Diets

Diets

1. Hepatic

   • Damage
     • Injuries
       • Trauma
     • Disease
       • inflammation
       • parasites
       • cancer
   • Signs
     • Loss of appetite
     • depression
     • weakness
     • hepatic encephalopathy
     • increased blood ammonia
   • Functions
     • removeal of ammonia and converts it to urea
       • ammonia is toxic and urea is not
       • occurs in hepatocytes
   • Dietary help
     • Carbohydrates
       • high-quality and highly digestible
         • Bacteria ferment undigested carbohydrates entering the colon. Such fermentation increases colonic bacteria that degrade proteins and urea to form ammonia
         • High dietary carbohydrate promotes insulin secretion and reduced glucagon release
           • promotes anabolic conditions
             • Catabolic conditions produce ammonia
         • simple carbs easy to digest
     • Fibre
       • promotes fecal excretion of ammonia, so less is absorbed
       • slows dietary carbohydrate absorption
         • maintains normal blood glucose
       • increase soluble fibre
         • binds to ammonia
           • keeps ammonia in GI tract
             • avoids toxicity in blood stream
     • Proteins
       • Hepatic regeneration requires maintained protein intake
         • protein requirements are greater during recovering from hepatic disease
       • only feed good quality protein
         • reduces ammonia when protein broken down
     • Plasma proteins
       • keeps fluid in blood vessels due to osmosis
         • causes odema if leaks out
     • Reduce sodium so less water is retained
     • Increase fat and carbs
       • increases glucose
         • stops gluconeogenesis from occuring
     • Vitamin K
       • increase
         • help clotting
       • deficiency in cases of liver damage
     • Ascorbic acid
       • stops damage by free radicals
         • helps maintian membrane of hepatocytes
           • prevents further damage
     • Copper
       • feed minimal amounts
         • hepatic disease reduces excretion of copper in bile
           • therefore hepatic copper levels rise
         • greater copper damages liver further and worsens ability of excretion of copper
     • Zinc
       • increase
         • reduces copper absorption
     • Vitamin E
       • increase
         • protects against lipid peroxidation in cell membranes
     • Vitamin A
       • reduce as hepatotoxic
     • Lysine
       • Increase
         • will help repair liver
           • will decrease arginine levels...
             • really bad as will increase ammonia levels

2. Renal

   • Common in older dogs
   • Renal physiology
     • Kidney
       • cortex
       • medulla
         • Nephrons
           • Blood in: afferent ateriole
             • Glomerulus in Bowman's Capsule
               • Blood out: Efferent arteriole
               • Tight capillary network restricts large molecules from filtering into nephron
                 • Filtrate: H2O, ions, urea, glucose, minerals, vitamins, some drugs
                 • Filtrate enters PCT
                   • Loop of Henle: creates a concentration gradient in the medulla of the kidney
                     • countercurrent multiplier system, which utilizes electrolyte pumps, the loop of Henle creates an area of high urine concentration deep in the medulla, near the collecting duct.
                     • Distal Convoluted Tubule
                       • partly responsible for the regulation of potassium, sodium, calcium, and pH. It is the primary site for the kidneys' hormone based regulation of calcium (Ca).
                       • Collecting Duct
                         • consists of a series of tubules and ducts that connect the nephrons to the ureter. It participates in electrolyte and fluid balance through reabsorption and excretion, processes regulated by the hormones aldosterone and antidiuretic hormone
                         • urea and kreatinine urinated out
                           • protein breaks down to amino acids and ammonia
                             • amino acids = usefull
                             • ammonia = v.v.v. toxic at low levels
                               • therefore it is convereted to urea as it is more tolerable but still toxic
             • high blood pressure forces small molecule out of circulation
   • Renal degeneration
     • damaged nephrons
       • re-apsorption and filtering not good
         • loss of water, ions and vits = dehydration
       • kidney will not function normally
         • there will be a build up of metabolites
           • urea
           • kreatinine
     • common in cat
     • clinical signs
       • weight loss
         • inappetence
           • ulceration
             • gingivitis
               • due to urea in saliva
                 • burns away tissue
       • reduction of kidney size
       • poor condition
       • depression
       • vomiting
       • polyuria
         • constant urination
       • polydipsia
       • pale mucous membranes
         • no regeneration of RBCs
           • produces release of erythropoetin for RBC production
       • uraemic breath
     • can lose up to 70-80% of kidney function before signs seen
     • Treatment
       • primary objective: maintian high fluid through-flow
       • anabolic steroids
         • stimulate protein anabolism
         • stimulate RBC production
         • improves survivbility, no cure
       • Dietary Control
         • Issue 1: waste products not excreted efficiently leading to an build up in the blood stream
           • Diet: restrict protein content
             • too much restriction = exacerbated muscle loss
           • Diet: provide high quality protein only
             • expensive
         • Issue 2: Protein loss through kidney increases (proteinurea)
           • Diet: use high energy density, using non-protein sources (fat)
           • holes in Bowmans capsule get blocked
         • Issue 3: Appetite decreased
           • Diet: make diet palatable!
         • Issue 4: Weight loss
           • Diet: high energy density using non-protein sources such as fat
         • Issue 5: Phosphorus retention increases
           • Diet: restrict phosphorus in diet or use phosphate binders
             • Phosphorus is needed for the growth, maintenance, and repair of all tissues and cells, and for the production of the genetic building blocks, DNA and RNA. Phosphorus is also needed to help balance and use other vitamins and minerals, including vitamin D, iodine, magnesium, and zinc.
               • can lead to calcium increasing if phospohrus increases. Leading to acidemia
                 • increasing bone reorption
                 • make diet non-acidifying
         • Issue 6: Blood pressure may rise (esp in cats)
           • makes nephrons deterorate quicker
           • Diet: Moderately restrict sodium content
             • means less water absorbed
         • Issue 7: Increased thirst, water soluble vitamins lost
           • enhance levels of B-complex vitamins
         • Issue 8: potassium loss via urine
           • supplement
           • Potassium: an electrolyte, a substance that conducts electricity in the body, along with sodium, chloride, calcium, and magnesium. Potassium is crucial to heart function and plays a key role in skeletal and smooth muscle contraction, making it important for normal digestive and muscular function

3. Obesity

   • Reduce calorie density
     • only for a few days in cats as they are more susceptible to issues
       • dogs more hardy
     • reduces nutritional value
   • Reduce Fat and carbohydrates
     • reduces energy supply from fat
     • fat is easy to break down
       • quires less energy
     • protein is harder to break down
       • takes more energy
         • dont decrease so much
   • Increase Fibre
     • satisfy appetite
   • increase joint supplement
     • glucosamine
     • chondroitin sulphate
   • Co-component
     • L-carnitine
       • required for the transport of fatty acids from the cytosol into the mitochondria during the breakdown of lipids (fats) for the generation of metabolic energy
   • use additives to increase palatibility
     • usually use fats which is bad
   • Reasons for obesity
     • hypothyroidism
     • neutering
       • decreased metabolism due to no oestrogen

4. Diabetes

   • Problem with carbohydrate metabolism
     • glucose is not taken up into cells
       • therefore cannot be used as energy
   • Diet
     • Fibre
       • soluble and insoluble
         • slows sugar release
         • reduces calorie density
         • satisfies apetite
     • needs to slowly release insulin into the blood stream to control carbohydrate metabolism
     • Fat
       • decrease
         • stops secondary hyperlipdeamia
           • elevated levels of any or all lipids
     • Co-component
       • L-carnitine
         • required for the transport of fatty acids from the cytosol into the mitochondria during the breakdown of lipids (fats) for the generation of metabolic energy