Macromineral Imbalance Flashcards
Name an effective method of preventing SUBCLINICAL hypocalcemia in high producing diary cattle (assuming it is logistically feasible).
PRE partum ration with a LOW DCAD
What is the primary site of Mg absorption in the adult ruminant?
Ruminoreticulum
When ration Mg concentration is low, active transport of Mg across the ruminoreticulum wall is critical to preventing clinical hypomagnesemic tetany.
What “poisons the pump” making the animals more prone to tetany?
Potassium
Describe the pathophysiologic insult resulting in the clinical signs of acute hypophosphatemia.
Profound hypocalcemia
Which macromineral imbalance problem is uncommon but associated with prolonged anorexia of late pregnant dairy cows or dairy cows given multiple doses of PRE-Def 2X (a mineralocorticoid) for treatment of “ketosis”.
Hypokalemia
Clinical hypocalcemia manifests as impaired skeletal muscle function and is categorized as Stage I, II, or III based on recumbency observed.
Treatment with IV calcium is appropriate for which of these stages?
Stage II
Stage III
All dairy animals are in negative calcium balance postpartum due to the calcium demands of colostrum and milk production.
True/False
True
An S-curved neck is associated with _________________.
This is a sign that if present is a positive, but its absence is not a negative for this differential diagnosis of a recumbent animal.
Hypocalcemia
Which of the following are signs of subclinical hypocalcemia at the herd level associated with impaired smooth muscle function?
Excessive clinical mastitis during the first 30 days of lactation in multiparous cows
Excessive retained placenta
Excessive metritis
Excessive non-infectious lameness
Excessive infectious lameness
Excessive clinical mastitis during the first 30 days of lactation in a multiparous cows
Excessive retained placenta
Excessive metritis
In cows, what is the predominant pathophysiologic insult of hypocalcemia and the clinical sign typically observed as a result?
Neuromuscular junction - decreased acetylcholine release - muscle weakness
In sheep, what is the predominant pathophysiologic insult of hypocalcemia and the clinical sign typically observed as a result?
Neuromuscular junction - decreased acetylcholine release - muscle weakness
In dogs, what is the predominant pathophysiologic insult of hypocalcemia and the clinical sign typically observed as a result?
Nerve and muscle cells - decreased cell membrane potential difference - muscle tetany
In horses, what is the predominant pathophysiologic insult of hypocalcemia and the clinical sign typically observed as a result?
Nerve and muscle cells - decreased cell membrane potential difference - muscle tetany
When treating a cow with Stage III clinical hypocalcemia with the IV calcium product shown below, which of the following statements are WRONG?
For each wrong statement, change it to make it correct.
If the cow isn’t able to get up after one bottle, a second bottle should be given.
If the cow has concurrent severe E. Coli mastitis, giving it subcutaneously is advised.
If the cow has concurrent acute hypophosphatemia, this product will not address that condition.
The dextrose contained in the product can’t hurt but likely isn’t needed by this cow.
If the cow isn’t able to get up after 1 bottle a second bottle should be given.
If the cow has concurrent severe E. Coli mastitis, giving it SQ is advised.
True or False:
Providing oral calcium after IV will help reduce the risk of relapse of recumbency in a cow with clinical hypocalcemia. Subcutaneous administration of an IV calcium product will help too but won’t raise blood calcium as long as oral.
True
True or False:
Because of how they are fed, grazing small ruminants on pasture and range often have concurrent hypocalcemia and hypomagnesemia. That is why the “textbook” description of the presenting signs fit with both imbalance problems. Therefore treatment with a combination of IV calcium product (e.g. one with Ca and Mg) is advised.
True
Describe the best method of monitoring the effectiveness of a LOW DCAD ration to prevent hypocalcemia in diary cattle.
Measure the urine pH of PRE partum cows
Which of the following would be the best follow-up treatment for a cow you diagnosed with Stage II hypocalcemia and treated with IV calcium but is still unable to rise and is now and “alert downer” exhibiting bilateral, symmetrical flexion of the hind fetlocks as she attempts to get away from you.
IV 500mL of CMPK (Ca, Mg, P, K)
IV 500mL of 23% Ca solution
IV 15mL of Phos-Aid (Phosphinic Acid)
IV 130mL of Na phosphate enema
IV 130 mL of Na phosphate enema
Which of the following are presenting signs consistent with hypomagnesemia?
Progression to recumbency and death
Hyperesthesia (individuals/herd)
Spastic gait
Heart sounds so loud you don’t need a stethoscope to hear them
Flaccid paralysis when in lateral recumbency
Hypermotile rumen
Hypermotile rumen
Spastic gait
Hyperesthesia (individual/herd)
Heart sounds so loud you don’t need a stethoscope to hear them
True or False:
The primary pathophysiologic insult of hypomagnesemia is increased acetylcholinesterase activity at the neuromuscular junction and neural synapses resulting in increased activity and the clinical signs observed.
False
What is the easiest, most reliable sample to submit from a beef cow found dead on lush green pasture with a “dirt angel” dug into the grass around her to confirm a diagnosis of hypomagnesemia?
This was an unexpected death, as she was seen “normal” the previous evening as a torrential downpour thunderstorm raged on all night.
Vitreous humor of the whole eye
True or False:
Even “poor quality” alfalfa hay has adequate Mg concentration to improve the Mg status of a herd at risk for hypomagnesemic tetany. Even two days of feeding it can prevent problems during a “high risk” time for tetany.
False
Which of the following is true about prevention of macromineral disorders in ruminant livestock?
Feeding higher concentration of calcium in the PRE partum ration can reduce the risk of acute hypophosphatemia.
Slow introduction to “lush, green pastures” can reduce the risk of hypokalemia.
Adequate daily consumption of a “high Mg” trace mineral supplement can reduce the risk of hypomagnesemia.
Feeding low potassium hays reduces the risk of hypocalcemia and hypomagnesemia.
Feeding low potassium hays reduces the risk of hypocalcemia and hypomagnesemia.
Adequate daily consumption of a “high Mg” trace mineral supplement can reduce the risk of hypomagnesemia.
