The best thing to use on dogs and cats and ferrets for tick control is
Frontline/TopSpot.  Revolution is new and when it originally came out
claimed to be essentially the "best thing since sliced bread" -ie. fleas,
ticks, heartworm,ear mites, mange,etc.  It provides good heartworm
protection and is good against fleas (though not as good as TopSpot) and
basically doesn't work well against ticks at all.  Since ticks seem to be
bad where Mary is, maybe switch to TopSpot.
 
Hope this is helpful info.
 
Kate
[Posted in FML issue 3037]