Training of dogs for detection of oestrus specific scent in saliva of cows

Dogs can be trained to identify an enormous variety of scents. We have trained dogs to identify oestrus specific odour in vaginal fluid, milk and urine (Fischer-Tenhagen et al., 2011) under laboratory conditions with accuracy of more than 80 %. To use dogs as heat detectors on dairy farms, it would be beneficial in terms of hygiene and safety, to have the dogs working to have the dog working on the feed alley with cows heads fixed in head lockers. The objective of this study was to test if dogs can smell oestrus specific scent in saliva of cows. Saliva samples were collected from cows in oestrus (n = 46) and dioestrus (n = 68). Thirteen scent identification dogs were trained in this experiment. In the test and training situation dogs had to find the positive sample in a one out of four situation. For determining the accuracy dog handlers were blinded regarding the position of the positive sample. The overall percentage of correct positive indications was 58.8 % (n = 316) with a range from 40% (1 dog) to 75 % (3 dogs). To our knowledge this is the first report that dogs are able to detect oestrus specific scent in saliva of cows. Although the accuracy of detection was lower as for vaginal fluid, a dog should be able to identify cows in oestrus sniffing at the mouth and nose.