Dogs and cats. Chronic renal failure (B15), Urolithiasis (B16) Flashcards
Chronic renal failure
- disease shows clinical signs in older age (but disease itself starts much earlier), no clinical signs until SEVERE damage of kidney
- congenital malformation, pyelonephritis, hypertension, diseases associated with immune system, acute kidney disease (poisoning)
- PD/PU (tubular reabsorption doesn’t work), lack of appetite and weight loss (esp in uremic phase —> flushing kidneys), anemia (EPO!), weakness (low K!), secondary renal hyperparathyroidism, high blood pressure (sodium content of diet should be considered!), ulcers (uremia)
Hyperparathyroidism <-> chronic renal failure
PTH is usually cleared by kidneys —> in case of kidney failure —> accumulation —> deposition of calcium phosphate in soft tissues
Diagnosis of chronic renal failure
- non-regenerative anemia (EPO!)
- increased blood urea nitrogen (BUN) and creatinine
- increased P (in dogs and cats; in horses will be low)
- Ca can be anything (in dogs and cats; in horses Ca will be high)
- dilute urine
- old patient
Does increased blood urea nitrogen always indicate renal problem?
No, it can also be connected to increased catabolic processes (increased cortisol —> increased GNG)
…?
Chronic renal failure. Pathophysiology. (That’s what should be said in exam!!)
- decreased ability to excrete N and products
- decreased ability to excrete P
- inability to produce calcitriol (active vit D)
- inability to degrade PTH
Treatment and dietetics in chronic renal failure
Therapy: fluid therapy and dialysis to reduce the amount of waste products
Dietetics (after stabilising metabolites):
- reduce the work for kidneys
- replace substances that are low (e.g K)
- reduce wastes that accumulate (e.g urea from protein; phosphorus)
It can take weeks and months to see effect of diet
Protein content in the diet of CKD patient
- just removing protein isn’t good (they are in catabolic state; can be even dangerous in cats)
- protein should be easily digestible, so it’s absorbed
- if not: nitrogen products won’t be absorbed —> large intestine: production of ammonia by bacteria
- protein should be of high biological value: AAs composition —> better to use protein of animal origin
- problem of meat protein: price and meat is high in P
- eggs, dairy products
- low quantity (within reference but on lower edge), high quality protein + appropriate amount of fats and CHs
- energy mainly comes from fats and CHs
- in dogs with mild to moderate renal disease: 12-28% protein
- in dogs with severe renal disease: 10-15%
Water in chronic renal failure
- kidneys can’t concentrate the urine —> important to have high water intake to prevent dehydration
- flavoured broths to encourage drinking (low in sodium!!)
- wet food»_space;>
- water soluble vitamins (e.g. B, C) are washed away —> that’s why Kinsey diet usually contain higher amount of water soluble vitamins
Diet in CKD patient. Potassium
- lack of appetite and increased loss of potassium —> hypokalemia (weakness, painful muscles)
- cats are more prone to have hypokalemia
- potassium gluconate or citrate can be given per os
- potassium chloride is acidifying ad is nit recommended
Phosphorus and calcium in CKD patients (dogs and cats)
- CKD: PTH is elevated —> draws calcium and phosphorus from the bones —> bones fracture
- moderate supplementation of vit D (for suppression of PTH)
- decrease phosphorus intake!
- if it doesn’t help —> phosphorus-binding agents
- it’s important to set up P before setting up Ca
- rechecking !
CKD. Acidosis and sodium
- dogs and cats have acidic urine
- CKD: reduced acid excretion —> risk of metabolic acidosis
- renal digests counteract acidosis
- in CKD kidneys can’t properly regulate sodium
- deficit of sodium: dehydration, excess: water retention
CKD. Fats, lipids
- prone to hyperlipidemia (WHY?)
- replacement of saturated FAs by unsaturated FAs
- also better to increase omega 3 : omega 6 ratio††
CKD. Fiber
- fibre is needed to stabilise large colon
- microflora will use up the ammonia —> feces
Diet change in CKD patients
- in uremic state they wont have appetite! —> first stabilise
- gradual change (1-2 weeks)
- usually less tasty
- try different brands
- special diet will elongate the life of the animal and better quality life
Urolithiasis
- cats! (drinking less, high amount of protein intake)
- urolithiasis — presence of urinary crystals within the bladder or lower urinary tract
- dogs: more common with infection of urease-producing bacteria
- identification of mineral composition of uroliths is important!
- most common: struvite, second most common: calcium oxalate
