(DON'T STUDY) Family Ancyclostomatidae Flashcards
What are these known as
hookworms
Hookworms are so called because the anterior end is
bent dorsally
The buccal capsule has __________ at the outer margin and ________ within the capsule.
cutting plates
teeth within the capsule
Typically hookworm larvae enter the host by the ___________ route and migrate via the ________ and ___________.
percutaneous
heart and lungs
Hookworms all mature in the _____ intestine and here primarily feed on _________.
small
blood
Name the two hookworms that occur in dogs in New Zealand; state which is most common, which is more pathogenic, how the adults may be distinguished and in what way the mode of infection of the host may differ.
1)Uncinaria stenocephala more common
less pathogenic
smooth cutting plates not in bitch’s milk
2)Ancylostoma caninum
less common
more pathogenic toothed cutting plates can infect via bitch’s milk
The hookworm found in New Zealand cattle is _____________.
Bunostomum phlebotomum - cattle
The hookworms found in New Zealand sheep is _____________.
trigonocephalum - sheep
Describe a simple flow diagram of their life cycle.
L3 exsheathes and penetrates skin ——> blood ——> heart ——-> ——> lungs —–> trachea ——> pharynx ——-> small intestine.
What genus of hookworm may be found in pigs in this country?
Globocephalus
Define “cutaneous larva migrans”.
Migration of nematode larvae in the skin of an abnormal host. (These are almost invariably hookworm
larvae).
The principal effect of hookworm infections is to cause _______.
Anaemia.
How would you expect the characteristics of this Anemia to change with increasing duration of infection?
Initially, the anaemia is simply due to blood loss, i.e. post-haemorrhagic; erythrocytes produced by the bone marrow to attempt to compensate for the loss are normal - the anaemia is normocytic and normochromic though some anisocytosis (irregularity in cell size) may develop. In longer standing infections the picture is complicated by loss of iron and the anaemia tends to become microcytic and hypochromic.
Hookworm infections in dogs in this country are much more common in working than in pet dogs. What do you think are the reasons for this?
The principal reason for the difference is in the management of dogs. Working dogs are often chained to kennels on the ground. They are forced to lie on soil that becomes heavily contaminated with faeces, and consequently with hookworm larvae. They are exposed to a continual high level of infection. This situation is often aggravated by poor diet of working dogs.
