Disseminated Idiopathic Myositis (DIM) in Ferrets


Several years ago vets came across a vague and apparently terminal illness in ferrets.

First discovered in 2003, Disseminated Idiopathic Myositis (DIM) — which is also known as ‘Polymyositis’ — is an inflammation of the muscles (from the terms ‘myositis’ and ‘polymyositis’).
The other two terms which make up the name of the disease show that it is present throughout the body (disseminated) and the cause of the problem is not yet understood (idiopathic).

Both male and female ferrets are susceptible to this disease and while it seems to affect those aged 18 months and younger, there have been cases of ferrets aged over 2 years having this problem.

The symptoms are vague and non-specific and can include:-

Severe lethargy and weakness
Persistent fever which fluctuates and can reach 42C (108F)
Lack of appetite
Reluctance to move around
Diarrhea &/or abnormal poop
Mild nasal discharge which is clear (serous)
Poor condition
Some ferrets with DIM will have one or more enlarged lymph nodes or other swellings not associated with lymph tissue

If you suspect your ferret is suffering from DIM and you live in the States, go to the American Ferret Association’s page on DIM to print out the DIM Case Report Form for Veterinarians as well as their DIM Alert pdf file.

For those of you who don’t live in the States then just print out the DIM Alert and take it to your ferret knowledgeable vet for him to see if the problem is, in fact, DIM.

I recently lost one of my boys, Otis, to what I’m sure was DIM.

I’ve written about the symptoms and the very short period between the time I first noticed something wrong with Otis to when he finally left us here.


You can read more on Disseminated Idiopathic Myositis (DIM) in Ferrets on these sites …

Disseminated Idiopathic Myositis (Polymyositis) in Ferrets (WagWalking.com)

Disseminated idiopathic myofasciitis by Cathy Johnson-Delaney, Joerg Mayer (VetStream)

Disseminated Idiopathic Myofasciitis in Ferrets by Simon Starkey BVSc, PhD, D ABVP(Avian) (VIN)

Myofasciitis (Vetbook)



There are a number of pdfs about Disseminated Idiopathic Myofasciitis which you can dowload …

Disseminated Idiopathic Myositis (DIM) (aka “Polymyo
(American Ferret Association).
You can download the pdf here.

Myofasciitis in the Domestic Ferret by MM Garner, K Ramsell, NJ Schoemaker, et al. Another technical document which would probably be of more interest to your vet.
It can be downloaded here.

Myofasciitis in the Domestic Ferret, an Emerging Fatal Disease by Michael Garner, DVM, Dipl ACVP & Katrina Ramsell, PhD, DVM.
It’s a technical document but might help your vet if he’s not ferret savvy. Download it here.


(Last updated November 2019)

DISCLAIMER: The information contained on this page is not meant to replace seeing a veterinarian if you think your ferret is ill. It’s only meant to supply general information on a particular illness which was obtained either from personal experience with my sick ferrets, or from books and/or the Internet.

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