Samples for testing must be obtained soon after death. A complete necropsy involves opening up body cavities and examining for gross abnormalities - small shrunken kidneys, a tumor on the lung or liver, enlarged lymph nodes, etc. Samples for testing for amyloidosis should be taken from the kidney (a full longitudinal 1/4" slice through the entire kidney so it includes both glomerular cortex and medullary tissue), liver, and spleen. I often find abnormalities in the mesenteric (intra-abdominal) lymph nodes so I usually submit one of these if I can. All grossly abnormal tissue (any tumors, etc.) is also submittted. Pieces the size of a fingertip from organs other than the kidney are usually sufficient. All of this is placed in 10% formalin which is a highly carcinogenic substance and must be handled and transported with great care. I would recommend submitting to a major universtiy pathology laboratory but you should discuss this with your veterinarian (I have ever found out that some small pathology labs don't stock CRS). Request that congo red special staining be done to check for the presence of amyloid in addition to routine stains.

If your dog dies at night or on a weekend when you are unable to get the body to your veterinarian, keep the body cool but not frozen until sampling can be done. Pack it in ice and/or in a cool basement or garage. The greater the time before sampling, the greater the amount of autolysis (breakdown and decay of tissues) will occur and the less likely precise results can be obtained microscopically. A good pathologist can usually differentiate between damage post-mortem through autolysis and ante-mortem lesions if the samples are not too old so it is still worth submitting.