Of the 1001 possible uses for a dog’s nose, a Spanish led group of researchers has come up with a new one: sniffing out wildlife infected with Sarcoptes scabiei. In humans, the mite causes scabies.
The skin parasite, Sacorptes, is found throughout the world. It infects over 100 species  spreading through direct body contact or by transfer from common burrow or den. In an urban environment this can also mean shelters, boarding kennels or dog day-care.
Symptoms of mange can include:
- hair loss
- skin thickening which can cause
- impaired hearing
- difficulty swallowing
- foul smell
- secondary infection
- death from exposure
Interestingly, despite the very distinct smell of mange-infected animals, no one had thought of using this trait to track or identify Sarcoptes in the wild. The authors of this study note that “to the best of our knowledge there are no cases of dogs having been trained to detect wildlife diseases”
Kudos to them for such innovative thinking.
The Bavarian Mountain Hound is a strong agile breed, and chose for its ability to withstand the cold weather, its endurance and has a long tradition of excelling at tracking.
The authors initially started with 1 Bavarian Mountain Hound in 1995 and brought on a second BMH in 1999.
While they paper doesn’t give too many specifics regarding the training; it is clear that once again the method of choice for effective, fast (“training of Ingo took approximately three months.”) and reliable behavior is positive reinforcement. They write:
“Ingo had been trained to bark in the proximity of the carcass, which prompted the giving of a reward, food and play (Pavlovian conditioning).”
While they don’t go into any further details, I assume that the quote below refers to social learning. Also possibly related to the work of Slabbert and Rasa (1997) who demonstrated puppies allowed to observed their mother in detection exercises showed enhanced trainability in those areas.
“Work-shadowing and “learning by contiguity” enabled this puppy the chance to become disease-detector dog much faster than Ingo.”
The training, specially for the second dog proved highly effective and “Buck was five months old, he detected his first mangy carcass under packed snow”
As far as the results go the dogs proved particularly effective in minimizing false positives and identifying mild cases thus preventing the unnecessary removal of healthy animals.
“Unfortunately, selective culling implies a reliable diagnosis from distance, and this is often hampered by “occult” presentations of the disease (e.g., crusty lesions embedded in thick fur or localized in poorly visible region, as the abdomen and inguine) generating false negatives.”
The dogs were even able to identify cases that would have been otherwise dismissed as starvation.
“Dogs were able to localize chamois even when
mildly affected (eg, in cases in which the true cause of the death was winter starvation, and only patches of scabietic skin were present).”
The mange detector-dogs performed flawlessly. Of the 292 mangy carcases and 63 Sarcoptes-infected wild animals there were no false negatives and they were far more effective in tracking down diseased animals. During the same period, hunters culled only 18 infected chamois and 65 carcases were found using traditional “dog-less” methods.
It will be interesting to see if this method of mange surveillance gets wider implementation and maybe even expanded into other diseases. It could very well prove to be a powerful tool in wildlife conservation.
15000 years into our relationship and they can still show us something new.
- Sarcoptic-mange detector dogs used to identify infected animals during outbreaks in wildlife. Veterinary Research 2012, 8:110. http://www.biomedcentral.com/1746-6148/8/110 DOI:10.1186/1746-6148-8-110
- Pence DB, Ueckermann E (2002) Sarcoptic Mange in Wildlife. Rev.sci. tech. Off. int. Epiz., 2002, 21 (2), 385-398.
- Slate D, Algeo TP, Nelson KM, Chipman RB, Donovan D, et al. (2009) Oral Rabies Vaccination in North America: Opportunities, Complexities, and Challenges. PLoS Negl Trop Dis 3(12): e549. doi:10.1371/journal.pntd.0000549 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2791170/
- Slabbert JM and Rasa OAE (1997). Observational learning of an acquired maternal behaviour pattern by working dog pups: An alternative training method? Appl Anim Behav Sci, 53:309–316.