Saliva crystallisation as a means of determining optimal mating time in bitches

To chart saliva crystallisation patterns throughout pro-oestrus and oestrus in bitches, and to assess their reliability as a tool for optimising the timing of breeding.

Six beagle bitches with normal reproductive activity were used. Saliva ferning patterns were established during pro-oestrus and oestrus. Vaginal cytology, progesterone (P4) levels and behavioural signs were used to determine the optimum mating time. Receiver operating characteristic (ROC) analysis was performed.

Different ferning patterns were scored from 0 to 2. Although variations in saliva crystallisation were noted during the follicular phase of the oestrous cycle in bitches, the test did not prove accurate; test sensitivity was 40.6%, i.e. too low to reliably discriminate the fertile period, while specificity was 86.1%.

This test could be used to complement other methods of determining the fertile period in bitches, but its potential capacity remains to be demonstrated.