| Proliferative
kidney disease (PKD) |
| Agent |
Sphaerospora
sp. (Myxosporidian) |
| Hosts |
Salmonids.
|
| Location |
Prespore
stages in kidney interstitium, spores in tile
tubules. |
| Type
of lesion |
Multifocal to diffuse granulomatous response
in the interstitium with subsequent reduction
in the number of melanomacrophages and destruction
of nephrons (pressure?). Granulomalous response
typically is centred around multinucleated "PKX"
cells. Macrophages and lymphocytes surround
the cells. The cells may also be found in the
portal vessels in high numbers. PKX ceils are
large eosinophilic cells with one to several
"daughter cells", frequently with macrophages
adhered to their surface. |
|
Special features |
|
| Diagnosis |
Characteristic
lesions and "PKX" cells that may also be demonstrated
in stained imprints. Sporogonic and extrasporogonic
stages may be demonstrated with certain lectins.
Other myxosporidean infections may be important
differential diagnosis. |
