Transcript Clinical Pathology of Feline Liver and Renal Disease

Laboratory Testing in Feline
Liver and Renal Disease
Nick Carmichael
BVM&S, BSc VetSci(Hons), Diploma VCS (Syd),
Diploma RC Path, Diplomate ECVCP, MRCVS
Shropshire Veterinary Association
24th February 2005
Feline Liver Disease
•
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Liver anatomy - what matters clinically
Liver enzymes - what they mean
Liver function tests
FBC changes in liver disease - how they
help
• Common feline liver disease patterns
• Primary Vs secondary liver changes
• Putting it together
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Hepatic Lobule Anatomy
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Hepatic Portal Anatomy
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Hepatic Lobule Anatomy
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Hepatocyte Enzyme Distribution
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Transaminases & Dehydrogenases
• ALT
• AST
• GLDH
Measure integrity of cell membranes
Degree of increase correlates with number of
hepatocytes involved
AST increases correlate with more severe hepatocelullar
injury
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Cholestatic Enzyme Markers
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Liver Enzymes In
Cats
Hepatocellular ALT:
High
Low
ALP 1/2 life:
66 hours
6 hours
Steroid induced ALP:
Yes
No
Bilirubinuria:
Normal
Abnormal
Cholangiohepatitis:
Rare
Common
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Screens Vs Profiles
Screens
Contains grouped tests
• Contains a single test
related to organ function
per organ
• Single most sensitive
Tests provide
test included
complimentary information
• Test array is fixed
Tests included relate to a
• Provides yes/no
presenting sign
information regarding
normality
Assists in localisation/
narrowing of the DDx
Diagnostic Profiles
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Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Bilirubin Metabolism & Excretion
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Bilirubin In Cats
•Measures uptake and excretion of
bilirubin
•Exclude prehepatic jaundice
•Intra- or post-hepatic cholestasis
•Direct/indirect bilirubin NBG
•Bilirubinuria is ALWAYS abnormal in
cats
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Bilirubin Assay Interference
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Liver Function Tests
• Endogenous
• Albumin, urea,
Glucose,
Cholesterol,
Coagulation
Factors, NH3
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Bleeding Disorders In Feline Liver
Disease
Abnormalities of PT and PTT
• Common, usually mild increase PTT only
• PTT <100 secs
• Vitamin K dependant coagulopathy on
EHBDO
• Increased PTT and PT
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Liver Function Tests
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Bile Acids In Cats
Detect
• Presence of diffuse morphologic change
• Significant functional impairment
• Best test for portosystemic shunt
• Fasting bile acids sensitivity = 49%
• Bile acid stimulation test sensitivity = 81%
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Red Cell Changes In Liver Disease
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Immune Mediated Haemolytic Anaemia
Normocytic normochromic anaemia
Microcytosis without anaemia
Acanthocytes
Red Cell Parasites
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
White Cell Changes In Liver Disease
White cell
• Inflammatory/toxic changes
• Lymphoproliferative disease
• Infiltrative conditions
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Common Feline Liver Diseases
The big 5
• Cholangiohepatitis:
– acute, chronic, lymphocytic
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Hepatic lipidosis
Pancreatitis
Hepatic neoplasia
Extrahepatic bile duct obstruction
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Acute Cholangiohepatitis
Clinical features
• Often young to middle aged cats, male
• Non specific clinical signs
– Fever, depression, dehydration
• Acute illness with pyrexia

•
T.Bilirubin, ALT, ALP, AST, GGT, bile acids
• Inflammatory leucogram
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Histopathology of Acute
Cholangiohepatitis
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Toxic Band Neutrophils In Acute
Cholangiohepatitis
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Chronic Cholangiohepatitis
Clinical features
• Often middle aged - older cats
• Non specific clinical signs
• Often concurrent pancreatic and small
intestinal inflammation “Triaditis”
T.Bilirubin, ALT, ALP, AST, GGT, bile
acids, mild NR anaemia, lymphocytosis
• Can progress to biliary cirrhosis

•
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Lymphocytic Cholangitis
Clinical features
• Young to middle aged cats, often persians
• Usually BAR and afebrile
• Abdominal effusion with high protein
count
T.Bilirubin, ALT, ALP, AST, GGT, bile
acids, hyperglobulinemia
• Differentiate from FIP
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•
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Hepatic Lipidosis
Clinical features
• Usually >2yrs old, obese, indoor cats
• Preceded by partial/complete anorexia
• Jaundice, vomiting, dehydration
• Can have encepalopathy:depression, ptyalism
T.Bilirubin, ALT, ALP, AST, bile acids, but
not GGT
• Cytology can help confirm diagnosis
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Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Histopathology Of Hepatic Lipidosis
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Liver Aspirate Cytology
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Nasogastric Feeding
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Feline Pancreatitis / Biliary Tract Disease
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Feline Pancreatitis
Clinical features
• Vague and non specific
– Lethargy, anorexia, dehydration
• Vomiting & abdominal pain less common 30%
• May have abdominal mass 23%, dyspnoea
20%
• May have concurrent bowel/biliary tract
disease
• 40%
of cats with lipidosis have pancreatitis
Nick Carmichael  2005
Feline Liver and Renal Clinical Pathology
Feline Pancreatitis
Laboratory findings
• +/- inflammatory leucogram
• Mild liver enzymes and bilirubin elevations
• Amylase and lipase usually WNL
• fTLI sensitivity 30%, specificity 83%
• fPLI sensitivity 70%, specificity 83%
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Extrahepatic Bile Duct Obstruction
• Causes
– stricture/fibrosis, neoplasia, inspisated bile, bile
stones
• Clinical signs
– Anorexia, depression, vomiting, icterus,
hepatomegally
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
•
ALT, ALP, GGT, T. Bilirubin, bile acids
• Acholic faeces, vitamin K responsive
coagulopathy, absence of urobilinogen
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Feline Hepatic Neoplasia
Primary - rare
• Hepoatocellular carcinoma
• Cholangiocellular carcinoma
Metastatic - common
• Lymphoma
• Myeloproliferative disease
• Mast cell neoplasia
• Haemangiosarcoma
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Feline Hepatic Neoplasia
• Variable clinical and physical signs
• Biochemical abnormalities - variable
• Differentiate from bile duct adenomas,
hepatic cysts
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Reactive/Induced Hepatic Changes
Liver changes without significant liver disease
• Endocrine disease
– hyperthyroidism, Diabetes mellitus
• Bystander hyperbilirubinaemia
– dehydration, sepsis, anorexia
• Reactive/secondary hepatopathies
– hypoxia, endotoxaemia, ?lymphocytic portal
hepatitis
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Systemic Infections Involving The
Liver
• Feline Infectious Peritonitis
– Clinical signs, profile changes, FCoV, cytology
• Toxoplasmosis
– Clinical signs, profile changes, toxoplasma
IgM &IgG
• Imported diseases
– Cytauxzoonosis, Hepatozoonosis
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Making The Diagnosis
• Is primary liver disease likely?
• Check an appropriate profile including a FBC
• If liver changes are present
– Rule out extrahepatic causes of the changes
– Bile acid stimulation test (if not icteric)
• For triaditis add PLI, folate and cobalamin
• Consider cytology if appropriate
• Often laparotomy & biopsy recommended
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Signalment: 15yrs, DSH, MN
History: Long term vomiting, weight loss.
Recent anorexia and hypersalivation.
Very weak.
Luna Granville
Biochemistry
Total protein
Albumin
Globulin
Albumin Globulin ratio
Sodium
Potassium
Na:K ratio
Chloride
Total calcium
Phosphate
Urea
Creatinine
Alk Phos
ALT
Gamma GT
Total bilirubin
Bile acids
Glucose
CK
Cholesterol
Feline Liver and Renal Clinical Pathology
* 50
* 17
33
* 0.5
145.0
* 2.7
* 54
* 115
2.15
* 0.93
6.1
99
* 994
* 299
8
* 49
* 77.9
* 11.8
* 209
4.3
g/L
g/L
g/L
Low (54.0 -80.0 )
Low (21.0 -39.0 )
(15.0 -57.0 )
Low (0.6 - 1.5 )
mmol/L
(125 -160 )
mmol/L Low (3.6 -6.0 )
High (32 -41 )
mmol/L Low (117 -140 )
mmol/L
(2.0 -3.0 )
mmol/L Low (1.2 -2.6 )
mmol/L
(4.0 -12.0 )
umol/L
(80.0 -180.0)
U/L
High (0.0 -50.0 )
U/L
High (0.0 -40.0 )
U/L
(0.0 -10.0 )
umol/L High (0.0 -10.0 )
umol/L High (0.1 - 5.0 )
mmol/L High (3.5 -6.6 )
U/L
High (0.0 -152.0)
mmol/L
(1.5 -6.0 )
Nick Carmichael  2005
Luna Granville
Signalment: 15yrs, DSH, MN
History: Long term vomiting, weight loss.
Recent anorexia and hypersalivation.
Very weak.
Biochemistry
Feline TLI
Alk Phos
ALT
* 346.7
* 435
* 280
Endocrinology
B12
Folate
1040
* 5.9
Feline Liver and Renal Clinical Pathology
U/L
U/L
High (12 -82 )
High (0.0 -50.0 )
High (0.0 -40.0 )
ng/L
ug/L
(240 - 1200)
Low (8.0 - 20.5)
Nick Carmichael  2005
Luna Granville
Signalment: 15yrs, DSH, MN
History: Long term vomiting, weight loss.
Recent anorexia and hypersalivation.
Very weak.
Haematology
RBC
* 3.01
x10^12/L Low (5.5 -10.0 )
Hb
* 5.4
g/dl
Low (9.0 -17.0 )
HCT
* 15.1
%
Low (27.0 -50.0 )
MCV
50.0
fl
(40.0 -55.0 )
MCH
17.8
pg
(13.0 -21.0 )
MCHC
35.5
g/dl
(30.5 -36.5 )
Platelets
* 162
x10^9/L Low (170 -650 )
WBC
* 19.61
x10^9/L High (4.0 -15.0 )
Neutrophils
63% 12.35x10^9/L
(2.5 -12.5 )
Lymphocytes
* 37% 7.26x10^9/L High (1.5 -7.0 )
Monocytes
0.% 0.00 x10^9/L
(0.0 -0.8 )
Eosinophils
0.% 0.00 x10^9/L
(0.0 -1.5 )
Nucleated RBC's
0.20
10^9/L
(0.0 -4.0 )
PT
* 13.7
Seconds
High (8.0 -13.0 )
APTT
* 28.4
Seconds
High (12.0 -25.0 )
Haematologist Comment:
Red cells appear normochromic with increased anisocytosis (+) and poikilocytosis
(+). There is no evidence of increased polychromasia despite the presence of
occasional late normoblasts. No abnormal white cells were seen and platelets
appeared in adequate numbers on the smears and of normal morphology.
There was no evidence of platelet clumping on the EDTA smear.
Nick Carmichael  2005
Feline Liver and Renal Clinical Pathology
Signalment: 15yrs, male, DSH
History: Exploratory laporotomy confirms mass
developing in one of the liver lobes
Tom Morrison
Biochemistry
Total protein
Albumin
Globulin
Albumin Globulin ratio
Sodium
Potassium
Na:K ratio
Chloride
Total calcium
Phosphate
Urea
Creatinine
Alk Phos
ALT
Gamma GT
Total bilirubin
Bile acids
Glucose
CK
Cholesterol
Feline Liver and Renal Clinical Pathology
80
24
56
* 0.4
156.0
4.7
33
124
2.35
1.27
* 15.1
160
* 178
* 185
6
6
* 5.2
5.8
57
2.8
g/L
g/L
g/L
(54.0 -80.0 )
(21.0 -39.0 )
(15.0 -57.0 )
Low (0.6 - 1.5 )
mmol/L
(125 -160 )
mmol/L
(3.6 -6.0 )
(32 -41 )
mmol/L
(117 -140 )
mmol/L
(2.0 -3.0 )
mmol/L
(1.2 -2.6 )
mmol/L High (4.0 -12.0 )
umol/L
(80.0 -180.0)
U/L
High (0.0 -50.0 )
U/L
High (0.0 -40.0 )
U/L
(0.0 -10.0 )
umol/L
(0.0 -10.0 )
umol/L High (0.1 - 5.0 )
mmol/L
(3.5 -6.6 )
U/L
(0.0 -152.0)
mmol/L
(1.5 -6.0 )
Nick Carmichael  2005
Signalment: 15yrs, male, DSH
History: Exploratory laporotomy confirms mass
developing in one of the liver lobes
Tom Morrison
Haematology
RBC
8.87
x10^12/L
(5.5 -10.0 )
Hb
13.4
g/dl
(9.0 -17.0 )
HCT
45.9
%
(27.0 -50.0 )
MCV
52.0
fl
(40.0 -55.0 )
MCH
15.1
pg
(13.0 -21.0 )
MCHC
* 29.2
g/dl
Low
(30.5 -36.5 )
Platelets
512
x10^9/L
(170 -650 )
WBC
13.90
x10^9/L
(4.0 -15.0 )
Neutrophils
73%
10.15 x10^9/L (2.5 -12.5 )
Lymphocytes
19% 2.64 x10^9/L
(1.5 -7.0 )
Monocytes
1% 0.14 x10^9/L
(0.0 -0.8 )
Eosinophils
6% 0.83 x10^9/L
(0.0 -1.5 )
Basophils
1% 0.14 x10^9/L
(0.0 -0.2 )
Haematologist Comment
Red cells appear normocytic and normochromic. White cells appear of normal
morphology and unremarkable. Platelets appear of normal morphology and in
adequate numbers on the smears with no evidence of platelet clumping on
the EDTA smear. Thank you for the fresh film sent with Tom's request.
Endocrinology
Total T4
Feline Liver and Renal Clinical Pathology
34.8
nmol/L
(15.0 -50.0 )
Nick Carmichael  2005
Tom Morrison
Progression
Biochemistry
Total protein
Albumin
Globulin
Albumin Globulin ratio
Urea
Creatinine
Alk Phos
ALT
AST
GLDH
Gamma GT
Total bilirubin
Bile acids
Glucose
Cholesterol
Feline Liver and Renal Clinical Pathology
Signalment: 15yrs, male, DSH
History: Exploratory laporotomy confirms mass
developing in one of the liver lobes
..1 Month Later
75
g/L
(54.0 -80.0 )
24
g/L
(21.0 -39.0 )
51
g/L
(15.0 -57.0 )
* 0.5
Low (0.6 - 1.5 )
* 23.4 mmol/L High (4.0 -12.0 )
144
umol/L
(80.0 -180.0)
* 393 U/L
High (0.0 -50.0 )
* 144 U/L
High (0.0 -40.0 )
30
U/L
(0.0 -69.0 )
6
U/L
(0.0 -10.0 )
8
U/L
(0.0 -10.0 )
3
umol/L
(0.0 -10.0 )
* 5.9
umol/L High (0.1 - 5.0 )
4.9
mmol/L
(3.5 -6.6 )
2.9
mmol/L
(1.5 -6.0 )
Nick Carmichael  2005
Smokey Bridges
Biochemistry
Total protein
80
Albumin
Globulin
Albumin Globulin ratio
Sodium
Potassium
Na:K ratio
Chloride
Total calcium
Phosphate
Urea
Creatinine
Alk Phos
ALT
Gamma GT
Total bilirubin
Bile acids
Glucose
CK
Cholesterol
Feline Liver and Renal Clinical Pathology
g/L
* 18
* 62
* 0.3
155.0
5.5
* 28
118
* 1.83
1.77
* 25.5
* 246
7
31
6
* 32
* 6.2
5.4
139
5.0
Signalment: 8yrs, Female, DSH
History: Acute inappetence, lethargy, polyuria.
Slight weight loss. Mucosae pale.
(54.0 -80.0 )
g/L
Low (21.0 -39.0 )
g/L
High (15.0 -57.0 )
Low (0.6 - 1.5 )
mmol/L
(125 -160 )
mmol/L
(3.6 -6.0 )
Low (32 -41 )
mmol/L
(117 -140 )
mmol/L
Low (2.0 -3.0 )
mmol/L
(1.2 -2.6 )
mmol/L
High (4.0 -12.0 )
umol/L
High (80.0 -180.0)
U/L
(0.0 -50.0 )
U/L
(0.0 -40.0 )
U/L
(0.0 -10.0 )
umol/L
High (0.0 -10.0 )
umol/L
High (0.1 - 5.0 )
mmol/L
(3.5 -6.6 )
U/L
(0.0 -152.0)
mmol/L
(1.5 -6.0 )
Nick Carmichael  2005
Smokey Bridges
Signalment: 8yrs, Female, DSH
History: Acute inappetence, lethargy, polyuria.
Slight weight loss. Mucosae pale.
Haematology
RBC
* 11.43 x10^12/L
High (5.5 -10.0 )
Hb
16.8
g/dl
(9.0 -17.0 )
HCT
* 54.4 %
High (27.0 -50.0 )
MCV
48.0
fl
(40.0 -55.0 )
MCH
14.7
pg
(13.0 -21.0 )
MCHC
30.8
g/dl
(30.5 -36.5 )
Platelets
* 140
x10^9/L
Low (170 -650 )
WBC
* 42.00 x10^9/L
High (4.0 -15.0 )
Neutrophils
* 94% 39.48 x10^9/L High (2.5 -12.5 )
Bands
* 2% 0.84 x10^9/L High (0.0 -0.3 )
Lymphocytes
* 2% 0.84 x10^9/L Low (1.5 -7.0 )
Monocytes
* 2% 0.84 x10^9/L High (0.0 -0.8 )
Eosinophils
0.% 0.00 x10^9/L
(0.0 -1.5 )
Haematologist Comment
Red cells appear normocytic and normochromic. Marked leucocytosis with a
mild left shift and toxic changes within neutrophils. Mild lymphopenia with
occasional enlarged reactive lymphocytes. Mild monocytosis. Platelets
appear mildly reduced and of normal morphology.
Endocrinology
Total T4
* 6.1
Feline Liver and Renal Clinical Pathology
nmol/L
Low (15.0 -50.0 )
Nick Carmichael  2005
Signalment: 11yrs, FN, DLH
History: Straining to urinate. Cervical mass.
Pinta Ibarra
Biochemistry
Total protein
Albumin
Globulin
Albumin Globulin ratio
Sodium
Potassium
Na:K ratio
Chloride
Total calcium
Phosphate
Urea
Creatinine
Alk Phos
ALT
Gamma GT
Total bilirubin
Bile acids
Glucose
CK
Cholesterol
Feline Liver and Renal Clinical Pathology
58
* 20
38
* 0.5
153.0
4.4
35
121
2.18
2.21
11.6
* 73
* 113
38
8
* 16
0.1
* 7.7
119
3.7
g/L
g/L
g/L
mmol/L
mmol/L
mmol/L
mmol/L
mmol/L
mmol/L
umol/L
U/L
U/L
U/L
umol/L
umol/L
mmol/L
U/L
mmol/L
(54.0 -80.0 )
Low (21.0 -39.0 )
(15.0 -57.0 )
Low (0.6 - 1.5 )
(125 -160 )
(3.6 -6.0 )
(32 -41 )
(117 -140 )
(2.0 -3.0 )
(1.2 -2.6 )
(4.0 -12.0 )
Low (80.0 -180.0)
High (0.0 -50.0 )
(0.0 -40.0 )
(0.0 -10.0 )
High (0.0 -10.0 )
(0.1 - 5.0 )
High (3.5 -6.6 )
(0.0 -152.0)
(1.5 -6.0 )
Nick Carmichael  2005
Signalment: 11yrs, FN, DLH
History: Straining to urinate. Cervical mass.
Pinta Ibarra
Haematology
RBC
6.79
x10^12/L
(5.5 -10.0 )
Hb
10.3
g/dl
(9.0 -17.0 )
HCT
32.1
%
(27.0 -50.0 )
MCV
47.0
fl
(40.0 -55.0 )
MCH
15.2
pg
(13.0 -21.0 )
MCHC
32.2
g/dl
(30.5 -36.5 )
Platelets
347
x10^9/L
(170 -650 )
WBC
8.53
x10^9/L
(4.0 -15.0 )
Neutrophils
71% 6.06 x10^9/L
(2.5 -12.5 )
Lymphocytes
27% 2.30 x10^9/L
(1.5 -7.0 )
Monocytes
1% 0.09 x10^9/L
(0.0 -0.8 )
Eosinophils
1% 0.09 x10^9/L
(0.0 -1.5 )
Haematologist Comment
Red cells appear normocytic and normochromic. White cells appear of
normal morphology and unremarkable. Normal platelets morphology and
numbers - there is some evidence of platelet clumping on th EDTA smear
which may have reduced the absolute count somewhat. Thanks for the fresh
blood film sent with Pinta's submission.
Endocrinology
Total T4
Feline Liver and Renal Clinical Pathology
* 94.1
nmol/L
High (15.0 -50.0 )
Nick Carmichael  2005
Signalment: 11yrs, FN, DLH
History: Straining to urinate. Cervical mass.
Pinta Ibarra
Microbiology
Urine creatinine
Urine protein
Urine protein:creatinine
Specific gravity
16.90
1.33
0.79
1.034
mmol/L
g/L
(0.0 -1.0 )
Urine biochemistry
pH
Protein
Glucose
Ketones
Urobilinogen
Bilirubin
Haemoglobin
7
* ++
Negative
Negative
Negative
Negative
* ++++
Urine sediment
RBCs
WBCs
Epithelial
Crystals
Casts
10-20
/hpf
*20-30 /hpf
Occasional epithelial seen
None seen
None seen
Feline Liver and Renal Clinical Pathology
Urine culture
* >100,000 colonies of coagulase negative Staph
Marbofloxacin
Enrofloxacin
Cephalexin
Synulox
Tribrissen
Clindamycin
Sensitive
Sensitive
Sensitive
Sensitive
Sensitive
Sensitive
Nick Carmichael  2005
Feline Chronic Renal Disease
What’s different about cats?
• Biochemistry
– Azotaemia
– Potassium
– Calcium
Feline Liver and Renal Clinical Pathology
• Urinalysis
– Retained
concentrating ability
– Leucocyte dipstick
response
– Crystaluria
significance
Nick Carmichael  2005
Feline Chronic Renal Disease
Azotaemia
Mild
Urea mmol/l Creatinine umol/l
20
250
Moderate
35
350
Marked
50
500
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Feline Chronic Renal Disease
Potassium
• High renal tubular flow promotes potassium loss
• Potassium depletion is only poorly reflected in
serum concentration
• Hypokalaemia exacerbates renal insufficiency
• Anorexia, vomiting, depression, muscle weakness
can all reflect hypokalaemia
• Hyperkalaemia in CRF is a poor prognostic sign
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Feline Chronic Renal Disease
Calcium
• Total calcium comprises 3 components
• Usually serum calcium is normal in CRF
• 10% of cats have increased total calcium
in CRF
• Phosphate restricted diets may increase
calcium
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Urine Specific Gravity In Cats
• Concentrating ability is retained later in
cats
• USG 1.030 need not exclude renal disease
• Measure on cat USG scale
• Dipstick SG scale is
useless
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Urinary Tract Infection In Cats
• Increasingly common with
age
• Need not be associated with
leuconuria
• Leucocyte dipstick gives
false positive
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Boric Acid Tubes
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Crystaluria In Cats
Struvite
•
•
•
•
Oxalate
Alkaline urine
• Acidic urine
Cooled urine
• Cooled urine
Concentrated urine
• Concentrated urine
May dissolve in boric acid
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005
Making The Diagnosis In Feline
Renal Disease
• Need blood and urinalysis
• Complete the renal profile
• Urine best examined/prepared whilst still
fresh
• Sediment and culture required
• Serial measurements are valuable for
monitoring progression/response to
treatment
Feline Liver and Renal Clinical Pathology
Nick Carmichael  2005