An Unusual Case of Generalized Soft-Tissue Mineralization in a Suckling Foal

An atypical case of severe soft-tissue mineralization in a 3-week-old foal from a herd of Andalusian horses is described. The herd clinical history and the laboratory findings were compatible with a diagnosis of secondary hyperparathyroidism due to a mineral imbalance in the diet (low calcium and high phosphorus intake). Mares showed a marked increase in serum parathyroid hormone (PTH) approximately 10 times normal levels. Serum PTH was marginally elevated in foals. Clinical signs (unthriftiness, painful joints, lameness in one or more limbs, and stiff gait) were more pronounced in foals than in mares. Two foals died and necropsy of one of them revealed extensive soft-tissue mineralization of arterial walls and pulmonary parenchyma. Clinical signs in mares and foals resolved by 4 weeks after diet adjustment.

Phosphorus metabolic disorder of Guizhou semi-fine wool sheep

Guizhou semi-fine wool sheep are affected by a disease, characterized by emaciation, lameness, stiffness in the gait, enlargement of the costochondral junctions, and abnormal curvature in the long bones. The objective of this study was to determine possible relationships between the disease and mineral deficiencies. Samples of tissue and blood were collected from affected and unaffected sheep. Samples of soil and forage were collected from affected and unaffected areas. The samples were used for biochemical analyses and mineral nutrient measurements. Results showed that phosphorus (P) concentrations in forage samples from affected areas were significantly lower than those from unaffected areas (P < 0.01) and the mean ratio of calcium (Ca) to P in the affected forage was 12:1. Meanwhile, P concentrations of blood, bone, tooth, and wool from the affected sheep were also significantly lower than those from the unaffected group (P < 0.01). Serum P levels of the affected animals were much lower than those of the unaffected ones, whereas serum alkaline phosphatase levels from the affected were significantly higher than those from the unaffected (P < 0.01). Inorganic P levels of the affected sheep were about half of those in the control group. Oral administration of disodium hydrogen phosphate prevented and cured the disease. The study clearly demonstrated that the disease of Guizhou semi-fine wool sheep was mainly caused by the P deficiency in forage, as a result of fenced pasture and animal habitat fragmentation.

Hypophosphatemia. Causes and clinical consequences

Severe hypophosphatemia (i.e., serum phosphorus concentration below 1 mg/dl) occurs infrequently in veterinary patients. It is most often associated with diabetic ketoacidosis in small animals. Phosphate is necessary for the production of 2,3 diphosphoglycerate (2,3-DPG) and adenosine triphosphate (ATP); both are important for normal cellular metabolism. Consequences of severe hypophosphatemia may include hemolytic anemia, seizures, altered mentation, cardiomyopathy, and skeletal muscle weakness. Parenteral phosphate therapy is necessary in most cases of severe hypophosphatemia.

[Influence of x-ray irradiation on phosphorus metabolism in rabbits]

Twenty four rabbits were used in the experiment. The animals were divided into four groups, 6 animals in each. The rabbits were irradiated with a total dose of 910 R. The activity of alkaline phosphatase and the level of inorganic phosphorus were measured on the 5th, 10th and 15th day after irradiation in erythrocytes, plasma, duodenum, muscles and liver. There was found a decrease of phosphatase activity in the plasma, liver and duodenum, and an increase in the muscles and erythrocytes. The level of inorganic phosphorus increased in the duodenum, liver and plasma, and decreased in the muscles and erythrocytes. In the latter two, the increase of the phosphatase activity was accompanied by a decrease of the phosphorus level; on the contrary, the decrease of the enzyme activity in the liver and duodenum was accompanied by an increase of the phosphorus level. During the whole experimental period, the phosphatase activity was higher by about 40% than in the control group.