5,582
edits
Changes
Urine Normal Composition (view source)
Revision as of 18:43, 17 September 2010
, 18:43, 17 September 2010no edit summary
|tablelink = Urinary System (Table) - Anatomy & Physiology
|tablelink = Urinary System (Table) - Anatomy & Physiology
}}
}}
==Introduction==
==Introduction==
The testing and evaluation of urine composition is an essential diagnostic indicator for many diseases. It is therefore essential to have an understanding of what is the normal composition of urine.
The testing and evaluation of urine composition is an essential diagnostic indicator for many diseases. It is therefore essential to have an understanding of what is the normal composition of urine.
==Normal Urine Volume==
==Normal Urine Volume==
Below are the normal urine volumes for the common domestic species. The units are '''ml/kg/day'''
Below are the normal urine volumes for the common domestic species. The units are '''ml/kg/day'''
<TABLE CELLPADDING="2" CELLSPACING="2" WIDTH="20%">
<TABLE CELLPADDING="2" CELLSPACING="2" WIDTH="20%">
==The Normal Appearance of Urine==
==The Normal Appearance of Urine==
Several pathological conditions can cause macroscopic changes to the urine. It is therefore essential to appreciate the normal appearance of urine. In many of the exotic species the urine has a very differant appearance and therefore use care when applying this to those species.
Several pathological conditions can cause macroscopic changes to the urine. It is therefore essential to appreciate the normal appearance of urine. In many of the exotic species the urine has a very differant appearance and therefore use care when applying this to those species.
===Colour===
===Colour===
In the majority of the domestic species the urine should be yellow in colour. The colour of the urine is very dependant on the '''urine specific gravity''' so it is important to account for this. If the urine is more concentrated it will be darker in colour and visa versa as a general rule . Equine urine can become brown if left standing. Discoloured urine should be taken into consideration when carrying out tests which involve a colour change such as dipsticks. The abnormal urine colour could affect the result.
In the majority of the domestic species the urine should be yellow in colour. The colour of the urine is very dependant on the '''urine specific gravity''' so it is important to account for this. If the urine is more concentrated it will be darker in colour and visa versa as a general rule . Equine urine can become brown if left standing. Discoloured urine should be taken into consideration when carrying out tests which involve a colour change such as dipsticks. The abnormal urine colour could affect the result.
===Turbidity===
===Turbidity===
If the urine is not clear then this could indicate a variety of pathological states. In the horse it is normal for it to be turbid due the mucous secreted in the renal pelvis and proximal ureters.
If the urine is not clear then this could indicate a variety of pathological states. In the horse it is normal for it to be turbid due the mucous secreted in the renal pelvis and proximal ureters.
===Odour===
===Odour===
It is normal for urine to have a slight odour from the ammonia. The odour increases with concentration and in some species such as the cat a pungent urine is normal. However a strong smelling urine could indicate a pathological state
It is normal for urine to have a slight odour from the ammonia. The odour increases with concentration and in some species such as the cat a pungent urine is normal. However a strong smelling urine could indicate a pathological state
==Urine Specific Gravity==
==Urine Specific Gravity==
Urine specific gravity is measured using a refractometer calibrated for veterinary use.
Urine specific gravity is measured using a refractometer calibrated for veterinary use.
==Urine Chemistry==
==Urine Chemistry==
The following are common chemicals or parameters whose levels in urine change in pathological vs normal conditions. It is therefore important to appreciate their normal levels
The following are common chemicals or parameters whose levels in urine change in pathological vs normal conditions. It is therefore important to appreciate their normal levels
====pH====
====pH====
In dogs and cats an acidc pH is normal. In the ruminants and horses the opposite is true and the urine is alkali. The pH does however vary with diet and medications as well as in pathological states so this needs to be accounted for. The normal range is 5-9
In dogs and cats an acidc pH is normal. In the ruminants and horses the opposite is true and the urine is alkali. The pH does however vary with diet and medications as well as in pathological states so this needs to be accounted for. The normal range is 5-9
====Protein====
====Protein====
It is not common to find protein in the urine of normal animals. However it can be normal for small amounts to be found in the urine of dogs with a high specific gravity. Therefore this needs to be taken into account.
It is not common to find protein in the urine of normal animals. However it can be normal for small amounts to be found in the urine of dogs with a high specific gravity. Therefore this needs to be taken into account.
====Glucose====
====Glucose====
The presence of glucose in the urine is termed glucosuria and occurs when the level of glucose reaches the [[Reabsorption and Secretion Along the Proximal Tubule - Anatomy & Physiology#Glucose|renal threshold]] for glucose reabsorption. It is not normal to find glucose in the urine.
The presence of glucose in the urine is termed glucosuria and occurs when the level of glucose reaches the [[Reabsorption and Secretion Along the Proximal Tubule - Anatomy & Physiology#Glucose|renal threshold]] for glucose reabsorption. It is not normal to find glucose in the urine.
====Ketones====
====Ketones====
It is not normal for ketones to be present in the urine and they are indicative of pathological states
It is not normal for ketones to be present in the urine and they are indicative of pathological states
====Bilirubin and Urobilinogen====
====Bilirubin and Urobilinogen====
Small amounts of bilirubin can be found in dogs with concentrated urine therefore this needs to be interpreted in light of the urine specific gravity. However as a rule it is not normal to find bilirubin in urine.
Small amounts of bilirubin can be found in dogs with concentrated urine therefore this needs to be interpreted in light of the urine specific gravity. However as a rule it is not normal to find bilirubin in urine.
====Blood====
====Blood====
The presence of blood in the urine is not normal and is usually related to a pathological state.
The presence of blood in the urine is not normal and is usually related to a pathological state.
==Microscopic Examination of Urine==
==Microscopic Examination of Urine==
[[LUT Obstruction - Pathology#Types of uroliths|Uroliths]] and [[Degenerations and Infiltrations - Pathology#Hyaline Degeneration|casts]] can be seem on microscopic examination. Neither of these are a normal finding.
[[LUT Obstruction - Pathology#Types of uroliths|Uroliths]] and [[Degenerations and Infiltrations - Pathology#Hyaline Degeneration|casts]] can be seem on microscopic examination. Neither of these are a normal finding.
The levels of bacteria that seen are very dependent on how sterile the procedure of urine collection has been, which part of the urinary tract the urine has been collected from and if an infection is present.
The levels of bacteria that seen are very dependent on how sterile the procedure of urine collection has been, which part of the urinary tract the urine has been collected from and if an infection is present.