Leucocytozoonosis Flashcards
(33 cards)
he invertebrate vectors primarily responsible for transmitting Leucocytozoon spp.
Black flies (Simulium spp.) and biting midges (Culicoides spp.)
Infections with Leucocytozoon spp. are most often _________
Subclinical
Mortality rates in Leucocytozoonosis are greatly influenced by factors such as ____
Strain of parasite, host species, age, and immune status
Outbreaks of Leucocytozoonosis have been reported in _________
Chickens, turkeys, and waterfowl
Which Leucocytozoon species is known to cause a lethal hemorrhagic disease of chickens in Southeast Asia?
L. caulleryi
Leucocytozoon simondi primarily causes mortality in _______
Ducks and geese
Clinical disease and mortality in Leucocytozoonosis result from anemia caused by
Antierythrocytic factors produced by the parasite
High numbers of large gametocytes can cause clinical signs by blocking
Pulmonary capillaries
In tissues, Leucocytozoon parasites can invade the endothelium of vessels and form large structures called ________
Megaloschizonts
Megaloschizonts in tissues can occlude vessels and result in _________
Multifocal necrosis
Parasitemia in Leucocytozoonosis often increases dramatically in late April and early May, a phenomenon called _______
Spring rise
The spring rise in parasitemia coincides with the increase in _______
Black flies and biting midges
Ducks recovered from L. simondi infection may relapse when _________
Light cycles are manipulated to increase egg production
Increased levels of which hormone have been suggested as a possible cause of relapse in ducks with L. simondi?
Prolactin
Acute Leucocytozoonosis is seen more often in ________
The young with high parasitemia
Clinical signs in ducklings or turkey poults with Leucocytozoonosis can include _____________
Anemia, leukocytosis, and tachypnea
Mortality rates in ducklings with Leucocytozoonosis can reach up to _____
70%
In visibly affected birds with Leucocytozoonosis, death may occur after how many days following the onset of parasitemia?
7-20 days
In chickens infected with L. caulleryi, the parasite has a tropism for the _______
Reproductive tract
Hemorrhages reported with severe L. caulleryi infection in chickens can be found in _______
Peritoneal, perirenal, and subdural
A key characteristic of Leucocytozoon gametocytes
Lack pigment and distort the host cell
The shape of Leucocytozoon gametocytes
Elongated with tapering extremities or round
Clopidol is a medication used to control which Leucocytozoon
L. smithi
Treatments with quinacrine hydrochloride or trimethoprim/sulfamethoxazole have been used in which avian group?
Raptors
