Swine GI

Question 1

describe pre-weaning versus post-weaning disease as relates to disease

Answer 1

3 site production

1. sow farm:
   1-4 weeks old
2. nursery: 5-10 weeks old
3. finisher: 11 weeks to harvest

pre-weaning disease on sow farms: primary impact is on morbidity and mortality with less subclinical disease

post-weaning disease: primary impact is on feed efficiency and less of a concern for mortality

Question 2

describe predisposing factors associated with development of neonatal diarrhea

Answer 2

1. poor milk production
2. low piglet vigor
3. low piglet birthweight
4. environmental stress: failure to maintain critical temperature due to poor heat lamp management, dampness, humidity, drafts, and facility design
5. immunity: FPT (IgG and IgM), failure of latrogenic immunity (IgA), failure to nurse at timely intervals (every 2 hours), ineffective immunity
6. split suckling in 1st 24hr may improve immunity: allow 1/3-1/2 of litter to nurse for short period of time and alternate groups

Question 3

describe colibacillosis

Answer 3

1. pathology caused by E.coli, specifically ETEC
2. clin signs:
   -age: dependent on presence of enterocyte receptors
   -severity dependent on degree of dehydration
   -high morbidity in affected litters (<80%)
   -mortality directly related to immune status of sow and ETEC pathogenicity: generally low-mod but co-infection can increase
3. therapy:
   -abx: based upon sensitivity; generally aminoglycosides. enrofloxacin, or 3rd gen cephalosporin
   -if abx fail: rethink dx and sensitivity
   -zinc oxide: unsure MOA but reduces diarrhea and mortality and improves growth
4. control:
   -sanitation and hygiene to prevent exposure
   -vaccination with avirulent live vaccine

Question 4

describe clostridial enteritis

Answer 4

1. C. perf type C, A, and difficile
2. A and C lesions:
   -fibronecrotic enteritis associated with hemmorhage and gas formation, leads to increased permeability, segmental necrosis, esp in chronic cases
3. C. diff lesion: fibronecrotic enteritis and arteritis (edema of spiral colon)

Question 5

describe clostridial enteritis diagnosis

Answer 5

1. clin signs:
   -lower morbidity rates with high case fatality rates
   -may not affect entire litters
2. gross lesions:
   -segmental pseudomembrane, hemorrhage and gas formation, mesocolonic edema with C. diff
3. impression smear demonstration, numerous large gram + rods
4. histopath
5. PCR for toxin gene

Question 6

describe clostridial enteritis treatment and control

Answer 6

1. abx no help, need sanitation and hygiene in farrowing facility
2. antitoxin: admin oral soon after birth
3. prevention: BMD admin as feed additive to sow 14d before birth until 21d post birth
4. vaccination:
   -C. perf toxoid admin to sow 4 and 2 weeks prior to birth, pigs MUST nurse soon after birth

Question 7

describe swine enteric coronavirus

Answer 7

1. transmissible gastroenteritis, (TGE) porcine epidemic diarrhea virus (PED), swine delta coronavirus (SDCoV)
   -not homologous virus so no cross protection
   -share common lesions
   -clinical presentation is indistiguishable
   -manage all similarly
2. epidemic disease:
   -acute fulminating disease
   -immunologically naive herd
   -affects all ages
   -profuse watery diarrhea
   -vomiting
   -high mortality in pigs less than 3 weeks of age
3. immunity:
   -virus neutralization in gut lumen
   -IgG and humoral antibody has little effect so IgA is key to protect neonate!! (lactogenic immunity, present throughout lactation, frequent nursing is critical)
   -during an outbreak, uniform herdwide immunity is essential

Question 8

describe rotavirus

Answer 8

1. type A, B,C
   -lesion: mild villous atrophy that predisposes piglets to secondary abcterial infection
2. clinically can’t distinguish from other diarrheal dz; mild transient diarrhea is common, mod to high morbid with low mortality, incidence depends on sow immunity
3. virus very resistant to environment
   -good hygiene is helpful but low effect on control
   -endemic form pretty common, low cross-protection between variants
4. age affects: 7 days and older

Question 9

describe swine coccidiosis

Answer 9

1. isospora suis and eimeria species
2. lesion: destruction of villus epi
   -cell destruction due to completion of both sexual and asexual replication
3. malabsorptive diarrhea
4. clin signs:
   -suckling pugs 5d and older (time required for IC repro of coccidian)
   -may also affect weaned pigs
   -emaciation and stunting most common
5. diagnosis:
   -gross lesion: yellow fibronecrotic pseudomembrane
   -direct fecal smear: caution tho bc may not be shedding oocysts
   -histopath: necrosis of gut mucosa and merozite
   -impression smear: merozites
6. weaning nutritional considerations:
   -transition from lipase to protease enzymes
   -soy hypersensitivity (if feeding soybean diet)
   -whey quality (ash content)
   -zinc and iron levels
   -water availability and intake: must teach piglets to use water system

Question 10

descirbe swine dysentery

Answer 10

1. gram negative anaerobic spirochete
   -most pathogenic = beta hemolytic
2. clinical signs:
   -gray mucoid to hemorrhagic diarrhea most common
   -hematochezia (anemia if severe)
   -dehydration if severe
   -mild fever
   -colic
   -acute death poss due to toxin prod
3. lesions:
   -LI, reddened gastric mucosa, mesentery are edematous and serosa may be opaque
   -microscopic: moderate nonsupperative colitis and typhlitis, mucosal metaplasia, edema, and superficial epithelial necrosis; spiral shaped organisms in crypts, enterocytes, and debris on silver stain

Question 11

describe porcine proliferative enteritis

Answer 11

1. lawsonia intracellularis: bent rod shaped gram neg causes proliferation og gut mucosa
2. possible carrer animals within herds = fecal oral spread
   -incub at least 2 weeks
   -seroconvert 2 weeks after infection
   -resolution of lesions 4 weeks post infection
3. clin signs:
   -growing/finishing pigs
   -not uncommon in young breeding stock
   -weight loss
   -melena
   -low morbidity
   -variable mortality
   -some subclin: big impact of herd feed conversion
4. lesions:
   -thickening of gut mucosa
   -ileum commonly affected and occasionally in prox LI
   -peyers patches may be hyperplastic
   -blood intestinal contents