Small Animal Health Parasites

Vocabulary Parasite: Organisms that live on or within another organism or host and derives its sustenance from the host. Host: animal parasite derives sustenance from

Helminth Worm usually parasitic Anthelmintic Commonly called a Wormer or Dewormer Zoonosis Animal disease which can transmit to humans

Coprophagy: Stool eating

hookworm

Hookworm

hookworm

Hookworm Live in small intestine. Zoonosis Humans get from walking in near tropical infected area. Dogs get from walking laying in infected area.

Cutaneous larval migran

roundworm hookworm

roundworm hookworm

roundworm

Roundworms

Roundworm More common worm issue with dogs. AKA ascarids Live in intestine and eat feed in there. Eggs can lie dormant for years in sand Dogs ingest eggs from infected food, water etc.

Ocular larval migran

Pulmonary larval migran

Heartworm Spread by mosquitoes. Live in areas near oak trees.

tapeworm

Tapeworm Like connected rice. Carried by fleas. If had fleas, possibly tapeworm also.

giardia

Giardia canis Much unknown about this parasite Difficult to detect. Multiple day tests required Diarrhea

Coccidia

Coccidia cause coccidiosis diarrhea common result.

flea

Flea

Ctenocephalides felis (the cat flea) C. Felis is the most common flea found on dogs and cats. C. Canis is actually very uncommon and occurs less frequently on dogs than cats!!

Fleas are tiny, but anyone who has seen one can usually recognize them with ease. They're tiny, flat, wingless insects that have a knack for jumping away before you can catch them. Their bodies are covered with hard plates called sclerites, so if you do catch one, squashing it can be a challenge. Their hard outer shell protects fleas from everything from an animal's teeth to hitting the floor after a long jump. Their flattened bodies and these backward-pointing hairs make it easy for fleas to crawl through their hosts' fur. If something tries to dislodge them, the hairs act like tiny Velcro anchors.

Two sawlike laciniae cut the skin. They also fit together to form a saliva channel. The epipharynx is like a needle. The laciniae surround the epipharynx, and together they form the stylet, or puncturing organ.. The mouth parts of the flea

As with all insects, a flea has three pairs of legs that attach to its thorax. The back legs are very long, and the flea can bend them at several joints. The flea bends its leg, and a pad of elastic protein called resilin stores energy the way a bowstring does. A tendon holds the bent leg in place. When the flea releases this tendon, the leg straightens almost instantly, and the flea accelerates like a bolt from a crossbow. As it lands, the flea uses tiny claws on the ends of its legs to grasp the surface under it.

A flea can jump about 7 inches (17.8 centimeters) vertically or 13 inches (33 centimeters) horizontally. In human proportions, that's a 250-foot (76-meter) vertical jump or a 450-foot (137-meter) horizontal jump!!!!

The Life Cycle of the Flea

At any time 1/3 of flea population in someone’s home is present in egg stage. Adult female lays up to 40 eggs daily. Eggs are laid on host where they fall off to hatch in the environment. Eggs incubate best in high humidity and temperatures of degrees. The Egg

About 57% of the fleas in someone’s home are in the larval stage. Like little caterpillars. Stage that picks up tapeworm eggs (also likely to be in the vicinity) as they graze. Time between hatching and pupating (ie larval stage) depends on environmental conditions. Can be as short as 9 days. Larva

By this stage most young fleas have been killed off by environmental factors. Only 8% make it to pupal stage but once they have spun cocoons they are nearly invincible. Cocoon is sticky and readily picks up dust and dirt. Inside cocoon, pupa is turning into flea Especially protected under carpet, which is why carpet has developed such a reputation as a shelter for fleas. *Pupa can remain dormant in cocoon for many months, maybe even up to a year as it waits for the right time to emerge. Pupae

After the pupa develops, it does not automatically emerge from its cocoon. Instead, able to remain in the cocoon until it detects a nearby host. The mature pupa is able to detect the vibrations of an approaching host, carbon dioxide gradients, and sound and light patterns. When mature pupa feels time is right, he emerges from cocoon, hungry and eager to find host. Young Adult Flea

A common scenario occurs when a dog is boarded while the owner is on vacation. The owner picks up the dog from the boarding kennel and returns home. The mature pupae have been waiting for a host and when the dog enters the home, a huge number of adult fleas emerge at once and attack the dog creating a sudden heavy infestation. Often the boarding kennel is blamed for giving the dog fleas. What likely happened was pupae waited to emerge while there was no host present and then all emerged suddenly when host arrived.

**The unfed flea is able to live for months without a blood meal but during that time it is aggressively using all its powers to locate a host. Once it finds a host, it will never purposely leave the host. Homeless & Hungry! Need a Hairy Dog

Flea allergy dermatitis

Demodectic Mange (Demodicosis or Red Mange)

Sarcoptes scabei (Scabies Mites)

Sarcoptse sacbei Mite Almost every domestic species has its own distinct variety of this mite. S. scabei var. canis (dogs) Notedres cati (cats) Very pruritic because burrow into skin. Scaly, crusty, skin lesions develop on the ears, lateral elbows and ventral abdomen.

Ear mites (Otodectes cyonits)

Ear mite debris

Common cause of otitis externa in dogs, cats and ferrets. Floppy ears worse because it creates hidden moist environment. Occur primarily in the external canal, ear mites may be found anywhere on the body. A common infestation site is the tail and head. Mites are spread by direct contact. Transmissible among and between canines and felines.

Ear Mite Egg

Ear Mite (Psorptes cuniculi) Rabbit Ear Mite

Ticks are dorsoventrally compressed, leathery bodies. The head serves as organ of cutting and attachment. Most ticks are unornate; reddish or mahogany without markings. Adult ticks have 8 legs, with claws on the ends.

Ticks Engorged Tick

tick

Ticks have a voracious blood-feeding activity. Transmit many parasitic, bacterial, viral and other diseases, such as borreliosis (Lyme disease), among animals and from animals to humans. Salivary secretions of some female ticks are toxic and can produce “tick paralysis” in human beings and animals.

Tick Life Cycle

After engorging on a blood meal, female ticks drop off host and seek protected places, such as within cracks and crevices or under leaves and branches to lay their eggs. The six-legged larva, or seed tick, hatch from the eggs and feed on a host. The larva molts to the eight-legged nymphal stage,. After one or two blood meals, nymph matures and molts to the adult stage. During stages, ticks may infest many different host species. Plays an important role in the transmission of disease pathogens to many hosts.

Engorged Tick

Lyme Disease Maps, etc. on lyme disease

A “disease of neglect.” Some of the most prolific ectoparasites of domestic animals. Infestation by lice is called pediculosis. Eggs are called nits. Dorsoventraly flattened, wingless insects. Transmitted by direct contact, but all life stages may be transmitted by fomites (inanimate objects such as blankets, brushes and other grooming equipment capable of transmitting infectious organisms). Species specific. Ex. Dog lice parasitize dogs only.

The head of a chewing louse is wider than the widest portion of the thorax. The thorax contains 3 pairs of legs. They are smaller than sucking lice. Usually yellow and have a large, round head.

Note : Humans cannot get lice from pets. The pet cannot get lice from humans. Remember, SPECIES SPECIFIC!!

The order Diptera includes many different species of flies. Most adults have only one pair of wings (di-(two),-ptera(wings). Diptera members vary in size, food source preference, and developmental stage that parasitizes the animal or produces lesions. Dipterans may feed intermittently on vertebrate blood, saliva, tears or mucus. As larvae, they may develop in the subcutaneous tissues or within internal organs.

Adult dipterans that make frequent visits to the vertebrate host to intermittently feed on blood are called periodic parasites. When larvae (maggots) of some flies develop in the tissue or organs of the vetebrate host, this is a condition called myasis.

Cuterebra species (Wolf Warble)

Larvae infest the skin of rabbits, squirrels, mice, rats, chipmunks, and occasionally, dogs and cats. 2 nd stage larvae are grublike, 5-10mm long and cream to grayish white in color. 3 rd stage larvae are large, robust, black, and heavily spined. Larval stages are usually found in swollen, cystlike subcutaneous sites, with a fistula or pore communicating to the outside environment. The larva breathes through this pore. m m Larval sites are most commonly found on the neck and face, however they have been discovered in the eye.

**Important: Cuterebra larva must be carefully removed. Usually, the breathing hole is enlarged and the larva is removed with thumb forceps. If the larva is crushed during extraction, anaphylaxis may occur. removal/