Parasites Flashcards
Examples of roundworms
Nematodes
Example of flatworms
Cestodes(tapeworm)
Trematodes (flukes)
Typical Nematode DIRECT life cycle
Egg-l1-l2-l3-immature-mature-repro product
How helminths differ from other pathogens
Parasitic infections are not contagious
Disease is associated with quantitative exposture
Host site specificity
Most adult helminths occupy organs with a direct connection to the external environment (GI tract, pulmonary, urinary)
Adaptations to unfavorable environments
Some parasites have extremely persistent infective stages
Some use vertical transmission and skip environment
Some can transmit infections through paratenic hosts
Some use arrested development
Examples of nematode life cycles and transmission strategies
Canine whip worm
Feline roundworm
Canine roundworm
Canine hook worm
Trichuris vulpis: canine whipworm: where is it?
Cecum and large intestine
Trichuris vulpis: canine whipworm: clinical signs
Bloody diarrhea, weight loss
Toxocara cati: feline roundworm: where is it
Small intestine
Toxocara cati (feline roundworm):infective stage
Larvated egg
VISERCAL larva migrans in humans
Toxocara cati (feline roundworm): clinical signs
Weight loss
Distended abdomen
Poor growth
Toxocara cati (feline roundworm): route of infection
Oral ingestion
Transparency (lactogenic) paratenic hosts
Ancylostoma caninum (canine hookworm): where is it
Small intestine
Ancylostoma caninum (canine hookworm): infected stage
Larva
Cutaneous larva in humans
Ancylostoma caninum (canine hookworm): clinical signs
Blood loss anemia
Hypoproteinemia
Ancylostoma caninum (canine hookworm): routes of infection
Oral ingestion
Percutaneous
TransmarrAry
Paratenic hosts
Toxocara canis (canine roundworm): where is it
Small intestine
Toxocara canis (canine roundworm): infected stage
Larvated egg
Visceral/ocular larva in humans
Toxocara canis (canine roundworm): clinical signs
Weight loss
Distended abdomen
Poor growth
Toxocara canis (canine roundworm): route of infection
Oral ingestion
Prenatal (intrauterine)
Paratenic hosts
Helminth parasites
Roundworms and flatworms
Typical indirect life cycle
Repro product: infect age stage-immature-mature-repro product
Dipylidium caninum (flea tapeworm): where is it
Small intestine
Dipylidium caninum (flea tapeworm): how is it passed
Passed within proglottids
Eggs must be ingested by a flea
Dogs and cats ingest infected flea
Dirofilaria immitis (canine heartworm): where is it
Right heart and pulmonary arteries
Dirofilaria immitus (canine heartworm): microfilaria
Reproductive product
Ingested by Mosquitos
INFECTED STAGE
Dirofilaria immitus (canine heartworm): clinical signs
Coughing
Weight loss
Exercise intolerance
Heart failure
Nematodes diagnosis
Fecal exam
Centrifugal flotation is most sensitive
Treatment: antihistamines ‘‘dewormers’’
NEMATODES- narrow spectrum
Piperazine-ascarids
Pyrantel pamoate, emodepside-ascarids and hook worms
Treatment:anthelmintics (nematodes broad spectrum)
Benzimidazoles (ascarids, hookworm, whipworm, tapeworm)
Macrocyclic lactones
Treatment: Cestodes
Benzimidazoles
Praziquantel
Adulticide
Kills the adult worms in the heart and lungs
Microfilaride
Kills the microfilaria circulating in the blood
Adulticide treatment
Imiticide: 2 24 hours apart in lumbar muscles
Microfilaricide
Usually four weeks after Adulticide treatment
Ivermectin can cause shock is MF in large numbers
Prevention
Yearly blood test
Preventative drugs
