Gastrointestinal disease Flashcards
Calf scour prevention
Ensure colostrum - clean management
Getting 4 litres within 2 hours, 4 litres within 12 hours
Good colostrum is above 22% on brix
Calving down into clean area
Treating calf scour
NSAIDs to reduce temperatures and increase appetite
Keep feeding milk
Give electrolyte feed as well
Needs antibiotics if down and sick - will die of sepsis - don’t use if bright and alert until known cause
Clinical exam
Rainbow scour test
Serum total proteins
Colostrum quality - FPT
Possible on farm PM
Causes of calf scour
Rotavirus
Coronavirus
Cryptosporidium
Coccidiosis
E.coli
Salmonella
Causes of diarrhoea in cattle
Infectious
- Salmonella
- Eimeria
- Rota virus
- Coronavirus
- Mycobacterium avium paratuberculosis
- Cryptosporidium parvum
- E.coli
- BVD
- Rinderpest
- Clostridium species
- Nematodes
- Yersinia
- Malignant Catarrhal fever
- Secondary to septicaemia
Non-infectious
- Nutritional
- Poisonous substances
- Mycotoxins
- Acidosis
- Copper deficiency/toxicity
- Cobalt +/or selenium deficiency
- Secondary to Das, peritonitis
Ddx for infectious diarrhoea in housed cattle - Pre-weaning calves
Any age pre weaning - Clostridium
Within 14 days - Rotavirus, E.coli, Coronavirus, Cryptosporidium
Few weeks old - Eimeria
Clostridium perfrigens
- Type A, B, C or D
Found everywhere
Commensal of GI tract and soil
Proliferates if sudden diet change
Causes death and severe D+
Pathology - haemorrhagic enteritis, intestinal mucosal ulceration, D+ in intestines
Pathophysiology - rapid bacterial overgrowth and enterotoxin release
Ddx for infectious diarrhoea in housed cattle - Post weaning calves
Eimeria
3 weeks to 6 months
Shedding can occur transiently throughout life
Clinical disease - D+ and poor DLWG, rarely rectal prolapses
Why - infection location - cecum, colon, and terminal ileum
Mucosa - congested, oedematous, thickened with haemorrhages, later sloughed away
Immunity - yes
depends on quality of oocysts picked up during primary infection
Species specific - not between sheep and cows
Diagnose - McMasters
Treat - supportive therapy
Predisposing factors
- High stocking density
- Poor hygeine
- Mixed age groups
- Stress factors
- Wet and warm weather
- Mixing calf groups
Prevent - oral drench - Toltrazuril decoquinate in feed
Hygiene - bedding management, stocking densities, group management
Ddx for infectious diarrhoea in housed cattle - Adult cattle
Winter dystentry - (coronavirus)
MAP - Johne’s
Coronavirus
Same pathogen causing D+ in calves and mild BRD in post weaning calves
Most cattle are seropositive
Highly contagious
Short lived (2-3 days) diarrhoea
Cattle in close confinement
Faeco-oral tranmission + suspected change in rumen microbiome
Colonisation of small intestine and colon
Voluminous D+ from hypersecretion due to inflammatory resposne
Destroys epithelial cells
Treatment
- Supportive
- NSAIDs
- Rehydration
Ddx for infectious diarrhoea in housed cattle Any age
Salmonella
Rinderpest
BVD
Salmonella - reportable
Rinderpest - notifiable
Salmonella - TMPS, NSAIDs, Hartmanns fluid
SARA
Sub acute ruminal acidosis
pH - 5.6-6.5
Should spend 10-12 hours ruminating
>70 L saliva
Contractions 3 in 2 minutes
End product - VFAs
Low pH - insufficient fibre - decreased rumination - from sorting or spring grass
OR - excess starch, rapid fermentation - concetrates or fed once a day
Decreased intakes - heat stress, poor cow comfort, poor transition cow management
Diagnosis
- Rumen fluid sample - stomach tube or rumenocentesis
Mycotoxins
Fusarium, Aspergillus, Penicillium - silage
Clinical signs
- Loss of appetite
- Reduced milk yield
- Poor weight gain
- Feed refusal
- Diarrhoea
- Pyrexia
- Pruritis
- Bleeding
- Illthrift
Not contagious
Often seasonal outbreaks
Prevention
- Harvest as early as possible - esp forage maize, avoiding soil contamination
Minimising top spoilage through oxygen barrier film
Mycotoxin binder in TMR
Causes of neonate sheep scour
Nutritional - incorrect mixing of milk replacer
Bacterial - E.coli - watery mouth, Clostridium perfringens (B - lamB dystentry), Salmonella
Viral - rotavirus
Parasitic - Cryptosporidium
Causes of lamb scour
Nutritional - Rumen acidosis - creep feeding
Parasitic - Coccidiosis, Nematodirus, Parasitic gastroenteritis (PGE)
Causes of adult sheep scour
Nutritional - Rumen acidosis/lush pasture
Bacterial - Salmonella, Johne’s
E.coli - watery mouth
Young lambs <4 days old
Lambs are pyrexic, lethargic and may scour
High mortality
Hypersalivation
Pot belly
Poor hygiene and FPT
Control
Clean bedding pens
50ml/kg colostrum ASAP after birth <6hours
200ml/kg in first 24 hours
Ewe nutrition and BCS - check forage/metabolic profiling pre lambing
LamB dysentry - Clostridium perfringens type B
- Gram positive anaerobic bacteria, ubiquitous in environment and commensal in GIT
- Rapid onset disease caused by toxins released when bacteria have opportunity to multiply
- Control is by vaccination of ewes (lambs can be vaccinated from 2-3w)
LamB dysentry
Sudden death +/- diarrhoea
Lambs may appear dull/listless before death
Affects young lambs (usually <3w)
Coccidiosis - Eimeria
Eimeria (protozoan parasite)
Many species but only 2 are pathogenic in sheep (E. ovinoidalisand E. crandallis)
NB oocyst counts; host specific
Timing of infection risk related to seasonality of lambing rather than seasonality of parasite (in housed dairy calves can seen infection almost any time of year)
Lambs 3-12 weeks old are most at risk from infection.
Typically lambs born in the first half of the lambing period exposed to a low level of challenge and develop immunity
Early lambs multiply up the oocysts in the shed or field whilst they develop immunity and the later born, youngest lambs then encounter a high challenge of infectious oocysts and suffer with clinical disease (scouring, dehydration) before they develop immunity
Risk factors
* Mixing age groups of lambs
* Moving young lambs to shed/pasture where older lambs were kept
* Intensively stocked systems
* Faecal contamination in/around feed/water troughs
Pathogenesis and clinical signs:
Damage to gut lining causes straining, abdominal pain and diarrhoea +/-mucus and blood; leads to dehydration and death in severe cases (young lambs exposed to high challenge)
Affected animals may also show ill thrift and poor growth rates
Concurrent infection with Nematodirus or Cryptosporidium can exacerbate clinical signs
Control measures:
Ensure adequate colostrum intake, maintain good hygiene and prevent faeco-oral transmission (e.g. raise feed and water troughs or move frequently)
Cryptosporidium parvum
Protozoal parasite that can cause disease in young lambs (usually <10d old) and calves
It is zoonotic
Faeco-oral transmission
Oocysts persist in environment and resistant to many disinfectants = infection levels build up over time
Causes diarrhoea, inappetence, abdominal pain and mild pyrexia
In mild infections may see reduced growth rates and general poor performance
May get mixed infections with E. coli/Nematodirus = severe clinical signs
Diagnosis by faecal sample/PM
Control measures:
Ensure adequate colostrum intake, maintaining good hygiene and preventing faeco-oral transmission (e.g. raising feed and water troughs)
Can be transmitted in water courses so could consider fencing these off
Older animals tend to shed the parasite which then causes disease in younger animals, so mixing animals of different ages should be avoided where possible
Check that any disinfectants used are effective against Cryptosporidium
Endoparasites of sheep
GI nematodes - roundworms - PGE
- Trichostrongylus
- Teladorsagia
- Nematodirus battus
- Haemonchus
Trematodes
- Fasciola hepatica
Coccidia/Cryptosporidium
Lungworm
- D.filaria
- M.capillaris
Tapeworms
Endoparasites of cattle
GI nematodes - roundworms - PGE
- Ostertagia ostertagi
- Cooperia oncophora
- Trichostrongylus axei
Trematodes
- Fasciola hepatica
- Rumen fluke
Coccidia/Cryptosporidia
Lungworm
- Dictocaulus viviparous
Tapeworms
What parasites do sheep and cattle NOT generate immunity to?
Fluke - sheep and cattle
Haemonchus - sheep
Lungworm - immunity in cattle is shortlived
Nematodirus
Immature larvae attack gut wall - dehydration and rapid death
PPP - before they reach adulthood - no eggs found on faecal egg count in outbreak
Control - benzomidazole - albendazole
Teladorsagia and Trichostrongylus
Main GI nematodes in lambs - adults develop immunity - bear in mind periparturient relaxation in immunity - 2-4 weeks pre and 6-8 weeks post lambing will have drop in immunity
Hypobiosis until following spring
Clinical - scouring, weight loss, poor fleece quality, dull, depressed, dehydrated, death
Subclinical - slower DLWG, reduced feed conversion efficiency, reduced immunity
May to march, peak in late summer/autumn
