Special Veterinary Pathology

Collection of parasitic samples

COLLECTION OF PARASITOLOGICAL SAMPLES AT NECROPSY

Collection of faeces

• Faeces intended for Parasitological examination should be collected from the rectum unless the animal is observed in the act of defaecation when the sample may be collected from the ground.
• Suitable containers for the despatch of samples to the laboratory are 30 ml wide mouthed screw capped bottles of glass or preferably of plastic, which should be filled to the top if possible so as to exclude air as much as possible and so diminish the rate of development and hatching of the eggs.
• Samples should be collected from several animals in an affected herd, some of which should be from the most seriously affected animals and a few from the less seriously diseased in order to observe the contrast in the counts.

Ectoparasites and endoparasites collected during necropsy for identification

• Collect samples of ectoparasites before the cadaver is cut open for
• examination.
• Ticks, fleas and lice should be carefully brushed off from the fur or
• feather and fixed in formalin.
• To disable these organisms, wet the fur or feather of the animal with a detergent solution.
• In collecting ticks, prevent the mouthparts from damage, by wiping the body part of the tick with ether.
• This will kill the tick and allow it to drop.
• Fix the collected specimens in 70% ethyl alcohol or in 10% formalin.
• Information about the degree of ectoparasites infestation should be provided along with the submission.
• Collect mange mites by scrapping the affected skin deeply, and put the scrapings in a glass slide with a drop of mineral oil.
• Roundworms collected from intestinal segments may be fixed in formalin immediately after collection.
• Allow it to relax by dipping in menthol solution or lukewarm water before fixation to prevent curling of the specimen.
• Tapeworm segments collected should include both mature and immature segments, with the scolex still intact. Never lift the tapeworm from its attachment for it will break the scolex.
• The scolex is important in species identification
• Excise the part where the scolex is attached and fix them in formalin.
• Press specimens of cestodes between two glass slides held together by a rubber band, a piece of twine or paper clips before immersion in the fixative.
• For total worm count in ruminants, tie the abomasum at both ends and save all its contents.
• Scrapping deeply the mucosa of the affected intestinal segment and examining the scrapings as a wet smear may do the diagnosis of coccidial infection