Strongyles - Revision history

Eca02csb: /* Hepatitis */

2010-08-20T17:40:20Z

Hepatitis

Bara at 22:19, 26 July 2010

2010-07-26T22:19:51Z

JamesSwann at 15:24, 7 July 2010

2010-07-07T15:24:57Z

JamesSwann at 15:24, 7 July 2010

2010-07-07T15:24:04Z

Bara: /* Strongyles (Red worms) */

2010-06-25T22:14:17Z

Strongyles (Red worms)

Bara at 22:13, 25 June 2010

2010-06-25T22:13:19Z

A.allison: Text replace - 'IgG' to 'IgG'

2010-06-12T16:32:19Z

Text replace - 'IgG' to 'IgG'

Bara at 14:37, 7 June 2010

2010-06-07T14:37:55Z

Bara at 21:59, 26 April 2010

2010-04-26T21:59:36Z

Bara at 21:58, 26 April 2010

2010-04-26T21:58:19Z

@@ Line 112: / Line 112: @@
 *it is common to find fibrous tags incidentally on the [[Liver - Anatomy & Physiology|liver]] surface and adjacent diaphragm
 *these are remnants of fibrous repair following the egress of the parasites from the [[Liver - Anatomy & Physiology|liver]]
 [[Category:Nematodes|C]]

@@ Line 113: / Line 113: @@
 *these are remnants of fibrous repair following the egress of the parasites from the [[Liver - Anatomy & Physiology|liver]]
-[[Category:Nematodes]]
+[[Category:Nematodes|C]]
 [[Category:Horse_Nematodes]]
 [[Category:Liver_Nematodes]]
 [[Category:To_Do_-_Parasites]]

← Older revision		Revision as of 15:24, 7 July 2010
Line 7:		Line 7:
	[[Ancylostomatoidea]]		[[Ancylostomatoidea]]

−	[[Metastrongyloidea]]	+	[[Metastrongyloidae\|Metastrongyloidea]]

← Older revision		Revision as of 15:24, 7 July 2010
Line 6:		Line 6:

	[[Ancylostomatoidea]]		[[Ancylostomatoidea]]
		+
		+	[[Metastrongyloidea]]

@@ Line 13: / Line 13: @@
 The strongyles that occur in the horse can be divided on the basis of size into two groups
 *[[Large Strongyles|'''Large''' strongyles]]
-**''[[Strongylus]]'' species (3 species; used to be widespread prior to the introduction of worm control programmes; now uncommon)
+**''Strongylus'' species (3 species; used to be widespread prior to the introduction of worm control programmes; now uncommon)
 **''[[Triodontophorus]]'' species (common)
 *'''Small''' strongyles

← Older revision		Revision as of 22:13, 25 June 2010
Line 114:		Line 114:
	[[Category:Horse_Nematodes]]		[[Category:Horse_Nematodes]]
	[[Category:Liver_Nematodes]]		[[Category:Liver_Nematodes]]
		+	[[Category:To_Do_-_Parasites]]

@@ Line 48: / Line 48: @@
 *Usually <5 years old
 *Sporadic, but increasing in incidence
-*Hyperglobulinaemia, especially IgG(T)
+*Hyperglobulinaemia, especially [[IgG]](T)
 *Hypoalbuminaemia
 *Leukocytosis

← Older revision		Revision as of 21:59, 26 April 2010
Line 9:		Line 9:

	Their eggs are very similar and all contribute to [[Parasitic Gastroenteritis\|parasitic gastroenteritis]].		Their eggs are very similar and all contribute to [[Parasitic Gastroenteritis\|parasitic gastroenteritis]].
		+
		+	== [[Strongyles]] (Red worms) ==
		+	The strongyles that occur in the horse can be divided on the basis of size into two groups
		+	*[[Large Strongyles\|'''Large''' strongyles]]
		+	**''[[Strongylus]]'' species (3 species; used to be widespread prior to the introduction of worm control programmes; now uncommon)
		+	**''[[Triodontophorus]]'' species (common)
		+	*'''Small''' strongyles
		+	**Also known as [[Cyathostomins]] (preferred term), cyathostomes, trichonemes or small redworms
		+	**Cyathostomins (widespread, including 4 genera and over 40 species of worms)

← Older revision		Revision as of 21:58, 26 April 2010
Line 9:		Line 9:

	Their eggs are very similar and all contribute to [[Parasitic Gastroenteritis\|parasitic gastroenteritis]].		Their eggs are very similar and all contribute to [[Parasitic Gastroenteritis\|parasitic gastroenteritis]].
		+
		+
		+	=== General epidemiology of large and small strongyles ===
		+	'''Strongylosis occurs in'''
		+	*Young horses
		+	*Adult animals (especially if overcrowding, poor hygiene)
		+	*Animals on permanent pasture
		+
		+	'''Sources of infection'''
		+	*Overwintered L3 on pasture
		+	*Many adult horses pass significant numbers of strongyle eggs throughout their lives
		+	*"Spring rise" in faecal egg output occurs in both breeding and non-breeding horses
		+
		+	'''Pattern of infection on pasture'''
		+	*Pattern of L3 on pasture is similar to gastrointestinal worms in cattle
		+	*Main difference is that the mare makes a major contribution to pasture contamination (c.f. cow)
		+
		+	'''Hypobiosis of cyathostomin larvae'''
		+	*Occurs throughout the year, but particularly in '''late summer/autumn'''
		+	*EL3 may remain arrested for years
		+	*Resumption of normal development can occur
		+	**seasonally in '''late winter/early spring'''
		+	**following removal of adult worm population via anthelmintic treatment
		+
		+	==== Larval cyathostominosis ====
		+	*Sudden onset diarrhoea and/or weight-loss
		+	*Diagnosis difficult, prognosis guarded
		+	*Generally in '''late winter/spring'''
		+	*Usually <5 years old
		+	*Sporadic, but increasing in incidence
		+	*Hyperglobulinaemia, especially IgG(T)
		+	*Hypoalbuminaemia
		+	*Leukocytosis
		+	*Sometimes peripheral oedema
		+	*Faecal egg-count low (disease caused by emerging larvae)
		+	*Larvae may be found in faeces or on faecal glove
		+
		+	==== Pathogenesis ====
		+	Resumed development of massive numbers of larvae → subsequent emergence of bright red L4 → massive eosinophilic infiltration of mucosa → catarrhal and haemorrhagic colitis
		+
		+	==== Control of cyathostomin infections in horses ====
		+	'''Anthelmintics'''
		+	*Only 3 chemical groups currently available
		+	**Avermectin/milbemycins
		+	**Benzimidazoles
		+	**Pyrantel
		+	*Resistance is an emerging problem (especially to benzimidazoles)
		+
		+	'''Target life-cycle stages'''
		+	*These are not all equally susceptible to each anthelmintic
		+	*Pyrantel is affective against
		+	**Adult worms in the lumen
		+	*Ivermectin or a one off administration of Fenbendazole is affective against
		+	**Adult worms and L4 in the lumen
		+	*Moxidectin or a 5 day course of Fenbendazole is affective against
		+	**Adult worms and L4 in the lumen
		+	**Developing and hypobiotic L3 in the mucosa
		+
		+	'''Egg reappearance period'''
		+	*This is the time from treatment until eggs reappear in the faeces. It is determined by
		+	**degree of activity against mucosal larval stages
		+	**persistency of anthelmintic treatment
		+
		+	'''Prevention of pasture contamination'''
		+	*The objective is to create safe grazing by preventing depostion of strongyle eggs onto pasture
		+	*Treat all grazing horses at intervals determined by
		+	**Egg reappearance time of chosen anthelmintic
		+	**Risk level
		+	*Treat all new arrivals and stable for 48-72 hours so that eggs are not passed onto pasture
		+	*Adopt strategy that will minimise risk of resistance developing (you may need to include tapeworm and stomach bots in your scheme)
		+	*No new eggs passed → no new L3 developing, however it is important to use epidemiological knowledge to predict how long existing L3 will survive as the pasture will not be safe for use before then
		+	*Remove faeces from paddocks at least weekly:
		+	**This markedly reduces dependence on anthelmintics
		+	**Increases available grazing
		+	**But is labour intensive and less effective in rainy weather
		+	*Examine faecal samples twice yearly to monitor effectiveness of your chosen strategy
		+
		+	'''Pasture management'''
		+	*Reserve clean grazing for nursing mares and foals
		+	*Rest pastures used the previous year until overwintered L3 have gone
		+	*Mixed or alternate grazing with cattle or sheep
		+	**These are refractory to most horse worms, except ''T.axei''
		+
		+	'''Chemoprophylaxis of larval cyathostominosis'''
		+	*Needed if a horse is known to have grazed heavily contaminated pasture and may therefore be harbouring massive numbers of hypobiotic larvae
		+	*Fenbendazole treatment given daily for 5 consecutive days in autumn or winter will reduce the risk of clinical disease developing.
		+
		+
		+
		+

	[[Category:Nematodes]]		[[Category:Nematodes]]
		+	[[Category:Horse_Nematodes]]