Lesson 40 - Parasitic Diseases in SA Medicine

What is the epidemiologic triad?

1. host

2. environment

3. parasite

What are the principles of herd health applied to companion animals?

1. surveillance

2. risk factor identification

3. monitoring

4. prevention

5. target intervention

6. evaluation

What are the scientific names for roundworm?

1. Toxocara canis

2. Toxocara cati

What is the clinical important of roundworms?

1. most common GI parasite of puppies and kittens

2. can cause severe disease in young

3. highly persistent in the environment

What is the herd importance of roundworms?

1. massive environmental contamination

2. one female worm can produce thousands of eggs daily

3. eggs survive for years

What is the public health importance of roundworms?

zoonotic parasite causes visceral and larval migrans

How do puppies and kittens present with roundworms?

1. pot-bellied appearance

2. poor growth

3. vomited worms

4. diarrhea

5. poor haircoat

6. weight loss

What results from heavy infections with roundworms?

1. intestinal obstruction

2. intussusception

3. death

What are the clinical signs in adults with roundworms?

often asymptomatic

How do we diagnose roundworms?

1. fecal flotation

2. adult worms in vomitus

3. adult worms in feces

What do roundworm eggs look like?

thick-shelled eggs

How do we treat roundworms?

1. pyrantel pamoate

2. fenbendazole

3. febantel

What is the puppy protocol for roundworms?

2 weeks, 4 weeks, 6 weeks, 8 weeks

Why do we stop puppy protocol at 8 weeks?

thats typically when heartworm treatment starts

What is the prepatent period for roundworms?

3-4 weeks

Why do we start treating for roundworms at 2 weeks?

if we start before they start producing eggs then we can prevent environmental contamination and egg production

How are roundworms transmitted in dogs?

1. transplacental

2. transmammary

3. ingestion of eggs

4. predation

How are roundworms transmitted in cats?

1. transmammary

2. ingestion of eggs

3. predation

How do we prevent roundworm infection?

1. deworm all litters on schedule

2. deworm all dams

3. daily feces removal

4. year-round broad-spectrum parasite prevention

What are the scientific names for hookworms?

1. ancylostoma spp.

2. uncinaria spp.

What is the clinical importance of hookworms?

1. most pathogenic intestinal parasites

What is the herd importance of hookworms?

1. rapid environmental buildup

2. major shelter problem

What is the public health importance of hookworms?

cutaneous larval migrans

How do puppies present with hookworms?

1. pale mucous membranes

2. melena

3. diarrhea

4. weakness

5. anemia

What are the clinical signs of hookworms in adults?

1. weight loss

2. chronic diarrhea

3. poor condition

A shelter housing 100 dogs has limited funds and must choose one intervention this month to reduce parasite transmission throughout the population. Which option is likely to provide the greatest overall reduction in parasite spread?

remove feces from all kennels at least twice daily

How do we diagnose hookworms?

fecal flotation

How do we treat hookworms?

1. pyrantel

2. fenbendazole

3. milbemycin

4. moxidectin

What puppy protocol do we use for hookworms?

same as roundworms

What is a treatment that severe cases of hookworms need?

blood transfusion, fluid therapy, hospitalization

How are hookworms transmitted?

1. skin penetration

2. oral ingestion

3. transmammary

4. environmental contamination

How do we prevent future cases of hookworms?

1. immediate feces removal

2. concrete runs cleaned regularly

3. monthly preventatives

4. strategic deworming

5. quarantine new arrivals

What is the scientific name for whipworms?

Trichuris vulpis

What is the clinical importance of whipworms?

major cause of chronic large bowel disease in dogs

What is the herd importance of whipworms?

eggs survive long in the environment

How do cases present with whipworms?

1. large bowel diarrhea with mucus

2. hematochezia

3. weight loss

4. chronic intermittent clinical signs

5. severe infections may mimic addisons disease

How do we diagnose whipworms?

fecal flotation but egg shedding may be intermittent so often requires multiple fecal examinations; eggs are heavy so try sedimentation

What are the treatments for whipworms?

1. fenbendazole

2. milbemycin

3. moxidectin

4. repeated treatments typically necessary

How are whipworms transmitted?

ingestion of infective eggs from contaminated environments

How do we prevent whipworm infections?

1. monthly preventatives

2. prompt feces removal

3. long-term environmental cleaning

4. routine surveillance

What is the clinical importance of giardia?

one of the most common causes of diarrhea

What is the herd importance for giardia?

1. frequently causes outbreaks because of hardy cysts

2. shelters

3. kennels

4. daycares

How do cases of giardia present?

1. soft stool

2. chronic diarrhea

3. weight loss

4. failure to thrive

5. many carriers show no signs

How do we diagnose giardia?

1. fecal antigen ELISA

2. zinc sulfate flotation

3. direct smear

What is the zinc sulfate flotation used to identify with giardia?

detects cysts

What is the direct smear used to identify with giardia?

detects trophozoites

What is the treatment for giardia?

1. fenbendazole with metronidazole

2. bathe animals at treatment completion to remove cysts from haircoats

How is giardia transmitted?

1. fecal-oral route

2. contaminated water

3. fomites

4. grooming behavior

How do we prevent future cases of giardia?

1. isolate diarrheic animals

2. disinfect appropriately

3. improve drainage

4. eliminate standing water

5. bathe infected animals

6. screen high-risk populations

A shelter routinely administers pyrantel to all puppies upon intake as part of its parasite prevention program. Despite this protocol, new cases of hookworm infection are diagnosed every few weeks, and fecal examinations continue to identify infected puppies throughout the season. Which explanation best accounts for the persistence of hookworm infection in the population?

ongoing environmental exposure is causing rapid reinfection after treatment

What is the scientific name for coccidia?

Cystoisospora spp.

What is the herd importance of coccidia?

can produce explosive outbreaks in crowded settings

What are the clinical signs of coccidia?

1. watery diarrhea

2. weight loss

3. dehydration

4. failure to thrive

5. most severe in young animals

How do we diagnose coccidia?

1. fecal flotation

2. fecal antigen test

How do we treat coccidia?

1. sulfadimethoxine

2. ponazuril (off-label)

3. provide supportive care if necessary

How is coccidia transmitted?

1. fecal-oral

2. contaminated housing

How do we prevent coccidia?

1. frequent cleaning

2. minimize overcrowding

3. separate age groups

4. rapid feces removal

5. quarantine incoming animals

What species of flea is important for small animals?

Ctenocephalides felis

What is the clinical importance of fleas?

1. most important external parasite in dogs and cats

2. flea allergy dermatitis

3. tapeworm transmission

4. bartonella transmission

5. anemia

What is the herd importance of fleas?

rapid environment spread due to 95% of the population exists in the environment

What are the clinical signs of fleas?

1. pruritus

2. hair loss

3. miliary dermatitis in cats

4. flea dirt

5. secondary infections

How do we diagnose fleas?

1. visual identification

2. flea dirt

3. flea combing

4. diagnosis is often clinical

What are the common treatments for fleas?

1. isoxazolines

2. selamectin

3. imidacloprid

4. spinosad

5. treat all animals in the population/household

How are fleas transmitted?

directly from host to host or environment to host

How do we prevent future cases of fleas?

1. treat every animal

2. environmental control

3. vacuuming

4. laundering bedding

5. continuous year-round prevention

What is the clinical importance of ticks?

1. blood loss, skin disease, tick paralysis

2. transmits anaplasma, ehrlichia, babesia, borrelia

What is the herd importance for ticks?

1. environmental risk for ongoing transmission

2. major vectors of multiple infectious diseases

What are the direct effects of ticks?

1. visible ticks

2. dermatitis

3. irritation

What are the vector-born disease signs with ticks?

1. lethargy

2. fever

3. lymphadenopathy

4. thrombocytopenia

How do we diagnose ticks?

1. physical examination

2. tick identification

3. serology or PCR for tick-borne diseases

What are the common treatments for ticks?

1. tick removal

2. isoxazolines

3. flumethrin

4. doxycycline for tick-borne disease

How are ticks transmitted?

environmental exposure to tick habitats

How do we prevent future cases of ticks?

1. year-round tick control

2. habitat management

3. routine screening

4. daily tick checks

A kennel experiences a parasite outbreak despite having few animals with obvious clinical signs. Which statement best explains why asymptomatic infections are important in population medicine?

asymptomatic animals can serve as ongoing sources of parasite transmission

What is the scientific name for heartworm?

Dirofilaria immitis

What is the clinical importance of heartworm?

potentially fatal cardiopulmonary disease

What is the herd importance of heartworm?

one infected dog serves as a reservoir for mosquitos

How do dogs with heartworms present?

1. cough

2. exercise intolerance

3. weight loss

4. right-sided heart failure

How do cats with heartworm present?

1. cough

2. asthma-like signs

3. sudden death

How do we diagnose heartworms in dogs?

1. antigen testing

2. microfilaria testing

3. thoracic radiographs

4. echocardiography

How do we diagnose heartworms in cats?

1. antibody testing

2. imaging

How do we treat heartworms in dogs?

1. melarsomine

2. macrocyclic lactones

3. doxycycline

4. exercise restriction

How do we treat heartworms in cats?

primarily supportive care

How do we prevent future heartworm cases?

1. universal monthly prevention

2. mosquito control

3. annual testing

What do most treatment complications from heartworms stem from?

dying worms and subsequent pulmonary inflammation so exercise restriction is important

What happens day 0 of three-dose melarsomine protocol?

1. diagnosis confirmed

2. start heartworm preventative

3. start doxycycline

4. start prednisone tapering dose if symptomatic

5. begin exercise restriction

What happens day 60 of three-dose melarsomine protocol?

1. first melarsomine injection

2. start prednisone tapering dose

What happens day 90 and 91 of three-dose melarsomine protocol?

second and third melarsomine injections

What is the best protocol for treating heartworms right now?

three-dose melarsomine protocol

Why do we start heartworm preventative before adulticide therapy?

1. prevent new infections during treatment by killing L3 and L4

2. reduces number of circulating microfilariae

3. improves overall treatment success

What is the purpose of prednisone during heartworm treatment?

reduces inflammation caused by dying heartworms

What parasite is this?

roundworms

What parasite is this?

hookworms

What parasite is this?

whipworms

What parasite is this?

giardia

What parasite is this?

coccidia