Veterinario

Acta Veterinaria Scandinavica

BioMed Central

Open Access

Research

Renal histomorphology in dogs with pyometra and control dogs,
and long term clinical outcome with respect to signs of kidney
disease
Reidun Heiene*1, Veronica Kristiansen1, Jon Teige2 and Johan Høgset Jansen2
Address: 1Department of Companion Animal Clinical Sciences, Norwegian School of Veterinary Science, PO Box8146 Dep., N-0033 Oslo, Norway
and 2Department of Basic Science and Aquatic Medicine, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway
Email: Reidun Heiene* - reidun.heiene@veths.no; Veronica Kristiansen - veronika.kristiansen@veths.no; Jon Teige - jon.teige@veths.no;
Johan Høgset Jansen - johan.hogset.jansen@veths.no
* Corresponding author

Published: 4 May 2007Acta Veterinaria Scandinavica 2007, 49:13

doi:10.1186/1751-0147-49-13

Received: 24 April 2007
Accepted: 4 May 2007

This article is available from: http://www.actavetscand.com/content/49/1/13
© 2007 Heiene et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License(http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract
Background: Age-related changes in renal histomorphology are described, while the presence of
glomerulonephritis in dogs with pyometra is controversial in current literature.
Methods: Dogs with pyometra were examined retrospectively for evidence ofsecondary renal
damage and persisting renal disease through two retrospective studies. In Study 1, light microscopic
lesions of renal tissue were graded and compared in nineteen dogs with pyometra and thirteen agematched control bitches. In Study 2, forty-one owners of dogs with pyometra were interviewed
approximately 8 years after surgery for evidence ofclinical signs of renal failure in order todocument causes of death/euthanasia.
Results: Interstitial inflammation and tubular atrophy were more pronounced in dogs with
pyometra than in the control animals. Glomerular lesions classified as glomerular sclerosis were
present in both groups. No unequivocal light microscopic features of glomerulonephritis were
observed in bitches in any of the groups.
Two bitches severely proteinuric at thetime of surgery had developed end stage renal disease
within 3 years. In five of the bitches polyuria persisted after surgery. Most bitches did not show
signs of kidney disease at the time of death/euthanasia.
Conclusion: Tubulointerstitial inflammation was observed, but glomerular damage beyond agerelated changes could not be demonstrated by light microscopy in the dogs with pyometra.However, severe proteinuria after surgery may predispose to development of renal failure.

Background
In both human [1] and veterinary nephrology [2,3]., proteinuria has been shown to contribute substantially to the
development of end stage renal disease. Clinical intervention by drug therapy is indicated to protect renal function
[4].

Proteinuria is the hallmark of glomerular disease. Polyuria,polydipsia (PU/PD), proteinuria and azotemia are
common features of canine pyometra [5-10]. Because
polyuria/polydipsia usually disappear after treatment, the
accompanying renal lesions are described as temporary.
The renal pathology and long term clinical outcome in
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Acta Veterinaria Scandinavica 2007, 49:13

dogs with pyometra ispoorly defined. Controversy exists
as to whether pathological findings indicative of a tubulointerstitial nephritis and glomerulonephritis are more
severe in dogs with pyometra than in healthy dogs ofcomparable ages.
In numerous textbooks, an immune complex mediated
glomerulonephritis has been suggested as secondary to
pyometra, although data is scarce and inconclusive [1113]. Obel et al [14]...