Equine gastrointestinal parasites and their management Flashcards
What are the clinical signs of Habroneam spp infection
skin sores conjunctivitis
When is Habronema spp. infection most common?
June- september
seen in all age of horses
Where do adult Habronema spp. reside in the horse?
stomach- mostly no disease
Why is Habronema spp hard to diagnose on FEC
eggs are very fragile and rupture- diagnosis on gastroscopy
List 5 ways to prevent Habronema spp
Good fly control and muck heap management
Frequent replacement of bedding
Collection/removal of droppings in paddocks
Cover wounds and treat ocular diseases causing ocular discharge
Will be killed in horse with worming for other parasites (Avermectins/Benzimidazoles to lesser extent)
What is Parascaris equorum
Ascarid
Which age group of horses are commonly affected by Parascaris equorum?
Horses <2 traditionally due to poor immune response
What is the reservoir for Parascaris equorum
adult horses – small numbers but shed enough eggs to infect foals/young stock
Is there vertical transmission of Parascaris equorum?
No - is from pasture
List the clinical signs of Parascaris equorum infection
Coughing
nasal discharge
poor coat
weight gain
dull
anorexia
occasional colicking
bone/tendon disorders
How does Parascaris equorum eggs spread?
coughed up then swallowed
Describe what Parascaris equorum eggs look like
round lumpy
very distinct
What is the resistance status of Parascaris equorum to avermectins?
Quite resistant
What can be used to treat Parascaris equorum infection?
Pyrantel
What should be considered when treating Parascaris equorum infection?
Be wary of impaction colic
What is Anoplocephala perfoliate/magna?
Tapeworm (a cestode)
Which age group of horses are commonly affected by Anoplocephala perfoliate/magna?
usually young horses
List the clinical signs of Anoplocephala perfoliate/magna infection?
ileal impaction
intussusception
caecal impaction
motility disorders
spasmodic colic
d+
How are Anoplocephala perfoliate/magna eggs transmitted?
Ingested by horses after infecting oribatid mites- indirect lifecycle
What is the PPP of Anoplocephala perfoliate/magna disease
6- 10 weeks
When is Anoplocephala perfoliate/magna disease most common?
October/ november
What diagnostic tests can be used for Anoplocephala perfoliate/magna?
Based on anti-body detection
ELISA (in populations)
saliva test
Describe how to treat A. perfoliata
2 drugs:
high dose pyrantel
praziquantel
How long should horses be stables after worming for A. perfoliata
48 hours- to prevent increased pasture contamination - can’t kill the mites
What is the most clinically important large strongyle
Strongylus vulgaris - because - causes ‘verminous arteritis’
T/F Strongylus vulgaris forms good immunity
False - get some but never complete to stop re-infection
what is the reservoir for Strongylus vulgaris
asymptomatic horses that shed large numbers of eggs
describe how to diagnose Strongylus vulgaris
difficult as pre-patent disease
may be able to feel thrombi on rectal exam
why is faecal analysis not good to diagnose Strongylus vulgaris
can’t tell from other strongyle eggs
no correlation between number of eggs and worm burden
when is Strongylus vulgaris seen
autumn/ winter
but infected in spring/summer due to high numbers on pasture
List the clinical signs of Strongylus vulgaris
colic
diarrhoea
anorexia
ischaemia
Can form thrombi at aorto-iliac junction – can lead to lameness and poor performance
Occasionally migrate aberrantly and end up in the brain, kidneys, lungs, liver and can form granulomas
Describe how to treat Strongylus vulgaris
All drug groups still OK for us- no resistance yet
benzimidazoles and avermectins – larvae and adults
Pyrantel – adults only
describe how to prevent Strongylus vulgaris
avoid over grazing (eggs often on ground)
pick up faeces regularly
What is the PPP of Strongylus edentatus
11 months
What is different about Strongylus equinus compared to other strongyles
they don’t enter blood vessels like the other two strongyles (vulgaris and edentatus)
what is the PPP of Strongylus equinus
9 months
describe how S. edentatus cause disease
colic due to liver disease or peritonitis
Describe how S. equinus causes disease
mild colic.
Some association with pancreatic disease and primary diabetes mellitus- RARE
what is the most important equine parasitic disease in terms of prevalence and severity of clinical signs seen
Cyathostomins
What is a problem with using anthelmintics against Cyathostomins
encysted, hypobiotic larvae largely unaffected by any anthelminitic
when do Cyathostominosis larvae tend to emerge
Spring- often many at once
how long is the PPP of Cyathostomins
6-14 weeks if no hypobiosis
T/F do we see immunity to Cyathostomins
True - but takes a long time and never complete
why is daignosing Cyathostomins difficult
PPP disease
describe how to diagnose Cyathostomins
history and clinical signs - young animals, poor worming history
may see larve in faeces or on glove after rectal
Future- ELISA being developed
List the clinical signs of acute larval Cyathostominosis
The one seen in spring
they are due to the mucosal damage caused by emergence of the late L3
colic
weight loss
D+- can be acute of chronic
wasting
or just death
what are the clinical signs of autumn syndrome of Cyathostomins
when larvae entering intestinal wall – less common than that seen in the Spring
colic
D+ due to inflammation
What age horse does O. equi affect
affect any age
T/F O. equi survives well in the environment
False- parasite of stabled horse
eggs don’t survive well outdoors
Describe the clinical signs of O. equi
anal pruritus and skin excoriation and/or myiasis
itchy tails
Describe how to diagnose O. equi
Eggs in the perianal region on examination
Sellotape test – put on slide and examine under the microscope
Describe how to treat O. equi
All anthelmintics should be effective
Can use topical or systemic anti-inflammatories to decrease pruritus and keep area clean with disposable material
Good stable hygiene – water troughs, mangers etc
Is there any resistance for cyathostomes against Ivermectin and moxidectin
emerging
what should you treat larval cyathastominosis with
moxidectin
What should you threat Colic due to high Parascaris burden with
pyrantel
what should you treat Recurrent colic and high ELSIA for Anaplocephala with
praziquantel
OR
double the standard dose of pyrantel
Describe how to prevent larval cyathastominosis through pasture management
appropriate stocking
faecal collection
dung heaps seperate from grazing area
pasture rotation
grazing with ruminants
which horses should we treat against parasites
Treat if faecal WEC > 250epg (Based on testing every 8-12 weeks throughout the grazing season) with ivermectin or pyrantel
Perform FEC reduction test 14 days after treatment
what should we do with new horses arriving on a yard - regarding parasites
Treat new arrivals at yard and hold away from turn out for a minimum of 3 days (or ideally until FWEC reduction) is assessed
when should we perform tapeworm ELISA in horses
in spring and autumn and treat if high Ab titre with pyrantel/ praziquantel
