Trematodes & Protozoa Large Animal Flashcards
What are the trematodes that effect large animal ?
Dicrocelium dendriticum
Fasciola hepatica
What trematode is known as the “liver lancet fluke”
Dicrocoelium dendriticum
What are the hosts for Dicrocoelium dendriticum?
Definitive: ruminants
Intermediate: terrestrial snail (1st) & ant (2nd)
Where is Dicrocoelium dendriticum in the body?
Bile duct branches. Common bile duct -> intestines -> feces
What is the lifecycle for Dicrocoelium dendriticum?
Eggs passed in biles/feces of direct host. Snail ingests egg & hatches to miracidium. Penetrates intestinal wall and becomes sporocysts. Sporocysts multiply and create ~100 daughter sporocysts. Sporocysts become cercariae and encyst in slime. Slime ball is expelled from snail and ant eats slime ball where it becomes infective. Cercariae moves to brain in ant and changes behaviour causing it to climb onto grass to be eaten by ruminant. Migrate to liver via bile duct
How do you diagnose Dicrocoelium dendriticum?
Fecal float
What is the zoonotic potential of Dicrocoelium dendriticum?
Ingestion of ant
Which trematode is known as the liver fluke?
Fasciola hepatica
What are the hosts for Fasciola hepatica?
Definitive: ruminant
Intermediate: aquatic snail
Where does Fasciola hepatica effect the body?
Hepatic bile ducts (liver)
What is the lifecycle of Fasciola hepatica?
Eggs passed from bile duct -> feces. Hatch into miracidium in water. Miracidium penetrates snail and becomes motile cercariae. Cercariae encyst on watercress and definitive eats watercress. (Humans also eat watercress). Penetrate intestine and migrate to peritoneum and liver
How do you diagnose Fasciola hepatica?
Fecal sedimentation
What is the zoonotic potential of Fasciola hepatica?
Eat watercress
Which protozoans effect large animal?
Eimeria spp
Cryptosporidium spp
Sarcocystis neurona
Who are the hosts of Eimeria spp and where does it live in the body?
Definitive: ruminant
Located in cecum and colon
What is the lifecycle of Eimeria spp?
(protozoa) Oocysts are passed and become infective. Oocysts are ingested and sporozoites excyst and invade enterocytes. Asexual reproduction created merozoites which invade enterocytes. Games form (micro & macrogamete). Fuse to create zygote and oocysts exit
How do you diagnose Eimeria spp?
Fecal float
What are the hosts of Cryptosporidium spp and where in the body does it effect?
Definitive: many species
Effects small intestines
What is the lifecycle of Cryptosporidium spp?
Oocysts exits host through feces. Hatch in water and is ingested by host. Mature and attach to small intestine
What is the zoonotic potential of Cryptosporidium spp?
Ingestion of oocysts
How do you diagnose Cryptosporidium spp?
Fecal float
Stained fecal smear
What are the hosts of Sarcocystis neurona?
Definitive: opossum
Intermediate: many mammals
Abberant host: hoses (cannot reproduce)
Where does Sarcocystis neurona effect in the body?
Nervous system (asexual stage)
What is the lifecycle of Sarcocystis neurona?
(protozoa) Opposums pass sporulated oocysts and is ingested by intermediate host. Multiple asexual cycles until it reaches it’s resting stage (sarcocyst). Sarcocyst ingested by definitive host and bradyzoites release. Sexual cycle releases sporulated oocysts that horse can ingest
What are the clinical symptoms of Sarcocystis neurona?
Ataxia, weight loss, muscle spasms, asymmetric weakness, cranial nerve defects, depression
How do you diagnose Sarcocystis neurona?
Neurologic exam. Serology
