VPA 211: General Veterinary Parasitology and Helminthology (3+1)

EXAMINATION OF NASAL WASHINGS

• The larvae and /or eggs of respiratory parasites found in the sputum or tracheal washes have the same characteristics as those found in the feces. An exception is Dictyocaulus, lungworms of cattle and sheep, which are usually seen as eggs containing larvae rather than as free larvae, as in the feces. Examination of nasal washings for Schistosoma nasale is highly useful technique to demonstrate its eggs.
• A drop of sputum or nasal discharge on a microscope slide is easily examined. Several slides should be examined. When the sputum is especially viscous, a drop of the material should be squashed between 2 microscope slides and microscopically examine both the slides.
  • Larger quantities of fluid obtained from the respiratory tract should be concentrated by centrifugation at 2000 rpm for 2 minutes.
  • If there is too much mucus add equal quantity of 2.5 % sodium bicarbonate and shake vigorously, which will dissolve the mucus and then centrifuge.
  • A drop of the sediment can then be placed on a slide and examined microscopically.