Oral Fluids

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Veterinary Diagnostic Laboratory
University of Minnesota
1333 Gortner Avenue
St. Paul, MN 55108-1098


Phone: (612) 625-8787
Toll Free: (800) 605-8787
Fax: (612) 624-8707

Submission Guidelines

Submission Form

Oral fluids are predominantly composed of salivary gland secretions (saliva) mixed with variable amounts of serum and inflammatory cells, bacteria, fungi, viruses, bronchial and nasal secretions, gingival epithelial cells, and food debris (2,3). Oral fluids collected from pigs have been used to detect Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), Porcine Circovirus-2 (PCV-2), Influenza A virus, and Mycoplasma hyopneumoniae (1,4,5). They have also been used for the detection of PRRSV antibodies using enzyme-linked immunosorbent assay (4).

Diagnostic tests available for testing oral fluids:

Viral PCR:

  • Hemagglutinating Encephalomyelitis Virus
  • Influenza A Virus
  • Porcine Circovirus Type 2
  • Porcine Reproductive and Respiratory Virus (NAEU differential and quantitative)
  • Also available are sequencing for Influenza A Virus, Porcine Circovirus Type 2 and Porcine Reproductive and Respiratory Virus, as well as Influenza A Virus subtyping.

Bacterial PCR:

  • Actinobacillus pleuropneumoniae
  • Actinobacillus suis
  • Haemophilus parasuis
  • Lawsonia intracelluaris
  • Mycoplasma hyopneumoniae
  • Mycoplasma hyorhinis
  • Mycoplasma hyosynoviae
  • Streptococcus suis

Virus Isolation:

  • Influenza A Virus
  • Porcine Reproductive and Respiratory Virus

Resources for Ropes

The recommended ropes are three-strand twisted, 100% cotton and 1/2” to 5/8” diameter. Cotton is absorbent and will hold the most oral secretions. Do not use nylon or poly blend ropes as they are not absorbent and my cause cuts in the gingival tissue.

These ropes can be purchased by the foot at some hardware stores, Farm and Fleet stores and online (www.webriggingsupply.com and www.knotandrope.com) by the foot or 600-foot reel. A complete collection kit is also available from ITL Animal Healthcare.

An alternative to ropes are cotton tube socks. These should be new socks so that they are not contaminated with bacteria or viral DNA/RNA.

All ropes and socks should only be used once and should not be re-used as it is difficult to remove the genetic material between uses.

If you have difficulty getting the pigs to chew on the rope the first time, you can entice them by shaking the rope and getting them to play with it or by flavoring it with soda, honey or sugar water.

Scientific References

  1. Detmer SE, Patnayak DP, Jiang Y, Gramer MR, Goyal SM. (2011) Detection of Influenza A virus in porcine oral fluid samples J Vet Diagn Invest. 2011 Mar;23(2):241-7.
    PMID: 21398442
    [PubMed - indexed for MEDLINE]
    Related citations
  2. Humphrey SP, Williamson RT (2001) A review of saliva: normal composition, flow, and function. J Prosthet Dent 85:162–169.
  3. Kaufman E, Lamster IB (2002) The diagnostic applications of saliva—a review. Crit Rev Oral Biol Med 13:197–212.
  4. Prickett J, Kim W, Simer R, et al. (2008) Oral-fluid samples for surveillance of commercial growing pigs for porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 infections. J Swine Health Prod 16:86–91.
  5. Prickett J, Simer R, Christopher-Hennings J, et al. (2008) Detection of Porcine reproductive and respiratory syndrome virus infection in porcine oral fluid samples: a longitudinal study under experimental conditions. J Vet Diagn Invest 20:156–163.
  6. Romagosa et al. (2011) Sensitivity of oral fluids for detecting influenza A virus in populations of vaccinated and non-vaccinated pigs. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2011.00276.x.