Livestock Parasites Flashcards
What are the two most common nematodes of the G.I. tract of ruminants
Haemonchus contortus in goats and sheep.
Ostertagia ostertagi in cows.
Describe Haemonchus contortus
Barberpole nematode. One of the most pathogenic nematodes of ruminants. Causes severe anemia and Edema and goats and sheep
Describe Ostertagia ostertagi
Male Calves are susceptible and adults are immune. Causes acute or chronic gastritis.
What happens in the acute form of Ostertagia ostertagi
Loss of protein, anemia, death
What happens in the chronic form of Ostertagia ostertagi
Kills HCL producing cells
How is haemonchus and ostertagia transmitted
From ingestion of infected ova
Located in abomasum and all intestines.
How is haemonchus and ostertagia diagnosed
On fecal flotation of ruminants. Shows a trichostrongyle.
If a trichostrongyle was recovered from a dog what would it be
A hookworm
How are haemonchus and ostertagia treated
With many common dewormers but it causes resistance
What is now the new way to prevent resistance from dewormers by nematodes.
Famacha method: anemia guide with pictures.
Fecal egg count: used to track parasite infestation levels, individual susceptibility and anthelmintic effectiveness. ***have to be reduced by at least 90% or considered a failure.
What are some other management strategies to reduce the need for deworming
Selective breeding for more parasite resistant sheep or goat’s by culling the most susceptible animals and introducing parasite resistant breeds.
Pasture management. Managed intensive rotational grazing with non-susceptible species such as horse, cattle, swine or poultry. Using cows to vacuum up after calves since adult females are resistant to Ostertagia.
What is the concept of refugia
Antihelminthic’s have contributed to severe drug resistance. Genetically resistant worms have become retained.
What is refugia
Worms that are genetically not as resistant to antihelminthics. Keep nonresistant ones so that they spread on the non resistant worms. Avoid deworming all animals before turning them out onto clean postures.
What is dictyocaulus
Affects cows, sheep and goats. It is a lungworm that is transmitted through the ingestion of larva.
How do you diagnose dictyocaulus
Baermann technique
What is thelazia
Eye worm that affects cows, sheep, goats and dogs.
What is the intermediate host for thelazia
Musca automnalis (face fly)
What are the two common Cestoda of farm animals
Moniezia in cows, sheep and goats.
Taenia saginata in cows.
What is moniezia.
Moniezia in cows, sheep and goats. Lives in GI tract and has various symptoms. More severe symptoms in young.
What is Taenia saginata
In muscles (larval stage) of cows. It’s the beef tapeworm of humans.
What are the two common Trematodes in farm animals
Fasciola hepatica in bo and ov
Fascioloides magna in domestic and wild ruminants
What is fasciola hepatica
In Bo and ov. Lives in the bile ducts.
Describe fascioloides magna
In domestic and wild ruminants
It is a giant liver fluke or Deer fluke.
What are the common apicomplexans of the GI tract in large animals
Eimeria (bovine, ovine, caprine) isospora.
Cryptosporidium (bovine, ovine, caprine).
What does eimeria cause
Diarrhea and dehydration
What does cyptosporidium cause
Diarrhea in calves that can be severe.
Zoonosis.
What is a flagellate of large animals
Tritrichomonas fetus that causes abortions
What are the types of lice that farm animals are affected with
Mallophaga and Anoplura.
List all the flies that farm animals are affected by
Tabanus (horse fly) Haematobia irritans (horn fly) Melophagus ovinus (wingless fly) M. Automnalis (face fly) Hypoderma (bot fly) Oestrus Ovis (nasal boy fly) Cochliomyia hominivorax (screw worm)
What does the Tabanus (horse fly) do
Have a painful bite. They are a nuisance.
What does the Haematobia irritans (horn fly) do
Lay eggs in dehorned animals wounds.
What does the Melophagus ovinus (wingless fly) do
Lives deep in wool or fleece. Feeds on blood causing anemia. Damages skin and wool and parasite infested feces cause wool staining.
What does the M. Automnalis (face fly) do
Feeds on ears, saliva, mucus. Vector of pink eye and thelazia.
What does the Hypoderma (bot fly) do
Burrows into the skin and pokes in and out for air.
What does the Oestrus Ovis (nasal boy fly) do
Burrows into the flesh of the nose
What does the Cochliomyia hominivorax (screw worm) do
Invade fresh and contaminated skin wounds like C-sections. Economically impact the United States because they attacked the livestock. Has the appearance of a screw. Reportable to state and federal authorities, it had been eradicated but importation of animals brought it back.
Where are the sarcoptidae scabiei mites found
Under surface of skin in bogus and Ovis.
Where are the psoroptidae mites found
On the surface of skin of cuniculi, bovis and Ovis.
Where is the psoroptidae chorioptes mite found
Foot and tail mite. Located on lower part of the body.
Where is the non sarcoptiform mite found
Demodex is found in hair follicles.
What ticks are large animals affected by
Ixodes scapularis: deer tick
Dermacentor andersoni: Rocky Mountain wood tick
Amblyoma americanum: lone star tick
Dermacentor albipictus: winter moose tick
What are the pig nematodes of the GI tract
Ascaris suum (roundworm) Trichuris suis (Whipworms)
Why is the pig nematode of the musculoskeletal system
Trichinella spiralis which is found in pig or horse muscle.
How do you diagnose trichinella spiralis
Examination of muscle (often diaphragm muscle)
Explain the zoonotic potential of trichinella spiralis
Undercooked meat. Also from bears, fox, seals. Cause a very painful infection due to fever and larva in body actively creating cysts.
What is the tapeworm of the pig
Taenia solium
What is Taenia solium
Zoonosis from undercooked pork. Forms a Metacestode in muscle. If eggs are ingested humans develop cysticercosis and become an intermediate host. This can lead to epilepsy and death
What are the ciliate protozoans of the GI tract
Balantidium coli. Only ciliate to parasitize humans. Wash all fruits and vegetables with clean water to prevent it.
What is the pig apicomplexans
Cystoisoapora
Cryptosporidium
What arthropods are pigs affected by
Lice
Flies
Mites (sarcoptes and demodex)
What are some generalities associated with livestock parasites
Parasite burdens are not evenly distributed in the herd. About 20% of animals harbor about 80% of parasites. Treatment is done for the herd and not the individual, the goal is not to eliminate but rather reduce the parasite burden. Severely affected individuals are often culled from the herd.
