Research or diagnostic conditions may require the storage of salivary samples for long periods before analysis is processed. The aim of this study was to evaluate the stability of canine salivary α-amylase, lysozyme, lactate dehydrogenase (LDH), and total calcium and phosphorus after storage for 1, 3 and 6 months at -20°C. Available saliva samples were 75 immediately after collection (T0) and 46 at 1 month (T1), 31 at 3 months (T3) and 18 at 6 months (T6) of storage, according to the number of aliquots collected from each saliva sample. Compared to T0, LDH declined by 92.3% after 1 month of storage (P<0.001), whereas lysozyme concentration significantly decreased as storage time increased (-29.3%, -43.4% and -59.1% at T1, T3, and T6 respectively, P<0.001). Amylase maintained basically the same concentration for the entire experimental period, whereas total calcium and phosphorus concentration decreased over time (calcium, P<0.001). Assessing the long-term stability of canine salivary analytes stored at -20°C may have important implications in diagnosis and research.
Keywords: Biochemistry; Dog; Freezing; Saliva; Storage.
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