2External ParasitesParasite: an organism living at the expense of another organism or host.Host: Animal which serves as a residence for a parasite.External Parasite: Live outside of the digestive, circulatory, and reproductive systems or other internal organs of livestock.
4Ticks Hosts 2 types All types of livestock Major threat to cattle and horses2 typesSoft ticks: outer shell is softFeed rapidly and then leave host.Hard ticks: outer shell is hardFeeds slowly and takes a large meal.Drops from host to lay eggs.
5Ticks Hard Shell Ticks Lone Star Tick: in wooded and brushy areas. Problem in the spring and summerGulf Coast Tick: found in gulf coast areaProblem in late summer and early fall
6Ticks Soft Shell Ticks Life Cycle Spinose Ear Tick: Attaches deep within the earNot a problem in Texas, it is a big pest in other states.Life CycleAdults lay eggs that hatch into larvaeLarvae find hosts such as birdsLarvae becomes NymphsNymphs attach to host (Livestock) and become adults
7TicksDamageCause inflammation, itching, and swelling at the site of the bite.Ticks suck animals blood which can result in anemia, weight loss, and even death.Ticks can also create wounds that can become infected if not taken care of.Spread diseases.
8Ticks Symptoms Usually found by visual inspection. Livestock will rub on objects, and sometimes carry their heads in an unnatural position.index.cfm?event=sit...
9Mites Hosts: All livestock 2 Types Life Cycle Surface mites- Stay on the surface of animalBurrowing mites-Burrow into the skinLife CycleSpend entire life on hostAdult lays eggs that hatch into larvaeLarvae molt & become nymphsNymphs molt and become adults
10MitesDamageHair comes out and skin can become rough and crusty.Also can be called mange or scabiesSymptomsFalling hair and rough, red skin can become visible.Animals will scratch on anything
11Lice Hosts: All species of livestock There is only one species that affects swine.Spread by animal to animal contact2 typesSucking lice- larger and take blood mealsBiting Lice- feed on dead skin and feathers
12Lice Life Cycle Adult female glues her eggs to hairs of host Eggs hatch into nymphsNymphs become mature adults
16Lice Damage Blood sucking can cause anemia Irritation and discomfort to the animalCan cause decrease in appetite which leads to decreased weight gainCan cause death if not taken care of.
17LiceSymptomsRough hair coatsRubbing and ScratchingIrritated animal
18Blowfly (screwworm) Hosts: All livestock Blowfly: the adult stage Screwworm: larval stageLife CycleBlowfly lays eggs around and on woundsEggs hatch into larvae or maggots (which feed on living flesh)Larvae drop to ground & burrow in soil & pupateFlies emerge after pupal stage
19Blowfly (Screwworm) Damage Symptoms Causes weight loss Permanent injuryDeathSymptomsUnpleasant odor from woundEnlargement of woundSeepage of blood from the wound
20Cattle Grub (Heel Fly)Host: Mainly cattle, but they have been found on other species of livestockEmerge in late winter, spring, or summerMainly a nuisance to cattle
21Cattle Grub (Heel Fly) Life Cycle Adult fly lays eggs on hairs of legs Eggs hatch into larvae which penetrate into the hosts bodyMigrate until they reach the backGrubs cut breathing holes & feed on fleshy skinReach maturity & burrow through the hide and drop to the groundGrub goes into the ground and pupatesFly emerges
22Cattle Grub (Heel Fly) Damage Symptoms Can cause economic loss from hide damage and decreased milk production.Decreased amount of feeding timeSymptomsCattle run from the fliesVisible swelling of the grubs on the back of the animals
23Horn Fly Host: Mainly cattle, but will attack other species. Mainly a nuisanceBlood sucking speciesLife CycleFemale lays eggs in manureHatch into larvae that mature and pupateYoung flies emerge and become adults quickly
24Horn Fly Damage Symptoms Bites and sucks blood from the back, neck, head, and belly of the hostCan result in transmission of diseaseAnnoys the animal causing weight lossSymptomsCan be easily seen on the animalsThey can cover an animal in the spring and summer
25Other Flies Hosts: All species of livestock Other flies include HorseflyStable FlyHouseflyThese flies bite and suck blood from the animalsMainly a nuisance to animals
26Other FliesLife CycleAdult females lay eggs in manure, debris, and other dead decaying organic matterEggs hatch into larvaeLarvae mature and pupateFlies emerge from pupae in about a week
27Other Flies Damage Symptoms Irritation from flies can cause loss of appetite and result in weight lossBiting and sucking can cause transmission of diseasesSymptomsEasily seenIrritated animals
28Horse BotsHosts: Horses onlyClosely related to the heel fly
29Horse Bot Life Cycle Adult fly emerges from pupae in feces Females lay about 500 eggs on hairs of horses legs, stomach, neck, and chin.Horse rubs or bites areas infected which stimulates hatchingLarvae enter mouth & migrate to the stomachLarvae attach to stomach wall & matureMature larvae pass out of animal into feces
30Horse Bot Damage Symptoms Can cause anemia Reduce digestion when bots infest the horses stomachCauses irritation to the horseFly is easily seenLoss of weightSometimes scoursIrritated animal
31Quiz Define Host What is an external parasite List three external parasites we discussed today.When you are finished please turn in your quiz.