch in the SI of host. L1 larvae pass into feces. L1 larvae develop into infective L3 larvae or into free-living adults. Infective L3 larvae penetrate the skin, enter bloodstream, travel to lungs, coughed and swallowed, and develop into adults in SI |
| What is autoinfection? | When L1 larvae develop into L3 larvae within the host’s gut, completing the lifecycle in one host (Strongyloides stercoralis) |
| What is the prepatent period for Strongyloides stercoralis? | About 2 weeks. |
| What clinical signs are associated with Strongyloides stercoralis infection? | Chronic diarrhea and pruritus (especially in the feet). |
| How is Strongyloides stercoralis diagnosed? | Through fecal exams (direct, float, sediment) and ELISA testing for antibodies. |
| What treatments are available for Strongyloides stercoralis? | Improving sanitation, ivermectin, and other drugs. Treatment should be repeated every two weeks due to auto-infection. |
| What are the final hosts for Thelazia californiensis? | Cats, dogs, sheep, cattle, and humans. |
| What is the intermediate host for Thelazia californiensis? | Various species of flies (house flies). |
| Where do adult Thelazia californiensis worms reside in the host? | In the conjunctival sac or tear ducts. |
| Describe the lifecycle of Thelazia californiensis. | Adult worms lay eggs in the tear ducts/tears. Flies pick up the eggs, which develop into larvae inside the flies. Larvae migrate to the fly’s mouthparts and are transferred to a new host. The larvae mature into adults in the new host’s eye. |
| What is the prepatent period for Thelazia californiensis? | 3-11 weeks. |
| What clinical signs are associated with Thelazia californiensis infection? | Conjunctivitis, eye irritation, and excessive tearing. |
| How is Thelazia californiensis diagnosed? | By finding adult worms in the conjunctival sac or detecting embryonated ova/first-stage larvae in tears. |
| How is Thelazia californiensis treated? | Removal of worms and administration of ivermectin or other drugs. |
| Can Thelazia californiensis infect humans? | Yes, humans can be a final host. |
| What are the final hosts for Spirocerca lupi? | Dogs and wild canines (mainly foxes). |
| What is the intermediate host for Spirocerca lupi? | Dung beetles. |
| What type of host involvement is sometimes seen in the lifecycle of Spirocerca lupi? | Paratenic hosts may be involved. |
| Where do adult Spirocerca lupi worms reside in the host? | In the esophagus. |
| What serious condition is Spirocerca lupi known to cause? | Esophageal cancer (fibrosarcoma). |
| Describe the lifecycle of Spirocerca lupi. | final host Ingests infected beetle. Larva released in stomach, moves to aorta, develops in wall. Larvae migrate to esophagus, body walls them off, nodules may become cancerous. Develop in esophagus, lay eggs, eggs excreted in feces. Dung beetles ingest eg |
| What is the prepatent period for Spirocerca lupi? | 3-6 months. |
| Why is diagnosing Spirocerca lupi challenging? | The parasite lays eggs sporadically, making them difficult to detect in fecal flotations. Imaging (radiographs, CT, MRI), endoscopy, or exploratory surgery may be needed. |
| What are the treatment options for Spirocerca lupi? | Specialized dewormers (normal dewormers do not work). Surgical removal of large nodules (complex surgery). Chemotherapy for fibrosarcoma cases. |
| What are filariae? | Long, threadlike nematodes that are parasitic as adults in the blood, lymphatic system, connective tissue, skin, or eyes of the host. |
| What are the larval stages of filariae called? | Microfilariae (singular: microfilaria), which are found in the host’s blood or lymph. |
| What is the usual intermediate host for filariae? | Blood-sucking arthropods. |
| What are the final hosts of Dirofilaria immitis? | Dogs (primarily) and, rarely, cats. |
| What is the intermediate host of Dirofilaria immitis? | Mosquitoes. |
| Where do adult Dirofilaria immitis worms live in the host? | In the pulmonary artery and the right side of the heart. |
| How large do adult Dirofilaria immitis worms grow? | Males: ~7 inches Females: ~10-12 inches |
| What is unique about Dirofilaria immitis reproduction? | Instead of laying eggs, females produce live microfilariae. |
| Where in the U.S. is Dirofilaria immitis most common? | The eastern seaboard, though it is spreading due to infected stray animals being moved to new areas. |
| What type of lifecycle does Dirofilaria immitis have? | Indirect, requiring a mosquito as an intermediate host. |
| Describe the lifecycle of Dirofilaria immitis in mosquitoes. | Mosquito takes blood meal from infected host and ingests L1 microfilariae, The microfilariae develop into L2 and then infective L3 larvae inside the mosquito, L3 larvae migrate to the mosquito’s salivary glands within 10-30 days, depending on temperature. |
| How does the mosquito transmit Dirofilaria immitis to a new host? | The mosquito bites an uninfected host, depositing L3 larvae into the wound. |
| Describe the development of Dirofilaria immitis larvae inside the final host. | L3 larvae develop into L4 in 3-4 days, L4 larvae migrate through the bloodstream to the thoracic cavity, developing into L5 (50-70 days), L5 larvae reach the pulmonary artery about 70-100 days post-infection, Adults mature + begin producing microfilariae. |
| What is the prepatent period for Dirofilaria immitis? | 6-7 months (time before microfilariae appear in the blood and the animal tests positive). |
| How long can adult heartworms live in a host? | Up to 5 years. |
| What are early clinical signs of Dirofilaria immitis infection? | Many infected animals are asymptomatic early on. |
| What are common chronic clinical signs of heartworm disease? | Deep cough Exercise intolerance (tires easily) Heart murmur Right-sided heart enlargement/failure |
| Can Dirofilaria immitis be transmitted prenatally? | Yes, a bitch with adult heartworms can pass microfilariae to puppies through the placenta, but these larvae do not develop into adults without an intermediate host (mosquito). |
| What is the most common test used to diagnose Dirofilaria immitis? | Antigen testing, which detects antigens from female heartworms in the blood. |
| How is heartworm infection confirmed? | By directly visualizing microfilariae in a blood sample. |
| What supportive diagnostic tests can be used for heartworm disease? | Complete blood count (CBC) Biochemistry profiles Urinalysis Electrocardiogram (EKG) Chest radiographs |
| What are the classifications of heartworm disease based on worm load and clinical signs? | Class 1: Usually asymptomatic. Class 2: Minimal clinical signs. Class 3: Signs of heart failure. Class 4: Caval syndrome (worms in the vena cava/right atrium, requiring surgical removal). |
| What is Caval Syndrome? | Adult worms migrate into the vena cava, causing a sudden shock-like collapse. Symptoms include difficulty breathing and pale gums due to hemolysis. Requires immediate surgical removal of worms. |
| How is heartworm disease prevented? | By killing microfilariae with "microfilaricides," which are effective against L1-L4 stages. |
| What are common heartworm preventatives? | Ivermectin (Heartgard) Selemectin (Revolution) Milbemycin (Sentinel, Interceptor) |
| What is the treatment for adult heartworms? | Melarsomine (Immiticide®): An arsenic-based compound requiring multiple treatments. Caparsolate (outdated drug). Cage rest for 4-6 months to prevent complications from increased heart rate. Preventatives to kill microfilariae and prevent reinfection. |
| Are cats a normal final host for Dirofilaria immitis? | No, but they can become infected. |
| How many adult heartworms are usually found in infected cats? | Only 1-2 adults, if any. |
| Why do cats not produce microfilariae? | Because only 1-2 adult worms are present, and if they are the same sex, they cannot reproduce. |
| What are the clinical signs of heartworm infection in cats? | Vomiting, cough, seizures, fluid accumulation in the abdomen, and sudden death. |
| What is the main diagnostic test for heartworms in cats? | Antigen testing. |
| Why is antigen testing not always accurate in cats? | Because of the low worm burden and the potential absence of female worms (which are required for antigen detection). |
| Why is heartworm treatment difficult in cats? | Cats are very sensitive to drugs, making treatment risky. |
| Can humans be infected with Dirofilaria immitis? | Yes, but it is rare and called “Dirofilariasis.” |
| What happens when Dirofilaria immitis infects humans? | The larvae usually do not survive passage through tissues, and if they do, they do not reach sexual maturity. |
| What clinical signs can humans develop from heartworm infection? | Often asymptomatic, but may experience coughing, chest pain, fever, and pleural effusion due to inflammatory reactions (granulomas) in the lungs. |
| What are the final hosts of Dipetalonema reconditum? | Dogs and monkeys. |
| What are the intermediate hosts of Dipetalonema reconditum? | Fleas and ticks. |
| Where do adult Dipetalonema reconditum live in the host? | In the subcutaneous tissue, as well as near the kidney and peritoneal cavity. |
| Does Dipetalonema reconditum have medical significance? | No, it is of little importance as a parasite. |
| Why is it important to distinguish Dipetalonema reconditum from Dirofilaria immitis? | Because they produce microfilariae, which can be confused with heartworm microfilariae in diagnostic tests. |
| What is the shape of cestodes? | Flat and ribbon-like. |
| What is the function of the scolex in tapeworms? | It is the “head” portion that contains hooks and suckers to attach to the intestinal wall. |
| How do tapeworms absorb nutrients? | Through their skin (cuticle) since they lack a mouth and digestive organs. |
| How do tapeworms grow? | They grow from the scolex downward, forming new proglottids at the base. |
| What is a strobila? | A chain of proglottids. |
| What are proglottids? | Segments of the tapeworm, each containing male and female reproductive parts. |
| What happens to mature proglottids? | They fill with ova, break off, and are excreted in the host’s feces. |
| How do tapeworm proglottids help spread infection? | They can "crawl" away from feces, dispersing eggs in the environment. |
| How are tapeworm eggs released into the environment? | In “packets” containing 6-12 eggs per proglottid. |
| How can tapeworm infections be detected visually? | Individual proglottids may appear as grains of rice around the anus, on hair, or on bedding. |
| What are the different forms of tapeworm larvae? A26: | Cysticercus: Marble-sized sac with one encapsulated scolex Cysticercoid: Microscopic form found in fleas Coenurus: Contains multiple invaginated scolices; each can develop into a worm Hydatid cyst: Large, fluid-filled sac containing multiple scolices |
| How do hydatid cysts affect the intermediate host? | They can grow to the size of an orange or larger, causing significant damage. |
| Do tapeworms cause serious harm to their final host? | Generally, no; they steal nutrients but rarely cause major medical issues. |
| How do tapeworms affect their intermediate hosts? | They can cause significant damage, often slowing down the intermediate host to make it easier for predators to catch. |
| Why are regular dewormers ineffective against tapeworms? | Because tapeworms require specific cestocidal drugs. |
| What is the most common drug used to treat tapeworms? | Praziquantel. |
| What are the final hosts of Dipylidium caninum? | Dogs, cats, and occasionally humans. |
| What are the common names for Dipylidium caninum? | “Cucumber tapeworm” (because its proglottids resemble cucumber seeds) and “flea tapeworm.” |
| Where can Dipylidium caninum proglottids be found? | Adhered to hair, around the tail, on carpets, bedding, or anywhere an infected animal rests. |
| What is a distinguishing movement pattern of Dipylidium caninum proglottids? | They exhibit an inchworm-like crawling motion. |
| How long can adult Dipylidium caninum worms grow? | 1-2 feet. |
| Where do adult Dipylidium caninum worms live in the host? | In the small intestine, attached to the intestinal mucosa. |
| What are the intermediate hosts of Dipylidium caninum? | Flea larvae and biting lice. |
| How do intermediate hosts become infected with Dipylidium caninum? | By ingesting tapeworm eggs from the environment. |
| How does Dipylidium caninum infect its final host? | Infected flea larvae or lice develop into cysticercoid-stage larvae. When a dog, cat, or human ingests the flea/louse, the larvae mature into adult tapeworms inside the intestine. |
| What is Taenia spp.? | A large, diverse genus of tapeworms; adults live in the small intestine of carnivores, with rodents, rabbits, and ruminants as intermediate hosts. |
| What is the final host of Taenia pisiformis? | Dogs. |
| What is the intermediate host of T. pisiformis? | Cottontail rabbits. |
| How does T. pisiformis complete its lifecycle? | Eggs shed in dog feces contaminate vegetation → rabbits ingest eggs → larvae penetrate rabbit intestine, migrate to liver, form cysticercus → dog eats infected rabbit liver. |
| What is the final host of Taenia taeniaeformis? | Cats. |
| What is the intermediate host? | Rodents. |
| How does T. taeniaeformis lifecycle compare to T. pisiformis? | Same lifecycle and larval form (cysticercus); cat eats infected rodent. |
| Who are the final hosts of Taenia hydatigena? | Dogs, wild canids, bobcats. |
| Intermediate hosts of T. hydatigena? | Ruminants, deer, elk. |
| Describe the lifecycle of T. hydatigena. | Eggs shed in feces → ruminant ingests eggs → cysticercus develops in liver → carnivore eats infected liver. |
| Who is the final host of T. multiceps? | Dogs. |
| Intermediate host of T. multiceps? | Sheep and other grazing animals. |
| What is the larval form of T. multiceps, and where does it develop? | Coenurus; develops in the brain of sheep. |
| What clinical signs does T. multiceps cause in sheep? | Blindness, incoordination, circling, paralysis, death (termed "sheep gid tapeworm"). |
| How does the parasite benefit from the clinical signs of T. multiceps? | Neurologic impairment makes it easier for dogs to catch sheep. |
| Who are the final hosts of Echinococcus granulosus & E. multilocularis? | Dogs and cats. |
| Intermediate hosts of E. granulosus? | Herbivores (especially sheep), humans. |
| Intermediate hosts of E. multilocularis? | Small rodents (especially mice), herbivores, swine, humans. |
| Describe the adult Echinococcus worm. | Very small (5 proglottids or fewer); only the last segment is gravid. |
| What does Gravid mean? | Contains ova. |
| What disease does Echinococcus granulosus & E. multilocularis cause in intermediate hosts? | Hydatid cysts in brain and liver. |
| What is the lifecycle of Echinococcus granulosus & E. multilocularis? | Infected carnivores shed eggs → intermediate host ingests eggs → cysts develop → final host eats infected tissue. |
| Where is E. multilocularis prevalent? | Canada, Alaska, northern US; human infection rates higher in fur trappers (e.g., Eskimo populations). |
| How is human infection treated for Echinococcus granulosus & E. multilocularis? | Surgical removal of cysts (careful to avoid rupture). |
| What is the common name of Hymenolepis nana? | Dwarf tapeworm. |
| Final hosts of Hymenolepis nana? | Rats, mice, humans. |
| What makes H. nana unique? | Direct lifecycle — no intermediate host needed. |
| How is Hymenolepis nana transmitted? | Fecal-oral. |
| Is Hymenolepis nana zoonotic? | Yes; lab techs are at higher risk. |
| Hymenolepis nana prevalence in the US vs. Moscow? | US: ~1%; Moscow: ~97%. |
| Hymenolepis nana clinical signs? | Usually benign, but heavy infections can cause diarrhea and weight loss. |
| What is the common name of Diphyllobothrium latum? | Broad fish tapeworm. |
| Final hosts of Diphyllobothrium latum? | Dogs, cats, swine, humans, and other fish-eaters. |
| Lifecycle stages of Diphyllobothrium latum? | Egg → small crustacean (first intermediate) → fish (second intermediate) → final host eats fish. |
| What larval stage of Diphyllobothrium latum develops in fish? | Cysticercoid. |
| Clinical signs of Diphyllobothrium latum in humans? | Pernicious anemia (vitamin B12 deficiency). |
| Diphyllobothrium latum diagnosis? | Finding ova in fecal float or segments in stool. |
| Diphyllobothrium latum prevention? | Cook fish thoroughly; avoid eating raw fish. |
| Where is Diphyllobothrium latum common? | Great Lakes region, mostly in women (tasting while cooking). |
| What is the common name for trematodes? | Flukes. |
| What is the shape of trematodes? | Flat, leaf-shaped worms. |
| What types of suckers do flukes have and what are their functions? | Oral sucker (for nutrients and excreting waste, aka "fluke puke") and ventral sucker (for attachment). |
| Do trematodes require intermediate hosts? | Yes, always (sometimes more than one). |
| Where are trematodes more common? | Large animals (LA) more than small animals (SA). |
| How are trematode eggs identified? | Eggs usually have one operculum. |
| What is the preferred diagnostic method for trematodes and why? | Fecal sedimentation because their eggs are heavy and sink to the bottom. |
| What are the larval stages of flukes? | 1st - Miracidium (cilia-covered), 2nd - Cercaria, sometimes Metacercaria (encysted cercaria). |
| What is the final host of Paragonimus kellicotti? | Dogs, cats, other carnivores, and humans. |
| What are the intermediate hosts for Paragonimus kellicotti? | 1st - snail, 2nd - crayfish. |
| Describe the lifecycle of Paragonimus kellicotti. | Eggs in feces → water → miracidium → snail → cercaria → crayfish → metacercaria → ingested by final host → migrate to lungs → eggs excreted via feces. |
| What are the clinical signs of Paragonimus kellicotti infection? | Coughing, respiratory issues (with heavy load). |
| How is Paragonimus kellicotti diagnosed? | Cysts on radiographs, eggs in feces (sedimentation) or sputum. |
| How is Paragonimus kellicotti controlled? | Prevent animals from eating crayfish or paratenic hosts. |
| Is Paragonimus kellicotti zoonotic? | Yes; can live 20 years in humans, causing fever, cough, weight loss, sometimes mistaken for tuberculosis. |
| What is the final host of Nanophyetus salmincola? | Dogs, cats, raccoons, and other carnivores. |
| What are the intermediate hosts for Nanophyetus salmincola? | 1st - snail, 2nd - salmon. |
| Describe the lifecycle of Nanophyetus salmincola. | Eggs in water → miracidium → snail → cercaria → salmon → metacercaria → ingested by final host → adults in small intestine. |
| Is the fluke itself pathogenic? | No, the fluke is nonpathogenic to the final host. |
| What makes Nanophyetus salmincola dangerous? | It carries the bacteria Neorickettsia helminthoeca, which causes salmon poisoning. |
| What are the clinical signs of salmon poisoning in dogs? | High fever, vomiting, diarrhea; 90% mortality rate if untreated. |
| How can you prevent salmon poisoning? | Cooking or freezing salmon kills the bacteria. |
| What are the symptoms in humans infected with Nanophyetus salmincola? | Mild diarrhea. |
| What are key characteristics of protozoa? | Single-celled, microscopic; most are nonpathogenic, but some can parasitize and cause disease, especially in young or immunocompromised hosts. They can live in blood, intestines, or other areas, and reproduce sexually, asexually, or both. |
| What is a trophozoite? | The activated, feeding stage of protozoa. |
| What is a cyst? | A non-motile, protective stage that helps protozoa survive outside the host. |
| What is an oocyst? | A rigid-walled cyst stage of certain protozoal parasites. |
| What is the final host of Cystoisospora spp.? | Dogs and cats (species-specific types exist for other animals). |
| Does Cystoisospora spp. have an intermediate host? | No, it has a direct lifecycle. |
| Where do adult Cystoisospora live in the host? | Small intestinal epithelium. |
| What is the lifecycle of Cystoisospora spp.? |
Created by:
user-1868551
Popular Veterinary sets