Lecture 23. GI Infections 4

Etiologic agent of porcine proliferative enteropathy

Lawsonia intracellularis, an intracellular gram-negative rod.

Cultivation of Lawsonia intracellularis is only in...

Only in cell culture.

Transmission of porcine proliferative enteropathy

Fecal-oral transmission.

Pathogenesis of porcine proliferative enteropathy

Causes mild, self-limiting hyperplasia and inflammation of jejunum, ileum, cecum, and colon.

Severe forms of porcine proliferative enteropathy lead to

Proliferative ileitis, proliferative hemorrhagic enteropathy, fibrinous casts, and blood clots.

Clinical signs of hemorrhagic form of porcine proliferative enteropathy

Melena, inappetence, and sudden death.

Clinical signs of non-hemorrhagic form of porcine proliferative enteropathy

Sudden reddish diarrhea and possibly chronic necrotic enteritis.

Confirmatory diagnosis for Lawsonia intracellularis

Identification of organism in the apical cytoplasm of proliferative enterocytes.

porcine proliferative enteropathy

this disease state is likely associated with what condition

Necropsy findings for porcine proliferative enteropathy

Thickened and corrugated ileal mucosa with blood clots.

Usefulness of PCR in diagnosing Lawsonia intracellularis

Often of limited diagnostic value.

Treatment for porcine proliferative enteropathy

Antimicrobials in feed or administered parenterally.

Lawsonia intracellularis

what is revealed in this tissue sample from the GIT

Prevention of porcine proliferative enteropathy

Modified live vaccine (MLV) and preventing introduction of carriers.

Etiologic agent of equine proliferative enteropathy

Lawsonia intracellularis.

Age group of horses affected by Lawsonia intracellularis

4-6-month-old foals.

Predisposing factors for equine proliferative enteropathy

Stress and secondary infections.

Morbidity and mortality of equine proliferative enteropathy

Low morbidity and mortality.

Clinical signs of equine proliferative enteropathy

Rapid weight loss, colic, subcutaneous edema, and protein-losing enteropathy.

Treatment for equine proliferative enteropathy

1. Oxytetracycline + doxycycline

2. mild cases treated with oral doxycycline.

equine proliferative enteropathy

this horse is likely suffering from what disease

Most common etiologic agent of swine dysentery

Brachyspira hyodysenteriae.

Other species of Brachyspira associated with swine dysentery

B. hampsonii and B. suanatina.

Key culture characteristic of Brachyspira species

Strong beta-hemolysis under anaerobic conditions.

Transmission of swine dysentery

Fecal-oral ingestion.

Location of Brachyspira multiplication in swine

In the large intestine.

Pathogenesis of swine dysentery

Muco-hemorrhagic diarrheal disease of the large intestine

How does swine dysentery decrease mucosal absorption leading to diarrhea

1. Degenerate and inflame superficial mucosa

2. Hypersecretion of mucus

3. Multifocal hemorrhage

Clinical signs associated with swine dysentery

1. Anorexia, soft feces (first)

2. rapidly progressing muco hemorrhagic diarrhea with mucus and blood

3. eventual weight loss.

Mortality rate of swine dysentery if untreated

Up to 50%.

Diagnosis of swine dysentery

1. Clinical signs, postmortem findings

2. histologic lesions in the large intestine

3. anaerobic culture of strongly beta-hemolytic Brachyspira.

Reason culture is preferred over PCR in diagnosing swine dysentery

PCR is less specific; culture provides more definitive identification.

Treatment for swine dysentery

Antimicrobials combined with minimum inhibitory concentration (MIC) testing due to AMR resistance

Prevention of swine dysentery

Control of rodent and waterfowl carriers.

swine dysentery

the disease state in these images points to what disease