Prognostic Indicators for Survival of Downer Cows Managed with a Floatation Tank System in a Referral Hospital
Recently, the use of flotation tank devices has improved the management of downer cows both in the field and hospital settings. The population of downer cows sent to or occurring in a referral hospital is challenging to manage as they have often been down for a long time and/or may be critically ill. Maintenance of a cow in a float tank can be costly, labor intensive and may be stressful for the patient. Our aim was to enable clinicians and owners to make informed decisions about whether or not to float a cow. The objective of this study was to evaluate prognostic indicators within the first 24 hours of hospitalization and flotation of the downer cow.
A retrospective study of all cows admitted to the Cornell University Farm Animal Hospital between January 1st 1997 and December 31st 2007 and managed with a float tank (Aqua Cow Rise System®) for recumbency was performed. Both cows that were admitted as downers and those that became downers during hospitalization were included. Data on signalment, history, biochemical parameters, stall and tank behavior and outcome was collected. Outcome was defined as survival to discharge. Data was analyzed using Wilcoxon rank sum and Chi square tests. Alpha was set at .05.
Of 46 total cows, 17 (37%) survived and 29 (63%) died or were euthanized. There was no significant difference between survivors and non-survivors in median weight, age, stage of lactation, number of days down prior to floating or having prior abdominal surgery. The longest time down prior to floatation in a survivor was 7 days. Median creatinine kinase (CK) concentration on admission was not significantly higher in the non-survivors (5284 U/L) compared to the survivors (4402 U/L). The highest admission [CK] recorded in a surviving cow was 68,545 U/L. Being able to back out without falling after the first flotation attempt was significantly associated with an increased chance of survival (p < 0.001). Cows that did not eat in the tank were 1.9 times more likely to die than those that had a good appetite (p = 0.03). Cows that stood square in the tank on the first flotation attempt were 2.6 times more likely to survive than those that were asymmetric or unable to stand (p = 0.02). This study has identified some objective parameters within the first 24 hours of flotation, associated with survival to discharge. Used in context with the individual's history, clinical picture and financial value, these findings will assist logical decision making with respect to floating of downer cows.