Parasitology slide set 4/fleas Flashcards
Infectious
caused by or capable of being communicated by infection
Infective
capable of producing infection
Pathogenesis
development of morbid conditions or disease; more specifically the cellular events and reactions and other pathological mechanisms occurring in the development of disease
Direct life cycle
only 1 host
Indirect life cycle
more than one host
Definitive host
host in which the parasite attians sexual (reproductive) maturity
Intermediate host
Serves as a temporary but NECESSARY environment for completion of immature stages of the life cycle
Paratenic host
aka transport host
Host not needed to complete life cycle but utilized as vehicle for reaching a necessary host
Aberrant host
an animal not usually used as a host by a parasite
Reservoir host
infected animals which serve as a source of infection for others (includes all infectious agents, not just parasites)
Vector
arthropods or other invertebrates which serve as hosts and carriers for parasites (may be intermediate or transport host)
Terminology for hosts from the parasite’s point of view
definitive
intermediate
paratenic
Terminology for hosts from the host’s point of view
normal
aberrant
vector
reservoir
Prepatent period
(infection to egg)
Time required following to reach reproductive maturity following infection of the definitive host; not the same as the generation time (egg to egg)
Parasitic infection is ______ to disease
not equivalent
Complete metamorphosis
larva bears no resemblance to the adult (ex. flies, fleas)
Incomplete metamorphosis
larva looks like a small adult
juvenile hormone inhibits metamorphosis (lice)
Order Siphonaptera
Fleas macroscopic, usually brown wingless laterally compressed complete metamorphosis
Ctenocephalides felis (felis) host
dogs, cats, ferrets, occasionally other animals
most common flea off cats and dogs
Environmental stages of C. felis prefer
high humidity and warm temperatures
C. felis larva
slender, white, 2-5 mm eat organic debris but require flea feces limited movement stay in this stage for about 1 week hate low humidity
C. felis pupa
sticky, silky cocoon
if warm and humid 5 days to adult
adult can stay in pupa a few months
Minimum life cycle under perfect conditions of C. felis
Egg hatching 2 days
Larva 6 days
Pupa 6 days
so Total of 14 days
C. felis overwinter survival
No stage of the life cycle can survive sustained cold weather, killed by 10 days at 37F
Fleas overwinter in your house and reservoir hosts (raccoons and opossums)
Clinical importance of fleas
common cause of vet visits
characteristic distribution: tailhead, thighs, abd, neck
Scratching, hair loss
Range of reactions to C. felis
Allergic type rxns to flea saliva antigens
Pruritus ranges from mild to extreme (flea bite hypersensitivity)
Possible cause of hot spots
Vector for tapeworms and cat scratch fever
Anemia
Adulticides for fleas
imidocloprid and fipronil can break the cycle in some situations by themselves
dinotefuran, nitenpyram, selamectin, indoxacarb, spinosad, pyrethroids, pyrethrins, natural products
Flea control products that are not effective
ultrasonic collars, brewer’s yeast, garlic
organophosphate flea collars are not very effective
Fleas are ______ species specific
generally
