>Don't they have chips that can be implanted in animals? ...
 
Yes, of a sort, but perhaps not quite the way you're thinking.  "Tracking
devices" are usually "active", that is they give off a signal that can
traced from a distance with special equipment.  That's what a Lojack
does.  If there are any available for animals at all, I must imagine that
they are expensive, bulky (for a ferret, anyway), not readily available
to the public, and not for everyday use.
 
What we do have are microchips from Avid.  These are about the size of a
grain of rice and are injected under the animal's skin.  They are really
"id" chips rather than tracking chips.  If someone finds your animal,
they can hold a special scanner up to where the chip is implanted (over
the shoulders) and find out the id number.  Then they can call the Avid
company and find out who the owner is.
 
So, the Avid chips can't be used to find an animal, but they can be used
to identify him after he's found.  They are very inexpensive and do give
you some peace of mind.  Many vets and shelters have scanners and check
strays for chips.
 
I haven't chipped my cats, but since ferrets tend to get lost easily, all
of my ferrets have them.  The implanting needle is scary (ever seen a
pheresis needle?  this is bigger....), but the ferrets never notice it
once it's implanted.
 
roger & the wolverine wannabees
missing bear
[Posted in FML issue 4069]