VPAR 55: Veterinary Helminthology Lecture Notes PDF

VPAR 55: VETERINARY HELMINTHOLOGY LECTURE | MA. CHRISTINA T. AGASANG, DVM L1. Introduction to Helminthology Flat worms, bilaterally symmetrical, leaf or ribbon- Helmins/Helminthos – Gk. Worm...

VPAR 55: VETERINARY HELMINTHOLOGY LECTURE | MA. CHRISTINA T. AGASANG, DVM L1. Introduction to Helminthology Flat worms, bilaterally symmetrical, leaf or ribbon- Helmins/Helminthos – Gk. Worm like almost all symmetrical - they both have male and Logos – Gk. Study female sex organs Helminthology - the study of worms parasitic to a. Class Trematoda - Flukes; leaf-shaped, vertebrate animals. It includes the study of their unsegmented with alimentary tract - can morphology, biology, pathogenicity, epidemiology metabolize food and control. b. Class Cestoda (Cestoidea) - Tapeworms; segmented and without alimentary canal - Terminologies absorbed the nutrients from the environment; Bionomics – the study of the mode of life of usually found in the small intestine. They use organisms involved and how they interact with their their integument to absorb nutrients from their natural habitat and their adaptations to their host. surroundings. Also known as ecology/environmental science. Phylum Nemathelminthes Biotic potential – rate at which species will Round bodied or cylindrical worms, radial reproduce with an ideal condition e.g. no predators, symmetry, usually sexes separate – monoecious no problem in food, and no threat to diseases. a. Class Nematoda - contain all roundworm of Dioecious and Monoecious (hermaphrodite) – veterinary importance refer to the reproductive organs. a. Dioecious have separate male and female Phylum Annelida reproductive organ Highly evolved of all helminths of minor veterinary b. Monoecious are hermaphrodite which means importance as leeches are the only parasitic that they have both male and female member. Earthworms serve as intermediate host. reproductive organs inside their body. Direct life cycle – parasite is directly transmitted from one host to another. Indirect life cycle – the parasite is transmitted from one host to another through a vector or an intermediate host. Final / Definitive host – the host to which the parasite reaches its adult stage; final host to accommodate the parasite. *Parasite of freshwater sp. Paratenic host – the host in which development is arrested; they can serve as a bridge to an ecological Phylum Platyhelminthes, Class Trematoda, Subclass gap in life cycle. Digenea Prepatent period (PPP) – like incubation period; Families period in which a parasite and the production of eggs 1. Dicrocoeliidae (3 genera) 2 by a female is going through developmental stage in 2. Opistorchiidae (4 genera) the host. 3. Fasciolidae (4 genera) Primary or Prime host – the host that a parasite or 4. Echinostomatidae (5 genera) any other oganism requires to become sexually 5. Heterophyidae (6 genera) mature in order for them to reproduce. It can be a 6. Plagiorchidae (2 genera) human or any other living organisms. 7. Notocotylidae (3 genera) Reservoir host – a host that would harbor the 8. Brachylaemidae (2 genera) pathogen and serve as a source of that infective 9. Troglotrematidae (4 genera) agent that transmit to a potential host. It sustains the 10. Cyclocoelidae (1 genus) transmission long enough to serve the final host. 11. Paramphistomatidae (10 genera) Transport host – anything that is temporrary and 12. Strigeidae (3 genera) just carry the organism. 13. Diplostomatidae (2 genera) Parthenogony – the production of new individuals 14. Schistosomatidae (3 genera) by single larval forms. This is usually done through asexual multiplication/reproduction e.g. when one Class Trematoda, Subclass Digenea, Order Plagiorchida trematode egg develops to 100 adults. Dorsoventrally flattened, some are long and Gravid – the parasite releases eggs that are passed narrow, some leaf-shaped and some like the in the feces and are immediately infectious. They are amphistomes have thick fleshy bodies. While the carrying eggs that will later on develop into an schitosomes are long and worm-like infective larva. All members of this order are parasitic in domesticated animals. Phylum Platyhelminthes Life cycle requires one, two, or more than two intermediate hosts. ces