Effects of intravenous administration of two volumes of calcium solution on plasma ionized calcium concentration and recovery from naturally occurring hypocalcemia in lactating dairy cows.
OBJECTIVE
To compare the effects of administration of 2 volumes of a calcium solution (calcium oxide and calcium gluconate) on plasma ionized calcium concentration (PICaC) and clinical recovery from naturally occurring hypocalcemia (NOHC; milk fever) in lactating dairy cows.


METHODS
123 cows with NOHC (PICaC < 0.95 mmol/L [3.81 mg/dL]) and 20 clinically normal control cows.


METHODS
Affected cows were treated IV once or repeatedly with 450 (n = 56) or 750 mL (67) of calcium solution (1.65 g of calcium/100 mL) until clinical recovery was achieved. The PICaC was assessed 48 hours after the first treatment or after the treatment that achieved clinical recovery. Biochemical recovery was defined as PICaC > or = 0.95 mmol/L. Plasma from control cows was used for PICaC reference range determination. Plasma samples from both groups were assessed after storage for 20 days at 20 degrees C.


RESULTS
The PICaC reference range derived from blood collected in tubes containing lithium heparin was 1.02 to 1.29 mmol/L (4.09 to 5.17 mg/dL). Following storage, plasma samples were suitable for PICaC assessment. All cows treated with > or = 1 volume of 450 and 750 mL of calcium solution recovered clinically; however, 31 of 83 (37%) evaluated cows were not biochemically recovered at 48 hours following treatment. Only cows with PICaC < 0.48 mmol/L (1.92 mg/dL) before the first treatment had to be treated > or = 3 times.


CONCLUSIONS
Results did not support the need to increase the administered volume of calcium solution from 450 to 750 mL for treatment of NOHC in dairy cows.
Doze
Johanna G
JG
Department of Equine Sciences, Medicine Section, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, The Netherlands.
Donders
Rogier
R
van der Kolk
Johannes H
JH
D000821:Animal Feed; D000818:Animals; D002118:Calcium / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000188:drug therapy*; D003612:Dairying; D005260:Female; D006996:Hypocalcemia / Q000097:blood / Q000188:drug therapy* / Q000662:veterinary*; D007262:Infusions, Intravenous / Q000379:methods / Q000662:veterinary; D007774:Lactation / Q000502:physiology*; D012016:Reference Values; D013048:Specimen Handling; D016896:Treatment Outcome
D002118:Calcium