Metabolic Diseases Flashcards
what are the two ways you can get a metabolic disease?
inherited (congenital), or acquired
which way to get a metabolic disease is more common in small animals?
inherited
which was to get a metabolic disease in more common in production animals?
acquired
what are metabolic storage disorders and inborn errors of metabolism?
commonly related to genetic storage disorders with accumulation of metabolic byproducts; related with enzyme deficiency or dysfunction
what are production-related metabolic disorders?
development of diseases are related with management factors, but pathogenesis is related with alteration in metabolism in high energy-demand animals
what type of metabolic disease is procine stress syndrome (PSS)?
metabolic storage disorder
what is porcine stress syndrome also called?
malignant hyperthermia
what is malignant hyperthermia in pigs (3)
a metabolic storage disorder that is a
- life-threatening inherited disorder
- disease of the skeletal muscle
- mutation in the ryanodine receptors in the sarcoplasmic reticulum in myofibrils
what happens in porcine stress syndrome?
deficiency of Ca2+ channels, so all are released and none are left to hold muscle fibers
is it possible to genetically test for porcine stress syndrome?
yes, has defined genes that carry it
what happend when the ryanodine receptors in the myofibrils of the sarcoplasmic reticulum are triggered to fuck up?
whole body contraction
what are triggers of porcine stress syndrome?
- halogenated inhalation anesthetics (isoflurane, desflurane, sevoflurane)
- depolarizing neuromuscular blocking drugs
- stress!!!!
- exercise!!!!!
describe the pathogenesis of porcine stress syndrome?
sudden release of calcium in the myofibril cytoplasm which produces extensive contraction of skeletal muscles and fatal hypermetabolic state, skin hemorrhage
can you manually pull an affected prcine stress syndrome pig out of the contracted state?
no, just have to wait it out like a seizure
what are the symptoms of porcine stress syndrome? (7)
- muscle and tail tremors
- labored and irregular breathing
- blanching and reddening of the skin
- rapid rise in body temp
- collapse
- muscle rigidity
- eventual death
what is the genotypic designation of malignant hyperthermia in pigs?
stress-resistant: NN
stress-carrier: Nn
stress-positive: nn
what kind of meat is porcine stress syndrome related with? why?
PSE (pale, soft, exudative) due to more rapid pH reduction after slaughter
what is equine metabolic syndrome also called, officially?
- insulin disregulation syndrome
2. equine syndrome X
how can you remember what equine metabolic syndrome is?
fat horse syndrome!
what kind of environment are horses made to thrive in?
harsher environments
why does domestication often lead to equine metabolic syndrome?
horses meant for a hard life are given cushy, overfed, and underworked, sedentary lives instead
in what kinds of horses is equine metabolic syndrome often found?
obese horses and ponies
why is equine metabolic syndrome often found in obese horses and ponies?
- increased adiposity
- insulin resistance!!!!
- hyperinsulinemia: need more insulin bc it no longer targets tissues in the same way
describe the pathogenesis of equine metabolic syndrome
obesity leads to increased leptin, adipokines, and inflammatory mediators, which increases fatty stores, which increases fat in the liver, which increases insulin resistance, which increases insulin levelsm which causes dysregulation of glucose metabolism
describe how equine metabolic syndrome causes predisposition to laminitis
insulin is related with vasoregulatory effect, and insulin resistance decreases nitric oxide which causes vasoconstriction, which leads to altered epidermal cell function and glucose uptake, which causes predisposition to laminitis
what is laminitis?
inflammation and pain in foot/hoof
what are the clinical findings of equine metabolic syndrome? (5)
- localized adiposity
- laminitis might exist
- patient might not lose weight with feed restriction
- increased appetite
- infertility and abnormal repro cycle in mares
why might a patient with equine metabolic syndrome not lose weight with feed restriction?
because it is hard to treat once horse reaches obesity
describe treatment and prevention of equine metabolic syndrome
- progressive dietary management, specifically carbohydrate restriction
- exercise
- if diet and exercise not enough, use medicine
- NO SUDDEN dietary changes
why are sudden dietary changes not effective as a course of treatment in a horse with equine metabolic syndrome?
might increase lipid release, which could cause liver failure in extreme cases
what is equine fatigue?
horse inability to continue when exercised for too long or too hard
list the symptoms of equine fatigue (11)
- panting
- profuse sweating
- dehydration
- acid-base imbalances
- electrolyte imbalances
- exhaustion, laying down
- decreased motivation
- respiratory issues
- lethargy and tiredness
- loss of muscle coordination
- death after 10-15% dehydration
what causes the acid-base imbalances observed in equine fatigue?
increased metabolism with no new food or water kicks in anaerobic exercise, which produces lactic ACID, leading to imbalance
what causes the electrolyte imbalances observed in equine fatigue?
the profuse sweat loss
when high intensity exercise causes equine fatigue, what happens? (pathogenesis)
increase in anaerobic metabolism of creatinine phosphate and glycogen leads to intracellular acidosis and negative feedback in glycolytic enzymes
what accumulates in the muscles when high intensity exercise causes equine fatigue?
hydrogen ions, lactate, phosphate, ammonia, and ADP
what decreases in the muscles when high intensity exercise causes equine fatigue?
ATP, phosphocreatine, and pH
what two types of exercise can cause equine fatigue?
- high intensity exercise
2. prolonged exercise
describe what happens when prolonged exercise causes equine fatigue (pathogenesis)?
increased temperature, increased use of liver and muscle glycogen causes hypoglycemia
for what duration of submaximal exercise does muscle provide 50% of glycogen?
30 minutes, drops down after that
how much of total energy used for exercise comes from blood glucose?
only 10%, the rest has to go to other places
what is the best way to prevent equine fatigue?
avoid heat
is transition cattle disease a specific disease itslef?
no, it covers a wide range of disease that all happen during the transition time period
what percentage of disease in dairy cattle happen between 3 weeks pre and 3 weeks post parturition?
80%
why do so many metabolic disease occur in dairy cattle in this transition period pre and post partum?
mom’s body transitions more to supporting baby than mom prepartum, baby grows so much that mom stomach shrinks and she is not taking in as many nutrients. then, once she calves, her stomach is still small but now her body is putting all its energy into rearranging body and producing milk that mom has a negative energy balance as her lactation is at its peak and body energy stores are at their lowest, will take from muscle, adipose tissue, etc to make up the gap
why does body condition score in dairy cattle matter so much in transition cattle diseases?
if mom too think before calving, will get sick because of the whole negative energy balance thing, and if cows with a BCS of > or equal to 3.75% are more likely to mobilize their body stores to produce milk = ketosis
what is ketosis also called?
acetonemia, ketonemia
when does ketosis typically occur in cattle?
in dairy cattle during early lactation
when does type II ketosis usually occur? what is it accompanied by?
very early lactation (after baby), usually accompanied by fatty liver
when does type I ketosis usually occur?
close to the peak of lactation (4-6 weeks post baby)
what is the pathogenesis of ketosis?
- feed intake does not meet energy demand
- insufficient ruminal production of proprionic acid, a volatile fatty acid and the main producer of glucose
- not enough glucose so cow become hypoglycemic (low blood sugar)
- low blood sugar makes cow metabolize fatty acids and glycerol supplies
- those fatty acid and glycerol stores are oxidized to form Acetyl-CoA (but makes a fuck ton) so
- excess Acetyl-CoA (due to lack of energy to convert more) is converted ketone bodies
- accumulation of ketone bodies excreted in milk and urine = ketosis
what happens to the liver in ketosis?
when feed intake does not match energy demand, there is a lack of energy and the liver can’t cope
can ketone bodies be used for energy? efficiently?
yes but they are inefficient, and some glucose-dependent tissues (like the liver) can’t use
describe the epidemiology of ketosis in cattle
- prevalence of 7-14%, a range that depends on management
- all cows can be affected
- no genetic predisposition
- there is greater risk in cows with BCS > or equal to 3.75
what clinical findings are associated with ketosis in cattle?
- apathy
- decreased feed intake
- decreased milk production
- empty abdomen
- CNS disturbances in a few cases
- increased BHB in blood, urine, and milk
what is BHB?
Beta Hydroxy Butane
what are the ranges of BHB?
0 (low) to 1.2 (normal) to greater than 1.2 (high)
how do you treat ketosis IV?
IV bolus of 50% dextrose with out without glucocorticoids
how do you make the decision to include glucocorticoids in the 50% dextrose IV bolus when treating ketosis in cattle?
glucocorticoids depress the immune system, which could icnrease the chance for mastitis or other infections, include glucocorticoids with caution
what is glucocorticoid?
a stress hromone that raises blood glucose when present
how do you treat ketosis with feed?
include propylene glycol (a glucoe precursor) in feed ration
how do you treat ketosis in cattle phrophylactically?
control BCS before dry period (cow not too thin or too fat)
what kind of diet is good for ketotic cattle during late lactation? why?
diets with highly digestible fiber and low starch, starch ferments super fast, not always time to get nutrients out before it’s gone
