>DR. Williams,
>I've just found out one of my cats has a kidney worm,and my vet thinks it
>came from one of the ferrets.I was wondering if you could send me any
>information on this parasite and the treatment for it in ferrets...
>They all seem healthy with good appetites.
 
The kidney worm, Dioctophyma renale, is a really amazing life form.
Following ingestion by a mammalian host, the larval worms migrate through
the body, taking up residence in the kidney.  AT this point, the worm
matures and grows up to a meter in length, directly consuming the kidney
tissue to supply its nutritional needs.  At the end, all you have left is
the kidney capsule and a big worm.  The females lay eggs which are passed
out in the animal's urine.  Another amazing fact is that is is often
asymptomatic, because the other kidney continues to function.  Bilateral
infections are exceedingly rare.
 
But shame on your vet for blaming your ferrets.  While it is true that in
the wild, mustelids are the most commonly affected hosts, this particular
parasite must pass through an intermediate host, a crayfish, before it
could become infectious to another animal.  It is the ingestion of this
crayfish - or another host which has eaten infective larva shed from the
crayfish, such as a fish, frog or snail, before true kidney infection can
take place.
 
The bottom line is even if your ferrets had these worms and were shedding
the eggs, they would have to pass through a crayfish before they were
infected.  If there is still a question - a simple ultrasound of the
kidneys would show the presence of a worm there.
 
Great question!
 
With kindest regards,
Bruce Williams
[Posted in FML issue 3196]