Ketotic cows: treatment and prognosis (Proceedings)
An absolute requirement for treating ketosis in cattle is to identify and treat the primary cause for the negative energy balance. Symptomatic treatment for ketosis without attacking the primary cause is doomed to failure.
Propylene glycol is a routine treatment for ketosis. Only 2 oral formulations are approved for use in cattle as a treatment and the dose rate is 8 oz, q 12 h, for up to 10 days (2 other formulations labeled for use as preventive treatment). Research suggests that 296 ml once/day as on oral drench is just as effective as 887 ml once/day. Propylene glycol is absorbed from the rumen as propylene glycol, some propylene glycol is metabolized to propionate in the rumen, but most is absorbed intact and metabolized to glucose in liver. Propylene glycol increases serum [glucose], decreases serum β-OH butyrate & NEFA concentrations but only if a functional liver as propylene glycol must be metabolized. Propylene glycol is only beneficial if rumen motility to aid mixing and absorption.
Glycerol (same dose rate as propylene glycol) and sodium propionate (uncertain dose rate) also reported to be of use but are both considered inferior to propylene glycol. Sodium propionate may have palatability problems. Calcium propionate has been examined, but the evidence is not convincing that it is superior to propylene glycol, even though it also has calcium. Not very soluble, and large volumes need to be administered.500 ml of 50% Dextrose IV is also a routine treatment (one time administration of 250 g). Numerous approved products for treating ketosis in cattle. A cow uses 50-70 g glucose/hour for maintenance and 200 g glucose/hour high production, from a total blood glucose pool <40 g. Milk is 4.5% lactose, 50 kg of milk contains 2.25 kg lactose (glucose and galactose), which is equivalent to 4.5 kg of glucose (18 bottles of 50% dextrose). A rough rule of thumb is 1.6 bottles of 50% glucose / 10 pounds of milk.
Dextrose suppresses NEFA release and hepatic ketogenesis for a few hours which is beneficial. There is a low renal threshold of 150 mg/dl glucose, serum glucose concentrations are back to normal after 2 to 4 hours. Hyperglycemia inhibits rumen and abomasal motility for at least two hours after administration, the effect appears to be insulin-mediated so not a problem in early lactation (dairy cows have very low serum insulin concentrations early in lactation).
Only two glucocorticoid products are currently approved for treataing ketosis, dexamethasone and isoflupredone acetate. Glucocorticoids promote release of amino acids from muscle and may be gluconeogenic. Glucocorticoids promotes conversion of amino acids in liver to glucose. Careful in cattle with concurrent infectious disease, as immunosuppressive dose of dexamethasone is 0.04-0.05 mg/kg, IM. Experimentally, 10-20 mg IM dexamethasone ester increases blood glucose concentration, decreases blood ketone concentration. Be carefeul with repeated injections of isoflupredone acetate as clinical hypokalemia may result.