External Parasites of Livestock Ms.Beasley

External Parasites Parasite: 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.

External Parasites Types of External Parasites Ticks Mites Flies Lice Bots

Ticks Hosts 2 types All types of livestock Major threat to cattle and horses 2 types Soft ticks: outer shell is soft Feed rapidly and then leave host. Hard ticks: outer shell is hard Feeds slowly and takes a large meal. Drops from host to lay eggs.

Ticks Hard Shell Ticks Lone Star Tick: in wooded and brushy areas. Problem in the spring and summer Gulf Coast Tick: found in gulf coast area Problem in late summer and early fall

Ticks Soft Shell Ticks Life Cycle Spinose Ear Tick: Attaches deep within the ear Not a problem in Texas, it is a big pest in other states. Life Cycle Adults lay eggs that hatch into larvae Larvae find hosts such as birds Larvae becomes Nymphs Nymphs attach to host (Livestock) and become adults

Ticks Damage Cause 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.

Ticks Symptoms Usually found by visual inspection. Livestock will rub on objects, and sometimes carry their heads in an unnatural position. www.scienceimage.csiro.au/ index.cfm?event=sit...

Mites Hosts: All livestock 2 Types Life Cycle Surface mites- Stay on the surface of animal Burrowing mites-Burrow into the skin Life Cycle Spend entire life on host Adult lays eggs that hatch into larvae Larvae molt & become nymphs Nymphs molt and become adults

Mites Damage Hair comes out and skin can become rough and crusty. Also can be called mange or scabies Symptoms Falling hair and rough, red skin can become visible. Animals will scratch on anything

Lice Hosts: All species of livestock There is only one species that affects swine. Spread by animal to animal contact 2 types Sucking lice- larger and take blood meals Biting Lice- feed on dead skin and feathers

Lice Life Cycle Adult female glues her eggs to hairs of host Eggs hatch into nymphs Nymphs become mature adults

Lice Cattle Biting Cattle Louse Short-nosed Cattle louse Long-nosed Cattle Louse Cattle Tail Louse Little Blue Louse

Lice Hogs Sheep Hog Louse- Only species that feeds on hogs Sheep Biting Louse Sheep Sucking Body Louse Sheep Foot Louse Hog Louse

Lice Goats Horses Goat Sucking Lice Large, Yellow Louse Angora Goat Biting Louse Goat Biting Louse Horses Horse Sucking Louse Horse Biting Louse

Lice Damage Blood sucking can cause anemia Irritation and discomfort to the animal Can cause decrease in appetite which leads to decreased weight gain Can cause death if not taken care of.

Lice Symptoms Rough hair coats Rubbing and Scratching Irritated animal

Blowfly (screwworm) Hosts: All livestock Blowfly: the adult stage Screwworm: larval stage Life Cycle Blowfly lays eggs around and on wounds Eggs hatch into larvae or maggots (which feed on living flesh) Larvae drop to ground & burrow in soil & pupate Flies emerge after pupal stage

Blowfly (Screwworm) Damage Symptoms Causes weight loss Permanent injury Death Symptoms Unpleasant odor from wound Enlargement of wound Seepage of blood from the wound

Cattle Grub (Heel Fly) Host: Mainly cattle, but they have been found on other species of livestock Emerge in late winter, spring, or summer Mainly a nuisance to cattle

Cattle Grub (Heel Fly) Life Cycle Adult fly lays eggs on hairs of legs Eggs hatch into larvae which penetrate into the hosts body Migrate until they reach the back Grubs cut breathing holes & feed on fleshy skin Reach maturity & burrow through the hide and drop to the ground Grub goes into the ground and pupates Fly emerges

Cattle Grub (Heel Fly) Damage Symptoms Can cause economic loss from hide damage and decreased milk production. Decreased amount of feeding time Symptoms Cattle run from the flies Visible swelling of the grubs on the back of the animals

Horn Fly Host: Mainly cattle, but will attack other species. Mainly a nuisance Blood sucking species Life Cycle Female lays eggs in manure Hatch into larvae that mature and pupate Young flies emerge and become adults quickly

Horn Fly Damage Symptoms Bites and sucks blood from the back, neck, head, and belly of the host Can result in transmission of disease Annoys the animal causing weight loss Symptoms Can be easily seen on the animals They can cover an animal in the spring and summer

Other Flies Hosts: All species of livestock Other flies include Horsefly Stable Fly Housefly These flies bite and suck blood from the animals Mainly a nuisance to animals

Other Flies Life Cycle Adult females lay eggs in manure, debris, and other dead decaying organic matter Eggs hatch into larvae Larvae mature and pupate Flies emerge from pupae in about a week

Other Flies Damage Symptoms Irritation from flies can cause loss of appetite and result in weight loss Biting and sucking can cause transmission of diseases Symptoms Easily seen Irritated animals

Horse Bots Hosts: Horses only Closely related to the heel fly

Horse 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 hatching Larvae enter mouth & migrate to the stomach Larvae attach to stomach wall & mature Mature larvae pass out of animal into feces

Horse Bot Damage Symptoms Can cause anemia Reduce digestion when bots infest the horses stomach Causes irritation to the horse Fly is easily seen Loss of weight Sometimes scours Irritated animal

Quiz Define Host What is an external parasite List three external parasites we discussed today. When you are finished please turn in your quiz.