A December 2020 study in the Journal of Dairy Science set out to determine how much effect the addition of dextrose IV has in treating ketotic cows. It has long been established that glycol treatment for at least 3 days is the most important part of therapy for ketosis, but it is common, especially when you have a vet on farm to do IV treatment, to add dextrose for certain cows. The study included over 1200 ketotic dairy cows between 2-16 DIM, divided into 3 treatment groups: 3 days of glycol only, 3 days of glycol and IV dextrose on day 1, and 3 days of glycol and IV dextrose for 3 days. The groups were then followed and measured for post-treatment resolution of ketosis, incidence of adverse events (sold, died, DA, metritis) for the first 60 DIM, and also milk production in the first 10 weeks.
This is the largest, well-designed clinical trial to date looking at dextrose treatment for ketosis cows. And what was the conclusion? There was no significant effect on resolution of ketosis, incidence of adverse events, and milk production between the treatment groups, concluding that dextrose is not proven to provide an advantage over glycol alone. However, the author does discuss that dextrose therapy is often included when treating cows with very high blood ketone values at diagnosis (>3.0). This is the typical protocol followed at our clinic by our vets. The problem with ketosis trials is that usually a very small number of cows fall into that high blood ketone range - this study only had 35 cows that hit that criteria. This doesn’t provide enough of a sample size to determine a difference in outcomes for these cows, and so a study would have to be designed with hundreds of these >3.0 cows to truly determine if dextrose has an effect on the outcomes for that specific population. This is not something that has been undertaken in the research field yet. When asked about this topic further, Dr. McArt (one of the study authors) says that she finds that typically these highly ketotic cows have other complicating factors, such as fatty liver, that makes these cows more difficult to turn around. She admits that a better treatment protocol for treating fatty liver needs to be developed!
So what can we take away:
Dextrose does not have a negative effect on the outcome of treating ketotic cows, although there is no specific advantage.
If restraint and administration of IV dextrose is difficult on-farm for you, it is not really worth the extra time and effort, simply focus on early diagnosis and consistent glycol treatment.
Dextrose may or may not have a positive effect on highly ketotic (>3.0 blood ketone) cows, but it has not been researched thoroughly enough.
Fatty liver is difficult to diagnose (either post-mortem, or during surgery), and will complicate the recovery of ketotic cows, but we simply do not have good treatment protocols for this condition. For many highly ketotic cows, it is fair to assume that they have some fatty liver contributing to their condition, and therefore need a little bit more TLC. Extended glycol treatment, vitamin B12, IV dextrose and individual housing with lots of dry hay are all part of the “kitchen sink” approach for helping these cows bounce back.
References for this Newsletter:
Capel, MB., Bach, KD., Mann, S., McArt, JAA. December, 2020. “A randomized controlled trial to evaluate propylene glycol alone or in combination with dextrose as a treatment for hyperketonemia in dairy cows”. Journal of Dairy Science. 104:2185-2194.
Gordon, JL., LeBlanc, SJ., Kelton, DF., Herdt, TH., Neuter, L., Duffield, TF. 2017. “Randomized clinical field trial on the effects of butaphosphan cyanocobalamin and propylene glycol on ketosis resolution and milk production”. Journal of Dairy Science. 100:3912–3921.
Gordon, JL., Leblanc, SJ., Kelton, DF. 2013. “Ketosis Treatment in Lactating Dairy Cattle.” Veterinary Clinics: Food Animal Practice. 29:433–445.