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98 Cards in this Set
- Front
- Back
What are the most common enteric infections in pigs from birth to weaning?
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ETEC
Rotavirus Cocci |
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What is the pathogenesis of ETEC?
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Adheres to the mucosa of the SI by fimbrial adhesins K88,K99 and F18. They colonise the SI and produce enterotoxins which act in the gut to stim hypersecretions of mucin and electrolytes. Reults in diarrhoea and dehydration.
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What are the enterotoxins that are produced in E. coli infections?
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Heat labile toxin (LT) or VTEC forms can produce heat stable toxins (STa/STb)
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How is E.coli transmitted?
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Faecal-oral
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What makes piglets susceptible to E. coli infection?
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Lack of colostrum
Low ambient temp |
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Can pigs be resistant to E.coli?
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Yes, there is an inheritable autosomal recessive trait for resistance to the K88 and F18 adhesins.
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What are the C/S of neonatal E.coli infection?
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Watery diarrhoea
Dehydration Metabolic acidosis Vomiting Sudden death |
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PM of neonatal E.coli?
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SI is congested and the contents are yellow and watery.
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Tx of neonatal E.coli infection?
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Oral rehydration fluids and AB
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Vaccination for E.coli?
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Yes, but good hygeine and mgmt should come first.
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How many serogroups of Rotavirus affect pigs?
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4 - ABCE
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What is the pathogenesis of rotavirus?
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Replicates in the cytoplasm of SI epithelial cells. Causes SI villus atrophy and severe enteritis.
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What age are pigs usually infected with E.coli?
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0-4 days old
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How old are pigs usually infected with rotavirus?
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Between 5-30 days
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How is rotavirus transmitted?
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Faecal-oral
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How long is MDA protection against rotavirus?
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3-4 weeks
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C/S of piglet rotavirus infection?
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Range from mild diarrhoea to severe fatal diarrhoea - lasts from 2-5 days
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PM of rotavirus?
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Thin-walled, pale SI wtih a large volume of watery yellow fluid. The caecum and colon may be similarly involved.
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Histology of rotavirus?
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Will show epi degeneration and detachment, villus atrophy and regenerating club-shaped villi
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Treatment of rotavirus?
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Electrolyte/fluid replacement
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Control methods for rotavirus?
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Excellent hygeine
Disinfection with peroxygen (Virkon S) Ensure colostrum intake Move sow and piglets to a cleaned/disinfected crate at 4-5 days post-farrowing |
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Vaccine for rota?
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No
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What is the most important protozoa in pigs?
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Isospora suis
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Pathogenesis of cocci in piglets?
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Sporulated oocysts are ingested and sporozoites leave the oocyst and penetrate the epi cells of the SI and multiply.
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Transmission of cocci?
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Faecal-oral
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C/S of cocci in piglets?
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Yellow-grey diarrhoea; piglets get thin and hairy. Concurrent infections causes a higher mortality.
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Immunity to cocci?
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MDA do not protect piglets from clinical cocci. After infection, survivors will develop immunity.
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How long will villus restoration take in cocci cases?
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5-10 days
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Diagnosis of cocci?
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PM several SI sites to detect the infection.
Examine for oocysts in faeces of piglets that are recovering (about 7 days after the onset of diarrhoea) |
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Tx of cocci?
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Toltrazuril PO or IV at 4-5 days of age. May need a repeat tx. Also TMPS. Consider electrolye solutions for the dehydration.
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What is the clostridial spp that affects piglets?
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C. perfringens Type C
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Pathogenesis of C. perfringens
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The bacteria adhere to the epithelial cells fo the jejunum and produce toxins (necrotising B-toxin most impt) - causes death from intestinal damage and toxaemia
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What age are piglets with C.perfringens?
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12 hours to 7 days
Most pigs with clin disease will die. |
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Transmission of C. perfringens?
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Faecal-oral
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C/S of C. perfringens infection?
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Sudden death
Watery/haemorrhagic diarrhoea with shreds of necrotic debris Low rectal temp |
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PM of C. perfringens piglet?
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Haemorrhagic SI
Blood-stained fluid in abd cavity Necrotic villi |
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Diagnosis of C. perfringens?
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Histopath demonstration of the B-toxin in the intestinal contents. Isolation of C. perfringens alone is not sufficient as the organism can be found as a seoncdary agent colonising lesions formed by something like rotavirus
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Tx of C. perfringens?
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Really useless...can try Penicillin injections to try and minimise losses during an outbreak.
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Vaccine for C. pefringens?
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Yes
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What is the crypto that infects piglets?
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Cryptosporidium parvum
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Transmission of Crypto?
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Faecal-oral
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Pathogenesis of crypto?
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Attaches to the brush border of the SI and multiplies, causing diarrhoea 3 days post-infection. Immunity develops rapidly.
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C/S of crypto?
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Watery, yellow-brown diarrhoea from 7 days of age that persists with some weight loss and dehydration
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Diagnosis of crypto?
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Oocysts in faeces of recovering piglets (at approx 10 days post-infection) as well as PM and histopath
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Tx of crypto?
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Electrolyte solutions to combat dehydration.
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Name of a good oocyst disinfectant?
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Oocide (Antec), can be used in crypto and cocci outbreaks.
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When are pigs usually weaned?
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Between 3 and 4 weeks.
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What is the reduction in height of villi during weaning?
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50%
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What are a couple of ways to prevent adverse weaning effects on the villi?
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Acheive good weaning weights for piglets (6kg at 21 days)
Use a good quality starter ration Group piglets accoridng to size and retain litter groups Warm and dry weaning accm |
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What are the most common enteric infections in weaners-to-finishers?
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E.coli
Rotavirus Spirochaetes (swine dysentery and porcine colonic spirochaetosis) Lawsonia Salmonella |
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What are the most common enteric infections in adult pics?
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Lawsonia
Swine dysentery (brachyspira) Salmonella |
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Post-weaning E.coli is caused by which strains? Which of the two causes the most issues?
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K88 and F18, with K88 predominating.
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What kind of disease does the F18 E.coli strain cause?
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Oedema disease - a toxaemia that affects the integrity of the vascular endothelium, allowing fluid exudation into perivascular tissues...causing oedema.
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Why does post-weaning E.coli infection occur?
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Becuase MDA wears off and there is increased stress factors
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C/S of post-weaning E.coli infection?
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Watery diarrhoea
Dehydration Vomiting Sudden death Seen in pigs 1-2 weeks after weaning, but sometimes longer. If there is toxaemia, CNS meningitis-type signs will be seen. |
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An addition preventional measure for post-weaning E.coli besudes good hygeine and minimising stress?
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High conc zinc oxide in the diet (2500-3000 ppm) for two weeks after weaning - reduced microbial proliferation in the gut.
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What are the 3 forms of proliferative enteropathy?
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1. Proliferative enteropathy
2. Necrotic Enteritis 3. Proliferative Haemorrhagic enteropathy |
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What organism causes proliferative enteropathy?
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Lawsonia intracellularis, an obligate, intracellular bacteria
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Pathogenesis of Lawsonia?
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Colonises epithelial cells of the SI and LI. The bacteria impedes maturation of epi cells and the crypts undergo hyperplasia. Changes really take affect 2-3 weeks after infection. Nutrient absorption gets blocked because of thickened intestinal mucosa - means poor growth.
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How does Lawsonia cause necrotic enteritis?
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Because of secondary infection worsening the Lawsonia situation.
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Do pigs get immunity to PE?
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Yes, and infection generally resolves in 3-4 weeks.
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What percentage of UK herds have PE?
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40%
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What is the typical age range for PE?
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6-14 weeks, post-weaning
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What type of pigs mostly get PHE?
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Susceptible adult gilts introduced into an infected environment - high mortality rate.
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C/S of Proliferative Enteropathy?
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Diarrhoea
Failure to sustain growth despite normal feed intake Scour with necrotic form PHE pigs are pale, anorexic and have diarrhoea that is black to port-wine in colour |
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Where are the pathological lesions normally found in PE cases?
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Distal SI and proximal third of colon - affects one or the other. Intestine will be thickened and there will be coagulative necrosis in some cases. PHE cases will have blood clots in ileum and colon.
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Diagnosis of PE?
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Demonstration of Lawsonia in faeces using PCR; PM; serology.
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Tx of PE?
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PO AB of clinically affected - Chlortetracycline, Tylosin, Tiamulin, etc. Regular strategic medication is done in endemic herds. For cleaning, quaternary ammonium and iodine-based solutions have an effect.
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Tx of PHE?
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Parenteral Tetracycline
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Vaccine for PE?
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Yes, administered to pigs 4-6 weeks of age, after MDA has waned.
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What causes swine dysentery?
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The spirochaete Brachyspira hyodysenteriae
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Pathogenesis of B. hyodysenteriae
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Colonises the LI in 2-4 days and multiplies in the crypts and goblet cells (get hyperplasia and tons of mucus prod), causing damage to the epithelial cells. Typhlocolitis (inflam of caecum and colon) dvps within 5-7 days.
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Transmission of Swine dysentery?
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Faecal-oral (introducing subclin infected pigs, infected pig lorries, contam boots)
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What age of pigs gets infected with swine dysentery?
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Any age from 6 weeks on
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C/S of swine dysentery
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Diarrhoea from 5-7 days post-infection
Fresh blood and mucus in it Disease lasts 10-14 days Death |
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PM of swine dysentery pig
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LI lesions with mucosal congestion and thickening with excess mucus overlying everything
Enlarged colonic LN |
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Diag of swine dysentery?
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Clinical signs, gross pathology and microscopic examination of colon for spirochaetes. Confrim with specific detection of agent with PCR.
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Treatment of swine dysentery?
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Tiamulin
Valnemulin Lincomycin Give in water incase pigs become anorexic. Tx individual sick pigs with parenteral AB as well. |
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Choices for eradication of swine dysentery?
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1. complete depop with thorough C+D, 3 weeks vacant, restock with SPF pigs
2. depop growing herd (weaning to finishing), sows on farm get in-feed Tiamulin; thorough C+D 3. number 2 but take sows OFF farm for a min 2 weks and get medicated feed |
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Vaccine for swine dysentery?
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No
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What organism causes porcine colonic spirochaetosis?
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Brachyspira pilosicoli
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Pathogenesis of B. pilosicoli?
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Same as B.dysenteriae (LI colonisation, mult in crypts) except inflamm is milder and haemorrhage is not a feature - usually doesnt result in fatalities.
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C/S of PCS?
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Cow-pat faeces to watery-grey diarrhoea
Lowered growth rates (remain BAR with a good appetite!) |
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Morbidity rate of PCS?
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10-50%
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Transmission of B.pilosicoli?
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Faecal-oral; pigs infected from contaminated environment or from in-contact pigs
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What percentage of colitis outbreaks are due to B.pilosicoli?
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50%
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Is PCS zoonotic?
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Yes (esp birds, cats, dogs)
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Difference between pathology of swine dysentery and PCS?
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PCS rarely has haemorrhagic mucosa
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Diag of B.pilosicoli?
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Same as for B.hyodysenteriae - C/S, pathology and specific detection with PCR
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Tx of PCS?
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Same as swine dysentery - tiamulin, valnemulin, lincomycin.
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What is the most common Salmonella spp to cause enteric pig disease?
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Salmonella enterica serovar typhimurium
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Pathogenesis of salmonella infection?
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Fimbriae and flagella attach to the SI and invade it. Multiplies and diarrhoea is the result of malabsorption and fluid leakage from the necrotic inflammed bowel.
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When is salmonella mostly seen?
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From weaning to 4 months of age; esp due to stress of transport or intercurrent disease
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C/S of salmonella?
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Clinical disease is rare, the majority of infections are subclinical. Diarrhoea is watery and yellow, without blood or mucus. Pigs are usually febrile (40.6-41.7) and have a loss of appetite.
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Special way of salmonella diagnosis?
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Meat juice ELISA from abattoirs which detects herds with high prevalence - allows control measure to be put into place.
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Tx of salmonella
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AB only indicated when there is an outbreak of clinical disease.
Good hygeine, control vermin, and consider the killed salmonella vaccine in breeding-age animals. |
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Main enteric parasites of pigs?
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Ascaris suum
Trichuris suis Oesophagostomum spp |
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Causes of gastric ulcers?
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Too fine of food particles
Pelleted feed Low fibre content High wheat diets |