21: Nutritional disorders and wellness diets 2 Flashcards
How many cats are affected by feline lower urinary tract disease? What age? How is it a syndrome?
0.1-1%% of pet cats
Adult cats; most between ages of 2 and 6
Not a single disease, a syndrome; collection of clinical signs of lower urinary tract diseases
Clinical signs of FLUTD depend on… What are they?
Non-specific
Depend on location, size and number of crystals or uroliths
Initial signs:
- frequent urination
- urination at inappropriate places
- hematuria (bloody urine)
- sometimes strong odor of ammonia
- painful urination (prolonged squatting, licking urogenital region)
Describe obstruction in FLUTD. If it occurs, what can the vet do?
Partial or total urethral obstruction may occur (more in male cats)
Complete obstruction = extremely painful
- Medical emergency (if untreated = rupture of bladder or uremia)
If occurs:
- flush out the urolith
- relief of bladder distention
best to prevent it
Two types of uroliths in FLUTD
- Struvite (too high urinary pH)
- Calcium oxalate (too low urinary pH)
How do we identify the type of urolith? Why does this matter?
Identification of mineral composition
Dietary management is directed toward eliminating specific type of urolith or crystalline plug
What type of urolith is more common now? Why?
Higher incidence of FLUTD with calcium oxalate
Die to increased use of urine-acidifying diets (formulated to prevent struvite formation)
What meal pattern would prevent struvite formation?
Ad libitum feeding
Less fluctuations in urinary pH when fed multiple times a day
What conditions promote struvite crystal formation
- high concentration of composite minerals (Magnesium, phosphorus, ammonium)
- sufficient time in urinary tract to allow crystallization
- urine pH >7
- small volumes of concentrated urine
What conditions promote calcium oxalate crystal formation
- Ca oxalate soluble in alkaline pH (urinary pH= 6.3-6.7)
- some cats have mild acidemia (bc of consumption of acidified diet)
^^ calcium comes from skeletal tissue to try to buffer low blood pH = more Ca in urine
Slide 10
Calcium oxalate vs struvite crystals
Dietary management to get rid of struvite uroliths
- dietary dissolution of struvites (can take months); reduces urinary Mg, produce acidic urine (6-6.3)
- monitor struvite dissolution every 2 to 4 weeks (palpation, radiography)
- feed special diet for 1 month following complete dissolution
- afterwards, switch to maintenance diet for prevention of struvite FLUTD
What should a maintenance diet for struvite prevention look like?
- should produce slightly acidified urine (<6.6)
- moderate in caloric density
- high in digestibility
- low level of Mg
Dietary ingredients that increase urinary acid excretion (lower urinary pH to prevent struvites)
Proteins of animal origin, corn gluten meal, methionine, phosphoric acid (avoid cereal grains)
Dietary management of struvites in cats that do not drink enough fresh water
Canned food
Increases urinary volume and lowers urine specific gravity (density)
Slide 13, 14
Look
How to remove calcium oxalate uroliths? Diet composition for calcium oxalate FLUTD?
Calcium oxalate uroliths cannot be dissolved, must be removed by surgical intervention or urohydropropulsion
Diet:
- reduce urinary concentrations of Ca and oxalate
- feed a diet w/o acid to increase urinary pH
- maintain dilute urine with pH = 6.5 to 6.9
- highly digestible ingredients
- optimal levels of Ca and Mg
- increase urine volume w more water or canned food
Basic explanation of what happens in chronic kidney disease? When do clinical signs appear? Why?
Progressive loss of functioning nephrons (functional unit of the kidney)
Clinical signs only appear w 70-85% loss of functioning nephrons
Kidney has large capacity to compensate; onset of CKD when compensatory mechanism breaks down = progressive loss of kidney function
Potential underlying causes of CKD
Trauma, infection, immunological disease, tumours, exposure to toxins, old age
Often no longer present when CKD presents
Clinical signs of CKD
- increased water intake (polydypsia) and increased urination
- Azotemia
- Uremia
Why does increased water intake/increased urination occur in CKD?
Reduced capacity to concentrate urine
Need to increase urine volume to excrete same amount of N
Higher water intake to maintain fluid balance
What is azotemia? Uremia?
Azotemia = build up of nitrogenous wastes e.g. creatinine in blood
Uremia = build up of urea in blood (not ammonia toxicity; urea produced but not excreted)
Symptoms of CKD
- decreased appetite
- vomiting
- depression
- mucosal ulcers
- weight loss
- bone demineralization
- anemia
- diarrhea
How can diet affect CKD?
Not a cure, but may minimize clinical signs and contribute to cat and dogs well being and longevity
Reduce pressure on kidney having to pee out N or excess P
Feeding protein for CKD
Feed diet containing high protein that meets but does not greatly exceed maintenance requirements
- restrict dietary protein only when need to control clinical signs
- cats do not tolerate restricted protein diets
CHO, fat, palatability of diets for CKD
Food should provide adequate calories from CHO and fat to minimize use of body tissues and dietary protein for E
Food should be highly palatable to prevent anorexia (dietary fat)
Vitamin, phosphorus in CKD diets
Extra water-soluble vitamins if polyuria leads to excessive losses
Restrict dietary P (needs to be excreted in urine)
Fiber, f.a. and Na in CKD
Food should contain fermentable fiber to increase fecal N excretion
Food should contain omega-3 f.a. to reduce renal inflammation
Restrict dietary Na if secondary hypertension develops
Slide 22
DOD in canines
- hip dysplasia
- nutritional secondary hyperparathyroidism
- osteochrondrosis
DOD in equines
- angular limb deformities
- physitis
- cervical vertebral malformation
- osteochondrosis
What is hip dysplasia in dogs? Osteochondrosis?
HD: abnormal development or growth of hip joint
Osteo: abnormal cartilage development in growing bones
Two types of osteochondrosis in horses
Idiopathic (hereditary) and acquired (trauma or nutrition/toxicity)
How does regular growth of bones occur? Where does it end?
Bones grow by initially forming cartilage template, onto which calcium is deposited to form bone
Ends growth in two places:
- epiphyseal plate
- cartilage
How does osteochondrosis affect regular bone growth
Causes inadequate blood supply to reach cartilage
- thickened cartilage layer
- abnormal cartilage is eventually weakened
- inflammation and arthritic changes
Three primary forms of osteochondrosis in dogs
- Ununited anconeal process
- Fragmented coronoid process
- Osteochondrosis dissecans
Clinical symptoms of osteochondrosis
Lameness and pain in joint
Compensation for lameness by restricting movement in affected joint
e.g. if elbow is affected, dog may swing leg outwards in circular motion to avoid bending it
Risk factor that increase DOD
- genetics: large or giant breed dogs, crooked legs on dams/sires
- management: free-choice feeding, exercise methods
- nutrition: feeding high-energy foods, excess intake of Ca, treats and supplements
Most critical period for DOD
During growth phase, before epiphyseal closure (<12 mo in dogs, <24 mo in horses)
What do dogs/horses at risk for osteochondrosis look like when young?
Many dogs are best looking, biggest, fastest growing in litter (push litter mates from feeding bowl)
In horses, mainly occurs in foals that are most rapidly growing
DOD and feeding of high-energy foods
- increased risk when highly palatable, energy-dense foods are fed free choice
- fat content of dog diet must be considered
- high energy intake (e.g. sugars and starch in horses) directly affects growth velocity
- articular cartilage less well supported by solid bone plated in rapidly growing animals
- biomechanical stress induced by rapid weight gain
DOD and feeding of high-calcium foods
- disrupts endochondral ossification, delays skeletal maturation
- absolute level of Ca in food is important
- related to stimulation of hormonal effects, competition w other minerals
How can calcitonin affect DOD
High blood calcitonin increases deposition of Ca in bones
- decreased bone turnover
- increased endochondral ossification
Steps for prevention of DOD (dietary management) (4)
- Determine if animal is at risk (breed)
- If yes, control nutrients of concern through food composition and feeding method (E, Ca, P, time-restrict in dogs)
- Do not add vitamin or mineral supplements to balanced foods (esp Ca, P, Vit D and A)
- Determine animal’s BCS
Treatment of DOD in affected dogs (6)
- Determine nutritional imbalance e.g. energy, Ca
- Food formulation for large or giant breed puppies
- Food should be meal fed
- If DOD occurs on well-balanced growth food, reduce intake up to 25%
- No vit or mineral supplements
- Treat specific problems: pain relief, exercise restriction, surgery
DOD treatment for affected horses (6)
- Determine nutritional imbalance (E, Ca)
- Food should be formulated for young, growing foals
- nonfiber CHOs should be meal-fed, forages should be low quality
- reduce nonfiber CHO intake if DOD occurs in well-balanced growth food
- no vit or mineral supplements
- treatment for specific problems: pain relief, voluntary exercise
