Urology AI 1 Flashcards
What can cause acute kidney injury (AKI)?
Severe hypercalcemia related to ingestion of certain rat poisons or psoriasis creams, and ethylene glycol intoxication.
What are the potential causes of hypocalcemia?
Ethylene glycol intoxication.
What concurrent changes in liver damage and function parameters are highly suspicious for possible leptospirosis?
Increased ALT, AST, ALP, bilirubin.
In suspected leptospirosis, what additional parameters, if present, suggest the possibility of active infection?
Anemia and/or thrombocytopenia on a complete blood count.
What is the importance of obtaining urine in AKI cases?
To check the specific gravity and exclude pre-renal azotemia.
What might sediment examination of urine reveal in cases of AKI?
Clues to the cause of AKI, such as calcium oxalate monohydrate crystals associated with ethylene glycol ingestion or concurrent bacterial infection suggesting pyelonephritis.
What does the presence of casts in the urine indicate?
Tubular damage in the kidneys, particularly cellular casts which represent the sloughing of tubular epithelium into the urine.
What imaging techniques can provide helpful information in diagnosing AKI?
Radiographs and ultrasound of the kidney.
What can be observed in cats with lymphoma on ultrasound?
Enlargement of both kidneys with hypoechoic subcapsular infiltrates.
What is the medullary rim sign observed in cases of ethylene glycol ingestion?
A line of increased opacity between the cortex and medulla of the kidney.
How can the diagnosis of leptospirosis be made in dogs?
By detecting specific antibodies through the microagglutination test (MAT) or detecting the organism itself by PCR in the blood or urine.
What is the diagnostic criteria for leptospirosis using the microagglutination test?
An acute titre >1:800 (or 1:1600 in a vaccinated dog) in the acute sample, or a four-fold increase in titre from acute to convalescent samples.
How can the diagnosis of ethylene glycol toxicity be challenging?
Because the animal is rarely seen ingesting it.
What clinical neurological signs in the initial presentation may help in diagnosing ethylene glycol toxicity?
Stupor or obtundation.
What are the biochemical abnormalities associated with ethylene glycol toxicity?
Azotemia, hypocalcemia, hyperglycemia.
What would be observed in the urine of an ethylene glycol toxic patient?
Calcium oxalate monohydrate crystals.
What can a Woods lamp reveal in cases of ethylene glycol toxicity?
The urine may fluoresce.
What is metabolic acidosis and how is it associated with ethylene glycol toxicity?
Metabolic acidosis is an acidosis of metabolic origin associated with a large anion gap, which is seen in ethylene glycol toxicity.
How is the anion gap calculated and what is considered a normal value?
The anion gap is calculated using the equation [Na+] - ([HCO3-] + [Cl-]). A normal value would be.
What is the preferred method for diagnosing leptospirosis?
Detecting specific antibodies through the microagglutination test (MAT).
Why is antibiotic treatment less likely to affect serology compared to PCR in diagnosing leptospirosis?
Because the immune response to the organism continues, whereas PCR may be affected by antibiotic treatment.
What features can help in diagnosing ethylene glycol toxicity?
Clinical neurological signs, biochemistry abnormalities, presence of calcium oxalate crystals in urine, and metabolic acidosis.
What can ultrasound reveal in dogs suspected of having leptospirosis?
Dilation of the renal pelvis (pyelectasia) and mass lesions in the kidney.
What is the significance of a line of increased opacity between the cortex and medulla of the kidney?
It is observed in ethylene glycol ingestion but is an unreliable sign of hypercalcemia.
How long does it take for specific antibodies to be produced in leptospirosis?
7-10 days after infection.
What is the time frame for collecting acute and convalescent samples in diagnosing leptospirosis?
7 days apart.
What can cause an increase in leptospirosis titers, other than active infection?
Recent vaccination or cross-reactivity between vaccinal and non-vaccinal serovars.
What can PCR detect in leptospirosis?
The organism itself in the blood or urine, and even in subclinical carriers.
What might help in diagnosing ethylene glycol toxicity if the animal is rarely seen ingesting it?
Clinical neurological signs, biochemical abnormalities, presence of calcium oxalate crystals in urine, and metabolic acidosis.
What are the possible outcomes of acute kidney injury (AKI)?
Possible outcomes of AKI include complete recovery, fatal AKI, or development of chronic kidney disease (CKD).
What is the recovery phase of AKI and how long can it last?
The recovery phase of AKI can last weeks to months.
How can chronic kidney disease (CKD) develop from AKI?
CKD can develop if AKI results in a greatly decreased GFR, leading to progressive kidney disease.
When can a dog or cat be considered to have CKD resulting from AKI?
A dog or cat can be considered to have CKD resulting from AKI if they are persistently azotaemic 3 months after the resolution of AKI.
Why may a renal diet not be necessary for an animal with AKI in the first 3 months?
A renal diet may not be necessary for an animal with AKI in the first 3 months because the GFR may return to normal levels over that period.
How can repeated GFR estimation be helpful during the recovery phase of AKI?
Repeated GFR estimation can help determine if an animal’s kidney function is changing during the recovery phase of AKI.
What are common signs of acute kidney injury (AKI) in dogs and cats?
Common signs of AKI include lethargy, decreased appetite, vomiting, nausea, and decreased urine output.
Why is it important to determine if affected animals had access to nephrotoxins?
Determining if affected animals had access to nephrotoxins is important because many cases of renal AKI are related to toxin exposure.
What can palpation of the kidneys reveal during a physical examination of an animal with AKI?
Palpation of the kidneys can reveal if they are enlarged or irregular in outline.
What does palpation of the bladder during a physical examination of an animal with AKI indicate?
Palpation of the bladder can help determine if urine is still being produced.
Why is evaluating the volume and hydration status important when assessing animals with possible AKI?
Evaluating volume and hydration status is important to guide fluid therapy and prevent excessive volume of intravenous fluids in animals that cannot produce urine.
What are the indicators of AKI in non-azotaemic animals based on serum creatinine levels?
An increase in serum creatinine of 26.4 μmol/l or more over 48 hours suggests developing AKI, even if values are within the reference interval.
What is the significance of confirmed oliguria/anuria over a period of 6 hours in diagnosing AKI?
Confirmed oliguria/anuria over 6 hours is sufficient to diagnose AKI in non-azotaemic animals.
What does an increased anion gap in the blood imply?
It implies a large amount of another unmeasured anion in the circulation, such as ethylene glycol.
What are some concerns regarding the diagnostic accuracy of direct ethylene glycol tests?
There are questions over the diagnostic accuracy of these tests and they may give false positive results in ketotic patients.
What is the purpose of the grading scheme produced by IRIS for animals with acute kidney injuries?
To assess the severity of its presentation and provide a shared framework for clinical studies.
How is the grading scheme for acute kidney injury different from the clinical stages of chronic kidney disease?
Animals with acute kidney injury are expected to change grades as they progress, while animals with chronic kidney disease remain at a particular stage for some time before gradually progressing.
What is the key principle for treatment of acute kidney injury?
To intervene at the earliest possible moment to decrease the severity of the induction and extension phases.
What is more effective than treating acute kidney injury?
Prevention of potentially damaging insults.
What are some examples of specific treatments for different causes of acute kidney injury?
Ethanol or 4-methylpyrazole for ethylene glycol, amoxicillin/clavulanate followed by doxycycline for leptospirosis, antimicrobials based on culture and sensitivity for pyelonephritis, placement of a catheter for urethral obstruction, placement of a stent or bypass device for ureteral obstruction, and administration of synthetic prostaglandin misoprostol for NSAID toxicity.
What treatment is required if there is no apparent cause and specific factors have been treated?
Most animals will require supportive treatment.
What is the key consideration in providing hydration and volume support for animals with acute kidney injury?
Balancing fluid administration to meet maintenance requirements without causing overhydration in anuric/oliguric patients.
What are some risks associated with overhydration in animals with kidney injury?
It can worsen kidney injury, cause hypertension, and lead to complications such as pulmonary edema.
How can the hydration and volume status of animals with acute kidney injury be monitored?
Through clinical examination of skin turgor and eyes for chemosis, frequent weighing to check for weight gain, and matching input to output in urine production.
What is one insult that can cause papillary necrosis?
Overdose of non-steroidal anti-inflammatory drugs (NSAIDs)
How do non-steroidal anti-inflammatory drugs (NSAIDs) disrupt the prostaglandins in the kidney?
They disrupt the prostaglandins that normally facilitate blood flow to hypoxic regions of the kidney
What do the afferent and efferent arterioles regulate in the glomerular capillaries?
The pressure of blood
What is the purpose of the pressure difference from the capillaries to the Bowman’s space?
To provide a gradient for filtration of blood plasma
How does constriction of the afferent arteriole affect pressure in the glomerulus?
It decreases pressure in the glomerulus by preventing the entry of blood into the glomerular capillaries
How does constriction of the efferent arteriole affect the pressure gradient between the glomerular capillaries and Bowman’s capsule?
It maintains the pressure gradient by limiting the exit of blood out of the glomerulus
What does the glomerular filtration rate (GFR) measure?
The volume of glomerular filtrate produced per unit time
What does a decrease in GFR indicate about kidney function?
The ability to filter blood and produce urine also decreases
What is the GFR an average of?
The individual GFRs of the nephrons in both kidneys
What is the product of afferent arterial flow and filtration fraction (FF)?
The GFR
What happens to the GFR if the afferent arterial flow decreases due to hypovolemia?
The GFR will drop
What happens to the GFR if the filtration fraction (FF) drops due to decreased glomerular permeability?
The GFR will drop
What governs the filtration fraction?
The balance of Starling forces
What are the chief Starling forces in the glomerular capillaries?
Difference in hydrostatic pressure and difference in capillary osmotic pressure
What is the main determinant of colloid osmotic pressure (COP)?
Blood protein concentration
What determines the reflection coefficient of the glomerulus?
The area of the glomerular capillaries and the permeability of the capillaries
What happens to the GFR if there are fewer glomerular capillaries?
The GFR will drop
What happens to the GFR if the capillary walls become less permeable?
The GFR will drop
What are critical determinants of the hydrostatic pressure gradient along the glomerular capillaries?
Constriction of the afferent and efferent arterioles
In the presence of aldosterone, what happens to sodium and potassium?
Sodium is reabsorbed and potassium is excreted into the urine.
What are the consequences of aldosterone deficiency in Addison’s disease?
Dogs with hypoadrenocorticism often present with hyperkalaemia and hyponatraemia.
How does the movement of potassium into cells help regulate potassium levels?
It provides a temporary buffer to prevent a spike in blood potassium concentration.
Where is potassium filtered and reabsorbed in the kidney?
Potassium is filtered in the glomerulus and reabsorbed in the proximal convoluted tubule (PCT) and loop of Henle.
How is potassium excreted in the distal convoluted tubule (DCT)?
Potassium can be excreted as sodium is reabsorbed using a channel activated by aldosterone.
What happens when there are severe reductions in GFR in kidney disease?
Potassium cannot be excreted as quickly as it is ingested, causing hyperkalaemia.
What can happen in some animals with CKD in terms of potassium excretion?
Dysfunction of the renal tubules may prevent reabsorption of potassium, leading to chronic hypokalaemia.
How is phosphorus regulated in the kidney tubules?
Reabsorption of phosphorus is closely controlled by the concentrations of parathyroid hormone (PTH) and fibroblast growth factor (FGF)-23.
What increases the secretion of PTH and FGF-23 in regards to phosphorus excretion?
Phosphorus forms a feedback loop by increasing the secretion of PTH and FGF-23.
What is the main regulator of calcium concentration in the extracellular fluid?
Parathyroid hormone (PTH)
Where is calcium reabsorbed in the kidney?
Calcium is reabsorbed in the proximal convoluted tubule (PCT) and loop of Henle.
What does PTH do to increase reabsorption of calcium?
PTH acts to increase blood calcium concentration by increasing intestinal, dietary, and bone reabsorption of calcium.
What do the kidneys regulate in addition to removing toxic products?
The kidneys regulate the normal osmolality and electrolyte composition of the extracellular fluid, as well as the total volume of this fluid.
What is the distribution of total body water among different compartments?
Approximately two thirds is intracellular fluid, one quarter is blood plasma, and almost all of the remainder is interstitial fluid between cells.
What is the difference between hypovolaemia and dehydration?
Hypovolaemia refers to reduced volume of fluid in the circulatory system, while dehydration refers to overall body water loss.
What treatment should be administered to restore cardiac excitability in sinoventricular rhythm?
Calcium gluconate 10% should be administered slowly IV over 15-30 minutes.
What is the main goal of correcting hyperkalaemia?
Re-establishing urine output and allowing intracellular movement.
How can intracellular movement be stimulated during the correction of hyperkalaemia?
Administering fluid with 5-10% dextrose and/or soluble insulin.
What should be monitored closely in non-diabetic animals receiving insulin during the correction of hyperkalaemia?
Blood glucose concentration.
How can nausea and inappetence be treated in animals with AKI?
Treatment with maropitant, gastroprotectants, and administration of food by oesophagostomy or naso-oesophageal tube.
What should be considered when administering food by oesophagostomy or naso-oesophageal tube to animals with AKI?
The solutions contribute to the total fluid input and potential overhydration.
What is the polyuric phase of AKI characterized by?
Severe polyuria as glomerular filtration occurs before tubular function has recovered.
What electrolytes may need to be supplemented in intravenous fluids for animals in the polyuric phase of AKI?
Sodium and potassium.
How can grape and raisin ingestion potentially cause AKI in dogs?
The toxin responsible is unknown, and even small amounts can cause disease.
What initial signs may dogs show after ingesting grapes or raisins?
Vomiting and/or diarrhea.
What precautions should be taken in treating dogs with recent grape or raisin ingestion?
Monitoring serum creatinine concentration and urine specific gravity frequently in the first 48 hours.
What factors are associated with a poor outcome for dogs with AKI?
Failure to produce urine again, high creatinine level, anemia, and hypocalcemia.
What is the survival rate for dogs with leptospirosis-induced AKI?
Approximately 80%.
What is the difference between dehydration and hypovolaemia?
Dehydration refers to a decreased amount of total body water, while hypovolaemia refers to a decreased circulating blood volume.
Give an example to explain the difference between dehydration and hypovolaemia.
In the example of a dog that has lost a large amount of blood, it would be severely hypovolaemic but only mildly dehydrated.
What is the treatment approach for a severely hypovolaemic dog?
Rapid administration of large amounts of fluid, such as boluses of crystalloids or a blood transfusion.
Describe the hydration deficit correction approach for a dog with chronic kidney disease.
Slow correction of the hydration deficit over a period of many hours or days.
Which hormone regulates the osmolality of extracellular fluid?
ADH (anti-diuretic hormone)
Where are the specialised osmoreceptors located?
In the supraoptic nucleus of the hypothalamus.
What happens when the osmolality of extracellular fluid increases?
ADH is released, increasing the permeability of the DCT and CD to water, allowing reabsorption of large amounts of water.
What is the role of increased osmolality in activating thirst receptors?
It causes the animal to drink more water.
What can result from inappropriate ADH secretion?
Hyponatraemia (a decreased concentration of sodium in the blood).
Which enzyme is released by the macula densa in response to decreased flow of sodium and chloride ions?
Renin
What is the principal action of angiotensin II?
It increases reabsorption of sodium in the proximal renal tubule and causes absorption of water by osmosis, expanding the ECF volume.
What actions does angiotensin II have on the glomerulus?
It causes constriction of the efferent arterioles.
What is the purpose of angiotensin II’s action on the glomerulus?
To maintain a normal GFR (glomerular filtration rate) despite decreased renal flow.
Who is the module developer for Urology I in the Small Animal Medicine Distance Learning Module 17?
James Swann
What are the learning objectives for Urology I in the Small Animal Medicine Distance Learning Module 17?
- Describe how the kidney removes toxic substances from the blood. 2. Explain how the kidney regulates the osmolality and volume of the extracellular fluid. 3. Distinguish between hypovolaemia and dehydration. 4. Identify the hormones produced by the kidney and their major roles. 5. Identify the major diagnostic tests used to assess kidney function. 6. Describe the advantages and limitations of the major diagnostic tests for assessing kidney disease in small animals. 7. Explain how diagnostic tests can be used to distinguish between acute and chronic kidney diseases. 8. Give examples of new biomarkers that have been described in cats and dogs. 9. Describe the major causes of acute kidney injury (AKI). 10. Grade cases of AKI according to the IRIS guidelines. 11. Outline a clinical approach to a case with suspected AKI. 12. Explain the components of treatment for an animal with AKI.
What will be covered in the first section of the module?
Basic aspects of renal physiology, including how the kidneys handle water and substances dissolved in the blood, maintaining the normal volume and concentration of solutes in the extracellular fluid, and the hormones produced by the kidneys.
What is the renal artery a direct branch of?
The abdominal aorta.
What are the two types of arteries formed from the renal artery within the kidney?
Interlobar arteries and arcuate arteries.
What form a tuft of capillaries within the kidney?
The afferent arterioles that enter the glomerulus.
What does the efferent arteriole form when it leaves the glomerulus?
Multiple peritubular capillaries, which are closely associated with the renal tubules.
What do the peritubular capillaries ultimately form?
Renal venules, which drain into the renal vein.
What happens if there is a reduction in blood flow to the renal artery?
The whole kidney may experience ischaemia since the kidney has no collateral blood supply.
What makes the central parts of the kidney vulnerable to ischaemia?
The progressive branching of blood vessels means that they become relatively hypoxic.
What can be seen on ultrasound scans of older animals’ kidneys due to hypoxia?
Old renal infarcts.
What is azotaemia?
Azotaemia is a syndrome of clinical signs occurring due to severe kidney disease.
Is uraemia a clinical diagnosis related to biochemical values?
No, uraemia is a clinical diagnosis made in azotaemic patients and is not related to biochemical values.
What is SDMA?
SDMA is an alternative biochemical measurement used to estimate kidney function.
How is SDMA related to bodyweight and muscle mass?
SDMA is not related to bodyweight or muscle mass in the same way as creatinine.
What were the major claims made about SDMA?
The major claims for SDMA were: 1. It detects decreased kidney function with more sensitivity than creatinine. 2. An increased SDMA can predict which animals will go on to become azotaemic later.
What was the correlation between GFR and SDMA in dogs with hereditary nephropathy?
The correlation between GFR and SDMA in dogs with hereditary nephropathy was 0.95.
What were the findings about the association between GFR and SDMA/creatinine in dogs with CKD?
There was no difference in the association between GFR and either SDMA or creatinine in dogs with CKD or non-azotaemic dogs.
Can an increased SDMA concentration predict the onset of kidney disease earlier?
In dogs with X-linked nephropathy, SDMA increased sooner than creatinine but the average difference was only 4-5 weeks.
How many dogs with post-mortem evidence of CKD had an increased SDMA before creatinine increased or euthanasia?
17 out of 19 dogs had an increased SDMA on average 9.8 months before creatinine increased or the dog was euthanised.
What is the main issue with the study on increased SDMA in dogs with post-mortem evidence of CKD?
The study is problematic because 10 dogs were euthanised without increased creatinine concentration, making it unclear if the increased SDMA had clinical significance.
Can an increased SDMA predict the onset of azotaemia in some dogs?
Yes, SDMA might predict the onset of azotaemia effectively in some dogs.
Did increased SDMA always correspond with clinically important kidney disease in the study of cats?
No, increased SDMA appeared to precede the onset of azotaemia or decreased GFR, but cats varied in the underlying nature of their kidney disease.
What is the most common cause of pre-renal acute kidney injury?
Prolonged pre-renal insult (ischaemia leading to infarction)
What is the main cause of renal acute kidney injury?
Damage to the renal tubules (acute tubular necrosis)
What are the two types of damage that can cause renal acute kidney injury?
Ischaemic (related to prolonged hypoperfusion) or toxic (exposure to nephrotoxins)
Which type of acute kidney injury is caused by obstruction to urine flow?
Post-renal acute kidney injury
What are some common causes of post-renal acute kidney injury?
Urethral obstructions, ureteroliths
What are some factors that increase the risk of developing hospital-acquired acute kidney injury?
Hypovolaemia/dehydration, nephrotoxic drugs, procedures that decrease renal blood flow or cause renal insult
Which phase of acute kidney injury is characterized by the first cellular damage occurring in the kidney?
Initiation phase
During which phase of acute kidney injury is the AKI clinically detectable and oliguria/anuria occurs?
Extension phase
During which phase of acute kidney injury is there irreversible damage but it is not progressing?
Maintenance phase
Which phase of acute kidney injury is characterized by signs of repair and the animal becoming extremely polyuric?
Recovery phase
What can a doubling of creatinine concentration within the reference interval represent?
A serious deterioration in kidney function.
Why can creatinine concentration vary between breeds?
Because production of creatinine is proportional to the animal’s muscle mass.
How do animals with muscle wastage affect the accuracy of creatinine for evaluating kidney function?
It decreases the accuracy because less creatinine is being produced.
How can animals with CKD and a low body condition score affect the measurement of serum creatinine concentrations?
Measured serum creatinine concentrations may underestimate the filtration capabilities of the kidneys.
What is the effect of small amounts of creatinine secretion in the renal tubules of male dogs?
It can affect the estimation of GFR if urine creatinine measurements are included.
How does a large drop in GFR affect serum creatinine concentration?
A large drop in GFR needs to occur before there is any change in serum creatinine concentration.
Is there a preclinical period for animals with kidney disease before any change in creatinine occurs?
Yes, there is potentially a long preclinical period before any change in creatinine.
How does the relationship between GFR and creatinine concentration change after creatinine increases above the reference interval?
Even large increases in GFR may not be of any clinical significance.
What substances can interfere with the optical detection of creatinine?
Glucose, ketone bodies, some antibiotics, haemolysis, hyperbilirubinaemia, and lipaemia.
Why is it recommended to fast animals for measurements of creatinine?
Because the serum creatinine concentration may be increased transiently after eating, especially after eating meat.
What is urea?
Urea is a nitrogenous waste product made from ammonia in the liver.
How is blood urea concentration different from creatinine concentration?
Blood urea concentration is more variable than creatinine and is affected by a larger number of other factors not related to kidney disease.
What could an increased urea on a biochemical sample be related to?
It could be related to kidney disease, gastrointestinal haemorrhage, or recent feeding.
What does azotaemia represent?
Azotaemia represents evidence of kidney dysfunction, which could be pre-renal, renal, or post-renal.
What is the difference between azotaemia and uraemia?
Azotaemia refers to a consistently increased creatinine concentration with or without increased urea, while uraemia refers specifically to an increased urea concentration in the absence of increased creatinine.
What is the rate at which intravenous fluids can be received?
0.5 ml/kg/hour
Why can intravenous fluids be received at a rate of 2.5 ml/kg/hour?
To reflect urine output + amount lost from insensible losses
What is one requirement to adopt the approach of adjusting fluid rate?
Placing a urinary catheter with a collection system
How often should the volume of urine be measured to adjust the fluid rate?
Every 2-4 hours
What is one indication for haemodialysis?
Severe overhydration
How does haemodialysis remove excess fluid?
By osmosis as the blood is filtered
What is the suggested initial bolus dose of furosemide for attempting to restore urine output?
2 mg/kg IV
What is the main role of furosemide?
To increase urine output to correct electrolyte abnormalities
What is the suggested dose of mannitol to increase urine output?
0.5-1 gram/kg over 15-20 minutes
When should mannitol be used with caution?
In patients that are overhydrated or dehydrated
Is there evidence that the use of diuretics improves outcome in animals with AKI?
No
Was the use of dopamine for AKI in dogs and cats recommended?
No
What parameter may cause severe physiological disturbances in animals with oligoanuric AKI?
Serum potassium concentration
What ECG changes are associated with hyperkalaemia?
Small, wide, or absent P wave and a wide QRS complex
What is the progression of ECG changes associated with hyperkalaemia?
Progressing to a…
What are the poor prognostic markers for cats with concurrent systemic diseases?
Hyperkalaemia, Anaemia, Low body temperature at presentation
What are the signs of shock in cats with concurrent systemic diseases?
Neurological or respiratory signs
In which year was the Symmetric Dimethylarginine Assay Validation published?
2015
Which biomarker was evaluated for the early detection of chronic kidney disease in dogs?
Symmetric Dimethylarginine
What is the diagnostic value of Symmetric Dimethylarginine, cystatin C, and creatinine for detecting decreased glomerular filtration rate in dogs?
Comparison
Which substance was used to compare serum iohexol clearance, serum SDMA concentration, and serum creatinine concentration in non-azotemic dogs?
Iohexol
What is a possible cause of decreased glomerular filtration rate in dogs?
Chronic Kidney Disease
In which year was the study conducted on serum concentrations of Symmetric Dimethylarginine and creatinine in dogs with naturally occurring Chronic Kidney Disease?
2016
Which kidney function biomarkers were compared in cats with Chronic Kidney Disease?
Symmetric Dimethylarginine and creatinine
What is a masked Chronic Kidney Disease in cats?
Chronic Kidney Disease in cats with Hyperthyroidism
What effect does boric acid have on bacterial culture of canine and feline urine?
Unknown
In which year was the study on the effect of boric acid on bacterial culture of canine and feline urine conducted?
2011
What does GFR stand for?
Glomerular Filtration Rate
How is iohexol clearance used to estimate GFR?
It is injected intravenously and its clearance is measured as it is excreted into the urine.
In which clinical scenarios might it be helpful to measure GFR?
Estimating renal function before giving a potentially nephrotoxic drug, determining kidney recovery after acute injury, if other parameters are unreliable.
What are the factors that can affect GFR?
Size, age, breed, and hydration status.
What is the normal range of GFR in cats and dogs?
1.8-2.1 ml/kg/min
What does a normal GFR measurement suggest about kidney function?
The kidneys are filtering blood appropriately in the glomeruli.
How does urea and creatinine help assess kidney function?
Increased serum concentration indicates impaired kidney function.
What is the relationship between creatinine and muscle mass?
Creatinine production is proportional to muscle mass.
What is the significance of Fanconi syndrome in relation to GFR?
Affected animals have normal GFR but a defect in reabsorption of certain substances in the proximal convoluted tubule.
What are the limitations of using creatinine as a measure of kidney function?
Creatinine increase is an insensitive measure and significant loss of kidney function is needed for it to rise above the reference interval.
What happens to the GFR when the efferent arteriole is moderately constricted?
The GFR increases due to an increase in the hydrostatic pressure gradient.
What happens to the GFR when the efferent arteriole is extremely constricted?
The GFR may decrease or stay the same compared to baseline due to an increase in colloid osmotic pressure gradient.
What is the effect of ACE inhibitors on the constriction of the afferent and efferent arterioles?
ACE inhibitors cause greater relaxation of the efferent arteriole than the afferent arteriole.
What is the clinical significance of defects in reabsorption mechanisms in the proximal convoluted tubule?
Defects in reabsorption mechanisms can lead to aminoaciduria and glucosuria in urine production.
Which segment of the loop of Henle reabsorbs sodium, potassium, and two chloride ions?
The thick ascending limb of the loop of Henle reabsorbs sodium, potassium, and two chloride ions.
What is the effect of vasopressin on the permeability of the distal convoluted tubule and collecting duct?
In the presence of vasopressin (ADH), the DCT and CD become permeable to water.
What hormone stimulates the exchange of sodium for potassium in the DCT?
Aldosterone stimulates the exchange of sodium for potassium in the DCT.
What does angiotensin II cause production and release of?
aldosterone from the zona glomerulosa of the adrenal glands
What are the effects of angiotensin II outside the kidneys?
production of ADH and direct constriction of the blood vessels to raise blood pressure
What is the function of aldosterone?
increases sodium reabsorption by increasing the exchange of sodium for potassium in the DCT
What does the renin-angiotensin-aldosterone system cause?
retention of water and sodium, expanding the ECF volume
What happens when sodium and chloride ions passing the macula densa are decreased due to kidney disease?
the same mechanisms are activated to expand the ECF volume inappropriately, contributing to hypertension
What hormone is produced by the kidneys in response to hypoxia?
erythropoietin (EPO)
What does erythropoietin stimulate in the bone marrow?
erythroid progenitors to produce more red blood cells
What can happen in animals with CKD when the kidneys are unable to produce enough EPO?
development of chronic non-regenerative anaemia
What enzyme in the kidneys converts 25-hydroxycholecalciferol to its active form?
1 alpha hydroxylase
What can happen in chronic kidney disease that interferes with the absorption of calcium?
preventing normal absorption of calcium from the glomerular filtrate and diet, contributing to mineral and bone disease (MBD)
What is an important measure of kidney function?
glomerular filtration rate (GFR)
Which substances can be measured to estimate GFR?
creatinine, inulin, and iohexol
What percentage of cats developed azotaemia after radioactive iodine treatment?
16%
How many cats had an increased SDMA before radioactive treatment?
14
What does SDMA stand for?
Symmetric Dimethylarginine
What biomarker does not predict GFR as well as creatinine?
Cystatin C
What does USG stand for?
Urine Specific Gravity
What does a hyposthenuric urine indicate?
Excessive sodium reabsorption
What does a hypersthenuric urine indicate?
Excessive water reabsorption
What is the purpose of urine analysis?
To provide information about kidney function
What is the most accurate way to quantify proteinuria?
Measuring the Protein:Creatinine ratio
What is haematuria?
The presence of blood in urine
What is CKD?
CKD stands for chronic kidney disease.
What are the common symptoms of CKD in animals?
Common symptoms of CKD in animals include muscle weakness and constipation.
How can the extent of cachexia caused by CKD be estimated?
The extent of cachexia caused by CKD can be estimated using a muscle mass score, such as the one produced by WSAVA.
What may be palpable in the descending colon of affected cats with CKD?
Large quantities of hard faeces may be palpable in the descending colon of affected cats with CKD.
What is the goal of treatment for CKD?
The goal of CKD treatment is to slow the progression of the disease, treat complications, and improve quality of life.
Why is feeding an appropriate diet beneficial for CKD patients?
Feeding an appropriate diet for months or years can help slow disease progression in CKD patients.
What is the intended impact of starting treatment for hypertension in CKD patients?
Starting treatment for hypertension aims to limit the impact of this feature of the disease, even if the owners cannot observe any immediate effects.
What should be continuously evaluated when treating CKD patients?
The combination of treatments should be continuously evaluated to determine if it is producing a positive impact on quality of life.
Which organization provides treatment guidelines for dogs and cats with CKD?
The International Renal Interest Society (IRIS) provides treatment guidelines for dogs and cats with CKD.
What is the distinction between hypovolaemia and dehydration in CKD patients?
Stable CKD patients usually have a normal plasma volume but may have some degree of chronic dehydration.
What can precipitate acute on chronic kidney injury in CKD patients?
Fluid loss due to vomiting or diarrhoea can precipitate acute on chronic kidney injury in CKD patients.
Is there a benefit to administering intravenous fluids to normally hydrated CKD patients?
No, there is no benefit to administering intravenous fluids because it will have no impact on GFR (glomerular filtration rate).
How should intravenous fluids be administered to dehydrated CKD patients?
For dehydrated CKD patients, the total hydration deficit should be estimated, and the fluids should be administered over 24 hours, along with maintenance requirements.
How can water intake be encouraged in CKD patients that become mildly dehydrated?
Water intake can be encouraged by feeding wet food to CKD patients that become mildly dehydrated.
What are some invasive methods to administer additional water to CKD patients?
Fluids can be injected subcutaneously periodically by the owner or a feeding tube, such as an oesophagostomy tube, can be placed to administer additional water.
What should the sodium concentration of rehydration fluids ideally be?
The sodium concentration of rehydration fluids should ideally be lower than physiological levels.
What is the impact of hypertension on disease progression in cats with CKD?
The impact of hypertension on disease progression in cats with CKD is complicated by its association with proteinuria.
Is hypertension associated with a poorer outcome in cats with CKD?
No, hypertension is not associated with a poorer outcome in cats with CKD.
When should blood pressure be measured in animals with known or suspected kidney disease?
Blood pressure should be measured in any animal with known or suspected kidney disease.
What should prompt investigation for an underlying cause of hypertension in animals with target organ damage?
Detection of target organ damage, such as hyphaema or acute blindness caused by retinal detachment, should prompt investigation for an underlying cause of hypertension.
What should be done if the blood pressure is 200 mmHg or more without obvious signs of situational hypertension?
Treatment should be started immediately if the blood pressure is 200 mmHg or more without obvious signs of situational hypertension.
What is proteinuria?
Proteinuria refers to excessive loss of protein in the urine.
Why is proteinuria associated with a poor outcome in animals with CKD?
Proteinuria is associated with a poor outcome in animals with CKD because renal tubular cells are damaged when exposed to large amounts of filtered protein.
How is proteinuria best quantified?
Proteinuria is best quantified by measurement of the urine protein: creatinine ratio.
What additional evaluation should be done when proteinuria is detected?
A thorough evaluation of the urine, including dipstick, sediment examination, and possible culture, should be done when proteinuria is detected.
What are the IRIS guidelines for defining proteinuria in dogs and cats?
For dogs: No treatment needed <0.2 UPC value, No treatment needed but close monitoring required 0.2-0.5 UPC value, Treatment recommended >0.5 UPC value. For cats: No treatment needed <0.2 UPC value, No treatment needed but close monitoring required 0.2-0.4 UPC value, Treatment recommended >0.4 UPC value.
What is the typical appearance of anemia in animals with CKD?
Anemia in animals with CKD is usually mild and non-regenerative, producing a normochromic and normocytic appearance.
What can cause more severe anemia in animals with CKD?
More severe anemia in animals with CKD can be related to episodes of gastrointestinal hemorrhage.
What is a risk factor for gastrointestinal ulceration in animals with CKD?
Azotaemia/uraemia is a risk factor for gastrointestinal ulceration in animals with CKD.
What is mild occult gastrointestinal blood loss?
Mild occult gastrointestinal blood loss refers to hidden, small amounts of blood loss in the gastrointestinal tract.
How is anaemia treated in animals?
Anaemia in animals is treated by administering darbopoietin (‘Aranesp’), which is a synthetic version of human erythropoietin.
What is the recommended dose for administering darbopoietin to animals?
Darbopoietin can be administered at a dose of 1 μg/kg per week.
What is the purpose of administering iron in conjunction with darbopoietin?
Increased erythropoiesis caused by darbopoietin creates increased demand for iron, so it is good practice to administer iron along with darbopoietin.
What are the options for administering iron as a supplement?
Iron can be administered as iron dextran through intramuscular injection or as oral supplementation.
What are the potential side effects of darbopoietin administration?
Potential side effects of darbopoietin administration include hypertension, polycythaemia, aplastic anemia, seizures, and fever.
What is the aim of treatment for anaemia in animals?
The aim of treatment is to increase the packed cell volume (PCV) by 1-3% per week, aiming for the lower end of the reference range.
How should animals with evidence of gastroduodenal ulceration be treated?
Animals with evidence of gastroduodenal ulceration should receive omeprazole at a dosage of 1 mg/kg twice daily for at least one week.
What are the potential complications of prolonged therapy with proton pump inhibitors?
Prolonged therapy with proton pump inhibitors should be avoided due to potential rebound hyperacidity when they are eventually stopped.
Which acid suppressant medications are less effective in controlling gastric acid production than proton pump inhibitors?
Other acid suppressant medications, such as H2 receptor antagonists like ranitidine and famotidine, are less effective than proton pump inhibitors.
What medication can be used to prevent vomiting in animals with episodes of vomiting, nausea, and inappetence?
Maropitant can be used to prevent vomiting in animals with these symptoms.
What are the recommended dosages for administering maropitant to cats and dogs?
The recommended dosage for cats is 1.88 mg every other day, and for dogs, it is 0.6-1 mg/kg every other day.
What is the use of mirtazapine in cats with CKD?
Mirtazapine is used as an appetite stimulant and antiemetic in cats with CKD.
What are the potential side effects of mirtazapine in cats?
Potential side effects of mirtazapine in cats include hyperexcitability, vocalization, and tremors.
What is the purpose of staging animals in the context of IRIS grading?
To estimate the prognosis of dogs and cats with CKD based on their disease severity.
Why is it important to stage animals when their disease is stable?
To accurately assess their disease progression and determine the appropriate treatment.
How does IRIS grading of AKI differ from IRIS staging of CKD?
AKI grading involves rapid progression between stages, while CKD staging requires stability before advancing to a higher stage.
What is the usual lower reference limit for creatinine in the context of IRIS stage 2 CKD?
The lower reference limit for creatinine falls within the IRIS stage 2 CKD definition.
What are the median survival times for dogs in IRIS Stages 1 and 2?
More than 400 days (limit not reached in the study).
What are the median survival times for dogs in IRIS Stages 3 and 4?
Approximately 130 days for Stage 3, and approximately 15 days for Stage 4.
What are the median survival times for cats in IRIS Stages 2, 3, and 4?
1151 days for Stage 2 (range 2-3107), 778 days for Stage 3 (range 22-2100), and 103 days for Stage 4 (range 1-1920).
Does dehydration correction affect the median survival time for cats in Stage 4 with severe azotaemia?
Yes, if dehydration is corrected but azotaemia persists, the median time decreases to 35 days (range 21-99).
Apart from the creatinine concentration, what other subgroups are considered in the IRIS staging scheme?
The IRIS scheme includes subgroups based on proteinuria and hypertension status.
Why may the definition of hypertension need adjustment for certain animals, such as sighthounds?
Sighthounds are known to have higher blood pressure values than other breeds of dog.
What is systemic hypertension and what is the most common disease process causing it?
Systemic hypertension refers to persistently increased systolic blood pressure. The most common disease process causing it is CKD.
What percentage of dogs and cats with CKD have hypertension at the time of diagnosis?
Approximately 30-50% of dogs and 30-60% of cats with CKD have hypertension at the point of diagnosis.
What are some possible causes of secondary hypertension in cats and dogs?
Hyperadrenocorticism, hyperthyroidism, diabetes mellitus, and certain adrenal tumours.
What is primary or idiopathic hypertension?
Primary or idiopathic hypertension refers to hypertension without a detected underlying cause.
How can hypertension be categorized based on the risk of target organ damage?
Hypertension can be categorized based on the extent of increase in systolic blood pressure above the normal upper limit.
What is the title of the article by Lu et al.?
The title of the article by Lu et al. is ‘care practice in the UK: a VetCompass(TM) study’.
What year was the article by Boyd et al. published?
The article by Boyd et al. was published in 2008.
What type of blood pressure measurements were taken in the study by Gill et al.?
The study by Gill et al. involved indirect Doppler flow systolic blood pressure measurements.
What was the effect of body position on blood pressure measurement in dogs in the study by Rondeau et al.?
The study by Rondeau et al. found that body position affected the indirect measurement of systolic arterial blood pressure in dogs.
How many cats were included in the study by Payne et al.?
The study by Payne et al. included 780 apparently healthy cats.
What breed of dogs were included in the study by Scansen et al.?
The study by Scansen et al. included healthy Shetland Sheepdogs.
What factors were investigated in the study by Mooney et al.?
The study by Mooney et al. investigated the effects of various factors on Doppler flow ultrasonic radial and coccygeal artery systolic blood pressure measurements in dogs.
What was compared in the study by Pape et al.?
The study by Pape et al. compared hemodynamics and left ventricular function in adult racing greyhounds and greyhounds completely untrained from birth.
What was the relationship between initial systolic blood pressure and risk in dogs with chronic renal failure in the study by Jacob et al.?
The study by Jacob et al. found an association between initial systolic blood pressure and the risk of developing a uremic crisis or of dying in dogs with chronic renal failure.
What did the study by Bijsmans et al. investigate?
The study by Bijsmans et al. investigated changes in systolic blood pressure over time in healthy cats and cats with chronic kidney disease.
What factor was survival in cats with chronic renal failure related to in the study by Syme et al.?
The study by Syme et al. found that survival of cats with chronic renal failure was related to the severity of proteinuria.
What were evaluated as predictors of the development of azotemia in cats in the study by Jepson et al.?
The study by Jepson et al. evaluated predictors of the development of azotemia in cats.
What was a common finding in dogs with chronic kidney disease in the study by Crivellenti et al.?
The study by Crivellenti et al. found that occult gastrointestinal bleeding was a common finding in dogs with chronic kidney disease.
What was evaluated as a marker of oxidative stress in dogs with chronic kidney disease in the study by Kogika et al.?
The study by Kogika et al. evaluated oxidative stress in the anemia of dogs with chronic kidney disease.
What factors were examined in relation to uremic gastropathy in cats with chronic kidney disease in the study by McLeland et al.?
The study by McLeland et al. examined the relationship among serum creatinine, serum gastrin, calcium-phosphorus product, and uremic gastropathy in cats with chronic kidney disease.
What percentage of dogs with CKD experience anaemia?
Up to 80%
How does anaemia affect animals with CKD?
It contributes to weakness and malaise, and limits exercise tolerance and quality of life.
What is the association between anaemia and CKD progression in cats?
Anaemia is associated with more rapid progression of CKD in cats.
How does anaemia increase cardiac work?
Anaemia increases cardiac work because the cardiac output increases to maintain normal oxygen delivery to tissues.
What are some causes of anaemia in CKD?
Decreased production of erythropoietin, decreased survival of red blood cells, decreased absorption or availability of iron, decreased erythropoiesis in the bone marrow, and uraemic thrombocytopathia.
What hormone is responsible for stimulating the bone marrow to produce new red blood cells?
Erythropoietin (EPO)
What is the effect of uraemic toxins on red blood cells?
Uraemic toxins cause metabolic damage to red blood cells, shortening their lifespan in the circulation.
What can cause traumatic damage to passing red blood cells in animals with severe uraemia?
Inflammation of the blood vessels (vasculitis)
What role does iron play in the synthesis of haemoglobin?
Iron is necessary for the synthesis of haemoglobin.
What type of iron deficiency is common in cats with CKD?
Functional iron deficiency
What are the characteristic blood sample findings in cats with functional iron deficiency?
Decreased serum iron, increased total iron binding capacity, but normal ferritin
How can anaemia and its regeneration status be detected?
Anaemia and its regeneration status can be detected on a complete blood cell count, especially if a reticulocyte count is available.
What factors should be considered when evaluating a severe anaemia in animals?
Possible concurrent gastrointestinal bleeding, high serum urea concentration, and decreased serum albumin concentration
What determines the need for specific treatment in anaemia?
The severity of the anaemia and associated clinical signs
What level of PCV is considered mild anaemia in dogs?
PCV of 30% or more
What level of PCV is considered mild anaemia in cats?
PCV of 28% or more
What are the indications for treating more severe anaemia in patients with CKD?
PCV of 20% or less, lethargy, decreased exercise tolerance, decreased appetite
What is the initiating event for the development of mineral and bone disease (MBD) in CKD?
Accumulation of phosphorus in the blood
What is the role of fibroblast growth factor (FGF)-23 in response to increased phosphorus in CKD?
Increase phosphorus excretion in the kidney, inhibit production of calcitriol, decrease phosphorus and calcium absorption from the gut
What is the role of parathyroid hormone (PTH) in response to increased phosphorus in CKD?
Increase calcium concentration, release calcium from bone
What are the clinical risks of MBD in CKD?
Mineralisation of soft tissues with increased concentrations of calcium and phosphorus in the blood
What is the prevalence of MBD in animals with CKD?
FGF-23 concentrations increase progressively with increasing IRIS stage, higher in animals with hyperphosphataemia, increased PTH less common in animals with mild CKD but occurs in 100% of dogs with stage 4 disease, concentration of calcitriol decreases progressively in cats with advancing stages of CKD
What are the consequences of extreme forms of MBD in CKD?
Renal osteodystrophy, loss of mineral from bone, rubbery flexible bones, ‘rubber jaw’ in dogs with juvenile onset CKD
What is CKD and why is it considered an irreversible disease process?
CKD is chronic kidney disease and it is considered irreversible because it does not improve within the expected timescale for AKI.
How does CKD progress in different individuals?
CKD progresses at different rates in different individuals, with some experiencing rapid progression to uraemia and others remaining non-azotaemic.
What is the relationship between AKI and CKD?
AKI may lead to persistent CKD if the kidneys do not recover normal function. Pre-existing CKD is a major risk factor for AKI.
What is ‘acute on chronic’ kidney disease?
‘Acute on chronic’ kidney disease occurs when a patient with compensated and stable CKD experiences an acute insult which worsens the CKD.
How can acute and chronic kidney diseases be distinguished based on serum phosphorus levels?
Serum phosphorus levels increase regardless of the cause of kidney disease, so it does not help distinguish between acute and chronic disease.
What factors can help distinguish between acute and chronic kidney diseases?
Factors such as duration of clinical signs, body condition score, packed cell volume, palpation of the kidneys, and enlargement of the parathyroid glands can help distinguish between acute and chronic kidney diseases.
What is the common histopathological diagnosis for CKD?
The common histopathological diagnosis for CKD is ‘interstitial nephritis’, characterized by mild and diffuse inflammation in the tissue between nephrons and glomeruli, often with fibrosis and loss of normal tubule structures.
What causes amyloidosis in the kidneys?
Amyloidosis in the kidneys is caused by the deposition of insoluble amyloid proteins in the glomeruli or renal medulla.
Which breeds are associated with congenital renal dysplasia?
Congenital renal dysplasia has been reported in breeds such as Lhasa apso, Shih tzu, standard Poodle, Alaskan malamute, and Golden retriever.
What is polycystic kidney disease and in which breed is it inherited as an autosomal dominant disease?
Polycystic kidney disease is a condition where cysts develop in the kidneys. In Persian cats, it is inherited as an autosomal dominant disease.
What is the risk of soft tissue metastatic calcification considered to be greatest with?
The risk of soft tissue metastatic calcification is considered to be greatest when the calcium x phosphorus product is above 70 mg2/dl2.
How do you calculate the calcium x phosphorus product?
To calculate the calcium x phosphorus product, you must convert the concentrations of calcium and phosphorus into mg/dl by multiplying calcium (in mmol/l) by 4 and phosphate (in mmol/l) by 3.1, then multiply the 2 results together.
Which analytes have been associated with survival in cats with CKD?
Both serum phosphorus and FGF-23 concentrations have been associated with survival in cats with CKD, indicating that cats with higher concentrations of either analyte have faster progression of CKD and shorter survival times.
Which concentrations are commonly measured during routine monitoring visits for animals with CKD?
The serum phosphate and total calcium concentrations are commonly measured during routine monitoring visits for animals with CKD.
What might act as an early biomarker for the onset of kidney disease?
FGF-23 could act as an early biomarker for the onset of kidney disease if it becomes possible to measure it as a clinical test in the future.
Why is the concentration of PTH rarely measured in animals with CKD?
The concentration of PTH is rarely measured in animals with CKD because an increased concentration is unlikely to change clinical management. However, it is occasionally measured to try to distinguish between acute and chronic kidney disease.
What is the current management of MBD in animals with CKD?
The current management of MBD relies on dietary phosphate restriction to reduce the amount of phosphate accumulating in the body and needing to be excreted. This may be supplemented with an oral phosphate binder if not effective alone. Calcitriol supplementation may also be administered, but its clinical benefits have not been proven in dogs and cats so far.
Why do animals with CKD frequently experience gastrointestinal complications?
Gastrointestinal complications in animals with CKD are thought to be caused by factors such as increased concentrations of gastrin, fibrosis and mineralization of the stomach wall, uraemic toxins affecting the chemoreceptor trigger zone, and interference with hormonal networks that control appetite.
What is a genuine finding in dogs with CKD in relation to gastrointestinal complications?
Dogs with CKD have a higher prevalence of gastroduodenal ulceration and a high prevalence of occult faecal blood, suggesting uraemic gastropathy/gastritis is a genuine finding in dogs.
What is frequently observed in animals with CKD in terms of bowel movements?
Chronic or intermittent constipation is frequently observed in animals with CKD, although the exact cause is unknown.
What is SBP and how does it relate to the risk of damage?
SBP stands for systolic blood pressure and the risk of damage is low unless it consistently exceeds the normal reference limit.
What are the most accurate methods to measure blood pressure?
Catheterisation of an artery permits direct measurement, but non-invasive, indirect methods like Doppler or oscillometric detectors are commonly used in veterinary practice.
How many separate measurements should be made when measuring SBP?
5-7 separate measurements should be made, with the first and last readings discarded.
What should be done if the values progressively decrease during the measurement of SBP?
The process should continue until a plateau is reached, as the animal is likely acclimatising to the process.
What should be recorded in the clinical notes along with the blood pressure result?
The size of the cuff and site of measurement should be recorded for future reference.
What is situational hypertension and how can it be reduced?
Situational hypertension is a temporary increase in blood pressure. It can be reduced by measuring blood pressure at the beginning of a physical examination and before other procedures.
How can a dedicated nurse clinic help reduce situational hypertension?
Creating a dedicated nurse clinic for blood pressure measurement allows animals to become used to the process and reduces the likelihood of situational hypertension.
Are Doppler sounds significant in affecting the SBP result?
No, the noise of the Doppler sounds has little impact on the SBP result.
What is recommended regarding the posture of the animal during blood pressure measurement?
In dogs, measurements taken while in right lateral recumbency are generally lower and less variable. In cats, there is no significant difference as long as the cuff is placed at the level of the right atrium.
Why is it important to take blood pressure readings from the same site on repeated visits?
Studies have shown that there can be variation in blood pressure readings taken from different sites on the same patient.
Do different dog breeds have different normal blood pressure values?
Yes, some dog breeds have higher blood pressure values than the average. For example, sighthounds have resting SBP values 10-20 mmHg higher than the species average.
How does the sex and neutering status of cats affect blood pressure values?
Male cats and neutered cats (male or female) tend to have higher blood pressure values than females or entire cats, respectively.
What are the defining features of chronic kidney disease (CKD)?
Azotaemia, decreased GFR, or kidney damage persisting for more than 3 months without improving.
How is chronic kidney disease (CKD) differentiated from acute kidney injury (AKI)?
CKD is determined by symptoms persisting for more than 3 months, while AKI is a reversible condition.
What are the specific causes of chronic kidney disease (CKD) in dogs and cats?
There are many different specific disease processes that can cause CKD.
How can chronic kidney disease (CKD) be staged using the IRIS guidelines?
CKD can be staged based on the presence of azotaemia, proteinuria, and imaging findings.
What are the major comorbidities observed in animals with chronic kidney disease (CKD)?
Comorbidities can include hypertension, anaemia, and mineral and bone disease.
How can hypertension be diagnosed and categorized in animals with CKD?
Hypertension can be diagnosed using blood pressure measurements and categorized based on severity.
What are the causes of anaemia in animals with chronic kidney disease (CKD)?
Anaemia in CKD can be caused by decreased production of erythropoietin and increased red blood cell destruction.
What are the major features and causes of mineral and bone disease in CKD?
Mineral and bone disease in CKD can be caused by deranged calcium and phosphorus metabolism.
What is the rationale for dietary modifications recommended for animals with CKD?
Dietary modifications aim to reduce workload on the kidneys and control electrolyte imbalances.
What are the indications for administration of ACE inhibitors in animals with CKD?
ACE inhibitors may be used to manage proteinuria and control blood pressure in animals with CKD.
How can a treatment plan be designed for animals with complications of CKD?
A treatment plan may involve managing complications such as anaemia and hypertension.
Which drugs could be used for symptomatic management of gastrointestinal problems in animals with CKD?
Specific drugs for symptomatic management depend on the nature of gastrointestinal problems.
What is the recommended diet for cats with renal disease?
A 50:50 mix of renal diet and senior cat food is recommended.
Why is it recommended not to use a calcium-containing product for cats with hypercalcaemia and CKD?
Calcium-containing products are not recommended to avoid worsening hypercalcaemia.
What percentage of cats with stage 2-3 CKD may experience hypokalaemia?
Approximately 20-30% of cats with stage 2-3 CKD may experience hypokalaemia.
What are the clinical signs of hypokalaemia in cats?
Muscle weakness, lethargy, plantigrade stance, and ventroflexion of the neck.
How can potassium deficiency in cats with CKD be supplemented?
Potassium can be supplemented orally with potassium gluconate or potassium citrate.
When should treatment for hypertension be introduced?
Treatment should be introduced immediately if there is target organ damage or if the pressure is 200 mmHg or more.
What is the aim of hypertension treatment in all cases?
To decrease the systolic pressure below 160 mmHg.
What medication is recommended as initial treatment for hypertension in dogs?
An ACE inhibitor like benazepril at a starting dosage of 0.25-0.5 mg/kg once or twice daily.
What should be checked after starting ACE inhibitor treatment in dogs?
A biochemistry panel should be checked to monitor azotaemia and potassium levels.
Which class of medication appears to be most effective in controlling blood pressure in cats?
Calcium channel blockers, with amlodipine given as initial treatment.
When should the blood pressure be checked after starting treatment in cats?
Until it is stably below 160 mmHg, and periodically thereafter (e.g., every 3 months).
What is the recommended treatment for nausea and decreased appetite in animals with CKD?
Maropitant and/or mirtazapine can be administered.
When can Maropitant and/or mirtazapine be administered to animals with CKD?
They can be administered as short courses during bouts of illness or can be kept in small supplies by owners to administer if they notice signs of nausea or decreased appetite.
How can Maropitant and/or mirtazapine be administered continuously as treatment for CKD?
They can be administered continuously as palliative treatment if tolerated.
What is the alternative treatment option for animals with severe inappetence in CKD?
Placement of a feeding tube may be indicated to improve their nutritional intake.
What additional benefits does a feeding tube provide for animals with CKD?
It allows administration of water to improve hydration and giving medications without needing to open the mouth.
How well do most cats and dogs tolerate an oesophagostomy tube placed at home?
Most cats and dogs will tolerate an oesophagostomy tube very well at home with an enthusiastic owner.
What may be added to the renal diet to manage constipation in animals with CKD?
A bulk forming laxative agent such as psyllium or canned pumpkin.
What prokinetic agent can be used to relieve constipation in cats with CKD?
Cisapride can be used at a dosage of 1 mg/kg q8 hours.
What are the key parameters that should be regularly monitored in animals with CKD?
Quality of life, serum biochemistry, complete blood count, urinalysis with UPC, and blood pressure.
How often should monitoring visits be scheduled for animals with stable and mild azotaemia?
Every 3-6 months.
How often should monitoring visits be scheduled for animals with progressive CKD?
Every 1-2 months.
What is the recommended feeding approach for animals in stage 1 CKD?
Renal diet not recommended
When is it suggested to consider feeding a renal diet for animals in stage 2 CKD?
At this stage to acclimate the animal and potentially slow disease progression
What is the recommendation for feeding renal diets for animals in stages 3 and 4 CKD?
Renal diet recommended
Why is it important not to force animals to eat renal diets?
To ensure they continue to eat and maintain a good bodyweight, muscle mass, and hydration status
What are some modifications in renal diets compared to normal maintenance diets?
Restricted protein content, restricted phosphorus and sodium, and less acidifying
What are some supplements often added to renal diets?
Antioxidants, B vitamins, and polyunsaturated fatty acids
Why are wet forms of renal diet preferred, especially for cats?
To increase water intake
What is the critical event in the development of mineral and bone disease in CKD?
Accumulation of phosphate due to decreased renal excretion
What are the recommended phosphorus concentrations for animals in stages 2, 3, and 4 CKD?
Below 1.5 mmol/l in stage 2, below 1.6 mmol/l in stage 3, and below 1.9 mmol/l in stage 4
What can be done if the phosphate concentration exceeds the recommended levels after introducing a renal diet?
An oral phosphate binder can be added
What are some examples of oral phosphate binders?
Chitosan with calcium carbonate, Lanthanum carbonate, Aluminium hydroxide
What should be monitored in cats after starting a renal diet with normal phosphate levels?
Calcium status
What is renal telangiectasia?
A developmental abnormality of the kidney that causes chronic haematuria.
Which breed is renal telangiectasia inherited in?
Pembroke Welsh Corgis.
What is renal neoplasia?
A form of renal cystadenocarcinoma with nodular dermatofibrosis.
Which breed is the inherited form of renal cystadenocarcinoma with nodular dermatofibrosis related to?
German Shepherd dogs.
What are the risk factors for CKD?
Periodontal disease, frequent vaccination in cats, comorbidities.
What is the suggested association between CKD and periodontal disease?
Mild chronic inflammatory state and/or bacteraemia may increase the risk of developing CKD.
What is the suggested association between CKD and frequent vaccination in cats?
Proteins from the CRFK cells used in vaccine production may cause an immune response damaging cats’ own kidneys.
What is the suggested association between CKD and comorbidities?
Other concurrent diseases may increase the risk of CKD.
What is the cardiorenal axis?
The close physiological association between the cardiovascular and renal systems.
What can happen to renal perfusion in dogs with cardiac disease?
It may be decreased.
What is the most common cause of death in cats older than 5 years in the UK?
Chronic kidney disease.
What is the overall prevalence of CKD in dogs according to UK veterinary practice data?
Approximately 0.2-0.35%.
What is the prevalence of kidney disease among cats presented to UK first opinion practices?
Approximately 4% overall, increasing in the geriatric population.
Which breeds of dogs are more likely to have CKD according to UK veterinary practice data?
Cocker spaniels and Cavalier King Charles spaniels.
What are the reasons for using IRIS staging for CKD?
To standardize definitions, observe rate of progression, and assist with research studies.
What is the prognostic value of IRIS stages?
Those at a higher stage have a poorer prognosis.
What are some organs that are sensitive to changes in blood pressure?
The eyes, kidneys, heart, and brain.
What are some signs of hypertension in the eyes?
Retinal haemorrhage, detachment of the retina, dilated and tortuous retinal vessels, oedema around the blood vessels, oedema of the optic nerve head (papilloedema), and sometimes secondary glaucoma.
How does hypertension affect the kidneys?
Hypertension can cause further damage to the kidneys by filtration of large molecules in the glomerulus, leading to increased protein in the glomerular filtrate and detrimental effect on tubular epithelial cells.
What is the effect of increased blood pressure on the heart?
Increased blood pressure causes resistance to ejection of the stroke volume and can lead to concentric cardiac hypertrophy, with valvular regurgitation often causing a systolic cardiac murmur.
What can exposure to prolonged high blood pressure cause in the brain?
Encephalopathy and stroke.
What is the prevalence of hypertension in dogs with CKD?
The reported prevalence varies, with studies suggesting 6-80% of cases could be hypertensive.
How does hypertension impact the progression of kidney disease in dogs?
Hypertension is associated with shorter survival times in dogs with CKD, but its relationship with disease progression is complicated by the impact of proteinuria.
What is the prevalence of hypertension in cats with CKD?
Hypertension occurs in approximately 20-65% of cats with CKD at the point of diagnosis.
What percentage of initially normotensive cats with CKD develop hypertension?
Approximately 17% of initially normotensive cats with CKD develop hypertension over an average follow-up period of ~1 year.
What factors are strongly associated with proteinuria, hypertension, and shorter survival times in dogs?
Proteinuria, hypertension, and shorter survival times are all strongly associated in dogs with CKD.
What are the recommended interventions for managing proteinuria?
Feeding a renal diet and administering an ACE inhibitor or angiotensin receptor II antagonist.
How does a renal diet help in managing proteinuria?
Moderate protein restriction in a renal diet appears to alleviate proteinuria.
What is the role of ACE inhibitors in managing proteinuria?
ACE inhibitors decrease the pressure gradient for filtration of protein and other substances.
What is the recommended starting dose of benazepril for managing proteinuria?
0.25-0.5 mg/kg PO SID
When should biochemistry and electrolyte levels be checked after starting ACE inhibitor or AII blocker treatment?
Approximately 1 week after starting the treatment.
What are the indications for administering benazepril in animals with CKD?
Hypertension in dogs and renal proteinuria in dogs and cats not related to other causes.
What is the risk associated with severe proteinuria in dogs?
Increased risk of thrombosis due to loss of anticoagulant proteins in the urine.
How can the risk of thromboembolic disease be decreased in animals with severe proteinuria?
Administering aspirin or clopidogrel.
When should anaemia generally be treated?
When the PCV drops to 20% or below.
What is the recommended total dose schedule for cats < 3 kg in bodyweight?
Every other day, or every 3 days.
When using prednisolone concurrently, what is the higher starting dose for cats?
2-3 mg/kg per day.
Within how many weeks should prednisolone be tapered and stopped?
Within 2-3 weeks.
What is currently known about the prognosis for individual types of glomerular disease?
Little is known, but it is likely to change in the future.
What is the median survival time for dogs with protein-losing nephropathy and no underlying cause?
105 days.
What factors affect the prognosis for dogs with protein-losing nephropathy?
Azotemia and presence of nephrotic syndrome.
What was the median survival time for dogs with amyloidosis in a study?
5 days.
What types of primary renal neoplasia are common in dogs?
Renal carcinomas, nephroblastoma, transitional cell carcinoma, lymphoma, and haemangiosarcoma.
What is the average age of detection for primary renal tumours in dogs?
~8 years.
Which breed of dogs may develop a clinical syndrome of renal cystadenocarcinoma?
German shepherd dogs.
What are the clinical signs of renal neoplasia in animals?
Weight loss, decreased appetite, lethargy, pain in the sublumbar region.
What are the common clinical signs of renal lymphoma in dogs?
Lethargy, intermittent vomiting, diarrhea, inappetence, azotemia, and erythrocytosis.
What is the most common renal tumor in cats?
Lymphoma.
What symptoms are usually associated with renal lymphoma in cats?
Inappetence, weight loss, polyuria, and azotemia.
Is bilateral involvement common in renal lymphoma?
Yes, it is found in 80-90% of cases.
When should two samples be obtained to determine the true value of UPC ratio?
If the UPC ratio result is 4 or more.
How many samples should be obtained to confirm persistent proteinuria?
At least 2 samples at least a week apart.
What is the effect of storing urine for more than 12 hours on the UPC result?
It causes some increase in the UPC result, but the extent is relatively small.
How does the UPC value differ between urine collected in a hospital and urine collected at home?
In 50% of dogs, urine collected in a hospital had a higher UPC value than urine collected at home.
Which collection methods for urine can be used for UPC measurements?
Voided urine or urine from a cystocentesis sample.
What are the normal UPC values in cats and dogs?
Less than 0.2.
What values of UPC ratio are considered borderline in dogs and cats?
0.2-0.5 in dogs and 0.2-0.4 in cats.
What does microalbuminuria refer to?
Increased albumin in the urine above the normal concentration but below the diagnostic threshold for proteinuria.
How can microalbuminuria be quantified?
By measurement of the urine albumin: creatinine ratio (UAC) or using immunoassays.
When is measurement of albuminuria most useful?
For early detection of the onset of disease in high-risk individuals or as a prognostic tool in animals with other conditions.
What are the categories of proteinuria based on the probable location of the disease?
Pre-glomerular proteinuria, renal or glomerular proteinuria, and post-glomerular proteinuria.
How can classification of proteinuria be helpful?
It narrows down the potential causes of the proteinuria, leading to a quicker diagnosis.
What does hypoalbuminemia indicate in cases of proteinuria?
Excessive loss of protein into the urine if other causes are excluded.
When is it necessary to investigate the cause of proteinuria?
When there are previous clinical signs suggesting an underlying kidney disease.
What should be checked when investigating hypertension in a dog?
Retinal fundus and blood pressure should be examined together.
Why is it important to treat hypertension before proceeding with invasive tests or treatments?
To evaluate if it improves proteinuria and determine the underlying cause.
What is the recommended method to distinguish between different pathological processes affecting the glomerulus?
Renal biopsy, ideally done by ultrasound-guided tru-cut biopsy of the renal cortex.
Why is it strongly recommended to refer animals for renal biopsy or consult with a referral center?
Taking a renal biopsy requires expertise and carries the risk of hemorrhage.
What are the different fixative solutions used for analyzing renal biopsy samples?
Normal histology, immunofluorescence, and electron microscopy.
Where should the renal biopsy samples be sent for analysis?
A Veterinary Renal Pathology Service in either Ohio, USA, or Milan, Italy.
When is renal biopsy not recommended in dogs?
If the dog has end-stage kidney disease.
When is renal biopsy recommended in dogs?
If the dog is azotaemic or unresponsive to standard treatment.
What clinical features are associated with immune complex-mediated glomerulonephritis in cats?
Cats with FIV or FeLV and cats with more severe proteinuria.
What causes immune complex-mediated glomerulonephritis in cats?
FIV and FeLV infections.
At what age are cats without immune complex-mediated glomerulonephritis slightly older?
Around 10 years.
Which glomerular disease is associated with deposition of antibodies of the IgA isotype?
IgA nephropathy
What is the term used for glomerular diseases causing proteinuria?
glomerulonephropathy
What is the condition called when glomeruli appear normal by light microscopy?
minimal change disease
What is the condition where there is proliferation and expansion of the mesangial cells in the glomerulus?
proliferative glomerulonephritis
Is glomerulosclerosis well understood in animals compared to humans?
No
What is one potential cause of proteinuria in animals that is related to damage to the tubules?
Leptospirosis
What are some factors that can be considered to determine the underlying cause of glomerular proteinuria?
Signalment, history, inflammatory diseases
What diagnostic tests can be considered for investigating glomerular proteinuria in dogs?
Haematology and biochemistry, abdominal ultrasound, thoracic radiographs
Which infectious disease should be tested for in the UK because it is endemic?
Borrelia burgdorferi antibodies (Lyme disease)
Which agent can cause MPGN and should be considered for serology testing in dogs that have traveled abroad?
Leishmania
Which two diseases should be tested for in cats as they may cause MPGN?
FIV and FeLV
What gastrointestinal diseases have been associated with MPGN?
IBD and pancreatitis
What test might be considered to measure chronic gastrointestinal diseases associated with MPGN?
Pancreatic lipase immunoreactivity (PLI)
Is there evidence indicating the usefulness of spironolactone in animals with PLN?
There is no evidence to indicate whether spironolactone is useful in animals with PLN.
What is ‘aldosterone escape’ in relation to ACE inhibitors or angiotensin receptor antagonists?
‘Aldosterone escape’ refers to the phenomenon where aldosterone concentration increases despite suppression of angiotensin II production or action.
Which animals would be expected to benefit the most from spironolactone?
Animals that already have an increased aldosterone concentration while receiving another class of drug would be expected to benefit the most from spironolactone.
What is the usual clinical approach to introducing RAAS inhibitors in proteinuric animals?
The usual clinical approach is to start either an ACE inhibitor or angiotensin receptor antagonist at the starting dose, followed by checks after ~1 week to ensure no adverse effects.
In cats with CKD, which drug was found to be more effective in decreasing proteinuria: telmisartan or benazepril?
There is some evidence that telmisartan was more effective in decreasing proteinuria than benazepril in cats with CKD.
If the target for treatment of proteinuria has not been met, how can the dose of ACE inhibitor be increased gradually, specifically for benazepril?
For benazepril, the dose can be initially increased to 0.5 mg/kg PO BID, then increased in increments of 0.5 mg/kg up to a maximum dose of 2 mg/kg per day.
What antithrombotic treatment should proteinuric animals receive?
Possible options include aspirin (1-5 mg/kg per day) or clopidogrel (1-2 mg/kg per day).
Is there evidence to suggest which antithrombotic drug is more effective in the context of glomerular disease?
There is no evidence to suggest which antithrombotic drug is more effective in the context of glomerular disease.
Is there evidence to suggest that administering an antithrombotic drug makes a difference in the ultimate outcome for proteinuric animals?
There is no evidence to suggest that administering an antithrombotic drug makes a difference in the ultimate outcome for proteinuric animals.
In dogs with nephrotic syndrome, when is diuretic treatment rarely required?
Diuretic treatment is rarely required for dogs with PLE and PLN, unless the effusions or edema interfere with respiration.
What is the initial dose of furosemide that may be administered as a diuretic for dogs with severe effusions or edema?
The initial dose of furosemide that may be administered is 1 mg/kg q6-12 hours.
