Horse Flashcards
What is the superfamily of cyathostominae?
Strongyloidea
What is the life cycle of cyathostominae?
Eggs pass out in faeces, L1-L3.
L3 migrates onto pasture.
L3 ingested by host and enters the mucosa of the large intestine. L3-L4.
L4 emerges into the lumen and develops into adults.
During late autumn/winter L3 can hyperbiose in the large intestinal mucosa for months/years.
What is the pre-patent period of cyathostominae?
6-8 weeks
What are the eggs of cyathostominae indistinguishable from? How can these eggs be differentiated?
Strongylus spp.
Needs to be cultured to L3 to be diagnosed.
What do the adults of cyathostominae look like?
Dark red in the faeces.
No larger than 12mm
What is the pathogenesis of cyathostominae?
Development of L3-L4 in large intestinal mucosa can lead to inflammation.
Mass emergence of hypobiosed L3 in early spring. Leads to severe protein losing enteropathy. Larval cyathostominosis.
What are the clinical signs of cyathostominae?
Ill thrift
Weight loss
Spasmodic colic
Larval cyathostominosis
What is the epidemiology of cyathostominae?
Adults develops poor immunity so infect pastures.
Most L3 die overwinter.
Emergence of hypobiosed larvae ‘seeds’ pasture in spring.
How can cyathostominae be diagnosed?
Faecal egg count. Larval culture is required to distinguish from strongylus.
ELISA for larval stages under development.
How can cyathostominae be controlled?
Pasture poo picking
Selective treatments with anthelmintics.
Treatment with larvicidals late-autumn.
Anthelmintic resistance threatens control.
What is the super family of strongylus vulgaris / equinus / edentatus?
Strongyloidea
What is the life cycle of strongylus vulgaris?
Eggs -> L3 in faeces.
L3 is ingested and molts to L4.
L4 penetrates submucosal arteries and migrates via caecal and colic arteries to the root of the cranial mesenteric artery.
Eggs are passed in the faeces.
What is the pre-patent period of strongylus vulgaris?
6-7 months.
What is the life cycle of strongylus endentatus?
Eggs -> L3 in faeces.
L3 is ingested travels via the portal system and molts to L4.
Migrates through the liver into sub-peritoneum.
What is the pre-patent period of strongylus endentatus?
10-12 months
What is the life cycle of strongylus equinus?
Eggs -> L3 in faeces.
L3 from nodules within the intestinal wall, then travel across peritoneum to the liver and the pancreas.
What is the pre-patent period of strongylus equinus?
8-9 months.
What is required to differentiate a strongylus egg?
Larval culture or molecular tools.
What are the features of strongylus adults?
Found in the large intestine.
Robus dark red worms <5cm.
Well developed buccal capsules.
What is the pathogeneis of strongylus
Pathology is mostly associates with strongylus vulgaris.
Migratory stages - endoarteritis in mesenteric circulation - thromboembolic infarction of the large bowel.
What are the clinical signs of strongylus?
Weight loss Anorexia Anaemia Diarrhoea Fever Colic Death from infarction
How can strongylus be diagnosed?
Faecal egg count and larval culture.
Long PPP may cause low egg counts.
Palpation of painful enlargement at root of mesentery rectally in verminous arteries.
Post-mortem or at surgery.
Adults in large intestine, larvae in cranial mesenteric artery.
How can strongylus be controlled?
Covered by routine controlled of cyathostominae.
May be more of an issue in yards using selective treatment.
What is the superfamily of triodontophorus?
Strongyloidea
What is the life cycle of triodontophorus?
Eggs are passed out into the faeces.
L1-L3 in faeces.
L3 migrates onto pasture and is ingested by host.
L4-L5 in the host.
Adult worms in caecum and colon produces eggs.
What are the clinical signs of triodontophorus?
Loss of condition
Anaemia
Weakness
Diarrhoea
What is the superfamily of dictyocaulus arnfieldi?
Trichostrongyloidea
What is the life cycle of dictyocaulus arnfieldi?
L3 is ingested by the grazing host. Penetrates the intestines. Travels to lymph nodes. L3-L4. L4 is carried to the lungs via the blood or lymph. L4 moults to adults in the lungs.
Adult worms reside in the lungs.
Females lay larvated eggs in the bronchi, which are coughed up and swallowed. Hatch to L1 and pass through the intestines.
L1-L3 in faeces.
Pilobolus fungus and rain aids the dispersion of L3
What is the pre-patent period of dictyocaulus arnfieldi?
21 days
What are the clinical signs of dictyocaulus arnfieldi?
Slightly hyperpnoea.
Harsh lung sounds.
Rarely patent horses, but it is common in donkeys.
Less pathogenic than in cattle.
What is the superfamily of parascaris equorum?
Ascaridoidea
What is the life cycle of parascaris equorum?
Eggs are excreted onto pasture.
L1-L2 in the egg.
Eggs are ingested.
L2 hatches in the gut and migrates to the liver. L2-L3.
L3 migrates to the lungs via the heart and pulmonary arteries.
L3 enters the lungs via alveolar capillaries and migrates up the trachea where they are coughed up and swallowed.
L3 adults in SI.
What is the pre-patent period of parascaris equorum?
12-16 weeks
What is the pathogeneis of parascaris equorum?
Migrate pahse causes focal haemorrhage in liver and lungs 4 weeks post-infection.
Heavy infections causes intestinal obstruction.
What are the clinical signs of parascaris equorum?
Coughing Nasal discharge Weight loss Intermittent diarrhoea Colic Intestinal obstruction Un-thrifty
What is the epidemiology of parascaris equorum?
Females are prolific egg layers.
Eggs survive for a long time in the environment.
Temperatures in spring/summer favours development of eggs.
How can parascaris equorum be diagnosed?
Clinical signs.
Faecal egg count
How can can parascaris equorum be controlled?
Treat foals from 8 weeks.
Avoid grazing foals successive years on pature.
Poo picking.
What is the superfamily of strongyloides westeri?
Rhabditoidea
What is the life cycle of strongyloides westeri?
Larvated egg passed in faeces.
Under certain conditions they hatch and may re-infect by ingestion or by skin penetration.
Larvae migrates via the venous system, lungs and trachea to develop to adults in the small intestine.
Larvae may arrest in ventral abdominal wall and milk leading to immediate infection of young.
What is the pre-patent period of strongyloides westeri?
8-14 days
What are the clinical signs of strongyloides westeri?
Enteritis and respiratory signs.
Large number of eggs.
What is the superfamily of oxyuris equi?
Oxyuroidea
What is the life cycle of oxyuris equi?
Become adults in the colon and deposits eggs here.
Eggs are rubbed onto surfaces/grass.
L3 develop within the eggs.
Eggs are ingested and hatch to L3 in the colon, where they moult to L5.
What is the pre-patent period of oxyuris equi?
5 months
What are the clinical signs of oxyuris equi?
Anal itching
Grey-yellow egg mass around the rectum
How can oxyuris equi be controlled?
Anthelmintics
Stable hygiene
What is the superfamily of habronema microstoma/muscae?
Spiruroidea
What is the life cycle of habronema microstoma/muscae?
Eggs in faeces hatch to L1.
Ingested by fly/maggots. L1-L3.
Adult flies transmit to host when feeding on secretions.
L3 ingested and develops to adults in the stomach.
What disease is caused by habronema microstoma/muscae?
Cutaneous habronemiasis - when L3 burrows into the skin and causes granulomatous lesions.
How can habronema microstoma/muscae be controlled?
Topical anti-inflammatories and anthelmintics.
What is the superfamily of thelazia lacrymalis?
Spiruroidea
What is the life cycle of thelazia lacrymalis?
Adult worms reside in the conjunctival sac of the DH and sheds L1 larvae.
L1 are ingested by IH when they feed on tears and other lacrimal secretions.
IH: L1-L3 in the digestive tract.
L3 larvae break out of capsules and migrate to the fly’s mouthparts, where they remain until the fly feeds on the tears of the DH.
The larvae invades the conjunctival sac of the DH and becomes adults after 1 month.
What disease is caused by thelazia lacrymalis?
Conjunctivitis
What is the treatment for thelazia lacrymalis?
5 day fenbendazole
Topical ivermectin