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==Introduction==

==Introduction==

'''Chronic renal failure''' is the end result of persistent, chronic renal disease - it is usually '''irreversible''' and involves the '''gradual and progressive loss of [[Nephron - Anatomy & Physiology|nephrons]]''' resulting in loss of function. Clinical signs include '''polyuria/polydipsia (PU/PD)''' and [[Uraemia|'''uraemia''']], and blood sample analysis shows [[Azotaemia|'''azotaemia''']], [[Regenerative and Non-Regenerative Anaemias|'''non-regenerative anaemia''']] and '''hyperphosphataemia'''. Often presented as 'end stage kidney' disease, on gross pathology kidneys are '''shrunken, fibrosed, pale and firm'''.

'''Chronic renal failure''' is the end result of persistent, chronic renal disease - it is usually '''irreversible''' and involves the '''gradual and progressive loss of [[Nephron - Anatomy & Physiology|nephrons]]''' resulting in loss of function. Clinical signs include '''polyuria/polydipsia (PU/PD)''' and [[Uraemia|'''uraemia''']], and blood sample analysis shows [[Azotaemia|'''azotaemia''']], [[Regenerative and Non-Regenerative Anaemias|'''non-regenerative anaemia''']] and '''hyperphosphataemia'''. Often presented as 'end stage kidney' disease, on gross pathology kidneys are '''shrunken, fibrosed, pale and firm'''.

==Signalment==

==Signalment==

Chronic kidney disease is most common in '''geriatric cats'''. In these cases the '''cause''' is generally '''unknown''' and assumed to be '''age-related'''. It can also occur in '''younger cats''', but in these cases there tends to be an underlying intrinsic cause such as '''[[Pyelonephritis|pyelonephritis]], [[FIP|FIP]], [[Lymphoma|lymphoma]], [[Hypercalcaemia|hypercalcaemia]], polycystic kidney disease, [[Amyloidosis|amyloidosis]], obstructive disease, [[Glomerulonephritis|glomerulonephritis]], [[Toxicology|toxins]] or [[Acute Renal Failure|acute renal failure]]'''. It can also occur in the '''dog''' in one of the following three presentations; young dogs with '''heritable''' or breed associated disease; '''geriatric dogs''' suffering from chronic kidney disease; and dogs presenting with '''proteinurea or nephrotic syndrome''' at any age. Disease in this final group of dogs can be caused by a number of things such as '''[[Pyelonephritis|pyelonephritis]], [[Leptospirosis - Cats and Dogs|leptospirosis]], [[Hypercalcaemia|hypercalcaemic]] nephropathy, [[Neoplasia - Pathology|neoplasia]], [[Amyloidosis|amyloidosis]], obstructive disease, [[Glomerulonephritis|glomerulonephritis]], [[Toxicology|toxins]] or [[Acute Renal Failure|acute renal failure]]'''.  

Chronic kidney disease is most common in '''geriatric cats'''. In these cases the '''cause''' is generally '''unknown''' and assumed to be '''age-related'''. It can also occur in '''younger cats''', but in these cases there tends to be an underlying intrinsic cause such as '''[[Pyelonephritis|pyelonephritis]], [[FIP|FIP]], [[Lymphoma|lymphoma]], [[Hypercalcaemia|hypercalcaemia]], polycystic kidney disease, [[Amyloidosis|amyloidosis]], obstructive disease, [[Glomerulonephritis|glomerulonephritis]], [[Toxicology|toxins]] or [[Acute Renal Failure|acute renal failure]]'''.  

 

It can also occur in the '''dog''' in one of the following three presentations; young dogs with '''heritable''' or breed associated disease; '''geriatric dogs''' suffering from chronic kidney disease; and dogs presenting with '''proteinurea or nephrotic syndrome''' at any age. Disease in this final group of dogs can be caused by a number of things such as '''[[Pyelonephritis|pyelonephritis]], [[Leptospirosis - Cats and Dogs|leptospirosis]], [[Hypercalcaemia|hypercalcaemic]] nephropathy, [[Neoplasia - Pathology|neoplasia]], [[Amyloidosis|amyloidosis]], obstructive disease, [[Glomerulonephritis|glomerulonephritis]], [[Toxicology|toxins]] or [[Acute Renal Failure|acute renal failure]]'''.  

==Clinical Signs==

==Clinical Signs==

==Staging/Classification==

==Staging/Classification==

The disease can be staged. This helps to guide the prognosis and diagnostic plan. In addition it allows the clinician to monitor the progression of the disease over time in an indivdual animal.

The disease can be staged. This helps to guide the prognosis and diagnostic plan. In addition it allows the clinician to monitor the progression of the disease over time in an individual animal.

 

 

(II) Non/mildly azotaemic with absent/mild clinical signs. Creatinine 125-250 in dogs/140-250 in cats

:(II) Non/mildly azotaemic with absent/mild clinical signs. Creatinine 125-250 in dogs/140-250 in cats

Renal failure can also be classed according to '''protein:creatinine ratios''' and '''blood pressure readings'''.

 

 

Renal failure can also be classed according to '''protein:creatinine ratios''' and '''blood pressure readings'''.  

==Management==

==Management==

(1)''' Search for an underlying cause''' - this may only be appropriate in young cats, cats with enlarged kidneys and in dogs. Otherwise it is very likely to be [[[[Interstitial Nephritis|tubulointerstitial nephritis]] which is very common in elderly cats.

(1)''' Search for an underlying cause''' - this may only be appropriate in young cats, cats with enlarged kidneys and in dogs. Otherwise it is very likely to be [[Interstitial Nephritis|tubulointerstitial nephritis]] which is very common in elderly cats.

(2) '''Control any factors important in disease progression''' - these are normally self perpetuating.

(2) '''Control any factors important in disease progression''' - these are normally self perpetuating.

(3) '''Control factors that increase patient morbidity and quality of life''', these are mainly complications of the '''[[Uraemia|'uraemic syndrome']]'''.  

(3) '''Control factors that increase patient morbidity and quality of life''', these are mainly complications of the '''[[Uraemia|'uraemic syndrome']]'''.

==Maladaptive mechanisms==

==Maladaptive mechanisms==

Several factors contribute to the non-regenerative anaemia of Chronic Renal failure:

Several factors contribute to the non-regenerative anaemia of Chronic Renal failure:

(1) Low levels of Erythropoetin (as it is produced in the kidney) - this is the most significant cause and the limiting factor in the cats recovery from the anaemia

(1) Low levels of [[Erythropoiesis#Regulation|erythropoetin]] (as it is produced in the kidney) - this is the most significant cause and the limiting factor in the cat's recovery from the anaemia

(2) Decreased lifespan of [[Erythrocytes|red blood cells]]

(2) Decreased lifespan of [[Erythrocytes|red blood cells]]

(5) Inhibition of [[Erythropoiesis|erythropoiesis]] by uraemic inhibition

(5) Inhibition of [[Erythropoiesis|erythropoiesis]] by uraemic inhibition

===[[Urinary System (Content Map) - Pathology|Urinary Tract]] Infection===

===Urinary Tract Infection===

These are very common in CRF cases. It can cause decompensation and a worsening of clinical signs. In some cases it may develop into pyelonephritis, ultimately causing progression of disease. In cats the most common causative organism is [[Escherichia coli|''E. coli'']]. The main reason for treatment is to improve quality of life.  

These are very common in CRF cases. It can cause decompensation and a worsening of clinical signs. In some cases it may develop into pyelonephritis, ultimately causing progression of disease. In cats the most common causative organism is [[Escherichia coli|''E. coli'']]. The main reason for treatment is to improve quality of life.  

In cases of hypokalaemia, '''potassium supplements''' may be given in food, however they are quite '''unpalatable''' so this may be difficult. Following treatment appetite and muscle strength should improve.

In cases of hypokalaemia, '''potassium supplements''' may be given in food, however they are quite '''unpalatable''' so this may be difficult. Following treatment appetite and muscle strength should improve.

Immedite treatment of metabolic acidosis is with '''IVFT''', with a product containing low levels of bicarbonate such as Hartmanns. Longterm an '''alkali dietary supplements''' can be fed.

Immedite treatment of metabolic acidosis is with [[Principles of Fluid Therapy|'''intravenous fluid therapy (IVFT)''', with a product containing low levels of bicarbonate such as Hartmanns. Longterm, an '''alkali dietary supplements''' can be fed.

Therapy of anaemia should be aimed at '''reducing blood loss''' and '''increasing RBC production''' where appropriate. '''Iron supplementation''' should be given. A specific therapy for low erythropoetin levels is the administration of '''recombinant human erythropoetin'''. However it is expensive and cross reactions are common (occuring at any point during the treatment course). Therefore its use should be carefully considered, and it should not be used unless the animal is demonstrating clear clinical signs associated with anaemia. Darbepoetin is an alternative with potentially fewer side-effects.  

Therapy of [[:Category:Anaemia|anaemia]] should be aimed at '''reducing blood loss''' and '''increasing RBC production''' where appropriate. '''Iron supplementation''' should be given. A specific therapy for low erythropoetin levels is the administration of '''recombinant human erythropoetin'''. However it is expensive and cross reactions are common (occuring at any point during the treatment course). Therefore its use should be carefully considered, and it should not be used unless the animal is demonstrating clear clinical signs associated with anaemia. Darbepoetin is an alternative with potentially fewer side-effects.  

Patients with chronic kidney disease should be monitored for UTI's - ideally '''cystocentesis''' should be performed at the time of each blood test. Treatment should be with an appropriate '''antibiotic''' and the animal should be encouraged to drink.  

Patients with chronic kidney disease should be monitored for urinary tract infections (UTI's) - ideally '''cystocentesis''' should be performed at the time of each blood test. Treatment should be with an appropriate '''antibiotic''' and the animal should be encouraged to drink.  

In dehydrated animals, '''fluids''' should be administered by; '''promoting oral intake'''; '''subcutaneous fluid administration'''; '''IVFT'''; or by '''oesophageal tube'''.

In dehydrated animals, '''fluids''' should be administered by; '''promoting oral intake'''; '''subcutaneous fluid administration'''; '''IVFT'''; or by '''oesophageal tube'''.

The disease is '''progressive''' and gradually more nephrons fail to function and fibrose. Eventually the cat will succumb to the disease, with the progression of clinical signs and a drop in the quality of life. However with appropriate management it may be several years before this occurs. '''Prognosis''' is clearly directly '''correlated to the stage of renal failure''', with a worse stage indicating a poorer prognosis and shorter survival time.

The disease is '''progressive''' and gradually more nephrons fail to function and fibrose. Eventually the cat will succumb to the disease, with the progression of clinical signs and a drop in the quality of life. However with appropriate management it may be several years before this occurs. '''Prognosis''' is clearly directly '''correlated to the stage of renal failure''', with a worse stage indicating a poorer prognosis and shorter survival time.

==References==

==References==

Barber, P (2003) '''Diagnosis and management of chronic renal failure in the cat''' ''In Practice 2003 25: 306-31''

Barber, P (2003) '''Diagnosis and management of chronic renal failure in the cat''' ''In Practice 2003 25: 306-31''

[http://www.iris-kidney.com/guidelines/en/staging_ckd.shtml|'''IRIS (International Renal Insufficiency Society)''']

[http://www.iris-kidney.com/ '''IRIS (International Renal Insufficiency Society)'''] accessed 7 September 2011

Merck & Co (2009) '''The Merck Veterinary Manual''' (Ninth Edition), ''Merial''

Merck & Co (2009) '''The Merck Veterinary Manual''' (Ninth Edition), ''Merial''

Sparks, AH & Caney, SMA (2005) '''Self-Assessment Colour Review Feline Medicine''' ''Manson''

Sparks, AH & Caney, SMA (2005) '''Self-Assessment Colour Review Feline Medicine''' ''Manson''

[[Category:Renal Failure]]

[[Category:Renal Failure]]

[[Category:To Do - Urinary]]

[[Category:Urological Diseases - Cat]]

[[Category: To Do - Siobhan Brade]]

[[Category: Urological Diseases - Dog]]

[[Category:To Do - Manson review]]

[[Category:Expert Review - Small Animal]]