Possible pseudogout in two dogs

Abstract

Pseudogout, the acute form of calcium pyrophosphate deposition disease, is a common condition in elderly human beings and is characterised by the sudden onset of intense joint pain and synovitis. It is rarely identified in animals but was diagnosed in two dogs that presented with acute lameness and pyrexia. Cytology of the synovial fluid showed a mildly elevated cell count with both non-degenerate neutrophils and mononuclear cells present. Many of the mononuclear cells and occasional neutrophils contained square or rhomboid-shaped crystals that were variable in shape and size and weakly birefringent on examination under polarised light. Clinical signs resolved following treatment with prednisolone.

The nature of coxofemoral joint pathology across family Canidae

“…We ask whether "osteoarthritis" is a valid universal descriptor of jointassociated dry bone features, absent of histological evaluations that allow visualizing of living cells, additional sub-classifying observations (Blom et al, 2004;Junker et al, 2016;Roelofs et al, 2020;van Lent et al, 2004), or analytical assessment of their unique biochemical properties (Xu et al, 2017). Furthermore, depending on the location of a given individual boney feature, is "osteophyte-like" a more appropriate general descriptor, given that features on dry bone can represent (a) enthesophyte (Lawler et al, 2019); (b) osteophyte (Roelofs et al, 2020); (c) pyrophosphate (pseudogout, chondrocalcinosis, Gibson & Roenigk, 1972;Woodard et al, 1982;Heimann et al, 1990;De Haan & Andreasen, 1992;Frank et al, 2002;Forsyth et al, 2007;Miksanek & Rosenthal, 2015;Bertram et al, 2019;Catelli et al, 2020;Henschen et al, 2020); (d) postdevelopmental boney remnant (Lawler et al, companion in this issue); (e) calcified fibrous remnant; (f) exostosis (Gambardella et al, 1975;Gee & Doige, 1970;Jacobson & Kirberger, 1996;Owens, 1982); (g) neoplasm (Kim et al, 2005;Owens, 1982;Scherrer et al, 2005;Valentine et al, 2002); (h) developmental or mechanical multi-tissue impingement (not well-researched in dogs); or (i) idiopathic? It must be recognized that underlying or incipient pathophysiology, and therefore the individual, population, and phylogenetic implications across these differential diagnoses, can be variable (Henschen et al, 2020;Litwic et al, 2013;Miksanek & Rosenthal, 2015;Roelofs et al, 2020;…”