dog vs cat nutrition Flashcards
dogs and cats are they carnivors?
- Are dogs carnivores? Both dogs and cats in the order carnivora, cats are obligate carnivores
- Do they require a carnivore diet? Dogs are neither true omnivore or carnivore.
dogs have adapted to domestic diet, but how?
-dogs/ wolves are not carnivores
- Wild/feral canids -> feast or famine
- Stomachs handle large volume of food if available
dogs were domesticated so genome diverged from modern wolves and they adapted mostly/ partially to omnivore diet.
domestic dogs carnivore status?
- Facultative or ‘Adaptive’ Carnivores
- Metabolically in between carnivore and omnivore
- Neither obligate carnivores or true omnivore
- Can survive without consuming ‘prey’
- More metabolic flexibility & ‘resourcefulness’ than cats but less than omnivores
feline evolution
- Cats probably self domesticated, genome is well conserved
- Hunting -> 10 – 20 small meals/day
- Rodents, birds, insects
- Obligate or ‘True’ carnivores**
- Require animal products to provide certain essential nutrients in natural diet
True Carnivores have requirements?
(cats)
* ↑ protein requirements
* ↑ Nitrogen & amino acid demands
* ↑ Arginine requirement
* Taurine – essential*
- ↑ fat requirements
- Arachidonic Acid (AA) - essential
- Alterations in starch & glucose metabolism
- Dietary fibre still beneficial, but lower total ‘capacity’ (shorter colon) compared to dogs
protein requirements cats vs dogs
-cats need more protein as they are true carnivores
What drives higher protein demand in cats?
* Nitrogen demand -> urea cycle & aminotransferases
-cats urea cycle enzyme is ALWAYS ACTIVE so always using AA = more protein needed.
- Glucose & energy needs ->gluconeogenesis * Glucose -> C6H12O
- Cats very adept at utilizing amino acids
rapidly & efficiently via gluconeogenesis
to meet their endogenous glucose demands
arginine
- Indispensable/essential amino acid
- Cats - higher dietary requirement**
- Dogs can synthesize some arginine
- Required to convert ammonia to urea
- Insufficient arginine = build-up of NH3
arginine free diet:
* Cats: acute death from ammonia toxicity after only 1 meal
* Dogs: frothing, emesis, muscle tremors, weight loss
* Plant proteins are lower in Arginine
Sulfur-Containing Amino Acids
Methionine, cysteine, taurine
- Cats - highest reqs for sulfur-amino acids
- Methionine + Cysteine ->
- Cysteine, non-essential but spares methionine
- Requirement for methionine + cysteine –
provided > 50% is methionine (essential) - Taurine (β-amino acid)
- Made from cysteine
- Essential in feline diet
-dogs are good at converting, non essential
Taurine
- BETA-sulphonic amino acid= Not incorporated into proteins, stays in tissues or conjugated to non protein compounds
- Not degraded, oxidized, or metabolized by mammals
- Microbes can metabolize taurine in gut
- Synthesized from sulfur alpha-
amino acids methionine & cysteine - Pathway very limited in cats
- Cats more likely to use cysteine for
energy (pyruvate) - Daily loss versus synthesis
determines dietary requirement** - Always essential for cats, always losing more than they can make. some circumstances essential for dogs
taurine sources of daily losses/ how to replace
Sources of daily loss:
* #1 = Bile acids
* Bile acids are obligatorily conjugated to taurine in cats & dogs
* Entero-hepatic recycling occurs but ~10% still normally lost daily
other: gut microbes or kidneys excrete some
To replace daily losses
* Dogs usually synthesize enough taurine if provided enough methionine+cystine
* Cats must consume enough taurine from diet (essential nutrient)
* Dietary requirements for taurine (in either species) affected by
* Bile acid losses & degradation by gut bacteria
* Type of diet
-individual metabolism and physiology
Causes of Taurine Deficiency
- Dietary
- Insufficient methionine + cystine in diet (dogs)
- Insufficient taurine in diet (cats, some dogs if taurine loss )
- Ileal resection or loss of ileo-ceco-colic valve (dogs or cats)
- Can’t recycle bile salts and/or retrograde movement of colonic bacteria
- Increased loss of protein – e.g. via gut or kidney
- Gut: malabsorptive diseases
- Kidney: dialysis or disease preventing proximal tubular reabsorption
Consequences of Taurine Deficiency
Dogs & Cats*
* DCM: Dilated Cardiomyopathy
Cats*
* Central Retinal Degeneration
* Reproductive impairment, developmental defects
* Abortion, still-birth, low birth weight
* Poor survival and slower growth of kittens
essential fatty acids
Omega-6 fatty acids:
LA = linoleic acid (18:2) essential in dogs and cats. only one essential in dogs as they can use to make other omega FA. cats cant do this
AA = arachidonic acid (20:4) essential CATS
Omega-3 fatty acids: not essential but recommended to help balance and conditionally essential for growing animals.
