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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #89221
Title: RESTORATION OF NORMAL BLOOD PHOSPHORUS LEVELS IN HYPOPHOSPHATEMIC CATTLE USING SODIUM MONOPHOSPHATE

Author
item CHENG, YA-HSIN - IOWA STATE UNIV., AMES
item Goff, Jesse
item Horst, Ronald

Submitted to: Veterinary Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Low blood phosphorus is a condition observed in some dairy cows at the time of calving which can lead to muscle weakness and an inability to stand. This can be a complication in approximately 1-2% of all dairy cows each year. Currently available intravenous solutions utilize phosphite salts to restore blood phosphorus levels back to normal. In this paper we demonstrate that these salts are totally ineffective. We have found that the only way to restore normal blood phosphorus levels is by utilizing phosphate salts as the source of phosphorus. Further, we demonstrate that oral administration of these salts may be more therapeutic than intravenous administration. These results will allow veterinary practitioners to effectively treat low blood phosphorus conditions in cattle.

Technical Abstract: Downer cow syndrome is an occasional sequelae to milk fever in dairy cows. Cows with milk fever are severely hypocalcemic and usually hypophosphatemic at the time of initial treatment for milk fever. In most cases, intravenous adeministration of calcium salts raises blood calcium concentrations immediately, followed within a few hours by a rise in blood phosphorus concentration. However, in some animals plasma phosphorus concentrations fail to increase following therapy for milk fever and it is felt that this results in a failure to rise after treatment and be classified as "downer cows." Effective methods to restore normal plasma phosphorus concentrations could be of aid in treatment and prevention of the downer cow syndrome. The majority of the products available to veterinarians in the US for intravenous treatment of hypophosphatemic cattle utilize phosphite salts as the source of phosphorus. Phosphite salts are used because they are very soluble in water and remain soluble even in the presence of calcium and magnesium, allowing preparation of solutions to treat low blood calcium, magnesium, and phosphorus conditions with the same product. However, phosphorus found in blood and body tissues is almost exclusively in the form of the phosphate anion. To our knowledge no pathway exists for the conversion of phosphite to phosphate salts in body tissues. This study was initiated to determine if intravenous use of phosphite salts results in a rise in plasma inorganic phosphorus concentration and to describe an intravenous and oral treatment, utilizing sodium monophosphate, that will effectively raise blood inorganic phosphorus concentrations in cattle.