Inf. diseases II - Swine diseases (diarrhea 2/2) Flashcards
(49 cards)
Name 3 swine diseases caused by coronaviruses.
Transmissible gastroenteritis in pigs (TGE) (Alphacoronavirus)
Porcine epidemic diarrhea (PED) (Alphacoronavirus)
Hemagglutinating encephalomyelitis virus disease (Betacoronavirus)
TRANSMISSIBLE GASTROENTERITIS (TGE) – is a highly contagious disease of
pigs at any age,
caused by Coronavirus,
characterized by acute diarrhea, vomiting, dehydration and high mortality.
TRANSMISSIBLE GASTROENTERITIS (TGE) – is a highly contagious disease of pigs at any age, caused by Coronavirus, characterized by
acute diarrhea, vomiting, dehydration and high mortality.
Causative agent of transmissible gastroenteritis virus (TGEV).
Genus, family and group.
Genus Alphacoronavirus,
family Coronaviridae
Group 1a
RNA virus
Enveloped virus
Type of virus causing transmissible gastroenteritis. (2)
RNA virus
Enveloped virus
Survival of TGEV in the environment.
Survives 3 days at room temperature,
6 days in slurry.
Host range and reservoirs for TGEV.
Host range: pigs. Affects pigs in all ages.
Most susceptible are newborn piglets.
Temporary biological reservoirs:
cats, dogs, foxes and rodents, birds.
Morbidity of TGEV.
Morbidity <100%
Mortality of TGEV.
Mortality <100% in pigs 10-14 days of age; lower with increasing age.
Low in post-weaned and adult pigs.
Describe an epidemic of TGE. (4)
Occurs when virus is first introduced into a susceptible herd.
Short duration.
No longer clinically evident after herd immunity develops.
Most commonly during winter months.
Describe endemic TGE.
Occurs when virus persists in a partially immune herd into which susceptible swine are introduced (endemic disease spreading to naive individuals) OR if the epidemic form of the disease is not well managed.
Common sequel to a primary epidemic in herds of more than 300 sows.
Clinical occurrence about 9 months after the first outbreak.
Transmission of TGEV.
Excretion: feces, urine, nasal discharge.
After clinical recovery excretion can go on for months!
Direct contact
Ingestion
Aerosols
Fomites
Route: oral or aerosols
IP of TGE
IP: 24-48h (piglets)
Clinical signs of TGE in piglets. (4)
Vomiting – yellow, foamy, slimy
Profuse diarrhea – watery, yellow-green, offensive odor
Depression, dehydration
Weakness, emaciation leading to death in 2-5 days
Clinical signs of TGE in older pigs. (3+)
Similar signs as piglets: yellow vomit, watery yellow diarrhea etc.
Recovery is much more likely – illness lasting up to 10 days.
Post mortem lesions for TGE. (4)
Lesions in intestine and stomach.
Thin and translucent intestinal wall.
Distended with fluid ingesta.
Histopathology: atrophy of villi in the small intestine.
Material for diagnosis of TGE. (4)
Feces
Content of intestines
Mucosal scrapings of small intestines
Biopsy – wall of small intestine, mesenteric LNs
Lab analyses for diagnosis of TGE. (3)
Identifying the agent
Histology – small intestines & stomach
Serology (ELISA)
Tx for TGE.
Fluid and electrolytes containing glucose are indicated.
If secondary bacterial infections in piglets at age 2-5 weeks use ABs.
Prevention of TGE. (5)
Recovered pigs are immune.
Buy new pigs from SPF herds.
Quarantine
All-in-all-out systems
Vaccination of pregnant sows, piglets – not in Estonia or Finland!
PORCINE EPIDEMIC DIARRHEA (PED) – is a contagious disease of pigs, caused by
Coronavirus, characterized by gastroenteritis.
Causative agent of Porcine epidemic diarrhea virus (PEDV).
Genus, family and group.
Genus Alphacoronavirus,
family Coronaviridae
Group 1b
Describe porcine epidemic diarrhea virus (PEDV) (2)
RNA virus
Less contagious than TGEV
Target demo. for porcine epidemic diarrhea virus (PEDV).
Infects pigs of all ages.
Older pigs have more severe infections tho.
