Today, after having lots of fun playing (uhh, I mean... working) at agility, we went to Lillydale Lake for a romp. By the way, it beats me why the township's name is spelled differently from the Lake's.
Anyway, Penny ran around chasing balls and then we wandered over to the creek - Olinda Creek - to have a look and Penny, following her unruly habit, jumped in without looking to check it was safe.
She was still on lead, which might have hampered her style, so she sank to the bottom and came up looking surprised. It took a lot of scrambling and struggling before she could clamber up the rocky bank. I took her off lead and tossed a ball into a safer-looking spot and she happily swam out to get it, so obviously she wasn't disturbed by her underwater adventure.
Not long after, we met a local guy who told me I should be careful letting her swim there because his friend's dog had been killed by a platypus. He said the dog died not long after getting out of the water and a platypus spur was found in the dog's leg.
Having looked around on the internet I've come to the conclusion that it would be unlikely the spur from a platypus was found in the dead dog - the male platypus does have a moveable spur on its hind leg which could inject enough venom to kill a dog, but I didn't find any mention of the spur breaking off.
It might be possible a local dog was killed by a platypus but I don't see how they would have worked that out - maybe by the symptoms? Yet an article from the Swiss Institute of Bioinformatics suggests the symptoms would be similar to a snake bite:
When a platypus feels inconvenienced, it digs its spur into its victim and releases its venom. Since it is only the male platypus that has the use of such artillery, it is thought that the spurs are probably used as an offensive weapon to assert dominance during the mating season and to lay down territorial boundaries. Venom production does indeed increase during the mating season, which sustains the theory. The venom has probably a defensive role too though the aim seems less to kill than to induce intensive pain. Human poisoning is not rare and results in excruciating pain accompanied by massive swelling. Snake venom and platypus venom do seem to cause the same physiological discomforts though snake venom is far more virulent. However, it has been shown that platypus venom can kill dogs when injected intravenously.
Even I, one of the all-time champion worriers, don't think I need to be on the look-out for platypuses in the water when Penny swims - however, it is an interesting topic to me because we are eagerly waiting for the return of platypuses to our local creek in suburban Melbourne. They've been missing for many years because of hunting and pollution.
I seems that platypus poison could be a useful substance because of its implications for pain relief in humans (and in dogs, one would hope).
Recent research shows that the venom could actually be useful as a new type of painkiller as it acts on pain receptor cells, which is a property unique among venoms but shared with the active ingredient of chillies.
Here's the address of a platypus fact file.