Food Ani. Med- Swine- Swine Diarrhea 3

drraythe's version from 2016-04-29 15:27


Question Answer
Proliferative Enteritis (PPE) is aka? (bunch of akas) Proliferative Hemorrhagic Enteropathy (PHE), Porcine Intestinal Adenomatosis (PIA), Porcine Proliferative Enteritis (PPE), Necrotic Enteritis (NE), Regional or Terminal Ileitis (RI), Ileitis, and Garden-Hose Gut.
how are enterocytes affected by PPE/ WHICH PART OF THE VILLI are affected?Hyperplasia of **crypt enterocytes with inflammation & sometimes ulceration or hemorrhage.
how are the mucous membranes affected by PPE?Thickening of the mucous membrane in the sm. & lg. intestine. (uh, it is called "proliferative")
who (Age) is most affected by PPE?Primarily diagnosed in growing/finishing pigs. (many other mammals show similar CSs and lesions)
what is the etiological agent of PPE?Lawsonia intracellularis is a bent, rod-shaped, Gram-negative bacteria in crypt enterocytes of swine.
why does PPE cause a thickened wall?since Lawsonia intracellularis attacks the CRYPTS, they are unable to grow new cells, so the villi are blunted and don't grow right, leading to a thickened wall
how do carrier swine shed PPE?(remember it's lawsonia intracellularis!) in feces
can Segregated early weaning techniques help with PPE?lol nope, dams can infect their bbs as early as 6d old
what are we looking at here?bacteria stained, you can see them on the crypt cells!
explain the pathogenesis of lawsonia intracellularis and how it leads to proliferative lesionsL. intracellularis infects epithelial cells & survives intracellularly. When enterocytes undergo mitosis, each cell retains some of the bacteria & enterocytes fail to mature. The resulting hallmark lesion is a proliferation of immature enterocytes.
the intestines response to infection?Crypt elongation, epithelial cell hyperplasia, degeneration & necrosis of enterocytes, fewer goblet cells, and an inflammatory response.
Acute cases of PPE are most frequently observed in late finishing pigs & young breeding stock. CSs you will see are..Acute diarrhea with brownish to black unclotted blood, pallor, weakness, & rapid death are common
main 2 lesions you see with PPE are?mucosal prolif and hge
Subacute to chronic cases occur more frequently in the grower stages, manifested by what CSs/lesions?sporadic diarrhea, wasting, and variation in growth rate. Lesions often include necrotic enteritis that is easily confused with salmonellosis
(not gonna ask Dxs he said but just to be safe theyre here)Silver stains, IHC, or FA tests on histologic sections. PCR on samples of affected mucosa or feces. (Negative tests do not rule out carrier status.), Serology has limited availability with unknown sensitivity.
what seems to be the main precipitation factor leads to outbreaks of lawsonia intracellularis?stress
what is the vx for PPE, is it good? when is it given? An avirulent live vaccine oral vaccine is widely available & appears to have very good efficacy when properly administered. Vaccination of growing pigs as well as breeding gilts during acclimatization
how do they try to tx/control PPE?Antibiotics often are added to feed or water for several weeks around periods of stress & during outbreaks for treatment and control. Tylosin, Tetracyclines, Lincomycin, Tiamulin, and Carbadox


Question Answer
what is the etiological agent of swine dysentary?Bracyspira hyodysenteriae
what kinda diarrhea (quality not cause) do you see with swine dysentery?Infectious disease characterized by mucohemorrhagic diarrhea & marked inflammation of the large intestine
who is the carrier of swine dysentery? Bracyspira hyodysenteriae infects & persists in rodents.
which age is most commonly affected by SD? Can affect all ages (rare in < 3 wks of age)
what is the seasonality of SD like?Occurs most often in late summer & early fall. (when rats running around trying to find places to live for the winter, i imagine)
explain what kinda etiological agent Bracyspira hyodysenteriae isspirochete bact Gram-negative, anaerobic.
the most pathogenic strains of Brachyspira hyosenteriae tend to be strongly...beta-hemolytic
what is brachyspira/swine dysentery sensitive to (what can you clean it with)Susceptible to heat, ultraviolet (UV) light, and desiccation, as well as soaps and disinfectants.
(i dont think super important but on slide) what is the other Brachyspira species which can cause diarrheal dz in swine?Brachyspira (Serpulina) pilosicoli= Recent work in describing a nonfatal, non-bloody, diarrheal disease in swine. Agent appears to be common in swine populations. Occasional cause of catarrhal colitis in young growing swine
which part of the intestines does swine dysentery/ Brachyspira hyosenteriae infect?large intestines
how does SD infect pigs?fecal oral
The exact mechanism of tissue destruction is not known.. what are the current theories?Lipopolysaccharide in the organism probably is involved. B. hyodysenteriae produces two known toxins & a hemolysin.
In typical lesions the organisms (brachyspira) can be seen where (histologically)within epithelial cells & lamina propria
how might you be able to distinguish SD from PPE?SD only affects the Lg int!!! PPE can affect both.
what are lesions like from Brachyspira/SD (and where?)remember lg int!! but all parts of lg int! you will see: Thick walled, congested, and edematous. The mucosa is thrown into folds and is covered, diffusely or in patches, with a layer of fibrin, necrotic debris & mucus. The colon contains fibrinonecrotic debris & excessive mucus, often mixed with blood. Edematous mesentery & serosa.
dx (said he wont ask us)B. hyodysenteriae often can be cultured & identified from rectal swabs, or colonic scrapings taken from acutely affected pigs. PCR is available for detection. Can be id'ed as stained spirochetes
which parasitic infection can closely resemble SD?Severe whipworm infections mimic mucohemorrhagic SD & worms are not grossly visible until 3-4 weeks after infestation.
how can you tell SD from a salmonella infection?Salmonellosis lesions are not usually confined to the large intestine, ALSO, Lesions of salmonellosis tend to extend deeper into the mucosa as ulcers & may be patchy in distribution with less mucus.
you can help control SD by Treating high-risk animals with _________ or _________ during quarantine.tiamulin or carbadox
Three methods are used to eliminate swine dysentery-- what are these?(1) US. Early weaned piglets (< 3 weeks) taken to a clean site and raised (2) Reduction of a herd to a minimal number of animals, followed by intensive treatment of those retained. (3) Complete depopulation during warm, dry weather (remember bc dz happens in late summer and early fall) and you then Clean & disinfect premises. Premises Should remain vacant for at least two weeks


Question Answer
in what environments are whipworms most likely to infect swine?Relatively common in swine raised on pasture or in dirt lots.
which ages are affected/which age is most commonly affected? All age groups are susceptible (most common in swine < 6mo).
CSs of whipworms often seen when..there is severe stress ( Commonly a subclinical infection that acts as a source of infection for other swine.)
explain the pathogenesis/lifecycle of whipwormsIngestion of larvated eggs --> L3 larvae hatch & enter the mucosa of the anterior small intestine --> Eventually deeply invade the mucosa or submucosa of the cecum & colon -->Diffuse mucofibrinous to mucohemorrhagic typhlocolitis.
aside from the worms themselves, another important part of the Dz process is..2* infxn
how is the intestinal wall affected by the worms? which part of the intestine?sm and lg. Diffuse mucofibrinous to mucohemorrhagic typhlocolitis. Inflammation around the parasites --> Edematous thickening of the intestinal wall
why is there so much inflammation with a whipworm infxn?bc head (thin part) actually embeds into the mucosa
Clinical effects are directly related to... (2)severity and presence of concurrent diseases.
CSs of whipworm infxn? Anorexia, Mucoid or Mucohemorrhagic diarrhea, Dehydration, and possibly death in severely affected animals (Signs are most apparent 2-4weeks following exposure to contaminated facilities.)
dx of whipworms (2) (said he wont ask)(1) Necropsy of a typically affected pig: Mature parasites are easily found in the cecum or colon, Immature worms require careful observation, perhaps with the aid of flotation over a dark background or use of a magnifying lens.. (2) The presence of ova can be determined by laboratory fecal examinations within seven weeks after infestation. (Clinical signs & lesions will often be quite severe before ova are present. The double operculated eggs are distinctive)
how can you reduce number of eggs in soil?Tillage of empty pastures or lots can reduce the number of eggs that survive.
how can you prevent exposure of neonates to whipworms?Treat the pregnant sows with an appropriate anthelmintic 1-2 weeks prior to farrowing &/or before moving them to clean pasture
how can you raise pigs to have good control over whipworm infestations? Raising swine in confinement, without access to soil, usually results in good control.