Objectives: 1.To learn the different stages, types and classes of parasites 2.To learn the host(s) of each, their life cycle, damage and symptoms 3.To learn control methods and common chemicals used for prevention

2 Parasites cause many economic losses Slow animals growth, lower feed conversion, decrease production and may cause death Early treatments decrease economic losses Parasites and Economics

3 1.parasite— organism living in or at the expense of another living organism 2.host— animal which serves as residence for parasite 3.larvae— first immature stage emerging from the egg 4.pupae— stage following the larval stage 5.nymph— any immature stage of a parasite (larvae or pupae) 6.adult— last stage, lay eggs and reproduce Terminology

4 Four types of parasitic organisms: 1.Fungi 2.Protozoa 3.Helminths – worms 4.Arthropods – ticks and insects Types of Parasites

5 1.External— live outside digestive, circulatory, reproductive and internal organs as adults 2.Internal— live within digestive, circulatory, reproductive and internal organs as adults Classes of Parasites

6 Since there are only two classes, there are only two ways to control them: 1.Externally— includes spraying, dusting, dipping, pour-ons, injections, sanitation and pasture rotation 2.Internally— putting chemicals into the body (worming) Control Methods

7 1.Water 2.Feed 3.Paste 4.Drenching with a drench gun 5.Tubing with plastic tube and drench gun 6.Bolus using a plastic balling gun 7.Injection Worming Methods

8 Two families of ticks are Argasidae and Ixodidae Three most important ticks: 1.Lone Star Tick – three host tick (argasidae) 2.Gulf Coast Tick – three host tick (argasidae) 3.Spinose Ear Tick – one host tick – (ixodidae) Host - all livestock External Parasites: Ticks

9 Life Cycle –adult lays eggs hatching in days –eggs hatch, find host, attach and feed on blood –stay attached until adult hood, then detach and lay eggs –life cycle ranges from a few days to several months External Parasites: Ticks

10 Damage –anemia –weight loss –death Symptoms –unthrifty –rubbing on objects –unnatural head and ear carriage Control –pasture rotation –cold winters –chemicals External Parasites: Ticks

11 Host – all species Life Cycle –adults lay and glue eggs to hair follicles –eggs hatch in 1-2 weeks and become adults in 2-4 weeks –live entire life on host, feeding on skin and blood External Parasites: Lice

12 Damage –irritation, rubbing and scratching –anemia –unthrifty –weight loss Symptoms –rough hair coat –rubbing –scratching Control –chemical control with sprays, dips, dust, pour-ons and injections External Parasites: Lice

13 Includes many species causing skin problems such as scabies, scabs, mange or barn itch Host – all species Life Cycle –adults lay eggs on skin of animal –eggs hatch in 4 days –feed on skin and reach adult stage in about 12 days –spend entire life cycle on host External Parasites: Mites

14 Damage –hair falls out –skin becomes rough and crusty Symptoms –spots of rough, crusty skin with no hair –scratching and itching Control –chemicals are used –some are serious and USDA will quarantine animal External Parasites: Mites

15 Larval stage is a flesh eating worm Adult stage is a fly Unless controlled, larval stage will kill host Host – all species External Parasites: Screwworm

16 Life Cycle –adult fly lays eggs at sight of a wound –eggs hatch in hours into maggots feeding on flesh –complete growth in five to seven days –drop to ground and then burrow into soil –pupal stage lasts for a few weeks –emerge as flies External Parasites: Screwworm

17 Damage –sores –weight loss –permanent injury and death Symptoms –unpleasant odor –large wounds –seepage of blood serum from wound External Parasites: Screwworm

18 Control –chemical control –contact Southwest Animal Research Foundation –eradication program in progress sterile male flies are produced and released female only mates once and lays unfertilized eggs There have only been a few cases in the past years External Parasites: Screwworm

19 Host – cattle Life Cycle –adult fly lays eggs on hair of rear legs (lower part) each spring –eggs hatch and larvae enter host’s body through hair follicles –larvae migrate from back legs, to stomach area, to shoulder, to middle back (many larvae die along the way) –larvae become grubs and cut a breathing hole in skin –at maturity, they “pop” out of hole and fall to the ground, burrowing into soil –emerge as a flies with no mouth in 2 months External Parasites: Heel Fly or Cattle Grub

20 Damage –holes in hide –cattle run from flies which causes injury and weight loss –damage to meat Symptoms –bumps on back –cattle running in spring for no apparent reason –presence of flies Control –systemic insecticide before larvae reach back External Parasites: Heel Fly or Cattle Grub

21 Host – all species Life Cycle –adults lay eggs in manure or dead decaying matter –eggs hatch into larvae in 24 hours –larvae mature into pupal stage in 5-10 days –flies emerge from pupae in 3-7 days –reach maturity in just a few days External Parasites: Horn Fly

22 Damage –flies bite and suck blood –animals become annoyed, results in weight loss –flies transmit diseases Symptoms –flies can be seen Control –chemical –feed additives –ear tags –sanitation External Parasites: Horn Fly

23 Host – all animals Life Cycle –adults live as blood sucking parasite attached to the stomach wall –eggs pass out with feces and hatch in days –larvae are eaten and travel to the stomach where they mature into adults Internal Parasites: Stomach Worm

24 Damage –holes in stomach lining –poor digestion Symptoms –anemia (paleness of gums and whites of eyes) –weight loss –dull hair coat –unthrifty Control –sanitation –pasture rotation –chemical wormer Internal Parasites: Stomach Worm

25 Effect mainly young animals Animals build an immunity as they grow older Also called blood worms Host – all species Internal Parasites: Strongyles

26 Life Cycle –adult lives as blood sucking parasite in small intestine –eggs are laid and pass out in feces –hatch into larvae in 5-20 days –larvae are eaten and travel to small intestine –larvae burrow holes into arteries and internal organs causing much damage Internal Parasites: Strongyles

27 Damage –most detrimental –reduced digestion –blocking of arteries Symptoms –anemia –weight loss –rough hair coats –scouring Control –sanitation –pasture rotation –chemical wormer Internal Parasites: Strongyles −organ damage −colic in horses

28 Largest of the round worms Host – cattle, sheep, hogs, horses Life Cycle –adults live in small intestine, lay eggs which pass out with feces –eggs are eaten, travel to small intestine, hatch into larvae and burrow holes through the intestinal wall –larvae migrate through liver, heart and into lungs –host coughs up larvae and swallows, returning larvae to small intestine to attach –adults may grow 8-15” in length Internal Parasites: Ascarids

29 Damage –to lungs and liver, causing disease and anemia Symptoms –dull hair coat –colic –weight loss –unthrifty Control –sanitation –pasture rotation –chemical wormers Internal Parasites: Ascarids

30 Host – all species Life Cycle –adults live in lungs and lay eggs –eggs are coughed up, swallowed, hatch and pass with feces –larvae are eaten and passed into small intestine –larvae burrow holes through intestinal wall and go to lungs where they mature Internal Parasites: Lungworms

31 Damage to lungs, trachea and bronchial tubes Symptoms –coughing and forceful breathing –fever, stops eating and becomes gaunt Control –sanitation –pasture rotation –chemical wormers Internal Parasites: Lungworms

32 Host –all species are a major host –mites are intermediate host Life Cycle –adults live in small intestine and feed on food, not host –may grow to lengths of feet –segments containing eggs break off and are passed with feces –eggs are eaten by mites and develop until eaten by a major host –eggs hatch in small intestine and mature Internal Parasites: Broad Tapeworms

33 Damage –no physical damage –compete for food Symptoms –weight loss –diarrhea –unthrifty Control –chemical control –must be edible to tapeworm Internal Parasites: Broad Tapeworm

34 Host –cattle, sheep, goats and humans Life Cycle –adults live in bile ducts and begin egg production approximately 3 months after entering host –eggs pass out through feces and must land in water to hatch –larva must attach to a snail to complete life cycle –larva then encyst on water plants eaten by livestock –young flukes pass to small intestine, where they burrow holes throughout the abdominal cavity and enter the liver to live on blood Internal Parasites: Liver Flukes

35 Damage –fibrosis of liver –thickening of bile duct Symptoms –anemia –weight loss –death Control –pasture rotation –no wet areas –use water troughs and chemical wormers –snail population control Internal Parasites: Liver Flukes

36 Parasites can cause numerous health problems for livestock and humans. There are various chemical and natural ways to prevent parasite infections. Necessary precautions are imperative in order to prevent infection. Summary