Diarrhea

A. History

  • Provide information on herd/flock size, animal age, numbers of animals affected, onset/duration of problem, vaccination history, and any treatment administered.

B.  Selecting and submitting samples

  • For best results, select acutely affected, untreated animals for sampling, OR submit feces from same.
  • Live acutely affected, untreated piglets, young ruminants (<40 kg), and rabbits may be submitted for postmortem examination. **Please call the lab first to arrange, and ensure arrival PRIOR to 15:00 h.

Live animals must be transported humanely.

  • Rapid tissue fixation of gut sections for histology is critical, preferably <10 min after death.
  • Since intestinal lesions may be segmental, always collect multiple intestinal tissue samples for histology,

preferably 3 segments each of ileum and jejunum, and one each of duodenum, cecum, colon and stomach.

Partially snip open one end of 1-2 cm gut sections with scissors to expose mucosa prior to immersion in formalin.

  • Please request specific tests, and submit separate tissue samples, in separate labeled Whirl-Pak bags, for each lab section and test requested.  Alternatively, ask for pathologist to select tests as appropriate.

C.  Samples required:

Swine enteritis

Histology: Formalin-fixed sections of esophagus, stomach, mesenteric lymph node, duodenum, jejunum, ileum with Peyer’s patch, cecum, colon including any area with gross lesions. Also include routine tissues, e.g., filtering organs including liver, kidney, spleen, lung. Remember to collect multiple sections from jejunum and ileum.

• Immunohistochemistry is available on formalin-fixed sections of intestine for TGEV, PCV-2, Lawsonia.

Bacteriology:  Feces, small and large intestine, mesenteric lymph node – routine culture.

Brachyspira spp. including B. hyodysenteriae, B. pilosicoli PCR: colon, feces, oral fluids.

Lawsonia intracellularis PCR: ileum, feces, oral fluids.

C. perfringens, C. difficile: Toxin ELISAs, anaerobic culture, PCR genotyping (feces or intestinal content).

Virology:

• Coronaviruses TGEV, PEDV, PDCoV triplex PCR (pcovpcr): rectal swabs in virus transport medium, small intestine.

• Rotavirus A, B and C PCR: feces, small intestine.

• PCV-2,3 PCR: small intestine, feces.

Serology:  TGEV: submit sera from dam, surviving litter/herd mates for differential ELISA.

Parasitology:  Fecal exam optional. Histology can be diagnostic for coccidia.

Bovine enteritis

Histology: Formalin-fixed sections of esophagus, forestomachs, abomasum, mesenteric lymph node, duodenum, jejunum, ileum with Peyer’s patch, spiral colon and cecum, including any area with gross lesions. Also include routine tissues, e.g., filtering organs liver, kidney, spleen, lung.  Remember to collect multiple sections from jejunum and ileum.

• Immunohistochemistry is available on formalin-fixed tissues for BVDV, BCV, bovine rotavirus.

  (Note that BVDV IHC is NOT available for routine PI screening).

Bacteriology:  Feces, small and large intestine, mesenteric lymph node, any other tissues with visible lesions – routine culture.

Mycobacterium paratuberculosis (Johne’s disease) PCR: intestine, mesenteric lymph nodes, feces.

Virology:

• BVDV PCR: EDTA blood for acute BVD, serum for PI; tissue with lesion and feces.  For further details of BVDV testing, see LabNote 1

• Rotavirus A and B PCR: feces, ileum/colon.

• Coronavirus PCR: feces; ileum/colon.

Serology:  Paired sera for BCV. For acute BVD, submit paired sera for both type 1 and type 2 BVDV VN tests.

Parasitology:  Feces for Cryptosporidium sp. (sucrose wet mount), coccidia, gastrointestinal nematodes (GIN) (fecal flotation).

Note: Bovine neonatal enteric panel – includes bovine coronavirus (BCov) – PCR, rotavirus ruminant group A and B – PCR (rocopcr), sucrose wet mount (sucwt), bacterial culture, food/fiber producing animals (other than swine) (cultf, bsetup).  Feces needs to be split into 3 separate sterile vials for distribution to the 3 lab sections involved.  If done at AHL, an extra splitting charge will be applied.

Sheep/goat enteritis

Histology: As for bovine histology above.  Remember to collect multiple sections from jejunum and ileum.

Bacteriology:  Feces, small and large intestine. – routine culture.

Clostridium  perfringens type D enterotoxemia: culture, and PCR genotyping (feces or intestine).

M. paratuberculosis (Johne’s disease) PCR: ileujm, mesenteric lymph node, feces.

Virology: Rotavirus A and B, coronavirus PCR: feces, ileum/spiral colon.

Serology:  Johne’s disease, AGID: 1 mL serum.

Parasitology:  Feces for Cryptosporidium sp. (sucrose wet mount), coccidia/GIN (fecal flotation).

Equine enteritis

Histology: Formalin any area with gross lesions. Also include routine tissues, e.g., filtering organs: liver, kidney, spleen, lung. Remember to collect multiple sections from jejunum and ileum.

Bacteriology:  Feces, small and large intestine, mesenteric lymph node – routine culture.

C. perfringens, C. difficile: toxin ELISAs, anaerobic culture, and PCR genotyping (feces, intestinal content).

Lawsonia intracellularis PCR: feces or ileum.

Neorickettsia risticii (Potomac horse fever) PCR: 2 mL EDTA blood, feces.

Virology: Equine coronavirus & rotavirus PCR panel: feces, colon.

Parasitology:  Feces for flotation (McMaster).

Molecular Biology: PCR (Potomac horse fever/Neorickettsia): feces, blood.

Dog/cat enteritis:

Histology: Formalin-fixed sections of esophagus, stomach, mesenteric lymph node, duodenum, jejunum, ileum with Peyer’s patch, colon including any area with gross lesions. Also include routine tissues, e.g., filtering organs including liver, kidney, spleen, lung.  Remember to collect multiple sections from jejunum and ileum.

• Immunohistochemistry is available on formalin-fixed tissues for canine parvovirus, feline parvovirus (panleukopenia), canine/feline coronavirus, canine distemper virus.

Bacteriology:  Feces, small and large intestine, mesenteric lymph node.

C. perfringens, C. difficile: toxin ELISAs, anaerobic culture, PCR genotyping (feces or intestinal content).

Virology:

Canine parvovirus 2 PCR: feces, small intestine.

Feline parvovirus (panleukopenia) PCR: feces, small intestine.

Parasitology:  Feces for flotation; Tritrichomonas fetus culture or PCR, Giardia (saline wet mount, antigen ELISA: fresh feces).

Molecular Biology: Feces

  • Tritrichomonas fetus PCR
  • Giardia duodenalis genotyping
  • Toxoplasma gondii

Rabbit enteritis

Note: Submission of 3 live, affected and untreated rabbits for postmortem examination is recommended.

Histology: Formalin-fixed sections of duodenum, jejunum, ileum, cecum, cecal appendix, proximal (sacculated) and distal colon including any area with gross lesions, stomach, mesenteric lymph node. Also include routine tissues, e.g., filtering organs: liver, kidney, spleen, lung. Collecting intestinal sections into small formalin containers individually labelled with the anatomic location of gut sampled is helpful. Remember to collect multiple sections from jejunum and ileum.

Bacteriology:  Aerobic and anaerobic culture: ileum, cecum.

        • Clostridium spiroforme smears: ileum, cecum.

Lawsonia intracellularis PCR: ileum, feces.

Parasitology:  Feces for flotation (coccidia).