Hypocalcemia COPY Flashcards
1
Q
What are the 5 M’s of “Downer” cows?
A
- Massive mastitis
- Massive metritis
- Massive peritonitis
- musculoskeletal: Spinal trauma, fractures, coxofemoral luxation, vertebral abscess
- Mineral Imbalance: hypocalcemia, hypomagnesemia, hypophosphatemia, hypokalemia
2
Q
What is Periparturient Hypocalcemia?
A
- Metabolic disorder occurring at onset of lactation
- Rapid decline in serum calcium due to colostrum formation
- 10L of colostrum contains ~23g Ca (9x the plasma pool)
- Clinical Symptoms
-
Stage I - Mild, subclinical hypocalcemia
- Ca = 5.5-7.5 mg/dL (1.37-1.87 mmol/L)
-
Stage II - Sternal recumbency depression, anorexia
- Ca - 3.5-6.5 mg/dL (0.87-1.62 mmol/L)
-
Stage III - Coma, rapid death
- Ca < 3mg/dL (0.75 mmol/L)
-
Stage I - Mild, subclinical hypocalcemia
3
Q
How is Calcium Homeostasis maintained during lactation?
A
- Extracellular pool of Ca++ is about 10g (9-11)
- Normal Plasma Ca++ 8.5-10mg/dL
- 600kg cow has about 3g of Ca++ in plasma pool
- 8g/day required for maintenance
- 18g/day for fetal skeleton development
- 600kg cow has about 3g of Ca++ in plasma pool
- Colostrum contain about 2.3g/Ca/Kg
- Avg 7.5 kg colostrum = 17g Ca
- Second milking = 13 g Ca
- 28-30g increase in net Ca utilization from day before to day after calving
4
Q
What are the messengers for calcium homeostasis?
A
- PTH - response to Low Ca++
- Bone - Ca mobilization
- Kidney
- Increases renal tubular reabsorption
- Stimulates 1,25-(OH)2D production from Vit D
- I,25-(OH)2D
- Small intestine - increase Ca++ absorption
5
Q
What chemical statuses can alter PTH? how?
A
- Hypomagesemia
- Decreased PTH secretion
- Decreased tissue sensitivity to PTH
- Acid-Base Status
- Metabolic alkalosis - decreases Ca++
- Alters conformation of PTH receptors in bone and kidney (decreases sensitivity)
- Metabolic alkalosis - decreases Ca++
- Age:
- Older cows = fewer osteoclasts = fewer PTH receptors
6
Q
What are the Clinical effects of hypocalcemia?
A
- Neuronal cell membrane stabilization
- Decrease results in Hyperexcitability
- Muscle twitching
- Decreased Ach release - muscle paresis
- ataxia
- muscle tremors
- recumbency
- Slow/Absent rumen contractions
- Tachycardia (80-100 bpm)
- Muffled - poor cardiac output
- Poor peripheral blood flow
- Poor thermoregulation
- Decreased uterine contraction
- Milk leaking
- Decreased swallow reflex
7
Q
What are the stages of clinical signs of hypocalcemia?
A
- Stage 1
- Ataxia, weakness, muscle fasciculations, hyperesthesia
- Stage 2
- Depression, recumbency (sternal) tachycardia, cold ears and extremities, decreased GI motility, decreased PLRs
- Stage 3
- Lateral recumbency, HR>100bpm (signs of severe hypovolemic shock)
8
Q
What conditions are associated with hypocalcemia?
A
- Reduced uterine contractions
- Retained fetal membranes and metritis
- Uterine prolapse
- Reduced ruminal and abomasal motility and reduced intake
- Ketosis
- Displaced abomasum
- Delayed closure of teat sphincter
- Mastitis
- Reduced innate immune responses (reduced neutrophil function)
- RFM, metritis, mastitis
9
Q
How can hypocalcemia be diagnosed?
A
- History/Signalment
- Clinical signs
- Clinicopathologic findings (not absolutely necessary)
- Serum calcium:
- Stage 1: 5.5-7.5 mg/dL (1.4-1.9 mmol/L)
- Stage 2: 3.5-6.5 mg/dL (0.87-1.6 mmol/L)
- Stage 3: <3mg/dL (0.75 mmol/L)
- Serum calcium:
10
Q
What are the differentials for Downer cow?
A
- 5Ms
- Neurological
- Spinal trauma
- Spinal lymphosarcoma
- Peripheral nerve paralysis
11
Q
What is the treatment of hypocalcemia?
A
- Owner:
- Remove calf from cow if present
- Soft bedding with good footing
- Keep cow in sternal recumbency (wall)
- Do not milk the cow
- Veterinarian: Complete PE
- calcium borogluconate (23%) 1gm/100lbs body weight, IV
- 500 ml bottle contains approximately 10.7 gm Ca++
- Administer slowly while monitoring pulse/HR
- Decreased heart rate/increased pulse intensity⇢ reduce rate of administration
- Serum Ca>25 mg/dL can stop heart
- calcium borogluconate (23%) 1gm/100lbs body weight, IV
- Other treatments:
- Subcutaneous calcium
- Oral calcium gel
- 50-75g every 12 hours for 1-2 days
- CaCl2, CaSO4, Ca proprionate
12
Q
What are the signs of positive response to Calcium borogluconate treatment?
A
- Eructation
- Urination
- Defecation
- Increased strength - Cow may stand
- Increased resp. rate and decrease heart rate
- Extremities warmer
- Sweating of muzzle
13
Q
How many cases of hypocalcemia relapse after treatment?
A
25-30% of cases in 24-48hrs
14
Q
What are the economic effects of Milk Fever in Dairy Cattle?
A
- Average Cost/MF case: $300-400
- (Treatment/Production loss and death)
- Shortens lifetime in herd
- Secondary Problems:
- Ketosis, Mastitis, Dystocia, RP, LDA, Uterine prolapse, Hip luxation, adductor muscle damage
15
Q
How can Milk Fever be prevented?
A
- Increase Ca++ flux
- Low calcium diets <20g/day
- DCAD = Dietary Cation Anion Difference Diet
- Compensated Metabolic Acidosis
- Increases urinary calcium excretion
- Increases PTH binding
- Anionic Salts:
- Increase consumption of anions (sulfates, chlorides)
- Most diets have excess K+ and Na+ (Cations)
- Increase chloride, Sulfates (Anions) to acidify blood pH, acidify urine
- work best when dietary calcium is high. Phosphorus 40-60mg/day
- Zeolite A
- Feed additive that binds calcium
- Rumen protected rice bran - calcium binder
- Serotonin
- In addition to (-)DCAD diet
