Abstract
In the present study 89 free-living birds of prey and owls were clinically
examined. Blood analysis and radiographs were also performed. After
stabilization the birds underwent endoscopy and kidney biopsy.
The aims of the study were:
1. Investigation of the feasibility and diagnostic reliability of kidney biopsies for
the diagnosis of renal disease in birds of prey and owls,
2. Evaluation of the compatibility of kidney biopsies and the effect on selected
blood parameters,
3. Investigation of the reliability of clinical examination, blood tests and
radiology for kidney diseases.
topic one: Kidney biopsies are a useful tool for the diagnosis of kidney
diseases. The lateral approach through the caudal thoracic and abdominal air
sacs allows the evaluation of one kidney and a specific biopsy. Due to the
anatomic arrangement only one kidney is completely visible using this
approach.
During endoscopy 2.2% (2/89) of the kidneys had severe changes, 13.5%
(12/89) moderate changes and 52.8% (47/89) slight changes. 31.5% (28/89)
of the birds had no macroscopically visible abnormalities. The visible changes
were only local abnormalities.
Biopsies with pathological findings (n = 66) showed one (53%), two (37.9%),
three (7.6%) and five (1.5%) concurrent pathological conditions. In 0.8%
(1/126) of the biopsies pathological alterations were found to be severe, in
10.3% (13/126) moderate and in 43.7% to a slight degree. 45.2% (57/126) of
the biopsies showed no histological abnormalities. Subcapsular bleeding
(19/126), local inflamation (16/126), cell cylinder (12/126), PAS-positive
material (8/126) and protein cylinders (6/126) were the most important
histological findings. 76.1% of the specimens showed an conformity between
endoscopy and biopsy results.
The histopathology of the biopsy material had similar results in 30.8% (12/39)
of cases when compared to post mortal examination.
No endoscopically detectable changes had 20.5% (8/39) of the histopathologic
examined animals.
topic two: Taking of biopsies with specific forceps was possible without
complications. Post biopsy haemorrhage averaged 67 seconds. The influence
of the biopsy on blood values was small. One day after the biopsy urea and
phosphorus rose significantly. Some birds showed a decrease of hematocrit up
to 10%. The analysis of hematocrit, phosphorus, uric acid and urea showed no
correlation over five days of monitoring.
The 126 biopsies had in average a length of 2.2 mm, a width of 1.3 mm and a
height of 1.0 mm. All samples contained proximal and distal tubuli and 1 - 89
glomeruli. The number of the globuli was estimated and the most biopsie
samples had 25 - 29 glomeruli per histological slice. 38.9% (49/126) of them
contained one to for intralobular veins.
Biopsy material consisted of 10.7% of air sac tissue.
A good estimation of the samples was possible in 89.7% (113/126) cases.
59.5% (75/126) of the specimens were not damaged.
topic three: No bird showed any indication of a kidney disease based on
clinical examination.
Uric acid levels above the reference value of 8.5 mg/dl had 28,3% (15/53) of
the Eurasian buzzards (Buteo buteo) and 5.7% (3/53) had urea levels above
36 mg/dl on the day of endoscopy.
One goshawk (Accipiter gentilis) showed uric acid levels above 14.3 mg/dl.
Two sparrowhawks had uric acid levels above the reference value of 9.1 mg/dl.
There was no correlation between radiological results and the histological
biopsy results.
Some kidneys without endoscopical and histological findings revealed
radiological alterations.
69.1% (38/55) of the kidneys pathological examined birds showed no bacterial
growth on microbiologic examination. E. coli was detected in 21.8% of this
kidneys. 10.9% of the samples revealed Streptokokkus, Proteus, Micrococcus,
coryneform bacteria, oxidase positive and gram positive bacteria. In 18.2% of
the specimens microorganisms and histological findings were diagnosed. |
