Vet Pathol. 2014 Oct 3. pii: 0300985814551423.
Hypervitaminosis D and Metastatic Calcification in a Colony of Inbred Strain 13 Guinea Pigs, Cavia porcellus.
Holcombe H1, Parry NM2, Rick M3, Brown DE4, Albers TM5, Refsal KR3, Morris J6, Kelly R7, Marko ST7.
"A commercial diet fed to a colony of inbred strain 13 guinea pigs for approximately 6 weeks was subsequently recalled for excessive levels of vitamin D."
1/3 of the 60+ guinea pigs showed various signs of illness, including anorexia, lethargy, and poor body condition.
Necropsies performed on 9 ill and 4 guinea pigs that appeared normal showed white discoloration in multiple organs in 8 animals. "...microscopic evaluation confirmed multiorgan mineralization in tissues from 7 animals."
"Serum 25-hydroxyvitamin D levels were elevated in 10 animals.
"Serum inorganic phosphorus and alkaline phosphatase levels were increased in all exposed animals; however, total calcium and ionized calcium levels were not significantly higher in exposed animals than in control strain 13 guinea pigs from a different institution.
They diagnosed the illness as hypervitaminosis D with metastatic calcification.
After the recalled food was replaced with new food, the guinea pigs ate more and improved.
Because necropsies performed on 8 guinea pigs 3 months after changing to the normal diet showed that:
1) serum parathyroid hormone remained significantly lower compared to controls and exposed animals
2) ionized calcium and ionized magnesium were significantly higher compared to controls and exposed animals
"These results indicate that diagnostic tests other than serum calcium are necessary for a diagnosis of hypervitaminosis D in guinea pigs."