Cattle- Macromineral Disorders
Card Set Information
Cattle- Macromineral Disorders
vetmed cattle minerals
vetmed cattle diseases
What are the most important macromolecules?
calcium, magnesium, potassium, and phosphorous
What are the functions of calcium? (3)
stabilizes neuronal membranes, secretion of Ach, muscle contraction
Hypocalcemia causes ________ of muscles.
What are the functions of magnesium? (7)
ATP formation/use, gene transcription, cAMP hormonal control, Ach breakdown, CNS, neuromuscular excitability
What are the functions of potassium? (3)
muscle/neuron excitability (resting cellular potential), glycogen synthesis (may lead to ischemia and muscle necrosis), acid-base balance
What are the functions of phosphorous? (5)
required for synthesis of phospholipids/proteins/nucleic acids, glucose homeostasis, production of ATP/GTP, buffer systems, matrix of bone/cartilage/extracellular tissues
What are the effects on mineral concentrations with milk fever?
hypocalcemia, normal to increased Mg, hypophosphatemia
What causes milk fever?
onset of lactation, there is a rapid decline in serum ionized calcium due to production of colostrum
What are the smooth muscles effects of hypocalcemia? (7)
dry muzzle (no sweat), cold extremities, dilated pupils, reduced anal tone, bloating, no defecation/urination, RP or uterine prolapse
What are the cardiac muscle effects of hypocalcemia?
increased HR, decreased strength/intensity of contraction, weak pulses, hypotension
Describe stage 1 of milk fever. (7)
[sometimes referred to as subclinical] standing, hyperexcitable, off feed or slug feeding, tremors, unsteady, mouth open/tongue out, gasping
What is the serum calcium level in stage 1 milk fever?
Describe stage 2 of milk fever. (12)
sternally recumbant, off feed, depressed, S-curve neck, dry muzzle, cold extremities, dilated pupils, no defecation/urination, decreased heart sounds, rapid pulse, rumen stasis, RP or prolapse
What is the serum calcium level in stage 2 milk fever?
Desrcibe stage 3 milk fever. (4)
lateral recumbancy, comatose, flaccid paralysis, bloat
What is a common sequealae to stage 3 milk fever?
What is the serum calcium level in stage 3 milk fever?
How do you treat milk fever? (4)
deep bedded stall, minimize stimuli, don't milk her, calcium gluconate 2g/100kg IV
What should you always check for when you have diagnosed milk fever?
coliform mastitis- may have endotoxemia or septicemia, in which case give the calcium slower or dilute it
How can you check for coliform mastitis on the spot?
if milk looks watery and yellow
What are positive responses to treatment for milk fever? (8)
eructation, urination, defecation, standing up, increased repirations, decreased HR, warmer extremities, sweating muzzle
How can you prevent milk fever? (2)
reduce potassium intake, give anionic salts to induce subclinical metabolic acidosis and urinary acid excretion
What are 2 anionic salts given to cows?
What is the Dietary cation-anion difference?
(Na+ + K+) - (Cl- + S) = DCAD
The DCAD should be maintained below _____ in the transitional period; increased ______ in the diet reduced the DCAD to increase __(2)__ absorption.
50mEg; anionic salts; Ca2+ and Mg2+
What is the best way to mointor use of anionic salts in the diet?
monitoring urine pH
What is the mean pH values of urine in pre-fresh dry cows?
Anion salts work best in preventing milk fever when the _____________.
dietary calcium is high
In order for anionic salts to be successful in preventing milk fever, they must be added to the feed at least _______.
10 days prior to calving
4 complications of hypomagnesmia.
hyperexcitability, tetany, convulsions, death
Describe grass tetany.
pastured cows in spring and fall, high K+ and N, low Mg2+ and Na+
Describe winter tetany.
feeding Mg deficient feed to beef cows in winter, low Mg
Describe milk tetany.
stressed calves fed milk only (milk is low in Mg)
Describe transport tetany.
cattle on marginal diets transported, lack of feed/water during transportation
What are predisposing factors for hypomagnesmia?(6)
high rainfall, warmth, roughage diet, periods of fasting, high K+, high protein diet
What are the clinical signs of tetany? (9)
anorexia, hyperexcitability, pounding heart, muscle fasiculations, staggering, convulsions, head back, snapping eyelids, death
What level of Mg in serum and CSF is associated with clinical signs of tetany?
How can you test for tetany within 12 hours of death?
get CSF sample or vitreous humor and test for Mg level (which is stable for 12 hours after death)
What are possible differentials for cows exhibiting signs of tetany? (5)
nervous ketosis, stage I milk fever, lead poisoning, rabies, listeriosis
How do you treat tetany?
Mg lactate/CMPK/Cal Phos IV solution, oral solutions
How can you prevent hypomagnesmia?
supplement with Mg salts; 60g/hd/day, 2oz/hd/day on silage
What is kyphosis?
S-shaped curve of neck
How can the txt of ketosis lead to hypokalemia syndrome?
multiple doses of dextrose IV and insulin causes cells to rapidly take up extracellular K+
What cows are most likely to be affected by hypokalemia syndrome?
lactating cows <60DIM, heifers/calves with significant anorexia
What are the early clinical signs of hypokalemia syndrome? (5)
rumen stasis, decreased defecation, anorexia, inability to stand for long periods, tachycardia/arrhythmia
What are the later clinical signs of hypokalemia syndrome? (4)
recumbancy, kyphosis, tachycardia/arrhythmia, fever
What is the most common arrhythmia in cattle? What is it associated with?
atrial fibrillation; hypokalemia and milk fever
What are etiologies of hypokalemia syndrome? (4)
txt with PreDef for ketosis/inflammation/udder edema, dextrose, insulin, and IV fluids for more than 2 days
Hypokalemia syndrome causes weakness that may lead to... (2)
recumbancy and myonecrosis
What are differential diagnoses for animals showing signs of hypokalemia syndrome, and how can you diagnose HKS?
hypocalcemia, botulism, tick paralysis, myelopathy, listeriosis, vertebral malformation, luxations/fractures, torticollis; lack of response to Ca2+ administration
What blood values can alert you to hypokalemia syndrome? (6)
K+<3mEq/L, elevated AST and CPK, metabolic alkalosis, hypochloremia, mild hyperglycemia
How do you treat hypokalemia syndrome? (5)
supportive care, float/ deep bedded stall, administer potassium chloride 50g/100kg, oral isotonic electrolyte fluids, K+ supplements for 5 days
Do not exceed ________ rate of oral/IV administration of isotonic electrolyte fluids for a cow with HKS.
Post-parturient hemoglobinuria associated hypophosphatemia occurs because...
love P causes RBC fragility.
What cows are at highest risk for hypophosphatemia? (5)
3rd trimester of pregnancy, pregnant with twins, rickets/osteomalacia, lactation associated, [other countries] post-parturient hemoglobinuria, chronic P deficiency
Most of the serum phosphorous is absorbed via the ________.
Phosphorous deficiency is almost always due to ___________.
low P in the ratio
_________ released during __________ causes an increase in phosphorous.
PTH (parathyroid hormone); hypocalcemia
PTH (parathyroid hormone) increases...
salivary and renal excretion of phosphorous.
Low phosphorous commonly indicates low _______.
In what animals does pregnancy-associated hypophosphatemia occur?
pregnant beef cattle fed P deficient diets; late gestation demands more P
How do you treat pregnancy-associated hypophosphatemia?
feed higher energy diet (grain, which has high P), 200g NaHPO4 in water or 23g NaHPO4 in 1L of saline IV
Why does lactation-associated hypophosphatemia occur?
hypocalcemia causes release of PTH, which subsequently causes loss of P in saliva and urine
How do you treat lactation-associated hypophosphatemia?
Ca2+ txt leads to lower PTH and retention of P
What is an alert downer cow?
P<1mg/dL, low Ca2+, low Mg, low glucose
If hypocalcemia txt does not restore phosphorous, the cow is probably a(n) ___________, and treat with _________.
alert downer cow; IV phosphorous (23g in saline) or oral phosphorous (200g)
In what cows does chronic P deficiency usually occur?
grazing cattle in a tropical/temperate climate
In what animals does rickets/osteomalacia causing hypophosphatemia occur?
young animals (rickets)-improperly mineralized bone; older animals (osteomalacia)- failure of mineralization of osteoid matrix
In what animals does post-parturient hypophosphatemia occur?
<6 weeks post-calving, cows treated for ketosis, diets deficient in Se, Cu, energy, saponins in diet