Digestion & Metabolism 2: SA Common GI Parasites

Question 1

ASCARIDS…
“common name?”
4 organisms? (not species)
prevalence?
adult worms… (4: where they live, size, color, morphology)
how FERTILE are these worms?
how RESISTANT are the eggs?

Answer 1

“ROUNDWORMS”

4 organisms?
1. TOXOCARA CANIS
2. TOXOCARA CATI
3. TOXASCARIS LEONINA
4. BAYLISASCARIS PROCYONIS

HIGHLY prevalent across US!

ADULT WORMS…
1. live in SI
2. LARGE
3. CREAM-colored
4. has 3 PROMINENT LIPS on ANTIERIOR end

Question 2

ID PARASITE

CERVICAL ALAE = ???

Answer 2

ROUNDWORM (ascarid)

CERVICAL ALAE = CUTICULAR EXPANSION

Question 3

TOXOCARA CANIS/CATI…
what type of parasite? (2 names)
commonality/age?
what type of life cycle?
2 types of hosts?
contagion?
PPP?

Answer 3

ASCARID/ROUNDWORM

VERY common among YOUNG ANIMALS

DIRECT life cycle

can have DEFINITIVE but SOMETIMES PARATENIC hosts

CAN BE ZOONOTIC

PPP = 1-2 MONTHS

Question 4

TOXOCARA LEONINA…
what organism is this? (2 names)
frequency when compared to T. canis?
can infect WHAT 3 SPECIES?
contagion?
what 2 methods of transmission DO NOT OCCUR?

Answer 4

ASCARID/ROUNDWORM

LESS frequent than T. canis

3 species…
1. CATS
2. DOGS
3. WILD ANIMALS

NOT zoonotic

2 methods of transmission that DOES NOT OCCUR?
1. TRANSPLACENTAL
2. TRANSMAMMARY

Question 5

BAYLISASCARIS PROCYONIS…
what organism is this? (2 names)
life cycle type?
what acts as the INTERMEDIATE host?
contagion/geography?

Answer 5

ASCARID/ROUNDWORM

has INDIRECT life cycle

SMALL MAMMALS are INTERMEDIATE HOSTS

is ZOONOTIC across NORTH AMERICA

Question 6

LIFE cycle of SA ROUNDWORMS…
how is the disease TRANSMITTED? (2)
TRACHEAL larval migration process? (2)
SOMATIC larval migration process? (2)
what determines the FATE of the larvae? give the two options

Answer 6

transmission?
1. INDIRECT OR DIRECT life cycle
2. INGESTION of INFECTIVE EGGS CONTAINING L3

TRACHEAL larval migration process?
1. LARVAE migrate through LIVER & LUNGS
2. then SWALLOWED to DEVELOP IN SI

SOMATIC larval migration process?
1. if LARVA DO NOT ENTER ALVEOLUS in lung, it’s RETURNED TO THE HEART by PULMONARY VEINS
2. larvae then MIGRATE TO SOMATIC TISSUE & ENCYST AS L3

FATE of larvae depends on AGE/IMMUNE status of dog..
1. DOGS < 5 WEEKS = develops in INTESTINE
2. DOGS > 5 WEEKS = migrates to SOMATIC tissue

Question 7

in CATS with ROUNDWORMS, what 2 kinds of transmission DO NOT OCCUR? what species CAN this occur in?

what method of transmissions is MOST COMMON?

Answer 7

1. TRANSPLACENTAL
2. PRENATAL
   –> THIS CAN OCCUR IN DOGS, SO PUPPIES CAN BE BORN INFECTED

common to have INGESTION OF PARATENIC HOST

Question 8

PATHOGENESIS of roundworms…
cause WHAT LEVEL of dz?
more common in what AGE/SPECIES?
4 clinical signs? (& one that’s most important)
if the common species is infected PRENATALLY, what DISEASE can occur? (2 names but it’s one thing)

Answer 8

causes SEVERE DISEASE!

more common in DOGS <1 YEAR OLD

clinical signs?
1. POT-BELLIED APPEARANCE (important)
2. POOR HAIR coat
3. OBSTRUCTION of intestine
4. FAILURE to gain weight

if dogs INFECTED PRENATALLY, can cause SECONDARY PNEUMONIA or VERMINOUS PNEUMONITIS

Question 9

what DZ should we suspect in this puppy?

Answer 9

ROUNDWORM/ASCARIDS

(T. canis, T. leonina)

Question 10

TOXOCARA CANIS…
commonality?
what’s the MOST IMPORTANT route of transmission?
what 2 things contribute to HIGH PREVALENCE of T. canis?

Answer 10

VERY common in YOUNG PUPS, “virtually all pups are born infected”

MOST IMPORTANT route of transmission = TRANSPLACENTAL

high prevalence?
1. TRANSPLACENTAL transmission
2. HARDY NATURE OF LARVATED EGGS

Question 11

TOXOCARA CATI…
severity of DZ compared to dogs with T. canis?
what is the most IMPORTANT route of transmission?
2 differences when compared to T. canis infection?

Answer 11

T. CATI tends to cause LESS SEVERE DZ than T. CANIS in DOGS

infection occurs via INGESTION OF PARATENIC HOST

when compared to T. canis…
1. PRENATAL INFECTION via PLACENTA DOES NOT OCCUR
2. TRACHEAL MIGRATION in EGG INFECTION remains HIGH THROUGHOUT CAT’S LIFE

Question 12

PUBLIC HEALTH considerations for ROUNDWORM…
who is it a danger for?
VLM (5 invasion sites) and OLM (2 possible outcomes) clinical presentations in HUMANS?
BAYLISASCARIS PROCYONIS can cause WHAT signs in humans?

Answer 12

who is it a danger for?
–> ACCIDENTAL INGESTION of EGGS CONTAINING L3 is MORE COMMON IN CHILDREN (put things in their mouths)

VLM = VISCERAL LARVA MIGRANS, invades…
1. CNS
2. LIVER
3. LUNG
4. SKELETAL MUSCLE
5. sometimes HEART

OLM = OCULAR LARVA MIGRANS, can cause…
1. BLINDNESS
2. GRANULOMATOUS RETINITIS

BAYLISASCARIS PROCYONIS has strong TROPISM for CNS

Question 13

TREATMENT/PREVENTION of roundworms…
4 possible drugs? can you use them in COMBINATION?
prevention in environment? (3)
prevention in PREGNANT animals?

Answer 13

drugs?
1. FENBENDAZOLE
2. MILBEMYCIN OXIME
3. MOXIDECTIN
4. PYRANTEL PAMOATE
–> COMBINATIONS (if FDA-approved) are OK!

prevention? = PREVENT environmental contamination with EGGS
1. puppies should be ROUTINELY TREATED WITH PYRANTEL PAMOATE at 2, 4, 6, & 8 WEEKS
2. MONTHLY preventatives should be given for life
3. ROUTINE fecal screening with wellness

prevention in PREGNANT animals = prevent VERTICAL TRANSMISSION (dogs)
1. DAILY FENBENDAZOLE or
2. 2-4X with HIGH DOSE OF IVERMECTIN

Question 14

CONTROL of roundworms…
environmental control is ____ & list 2 reasons why
what PRODUCT can we use to disinfect roundworms?
2 ways we can KILL eggs?
how long does it TAKE for EGGS TO BECOME INFECTIVE & how long do EGGS REMAIN INFECTIVE IN ENVIRONMENT?
SANITARY measure we can take?

Answer 14

ENVIRONMENTAL CONTROL IS DIFFICULT!
1. eggs survive MOST disinfectants
2. STICKY EGG SHELL is DIFFICULT TO REMOVE from surfaces

can use BLEACH to remove STICKY LAYER OF EGGS

KILL eggs?
1. HEAT (steam cleaning)
2. LONG-TERM EXPOSURE TO SUNLIGHT

eggs can BECOME infective after 2-4 WEEKS BUT EGGS REMAIN INFECTIVE IN ENVIRONMENT for YEARS!!!

SANITARY measure?
–> PICK UP POOP ASAP

Question 15

ANCYLOSTOMA sp…
what type of parasite is this?
3 organisms?
prevalence in US and most common species?
where do adult worms live?
3 morphological findings?

Answer 15

HOOKWORMS

3 organisms?
1. ANCYLOSTOMA CANINUM
2. ANCYLOSTOMA BRAZILIENSE
3. UNCINARIA STENOCEPHALA

VERY prevalent in US and DOGS&raquo_space; CATS

ADULT worms live in SMALL INTESTINE

3 morphologies?
1. HOOKED HEAD
2. BUCCAL CAPSULA with 1-3 PAIRS OF TEETH
3. FEED ON BLOOD & attach to INTESTINAL VILLI via mouth

Question 16

ID PARASITE

Answer 16

ANCYLOSTOMA SPP or “HOOKWORM”

Question 17

ID PARASITE

Answer 17

ANCYLOSTOMA SPP or “HOOKWORM”

Question 18

ANCYLOSTOMA CANINUM/TUBAEFORMAE…
what type of organism is this?
commonality?
what species/age is this most severe in?
contagion?
2 species infected?

Answer 18

HOOKWORMS

VERY COMMON

most SEVERE in YOUNG PUPS

VERY ZOONOTIC

2 species = DOGS & CATS

Question 19

UNCINARIA STENOCEPHALA…
what type of organism is this?
prefers what KIND of climates? 2 geographical regions?
2 species infected?

Answer 19

HOOKWORM

prefers COLDER climates
1. NORTH AMERICA
2. EUROPE

2 species?
1. DOGS
2. CATS

Question 20

ANCYLOSTOMA BRAZILIENSE…
what type of organism is this?
pathogenicity compared to A. CANINUM?
infection in CATS? what other species does it infect?
geographic region?

Answer 20

HOOKWORM

LESS pathogenic than A. caninum

RARELY infects cats, MORE COMMONLY INFECTS DOGS

GULF COAST REGION OF US

Question 21

TRANSMISSION of ANCYLOSTOMA….
what is the infective stage?
3 modes of transmission?
what kind of infection DOESN’T occur?
PPP?

Answer 21

infective stage = THIRD STAGE LARVAE

3 modes?
1. ORAL = ingestion of L3
2. PERCUTANEOUS = L3 penetrates skin
3. TRANSMAMMARY = L3 via MILK and is ARRESTED IN MUSCLES

NO TRANSPLACENTAL INFECTION

PPP = 2 weeks

Question 22

LARVAL LEAK SYNDROME…
occurs in WHAT parasite? (2 names)
= what is it?
what happens if you try and deworm these dogs?

Answer 22

occurs in ANCYLOSTOMA/HOOKWORMS

= NOT ALL LARVAE MATURE, some invade OTHER TISSUES and ENTER IN AN ARRESTED STATE OF DEVELOPMENT

even if you deworm these dogs, STILL SHED EGGS because INTESTINE IS REPOPULATED BY ARRESTED LARVAE

Question 23

ID PARASITE

Answer 23

HOOKWORMS

Question 24

CLINICAL dz from hookworms…
PERACUTE (2)
ACUTE (1)
CHRONIC (1)
in ALL cases, we see WHAT 3 clinical signs?

Answer 24

PERACUTE…
1. SEVERE anemia
2. 1-2 week old puppies with HIGH worm numbers

ACUTE…
1. SLOWER ONSET of ANEMIA but it STILL OCCURS

CHRONIC…
1. dogs become IMMUNOCOMPROMISED

in ALL cases…
1. ANEMIA
2. WEIGHT LOSS
3. MELENA

Question 25

ANCYLOSTOMA CANINUM…
what type of parasite is this?
what CLINICAL SIGN does it majorly cause?
how does infective stage enter host? what 3 clinical signs would we see?

Answer 25

type of parasite = HOOKWORM

majorly causes SEVERE ANEMIA

PERCUTANEOUS PENETRATION by L3…
1. DERMATITIS w/ ERYTHEMA
2. PRURITUS
3. PAPULES

Question 26

ALL HOOKWORMS are WELL-DOCUMENTED ____ ____ agents and are the MOST COMMON CAUSE of ____ ____ ____ in people

Answer 26

ZOONOTIC DZ, CUTANEOUS LARVA MIGRANS

Question 27

GOAL of treating HOOKWORMS?

what DRUG can we use?

what PREVENTATIVES should we put the pet on?

Answer 27

GOAL = PREVENT ENVIRONMENTAL CONTAMINATION with EGGS

drug = MOST BROAD-SPECTRUM ANTIHELMINTIC DRUGS are effective

KEEP THEM ON HEARTWORM PREVENTATIVES

Question 28

how to DISINFECT environment for HOOKWORMS…
what stage is LESS resistant?
what 2 ways can we disinfect?
we should treat puppies ____
how often should we pick up poop?

Answer 28

LARVAE are LESS RESISTANT THAN EGGS to disinfection

2 ways?
1. DIRECT SUNLIGHT can lead to dessication
2. 1% CHLOROX FOR HARD, NON-POROUS SURFACES

treat PUPPIES PROPHYLACTICALLY

PICK UP POOP AT LEAST 2X/WEEK

Question 29

MULTI-antihelmintic drug resistant HOOKWORMS…
what SPECIFIC organism has shown this resistance?
what 3 places was it found?
where did this ORIGINATE?
if we suspect treatment has FAILED, what should we do as vets?

Answer 29

A. CANINUM!!!

3 places…
1. SOUTHEAST
2. NORTHEAST
3. CA

originated in GREYHOUND RACING POP’N

if FAILED TREATMENT, vets need to report to PRODUCT MANUFACTURER or FDA

Question 30

DIPYLIDIUM CANINUM
classification/”common name?”
commonality?
adult worms are found…
who are the DEFINITIVE hosts? (2)
who are the INTERMEDIATE hosts? (2)
transmission?
generally considered….
3 clinical signs?

Answer 30

GI CESTODE/”THE FLEA TAPEWORM”

the MOST COMMON TAPEWORMS OF DOGS/CATS

adult worms are found in the SI

DEFINITIVE HOSTS = DOGS/CATS

INTERMEDIATE HOSTS = FLEAS/LOUSE

transmission via INGESTION OF FLEA INFECTED WITH LARVAL TAPEWORM (CYSTICERCOID), NOT FLEA BITE!

GENERALLY considered NON-PATHOGENIC

3 clinical signs?
1. ANAL PRURITUS
2. CHRONIC ENTERITIS
3. VOMITING

Question 31

LIFE CYCLE of DIPYLIDIUM CANINUM…
what TYPE of life cycle?
4 life cycle steps? (start with egg shedding, end with dog/cat ingesting)

Answer 31

INDIRECT life cycle

steps?
1. eggs are shed via DEFINITIVE HOSTS shedding EGG-LADEN PROGLOTTIDS in FECES

2. the eggs are then INGESTED BY FLEA LARVAE (or lice)
3. once ingested, develop into INFECTIVE CYSTICERCOID
4. DOGS/CATS become infected when they INGEST FLEA/LOUSE (IH) during NORMAL GROOMING

Question 32

TREATMENT/PREVENTION of DIPYLIDIUM CANINUM…
2 drugs?
infection is LIKELY TO RECUR if…

Answer 32

drugs?
1. ANTIHELMINTICS (praziquantel)
2. FLEA CONTROL

if FLEAS ARE NOT ERADICATED, then INFECTION LIKELY TO RECUR

Question 33

FLAGELLATES…
what type of parasite is this?
2 organisms?
& locations?
which one is considered a COMMENSAL organism?

Answer 33

GI PROTOZOA

2 organisms?
1. GIARDIA DUODENALIS –> COMMENSAL organism
2. TRITRCHOMONAS BLAGBURNI

locations?
1. GIARDIA = in SI of DOGS, CATS, FARM ANIMALS, HUMANS
2. TRITRICHOMONAS = in COLON & CECUM of CATS

Question 34

ID PARASITE

Answer 34

GIARDIA DUODENALIS

Question 35

GIARDIA…
life cycle type?
life cycle duration?
SI?
how does transmission occur?
4 sources?

Answer 35

DIRECT cycle?

~7 days

localizes to SI

transmission upon INGESTION of CYSTS shed by ANIMALS/HUMANS

4 sources?
1. FECAL-CONTAMINATED WATER
2. FOOD
3. FOMITES
4. SELF-GROOMING

Question 36

CLINICAL SIGNS of GIARDIA…
MOST animals… (3)
b/m? (2)
disease is often ____ because…

Answer 36

MOST animals…
1. ARE YOUNG
2. DO NOT PRESENT WITH CLINICAL SIGNS
3. or have SPONTANEOUS RESOLUTION of D+, but it can take YEARS

b/m?
1. DIARRHEA –> SOFT, MUCOID FECES
2. can be INTERMITTENT D+

disease is often CHRONIC because of FAILURE TO RECOGNIZE/DIAGNOSE

Question 37

GIARDIA diagnostic tests? (3)

TRITRICHOMONAS diagnostic tests? (3)

Answer 37

GIARDIA
1. FECAL FLOAT
2. ANTIGEN TEST
3. PCR

TRITRICHOMONAS
1. DIRECT SMEAR
2. InPouch Culture test
3. PCR

Question 38

can giardia be transmitted from dogs to humans?

Answer 38

humans MOSTLY get it from OTHER HUMANS, but rarely could get it from dogs

Question 39

TREATMENT of giardia duodenal…
if ASYMPTOMATIC…
MOST POPULAR OPTION/DURATION for drug?
prevention? (3)

Answer 39

if ASYMPTOMATIC = MAY NOT REQUIRE TREATMENT

drug?
= FENBENDAZOLE SID for 3-5 DAYS, extra-label use

prevention?
1. CLEAN PREMISES
2. REMOVE FECES
3. BATHING

Question 40

TREATMENT of TRITRICHOMONAS BLAGBURNI…
actually, there is…
which treatment/duration is USUALLY done?
prevention? (3)

Answer 40

THERE IS NO APPROVED TREATMENT

usually RONIDAZOLE SID for 2 weeks

prevention?
1. FREQUENT BATHING/LITTER BOX CHANGES
2. DIETARY management can cause improvement
3. FOLLOW-UP TESTS