T2: Renal (done) Flashcards
What is in the upper tract of the urinary tract?
two kidneys: Filtration/biochemical processes
two slender muscular tubes (ureters): one from each kidney, that deliver waste-containing urine from the kidneys down to the lower tract (bladder)
What is a part of the lower tract of the urinary tract? Why is it important?
- only excretory function
the bladder: its epithelium (transitional epithelium) accommodates for the change in size of the organ
the urethra: a thin tube from the bladder to the outside of the environment
What are the functions of the kidney?
- Filtering waste products and water from the blood
- Regulating electrolytes
- Producing and concentrating urine
- Producing erythropoietin (EPO: hormone) to stimulate the bone marrow to create new red blood cells
- Producing renin (enzyme): to control the body’s blood pressure (renin-angiotensin-aldosterone system)
- Producing vasodilator prostaglandins (hormones)
Describe the kidney
the kidneys are separated from the abdominal cavity by their envelopment of peritoneum “retroperitoneal” structures
-bean-shaped organs
-outer cortex and inner medulla
Describe the functional unit of the kidney
-nephron
-renal corpuscle: glomerulus (afferent arterioles, capillaries, efferent arterioles) and the bowman’s capsule
-renal tubule: proximal convoluted tubule, loop of Henle, descending limb of Henle, ascending limb of Henle, distal convoluted tubule
How many nephrons are there among species
dogs: 415,000
cats: 190,000
What are the cortical nephrons
these nephrons have glomeruli in the outer cortex and their loops of Henle barely penetrate the medulla: they have very limited concentrating ability
What are the juxtamedullary nephrons
have glomeruli in the cortex and loops of Henle which descend into the medulla; significant urine concentration because of the hyperosmolar medulla achieved via the countercurrent multiplier
AVP =
ADH
What is diabetes insipidus
it is not related to diabetes mellitus and does not involve insulting or sugar metabolism
-antidiuretic hormone (ADH) or vasopressin (AVP) (pituitary gland hormone) is responsible for maintaining the correct level of fluid in the body
What is the normal water intake across the species?
normal water intake for dogs/cats: 20-70 ml/kg/day; normal urine output: 20-45 ml/kg/day
Animals are considered polydipsic: water consumption greater than 100 ml/kg/day, polyuric urine production is greater than 50/ml/kg
what is central diabetes inspidus
the pituitary gland does not secrete enough ADH
What is nephrogenic diabetes inspidus
the kidneys do not respond normally ADH
who is affected with diabetes inspidus
affected dogs: polyuria and polydipsia: urine very dilute even if the animal is deprived of water
the dog can become dehydrated from urinating so much
–water deprivation test: change in central and nephrogenic diabetes inspidius
– rare in cats
What are considered urinary stones (CATS)
urolithiasis
-stones can develop anywhere within either the upper or lower tracts of the urinary system
-most cats will go through life without experiencing “stones” ; others will experience urolithiasis, a potentially lethal condition marked by the formation of small stones (uroliths)
what are kidney stones?
always made of calcium oxalate
What can bladder stones be?
either struvite or calcium oxalate
Are stones made present naturally in a cat’s body?
the stones form when the minerals exceed a certain threshold of concentration in the urinary system – crystals – they accumulate and may grow into stones
what do male cats get commonly?
blockages since they have a very narrow and easily obstructed urethra
what do not typically cause noticeable signs of disease until they become very large (CATS)
kidney stones
may be small, harmless, some times they can grow and irritate the tract leading to internal bleeding
complete blockage is a medical emergency (CATS)
bladder stones
What are bladder stones for dogs
uroliths or cystic calculi: more common than kidney stones
“struvite bladder stone”
What is a normal component of a dog’s urine?
normal dog urine is slightly acidic and contains waste products from metabolism.
struvite is a normal component of a dog’s urine and will remain dissolved as long as the urine is acidic
if the urine becomes exceptionally concentrated or alkaline, struvite crystals will precipitate
a complication of bladder infections by bacteria that produce urease
struvite bladder stones
urease breaks down the urea that is normally present in the urine causing an excess production of ammonia – urine becomes alkaline – struvite crystals
___ tend to get these types of bladder infections and stones much more frequently than ____
why ?
female dogs/males dogs
shorter and wider urethra makes it easier for bacteria to pass up the urethra into the bladder
Struvite uroliths are more common in ___ and calcium oxalate uroliths are common in ____ dogs
what breeds?
female and male
shih tzu, miniature schnauzer, bichone frise, lhasa apso, yorkshire terrier
How could other stones form?
metabolic abnormalities, like liver disease, nutrient imbalances from the diet or supplements, genetic conditions
how do struvite stones form
infection in dogs
Sometimes crystals in the urine but not stones…
they may or may not be a warning sign of stone risk
what are ways to prevent stones
- dilution of the urine by increasing the amount of water the pet drinks
- reducing the amount of the compounds that make up the stones in the diet
can often be dissolved in both dogs and cars using special diets of increased water and controlled protein
struvite stones
cannot be dissolved and have to be removed usually with surgery
calcium oxalate stone
in dogs (urinary tract infections): a special diet is not needed for dogs with ___ stones once the stones are dissolved or surgical removed
struvite stones
these stones are sometimes seen in the urine of dogs with no urinary tract infection: samples have been refrigerating or have sat around for a few hours
struvite crystals
In cats, struvite stones can form …
without an infection
these stones are found in cat urine, especially in fresh samples, suggesting that the cat may have be higher risk of stone development
struvite crystals
what are the breeds of dogs that are affected by calcium oxalate stones
Yorkshire, miniature schnauzers, shih tzus and cats
these stones can not be dissolved and have to be removed, usually with surgery
calcium oxalate stones
can suggest an increased risk of stone formation in both dogs and cats
over usage of antibiotics may decrease the intestinal bacteria Oxalaobacter formigenes whose sole nutrient is oxalate
calcium oxalate crystals
what stones are caused by a genetic condition in some dog breeds (dalmatians, Jack Russel, bulldogs)
Urate (ammonium biurate) stones: commonly seen with liver disease
How can urate stone be dissovled
combo of low purine diet and medication
how are urate stones made
from purines which are present in DNA, high in meat, organs, seafood
what are the prevention of urate stones for dogs
dogs with liver disease; diet changes and treating the liver disease
genetic condition: diet change with meds
What is Fanconi syndrome in dogs?
a generalized proximal tubular reabsorptive defect resulting in excessive loss of many solutes in the urine
acquire condition: chicken jerky treat ingestion, gentamicin
heritable form: in many breeds (basenji)
What are the symptoms of Fanconi syndrome in dogs
excessive urinary loss of glucose, Na +, K +, P, uric acid, bicarbonate, amino acids
a genetic marker
the heritable disease is slowly progressive and usually results in death from uremia
What is feline chronic kidney disease
can damage the kidney so severely that it can’t function properly, progressive and irreversible diseases (many months or years before any signs)
starting at age 5-6 years, chronic kidney disease becomes more common affecting up to 35 % of older cats
Describe the stages of feline chronic kidney disease
1: damage but no signs, rarely diagnosed
2: signs may be present, increased water in the urine, more urine is seen (slow filtering)
3. filtering slows more, water chemicals are more concentrated, and signs of disease are seen
4. continued kidney damage, more waste accumulation, fatal
What are the earliest signs of kidney disease?
polyuria, polydipsia
animals usually have no signs of kidney disease until they are at stages 3 or 4
What is feline idiopathic cystitis (FIC) ?
an inflammation of the urinary bladder of unknown origin
both male and female
signs: dysuria, pollakiuria, haematuria and periuria
