Comparison of serum parathyroid hormone and ionized calcium and magnesium concentrations and fractional urinary clearance of calcium and phosphorus in healthy horses and horses with enterocolitis

Ramiro E. Toribio Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH43210.

Search for other papers by Ramiro E. Toribio in
Current site
Google Scholar
PubMed
Close
 MV, MS
,
Catherine W. Kohn Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH43210.

Search for other papers by Catherine W. Kohn in
Current site
Google Scholar
PubMed
Close
 VMD
,
Dennis J. Chew Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH43210.

Search for other papers by Dennis J. Chew in
Current site
Google Scholar
PubMed
Close
 DVM
,
Richard A. Sams Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH43210.

Search for other papers by Richard A. Sams in
Current site
Google Scholar
PubMed
Close
 PhD
, and
Thomas J. Rosol Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH43210.

Search for other papers by Thomas J. Rosol in
Current site
Google Scholar
PubMed
Close
 DVM, PhD

Abstract

Objective—To evaluate calcium balance and parathyroid gland function in healthy horses and horses with enterocolitis and compare results of an immunochemiluminometric assay (ICMA) with those of an immunoradiometric assay (IRMA) for determination of serum intact parathyroid hormone (PTH) concentrations in horses.

Animals—64 horses with enterocolitis and 62 healthy horses.

Procedures—Blood and urine samples were collected for determination of serum total calcium, ionized calcium (Ca2+) and magnesium (Mg2+), phosphorus, BUN, total protein, creatinine, albumin, and PTH concentrations, venous blood gases, and fractional urinary clearance of calcium (FCa) and phosphorus (FP). Serum concentrations of PTH were measured in 40 horses by use of both the IRMA and ICMA.

Results—Most (48/64; 75%) horses with enterocolitis had decreased serum total calcium, Ca2+, and Mg2+ concentrations and increased phosphorus concentrations, compared with healthy horses. Serum PTH concentration was increased in most (36/51; 70.6%) horses with hypocalcemia. In addition, FCa was significantly decreased and FP significantly increased in horses with enterocolitis, compared with healthy horses. Results of ICMA were in agreement with results of IRMA.

Conclusions and Clinical Relevance—Enterocolitis in horses is often associated with hypocalcemia; 79.7% of affected horses had ionized hypocalcemia. Because FCa was low, it is unlikely that renal calcium loss was the cause of hypocalcemia. Serum PTH concentrations varied in horses with enterocolitis and concomitant hypocalcemia. However, we believe low PTH concentration in some hypocalcemic horses may be the result of impaired parathyroid gland function. ( Am J Vet Res 2001;62:938–947)

Abstract

Objective—To evaluate calcium balance and parathyroid gland function in healthy horses and horses with enterocolitis and compare results of an immunochemiluminometric assay (ICMA) with those of an immunoradiometric assay (IRMA) for determination of serum intact parathyroid hormone (PTH) concentrations in horses.

Animals—64 horses with enterocolitis and 62 healthy horses.

Procedures—Blood and urine samples were collected for determination of serum total calcium, ionized calcium (Ca2+) and magnesium (Mg2+), phosphorus, BUN, total protein, creatinine, albumin, and PTH concentrations, venous blood gases, and fractional urinary clearance of calcium (FCa) and phosphorus (FP). Serum concentrations of PTH were measured in 40 horses by use of both the IRMA and ICMA.

Results—Most (48/64; 75%) horses with enterocolitis had decreased serum total calcium, Ca2+, and Mg2+ concentrations and increased phosphorus concentrations, compared with healthy horses. Serum PTH concentration was increased in most (36/51; 70.6%) horses with hypocalcemia. In addition, FCa was significantly decreased and FP significantly increased in horses with enterocolitis, compared with healthy horses. Results of ICMA were in agreement with results of IRMA.

Conclusions and Clinical Relevance—Enterocolitis in horses is often associated with hypocalcemia; 79.7% of affected horses had ionized hypocalcemia. Because FCa was low, it is unlikely that renal calcium loss was the cause of hypocalcemia. Serum PTH concentrations varied in horses with enterocolitis and concomitant hypocalcemia. However, we believe low PTH concentration in some hypocalcemic horses may be the result of impaired parathyroid gland function. ( Am J Vet Res 2001;62:938–947)

All Time Past Year Past 30 Days
Abstract Views 101 0 0
Full Text Views 1657 1381 509
PDF Downloads 275 142 11
Advertisement