Seasonal changes in serum calcium, phosphorus, and vitamin D concentrations in llamas and alpacas

Bradford B. Smith Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802.

Search for other papers by Bradford B. Smith in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
and
Robert J. Van Saun Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802.
Present address is Department of Veterinary Science, College of Agriculture, Pennsylvania State University, University Park, PA 16802-3500.

Search for other papers by Robert J. Van Saun in
Current site
Google Scholar
PubMed
Close
 DVM, PhD

Click on author name to view affiliation information

Abstract

Objective—To evaluate the interaction of season and age on serum calcium, phosphorus, and vitamin D3 concentrations in llamas and alpacas.

Animals—23 clinically normal llamas and 7 alpacas.

Procedures—Animals were assigned to 1 of the 3 following groups on the basis of age at the start of the study: adult (age, ≥ 24 months; n = 8), yearling (> 12 but < 20 months; 5), and neonate (< 6 months; 17). Twelve serum samples were obtained at monthly intervals. Calcium, phosphorus, and vitamin D3 concentrations were measured, and the calcium-to-phosphorus concentration (Ca:P) ratio calculated. Effect of season and age on each of these variables was determined.

Results—Vitamin D3 concentrations varied significantly as a function of season; the highest and lowest concentrations were detected September through October and February through March, respectively. The seasonal decrease in vitamin D3 concentration was significantly greater in neonates and yearlings, compared with adults. Serum phosphorus concentration decreased as a function of age, with the most significant seasonal change detected in the neonate group. The Ca:P ratio in neonates varied between 1.1 and 1.3 except during winter months when it increased to ≥ 2.0.

Conclusions and Clinical Relevance—Mean vitamin D3 concentration varied by > 6 fold in neonatal and yearling llamas and alpacas and > 3 fold in adult animals as a function of season. These results support the hypothesis that seasonal alterations in vitamin D3 concentrations are a key factor in the development of hypophosphatemic rickets in llamas and alpacas. (Am J Vet Res 2001;62:1187–1193)

Abstract

Objective—To evaluate the interaction of season and age on serum calcium, phosphorus, and vitamin D3 concentrations in llamas and alpacas.

Animals—23 clinically normal llamas and 7 alpacas.

Procedures—Animals were assigned to 1 of the 3 following groups on the basis of age at the start of the study: adult (age, ≥ 24 months; n = 8), yearling (> 12 but < 20 months; 5), and neonate (< 6 months; 17). Twelve serum samples were obtained at monthly intervals. Calcium, phosphorus, and vitamin D3 concentrations were measured, and the calcium-to-phosphorus concentration (Ca:P) ratio calculated. Effect of season and age on each of these variables was determined.

Results—Vitamin D3 concentrations varied significantly as a function of season; the highest and lowest concentrations were detected September through October and February through March, respectively. The seasonal decrease in vitamin D3 concentration was significantly greater in neonates and yearlings, compared with adults. Serum phosphorus concentration decreased as a function of age, with the most significant seasonal change detected in the neonate group. The Ca:P ratio in neonates varied between 1.1 and 1.3 except during winter months when it increased to ≥ 2.0.

Conclusions and Clinical Relevance—Mean vitamin D3 concentration varied by > 6 fold in neonatal and yearling llamas and alpacas and > 3 fold in adult animals as a function of season. These results support the hypothesis that seasonal alterations in vitamin D3 concentrations are a key factor in the development of hypophosphatemic rickets in llamas and alpacas. (Am J Vet Res 2001;62:1187–1193)

All Time Past Year Past 30 Days
Abstract Views 79 0 0
Full Text Views 461 188 29
PDF Downloads 348 155 13
Advertisement