From: jeffp@wsuaix.csc.wsu.edu (Jeff Parke;S10000)
Newsgroups: rec.pets.dogs
Subject: Re: writing a nasty letter to breeder
Summary: Demodex canis infections
Date: 15 Aug 92 20:59:06 GMT
Organization: Washington State University


RE: From: amiranda@ariel.aero.org (Ann Miranda)
Subject: Need help writing Nasty Letter


This *is* an interesting post.  Ann really stirred things up in some areas of 
breeding philosophy and sexuality, and I'd like to add to Sue Honig's 
well-informed reply.

>         Anyhow, it turns out that  Shelby has mange, a skin disease
>which is caused by microscopic critters (parasitic mites).
>     We first noticed the mange actually when we got her, as a small
>scratch looking patch on her forehead.  But, we assumed it was just
>a scratch.  A month later, when a bulge appeared in the same spot,
>and kept growing, we became suspicious, and took her to the vet to
>have it checked.  He took a skin scraping and saw the mites and lots
>of eggs on her skin.  The vet told us that mange is passed from the
>mother while nursing the puppies.  He said there is no other way
>she could have gotten it.  I realize that the breeder had no guarantee
>on her dogs, so we basically have no recourse against her.  The vet
>told us she may not even be aware that the mother had mange (it could
>be dormant).  (The mother actually didn't look mangy, although
>she was pretty scrawny!)
>...
>And, the vet told us not to breed Shelby because, even if she
>is cured of the mange, the probability of her passing it onto her
>pups is high.

I deleted the part of the post that mentioned Mitoban as the treatment.  This 
mitocide identifies the mites (along with the information your vet gave you) as 
Demodex canis.

I hope I can clear up some confusion about Demodex.  A few Demodex canis are 
found on nearly every dog!  But you don't want to waste your time looking for 
them.

Demodicosis is the skin disease that happens when the mites become numerous, 
and irritate the skin in various ways.  There are two forms - localized and 
generalized.  Both tend to occur in young purebred dogs.  Localized is a milder 
form, more focal lesions, less severe secondary infections, etc.  Generalized 
demodicosis is pretty nasty business.  Now, here's the rub (so to speak)...

Localized demodicosis will spontaneously regress in about 90% of dogs showing 
signs.  In such animals, regression is independent of treatment.

Generalized demodicosis occurs in the 10% of localized cases that don't 
regress.  Although it is considered a separate disease entity, it is likely 
that generalized cases start out looking like localized cases in the beginning.  
There is a strong genetic factor in generalized demodicosis, so any dog with it 
should not be bred.  It is very difficult to cure in some dogs, and it can be a 
life-threatening condition.

Based on the information given, it seems Shelby was diagnosed with the 
generalized form.

The causes of generalized demodicosis are not well known.  What genes are 
involved isn't understood yet.  It is clear we can't blame the mites, since 
they are present on many dogs that never show the disease (although they are 
necessary for demodicosis to occur).  Essentially the disease is blamed on 
immune system being unable to properly combat demodex.  The immune system can 
be thrown out of wack by countless causes, most being infection by some other 
agent (parasite, bacteria, virus, rickettsia, etc.).  But there are numerous 
idiopathic immunologic deficits that happen.

So it is important to diagnose and treat any underlying problems in cases of 
demodicosis.

Finally, it is true that demodex are acquired in the first few days of life 
from the bitch.  Apparently efforts to prove infection of adult dogs by 
contact, ingestion, injection and all sorts of routes have failed.  Nursing 
pups seem to be the only route.

So, in the case in question, *if* the alleged back-yard breeders knew the 
bitch or sire of the litter had generalized demodicosis, they were very 
irresponsible to breed them.  However, it is perfectly plausible that neither 
parent had a history of the disease.

In the Monday morning quarterback department... If you are purchasing a puppy 
and there is *any* type of skin lesion, have it checked out before committing 
money or emotional energy in the puppy.

-Jeff
-------------------
jeffp@wsuaix.csc.wsu.edu ...uunet!wsuaix.csc.wsu.edu!jeffp
jeffp@WSUVM1.bitnet CIS: 71511,1512  AOL: JeffParke
a.k.a. Jeff Parke,  Washington State University College of Vet. Medicine