Exam 1 Flashcards
Nematode structure
Large body cavity containing fluid under pressure
Longitudinal muscle fibers
How to decide male or female nematode
Buccaneers cavity, bursate vs non-bursate, vulva or not
What is different of strongyloidea?
Cannot tell them about
How do we distinguish strongyles?
Life cycle and baccalaureate cavity
Large vs small strongyles are distinguished by?
Buccal cavity - large have deeper buccal cavities than small
Cyathostomes are another name for
Small strongyles in equids
What is the most common parasite of well-managed mature horses?
Small strongyles
Hosts for small strongyles
Equids (DH)
Small strongyles habitat
Intestines
What is the most infectious stage of small strongyles?
When larvae molt to L3
Identification of small strongyles
Clear, smooth shell surface
Dark, morula-stage in fresh feces
Buccal cavity (usually shallow)
What type of lifecycle do small strongyles have?
Direct
Route of infection for small strongyles
Ingestion of l3
Pre-patent period for small strongyles
5+ weeks
What is a pre-patent period?
Period where larvae are maturing in the body
What is arrested development?
When a parasite is able to hangout in the stable gut of an animal until they deem the environment safe
What is encystment?
Embedding of parasite into the body (I.e. embedding in mucosal walls)
What can cause mechanical damage and inflammation in small strongyles?
L4 encystment
What does Larval cyathostominosis?
Synchronous emergence of arrested larvae
What symptoms does L4 encystment cause?
Non-responsive diarrhea, hypoproteinemia, edema, weight loss
What are the typical constraints for LC?
Seasonal, ages 1 to 4 typically that have been recently dewormed
What is chronic cyathostominosis?
Normal maturation/life cycle of a parasite
What symptoms are seen with CC?
Poor hair coat, weight loss, loose stool, pot-belly
How do we diagnosis small strongyles for equids?
Fecal float/Fecal egg count
What type of treatment do we use for small strongyles of equids?
Selective deworming
- 80/20 rule: identify and treat the 20%
How do we treat foals that present with small strongyles?
Fenbendazoles
How do we treat mature horses that present with small strongyles?
Macrocyclic
Other than deworming, what is recommended for equids with LC?
Steroids to help with inflammation
Large strongyles of equids are now
Emerging from extinction
Large strongyles host
Equids (DH)
Large strongyles habitat
Intestine or extra-intestinal stages
Large strongyles juveniles
Migrate and cause disease
- S. Vulgaris: Cranial Mesatamic Artery (o2 to organs)
- others: liver and other organs
Large strongyles environment
L3
Identification for Large strongyles of equids
Deep, rounded buccal cavity with teeth
Life cycle of large strongyles of equids
Direct
Routes of infection for large strongyles
Ingestion of L3
Pre-patent period of S. Vulgaris
5-7 months - CMA
Clinical signs from migrating larvae in large strongyles
Mechanical damage, inflammation
- thromboembolic colic/ verminous arteritis
What does thromboembolic colic/verminous artertiris?
Liver and/or pancreas fibrosis
- can see vascular disease
Clinical signs from adults of large strongyles
Minimal blood loss, inflammation and ulceration
How do we diagnosis large strongyles of equids?
Fecal float/ fecal egg count
- clinical signs
- lesions at necropsy (hind gut and CMA)
How do we treat large strongyles? Resistance?
Many drugs, none known for resistance
How do we prevent/control large and small strongyles
-deworm high shedders
- stall vs pasture
-prompt removal of fresh feces
What is the common name for Oesophagostomum spp. ?
Nodular worms
What are the hosts for Oesophagostomum spp.?
Cattle, sheep, goats, swine (all DH)
What is the habitat for Oesophagostomum spp?
Intestinal and mucosal stages
- adults live in large intestine
- juveniles migrate (mucosal only)
What is the environment for Oesophagostomum spp.?
L1 hatch from egg, molt to L3
What is the best way to identify Oesophagostomum spp.?
Who it came out of
- have cervical vesicle, shallow buccal cavity
If you see nodules on the intestines of ruminants and swine, what parasite are you dealing with?
Oesophagostomum spp.
What type of lifecycle does Oesophagostomum spp. have? What is it’s ROI?
Direct
Ingestion of L3
What is the PPP of Oesophagostomum spp.?
3-7+ weeks
- can go into arrested development
Clinical signs of Oesophagostomum spp.?
Nodules (subsequent infections= larger nodules)
Malabsorption, ulceration, anorexia, diarrhea, straining to deficate, weight loss, emaciation, weakness
Diagnosis of Oesophagostomum? What do we look for?
Fecal float- look for eggs similar to equine strongyles
- id adults and nodules at necropsy
How do we treat Oesophagostomum spp.? Resistance?
Many drugs work, none can target encystment larvae
- most popular: eprinomectin/doramectin
No resistance known
Prevention and control for Oesophagostomum spp.?
Prompt removal of feces is best
Keep feces away from animals (i.e. slatted floors)
What is the parasite known as the swine kidney worm?
Stephanurus dentatus
What parasite causes 95% of liver condemnations?
Stephanurus dentatus
Where geographically is Stephanurus dentatus most common?
The South
What hosts does Stephanurus dentatus have?
DH: swine
PH: earthworm
Habitat for Stephanurus dentatus?
Intestinal and extra-intestinal stages
- larval migration to the liver (cause disease)
- adults in the kidney
Environment for Stephanurus dentatus?
L1 hatch from egg, molt to L3
How to identify Stephanurus dentatus?
Dark, morula-stage internally in fresh URINE
Lifecycle and ROI of Stephanurus dentatus
Direct
-ingestion of L3
-skin penetration by L3
- ingest PH
PPP of Stephanurus dentatus
9-16 months (LONG)!!!!
- stay in the liver for a while
Clinical signs of Stephanurus dentatus
Liver condemnation, dermatitis (if penetrates the skin), aberrant migration to muscle and spinal cord
Diagnosis of Stephanurus dentatus
Eggs in urine
Lesions at necropsy, liver scarring
Treatment of Stephanurus dentatus
3 classes of swine dewormers should work
- fenbendazole, ivermectin/doramectin, levamisole
Prevention/control of Stephanurus dentatus
Bio-secure facility vs outdoor rearing
- keep movement of paramedic hosts and bugs out of environment
Trichostrongyloidea: what is specific about this parasite family?
Some genera are VERY important pathogens
- cannot tell them apart
HOTC parasites and Nematodirus spp. : Habitat
Gastrointestinal and mucosal stages
- adults in GI lumen
- juveniles migrate: mucosal only
HOTC parasites and Nematodirus spp. : environment
L1 hatch from egg, molt to L3
Haemonchus contortus host
Sheep and goats (DH)
Haemonchus contortus looks like
Baberpole worm (due to color changes)
Ostertagia ostertagi host
Most important in cattle
Ostertagia ostertagi is known as
Brown stomach worm
Trichostrongylus spp. host
Horses, ruminants and swine
Trichostrongulus spp. is known as
“Hair” worm
Cooperate spp. is known as
“Cooper’s” worm
Nematodirus spp. is known as
Intestinal “threadworm”
HOTC parasites identification
Larval lesions
- cannot identify difference in eggs
Morroco leather abomasum is found in
O. Ostertagi
Nematodirus spp. identification
Huge in size, can be differentiated
HOTC parasites and Nematodirus spp. : Lifecycle and ROI
Direct
Ingestion of L3
HOTC parasites and Nematodirus spp. : PPP
3+ weeks
HOTC parasites and Nematodirus spp. : clinical signs for Haemonchus and Ostertagia
Anemia/pale, edema/“bottle jaw”, emaciation, fatalities
What happens during Morocco leather abomasum?
L3 enter mucosa, L4 emerge
Type 1 Ostertagiasis
- equivalent to CC in equids
- chronic effects over time (no AD)
- clinical signs worse @ end of grazing season
- egg counts usually high
Type 2 Ostertagiasis
- equivalent to LC in equids
- acute presentation (simultaneous of arrested larvae)
- clinical signs worse @ beginning of grazing season
- egg counts typically low
more damaging
HOTC parasites and Nematodirus spp. : diagnosis
Fecal flotation for eggs/ fecal egg count
- Nematodirus spp. eggs are much larger
- FAMACHA/PCV (Haemonchus)
What is FAMACHA and what parasite is it associated with?
Visual scale of anemia to guide selective treatments
- Haemonchus
HOTC parasites and Nematodirus spp. : treatment? Resistance?
Many drugs work
- moxidectin best for Haemonchus
Resistance
- Haemonchus over others
HOTC parasites and Nematodirus spp. : prevention/control
Prompt removal of feces
Co-grazing with non-susceptible species
Dictyocaulus spp. known as
Trichostrongyle lungworm
Dictyocaulus spp. hosts
Donkeys and cattle
Dictyocaulus spp. habitat
Intestinal to extra-intestinal stages
- adults in trachea/bronchi/bronchioles to larvated eggs in feces
Dictyocaulus spp. environment
-mature quickly
-free L1, molt to L3
Dictyocaulus spp. identification
Contains L1 (may hatch before passed in feces)
Dictyocaulus spp. lifecycle, ROI and PPP
Direct
Ingestion of L3
3-4 weeks
Dictyocaulus spp. clinical signs
Dyspnea “Husk” cough, nasal discharge
(Dyspnea- trouble breathing)
Dictyocaulus spp. diagnosis
Fecal float and baermann (look for larvae)
Dictyocaulus spp. treatment
Several anthelminitics should work
Dictyocaulus spp. prevention and control
Pasture management
Vaccine for cattle in Europe
Co-grazing (not donkeys with horses)
Metastrongyloidea general characteristics
some genera are important pathogens for animal and human health
- life cycle: indirect
- diagnostic stage: Larvae (L1) passed in feces
Muellerius capillaris common name
hair lungworm
Muellerius capillaris hosts
DH: sheep, goats, wild ruminants
IH: snails
Muellerius capillaris habitat
intestinal to lymph/blood to lungs
- adults in parenchyma/nodules
Muellerius capillaris environment
L1 must penetrate snail/slug
L1 to L3 in snail (parasite only alive if snail is alive)
Muellerius capillaris identification
clear, kinked tail with dorsal appendage
Muellerius capillaris lifecycle, ROI, PPP
-indirect
-ingestion of IH (snail)
-3-5 weeks
Muellerius capillaris clinical signs
adults: minimal damage
L1 break through alveoli (cause inflammation)
Heavy infections cause pneumonia/fibrinous pleuritis
Muellerius capillaris diagnosis
fecal floatation +/- baermann
- start with fecal float to rule out Haemonchus
Muellerius capillaris treatment
many drugs with success
- if treating for another clinical sign the medication will most likely work
Muellerius capillaris prevention/control
- co-grazing with non-susceptible species (not with other small ruminants)
Parelaphostrongylus tenuis common name
meningeal worm
brain worm
Parelaphostrongylus tenuis hosts
DH: white-tailed deer
AH: goats, camelids, sheep, wild cervids, cattle
IH: snail/slug
Parelaphostrongylus tenuis habitat
intestines to meninges (nervous tissue)
- still go to lungs but are in there shortly
- adults in meninges in DH
- larvae in nervous tissue in AH
Parelaphostrongylus tenuis environment
L1 must penetrate snail/slug
L1 to L3 in snail
Parelaphostrongylus tenuis identification
can only see at necropsy if sample is sent in
Parelaphostrongylus tenuis lifecycle, ROI, PPP
- indirect
- ingestion of IH
- 3-4 months in DH
Parelaphostrongylus tenuis clinical signs
WTD: none
AH: neurologic
- lameness, stumbling, head tilt, circling, blindness, loss of fear, death
Parelaphostrongylus tenuis diagnosis
clinical signs/history
CSF tap (eosinophils)
Parelaphostrongylus tenuis treatment
steroids (or NSAIDS) to control inflammation
Parelaphostrongylus tenuis prevention/control
-deer control
-snail control
-prophylactic deworming q 30 days with ivermectin (resistance)
Metastrongylus spp. common name
swine lungworms
Metastrongylus spp. hosts
DH: swine
IH: earthworm
Metastrongylus spp. habitat
intestines to bronchi/bronchioles
Metastrongylus spp. environment
lariated egg ingested by earthworm
- L1 to L3 in earthworm
Metastrongylus spp. identification
eggs (larvated)
- cannot use baermann
Metastrongylus spp. lifecycle, ROI, PPP
indirect
ingestion of IH
3-4 weeks
Metastrongylus spp. clinical signs
- coughing
- airway obstruction
Metastrongylus spp. diagnosis
fecal float for lariated eggs
Metastrongylus spp. treatment
- several drugs work
Metastrongylus spp. prevention/control
bio-secure vs pasture/dirt-raised (no earthworms)
Aelurostrongylus abstrusus common name
the feline lungworm
Aelurostrongylus abstrusus hosts
DH: felids
IH: snails/slugs
PH: birds/rodents/amphibians/reptiles
Aelurostrongylus abstrusus habitat
L3 migrate from intestines to lungs
L1 hatch from eggs prior to passage in feces
Aelurostrongylus abstrusus identification
kinked tail with a dorsal spine
Aelurostrongylus abstrusus lifecycle/ROI/PPP
-indirect
-ROI: ingestion of IH, ingestion of a PH
-6 wks
- L1 passed in feces
Aelurostrongylus abstrusus clinical signs
chronic cough, usually no signs
Aelurostrongylus abstrusus diagnosis
Hx (cough, prey)
fecal floatation
- baermann
- BAL
Aelurostrongylus abstrusus treatment
nothing labeled in US, some drugs kill adult worms
- bravest plus, advantage multi
recommend monthly heart worm preventative
Aelurostrongylus abstrusus prevention/control
routine deworming
prevent predation/scavenging
Crenosoma vulpis common name
the fox bronchial worm
Crenosoma vulpis habitat
L3 migrate from intestines to lungs
- adults in bronchi
- L1 in feces
Crenosoma vulpis hosts
DH: foxes, raccoons, domestic and wild canids
IH: snails/slugs
- ingest L1 which mature to L3
Crenosoma vulpis identification
tapered tail; no spine
Crenosoma vulpis lifecycle/ ppp
indirect
19 days
Crenosoma vulpis clinical signs
absent to a persistent cough
Crenosoma vulpis diagnosis
L1 in feces (float/baermann/BAL)
- adults in bronchi
Crenosoma vulpis treatment/prevention
- nothing labeled, some drugs kill adult worms
- prevent scavenging
Filaroides and Oslerus spp. common name
canine lungworm
Filaroides and Oslerus spp. habitat
L1 migrate from intestines
L1 in feces/respiratory secretions= infection
Filaroides and Oslerus spp. hosts
DH: domestic and wild canids
only lungworm that is direct
Filaroides and Oslerus spp. lifecycle/ppp
direct
5 weeks (filaroides)
6-7 months (oslerus)
Filaroides and Oslerus spp. diagnosis
FECAL FLOAT
- L1 in feces
Filaroides and Oslerus spp. treatment
none labeled, some drugs kill adult worms
Angiostrongylus cantonensis common name
the rat lungworm
Angiostrongylus cantonensis habitat
L3 migrate from intestines to brain to pulmonary arteries
- L1 in feces
Angiostrongylus cantonensis hosts
DH: rats/rodents
IH: mollusks
PH: crustacea, amphibians
AH: people, dogs, other mammals
(most of time it is from a snail or slug)
Angiostrongylus cantonensis clinical signs
eosinophilic meningitis/encephalomyelitis (CSF tap)
Angiostrongylus cantonensis diagnosis
history and clinical signs
- CSF tap
- PCR available
Angiostrongylus cantonensis treatment
Anthelmintics CONTRAINDICATED if near signs
-steroids/immunosuppressants/supportive care
Angiostrongylus cantonensis zoonotic implications
humans usually infected by ingestion of raw snails or crustacean
Ancylostoma spp. different species
A. caninum-dogs
A. tubaeforme - cats
A. braziliense- cats/dogs (more tropical)
Ancylostoma spp. habitat
intestinal and/or extra-intestinal stages
where does a. caninum travel to?
to somatic tissues to mammary tissue
Ancylostoma spp. hosts
DH: carnivores
- eggs have morula stage
PH: ingest L3 and larvae arrest in tissues
Ancylostoma spp. identification
teeth/plates in buccal cavity
Ancylostoma spp. lifecycle/roi/ppp
direct
roi’s:
-ingestion of L3
-skin penetration by L3
-ingestion of a PH (predation)
-transmammary
ppp: 16-28 days
Ancylostoma spp. clinical signs
-voracious bloodsuckers
-larval leak
-anemia; dark, tarry stool
what is larval leak?
-normal biology for hooks
-larvae take a break (type of arrested development)
-come out during immunosuprecency
- commonly discussed as resistance
- recheck fecal in 10-14 days
Ancylostoma spp. diagnosis
Fecal float
- idexx tests (PCR)
- A.I. fecal analyzers
Ancylostoma spp. treatment
STOP THE BLEEDING!
- many drugs kill adult worms, a couple kill L4
-pyrantel-liquid: start at 2 weeks, repeat q2 wks until on monthly preventative
- fenbendazole
-Heart worm preventatives
Drug resistant A. caninum
REPLACE LOST BLOOD IF NEEDED
Ancylostoma spp. prevention/control
prompt removal of feces
routine deworming
recheck fecals
prevent predation
deworm pregnant/nursing females
Ancylostoma spp. zoonotic implications
clm: cutaneous larva migrans (creeping eruptions)
- intense pruritus, serpentine lesions
- eventually parasites die due to being in wrong last