parasites worms

Toxascaris leonina- t. canis, t. cati, t. leonina

Round worm

Round worm host

Cats and dogs

Roundworm location adults

Small intestine

Roundworm transmission route

Ingestion of egg, trans-placental in dogs, trans-mammary in cats

Are roundworms zoonotic

Yes, except t leonina

Life cycle of the roundworm

1. Adult roundworms live in the animal’s small intestine.

1. Adults produce eggs, which leave the animal in the feces.

2. Eggs develop in the environment and become infective.

3. The animal eats/swallow the infective eggs.

4. Larvae hatch in the intestine and travel through the body.

5. Larvae eventually return to the intestine.

6. Larvae grow into adult roundworms.

7. Adults lay eggs, and the cycle starts again.

Easy way to remember:
Adult → Eggs → Environment → Ingested → Larvae → Intestine → Adult

Infective stage of the round worm

L3

4 specific clinical signs of roundworm

Usually subclinical, emesis, general GI issues, potbelly, poor growth rate

How long do round worms take to mature

2 weeks, this is when we start deworming porceses

Roundworm diagnosis

History, physical exam, fecal floatation

Roundworm treatment

Panacur- fenbendazole

Selavectine- selamectin

Pre-patent period

Before its detectable

Ancylostoma tubaeforme- a. Caninum

Hookworm, common in bc/canada

hook worm host

Dogs, cats, humans

Hookworm location

Small intestine

Hookworm transmission

Skin penetration, transmammary

Is hookworm zoonotic

Yes

What does hookworm feed on and how

blood, secretes an anticoagulant from its mouth causing continuous bleeding from host

Hookworm life cycle

1. Adult hookworms in animal’s small intestine.

2. Eggs are passed out in the feces.

3. Eggs hatch in the environment and develop into infective larvae.

4. The animal becomes infected by swallowing larvae or through the skin.

5. Larvae travel through the body and reach the small intestine.

6. Larvae mature into adult hookworms.

7. Adults produce eggs, which are passed out in feces.

8. The cycle starts again.

Easy way to remember:
Adult → Eggs → Feces → Larvae → Infection → Intestine → Adult

Hookworm infective stage

L3

4 specific clinical signs of hookworm

Enteritis, severe diarrhea, melena, anemia

Hookworm treatment

Anything that will cure roundworm

What is enteritis

Inflammation of the intestines

What is erythema

Redness of the skin

What is melena

Black or tarry bloody stool

hookworm diagnosis

History, physical exam, centrifuge fecal float, fecal pcr

T/F- anything that can treat hookworm will treat roundworm

true

Trichuris vulpis

Whipworm

whipworm host

dogs

is whipworm zoonotic

no

location of whipworm

cecum and colon

whipworm transmission route

ingestion of eggs, indirect transmission between animals via paratenic host

what do whipworm feed on

blood

T/F- the thin end of the whipworm is the head

true

whipworm life cycle

1. larva develop in the small and large intestine

2. females lay eggs which leave the body via feces

3. eggs develop in warm, moist soil and become infective after 2-3 weeks

4. egg is swallowed, infecting the host

5. eggs hatch in small intestine and release larvae

6. larvae move into large intestine to mature

7. adults attach to intestinal lining and produce eggs

8. eggs leave body via feces

9. eggs are ingested thus infection occurs

whipworm clinical signs

hemorrhagic colitis, dehydration, anemia, weight loss, death

whipworm transmission

ingestion of infected eggs from soil, indirect transmission between hosts

whipworm diagnosis

History, physical exam, clinical signs, centrifuge fecal float, fecal elisa test, fecal pcr

Whipworm treatment

Panacur, trifexis, will also treat hook and roundworm in dogs

Dirofilaria immitis

Heart worm

Heartworm life cycle

1. Mosquito bites infected animal → picks up microfilariae

2. Microfilariae develop into infective L3 larvae inside the mosquito

3. Mosquito bites another animal → L3 larvae enter the animal

4. L3 larvae migrate through tissues → develop into adult heartworms

5. Adult heartworms live in the pulmonary arteries → produce microfilariae

6. Microfilariae circulate in the bloodstream → another mosquito picks them up

7. Cycle repeats

Heartworm clinical signs

Exercise intolerance, Persistent cough, Dyspnea, Cyanosis, Fainting, Ascites

Heartworm treatment

vasodilators, corticosteroids, diuretics

What is dyspnea

Trouble breathing

What is cyanosis

Blue gums

What is ascites

Edema in abdominal cavity

Heartworm transmission

Indirect transmission, Requires mosquito as intermediate host

Heartworm diagnosis

History, Physical exam, Clinical Signs, Echocardiography, Elisa Test, Blood smear, Modified knotts test

Heartworm lifespan

5-7 years in dogs

spirocerca lupi

esophageal worm

Esophageal worm transmission

Ingestion of eggs, dung beetles

T/F- Esophageal worm is zoonotic

false

Esophageal worm Clinical signs

Emesis, Coughing, Gag reflex

Esophageal worm Diagnosis

History, Physical exam, Clinical Signs, Endoscopy, Fecal float

Esophageal worm Treatment

Excision of mass, milbemicyn and imidacloprid combo

What is a definitive host

Where the parasite becomes an adult and reproduces in it

example: dog with adult tapeworm

What is a paratenic host

Temporary carrier, parasite does not develop inside

Example: rodent carrying toxocara larvae→ dog eats rodent

What is intermediate host

Parasite develops inside it but does not fully mature

Example: flea carrying tapeworm larvae → dog eats flea

What is reservoir host

Host that keeps the parasite in the environment and can spread it to other hosts

Example: rodents carrying leptospirosis, urinated on ground, other animal is exposed to the urine this spreading the infection

Direct vs indirect transmission

Direct: parasite spreads directly from one host to another

Indirect: parasite spreads through something else first such as food, water, soil, or another animal