Prognostic indicators for nonambulatory cattle treated by use of a flotation tank system in a referral hospital: 51 cases (1997–2008)

Alexandra J. Burton Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Alexandra J. Burton in
Current site
Google Scholar
PubMed
Close
 BVSc
,
Daryl V. Nydam Department of Population Medicine and Diagnostic Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Daryl V. Nydam in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
Theresa L. Ollivett Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Theresa L. Ollivett in
Current site
Google Scholar
PubMed
Close
 DVM
, and
Thomas J. Divers Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Thomas J. Divers in
Current site
Google Scholar
PubMed
Close
 DVM, DACVIM

Click on author name to view affiliation information

Abstract

Objective—To evaluate clinical variables assessed during the first 24 hours of hospitalization as prognostic indicators for nonambulatory cattle treated by use of a flotation tank.

Design—Retrospective case series.

Animals—51 nonambulatory cattle that underwent flotation treatment.

Procedures—Signalment, history, serum biochemical analyses, patient behavior during flotation, and outcome data were collected from medical records. Outcome was survival to discharge from the hospital or nonsurvival (death or euthanasia). Data were analyzed by use of Wilcoxon rank sum, Fisher exact, and χ2 tests.

Results—19 of 51 cattle survived. Survivors and nonsurvivors did not differ significantly with regard to median weight; age; stage of lactation; duration of recumbency prior to flotation; serum potassium, ionized calcium, or phosphate concentrations at admission to the hospital; or serum creatine kinase activity (value at admission to the hospital, highest value, and last recorded value). Cattle that were able to walk out of the tank after the first flotation treatment were 4.8 times as likely to survive as those that could not. Cattle that did not eat during flotation treatment were 1.9 times as likely to die as those that ate. Cattle that stood apparently normally on all limbs during the first flotation treatment were 2.9 times as likely to survive as those that had an asymmetric stance or were unable to stand.

Conclusions and Clinical Relevance—Results indicated that objective variables evaluated during the first 24 hours of hospitalization and flotation treatment are associated with outcome among nonambulatory cattle; findings might assist in logical decision making with respect to treatment options.

Abstract

Objective—To evaluate clinical variables assessed during the first 24 hours of hospitalization as prognostic indicators for nonambulatory cattle treated by use of a flotation tank.

Design—Retrospective case series.

Animals—51 nonambulatory cattle that underwent flotation treatment.

Procedures—Signalment, history, serum biochemical analyses, patient behavior during flotation, and outcome data were collected from medical records. Outcome was survival to discharge from the hospital or nonsurvival (death or euthanasia). Data were analyzed by use of Wilcoxon rank sum, Fisher exact, and χ2 tests.

Results—19 of 51 cattle survived. Survivors and nonsurvivors did not differ significantly with regard to median weight; age; stage of lactation; duration of recumbency prior to flotation; serum potassium, ionized calcium, or phosphate concentrations at admission to the hospital; or serum creatine kinase activity (value at admission to the hospital, highest value, and last recorded value). Cattle that were able to walk out of the tank after the first flotation treatment were 4.8 times as likely to survive as those that could not. Cattle that did not eat during flotation treatment were 1.9 times as likely to die as those that ate. Cattle that stood apparently normally on all limbs during the first flotation treatment were 2.9 times as likely to survive as those that had an asymmetric stance or were unable to stand.

Conclusions and Clinical Relevance—Results indicated that objective variables evaluated during the first 24 hours of hospitalization and flotation treatment are associated with outcome among nonambulatory cattle; findings might assist in logical decision making with respect to treatment options.

Nonambulatory cattle, commonly called downer cows, are animals that are recumbent for ≥ 12 hours and that are unable or unwilling to stand during recumben-cy.1,2 These cattle can be further classified as alert nonambulatory cattle, which have signs consistent with apparently normal mentation and are often willing to eat, and nonalert nonambulatory cattle, which have signs of altered mental status, abnormal vital signs (heart rate, respiratory rate, and rectal temperature), or both. Alert nonambulatory cattle often have musculoskeletal or neurologic injuries, such as luxation of the hip joint, dystocia-induced (calving) paralysis (trauma to the lumbar root of the sciatic and obturator nerves secondary to dystocia or fetopelvic disproportion), spinal cord compression, severe myopathy, or long-bone or pelvic fractures.1,3,4 The nonalert group is comprised of cattle with conditions such as hypocalcemia, severe endotoxic mastitis, septic metritis, diffuse peritonitis, hemorrhage (bleeding abomasal ulcer or hemorrhagic bowel syndrome), or diseases of the brainstem or cerebral cortex. However, these 2 groups of nonambulatory cattle are not mutually exclusive; an initially alert nonambulatory animal may become compromised and subsequently be reclassified as nonalert, and conversely a nonalert animal may have improvement of its underlying condition and subsequently be reclassified as alert.1,2

Regardless of the initial cause, prolonged recumbency, especially on hard surfaces, induces rapid development of secondary pressure ischemia and associated neuropathies.5 Additionally, muscle and ligament tears often occur because of struggling during recumbency or during attempts to move from unsuitable locations (eg, a ditch or under a neck rail).1,6 Nonambulatory cattle are common; most US dairy operations have at least 1 nonambulatory cow/y.7 In a 2-year investigation8 involving 10 large dairy herds, musculoskeletal and nerve injuries comprised the highest percentage (19.7%) of underlying causes associated with death among adult cattle.

The first step in management of nonambulatory cattle is diagnosis and treatment of the primary underlying problem. However, accurate diagnosis, especially in alert nonambulatory cattle with suspected musculoskeletal or nerve injury, can be difficult because of the body size of cattle and limited imaging capabilities. For cattle that have injuries or systemic illnesses from which recovery is possible, prevention of secondary myopathy and neuropathy is an essential component of management. Necessary procedures include provision of a soft, safe environment (eg, a sand box stall), regular repositioning among sternally recumbent positions to prevent prolonged pressure on the pelvic limb that is underneath the animal, and careful positioning of the limbs.9

Ideally, it is desirable to manipulate nonambulatory cattle so they can stand to prevent further neuromuscular injury and development of pressure sores, reduce the risk of mastitis in cows, and hasten recovery. Hip lifters (hip clamps) can be successful in helping cattle with generalized weakness or an injury to the pelvic limbs or lumbar area to rise. However, these clamps should not be applied for > 5 minutes because they generate immense pressure on the tuber coxae and can result in pressure necrosis.6 If nonambulatory cattle have a neuromuscular injury of the thoracic limb or are very weak, then hip lifters will not provide enough support to allow them to stand. Slings and inflatable bags have been used to provide support for standing. However, in cows, these devices are difficult to maintain because interference from the udder can prohibit proper positioning of the slings or bags. Also, ventral pressure induced by the slings or bags forces abdominal viscera against the diaphragm, which leads to respiratory distress.10

Recently, flotation tank devices (watertight metal boxes approx 130 cm in height with a base measuring approx 234 × 109 cm) have been used in the management of alert nonambulatory cattle. In water, an affected animal's body weight is evenly supported, which avoids the development of pressure necrosis. Warm water also has therapeutic benefit, aiding blood circulation in muscles that were previously compressed. Flotation tank systems can be portable and transported for management of nonambulatory cattle at farms. In addition, several referral hospitals have flotation tank systems. In our hospital referral area (northeastern United States), some clients prefer to send valuable nonambulatory cattle to the hospital for flotation tank treatment. This may be because of cold environmental temperatures, labor requirements (24-hour monitoring and nursing care), and need for additional treatments and diagnostic assessments.

To our knowledge, there has only been 1 previous report1 regarding the use of flotation tank treatment for nonambulatory cattle. In that report,1 the success rate in manipulating 70 previously unresponsive cattle to rise and walk was 46%, with an increased success rate of 78% if only cows with dystocia-induced paralysis were considered. Maintenance of a bovid in a flotation tank in a referral hospital can be costly, labor intensive, and stressful or painful for the patient. The objective of the study reported here was to evaluate clinical variables during the first 24 hours of hospitalization and flotation of nonambulatory cattle as potential prognostic indicators, specifically to determine whether any risk factors evaluated during the initial flotation tank treatments were associated with outcome. Our aim was to provide information that might enable clinicians and owners to make informed decisions about the expected benefit of flotation tank treatment for nonambulatory cattle.

Materials and Methods

Case selection—All cattle admitted to the Cornell University Farm Animal Hospital between January 1, 1997, and March 31, 2008, that underwent treatment for prolonged recumbency by use of a flotation tanka were eligible for inclusion in the study. Cattle that were nonambulatory at the time of admission to the hospital and those that became nonambulatory during hospitalization for other conditions were included.

Medical records review—Data obtained from the medical records included signalment and history (age, breed, sex, and weight at admission and at discharge from the hospital for survivors or at necropsy for nonsurvivors); for females, stage of lactation cycle was noted (heifers [nonbred or early bred] or cows ≤ 14 days after start of lactation, > 14 days after the start of lactation, or nonlactating). Information regarding duration of recumbency prior to the first flotation tank treatment at the hospital, whether the animal had been manipulated to stand at the farm prior to hospitalization, and whether abdominal surgery had been performed within 3 days prior to flotation tank treatment was also collected. Data regarding each animal's behavior during the first 24 hours of hospitalization were obtained; these data included stall behavior prior to flotation tank treatment (resting quietly in sternal recumbency or crawling around the stall [including attempts to stand or violent struggling]), tank behavior during the first treatment (standing apparently normally on all 4 limbs, standing apparently normally on the thoracic limbs only, standing apparently normally on the pelvic limbs only, or unable or unwilling to stand at all), and performance after the water was removed from the tank following the first treatment (able to walk out of the tank and stand in the stall, able to stand and walk a few steps but then falls to the ground, or unable to stand).

Additional clinical data collected for each animal included appetite (eating or not eating) during the first flotation tank treatment, duration of the first flotation tank treatment, and number of days on which flotation tank treatment was performed or attempted. Data obtained from laboratory test results included serum potassium, phosphate, and ionized calcium concentrations and CK activity at admission to the hospital; highest and last serum CK activity recorded during hospitalization; and results of California mastitis tests on milk samples collected from all 4 mammary glands at admission to detect whether at least 1 mammary gland had mastitis. Additionally, it was noted whether a CSF sample was collected for analysis and, if so, whether the results revealed expected cell populations.

Outcome was defined as survival to discharge from the hospital (survivors) or nonsurvival (death or euthanasia). Complications that were associated with flotation tank treatment were recorded.

Statistical analysis—Data were analyzed by use of descriptive and inferential methods. Data that were continuous were described as medians and interquartile ranges, and categoric data were summarized in contingency tables. Comparisons between survivors and nonsurvivors for continuous data were analyzed by use of Wilcoxon rank sum tests because these data often did not have normal distributions.11 Categoric data were analyzed by use of χ2 or Fisher exact tests with calculation of relative risk and CI.12 An acceptable type I error rate was set at 0.05. Statistical analyses were performed by use of commercial software.b

Results

Fifty-one cattle met the inclusion criteria for the study. There were 49 Holsteins, 1 Milking Shorthorn, and 1 Hereford. All were female, and 9 were heifers under 24 months of age. Nineteen (37%) cattle survived, and 32 (63%) cattle did not survive (3 died and 29 were euthanatized).

Most cows (32/51 [63%]) underwent parturition within 2 weeks prior to admission. There was no significant (P = 0.98) difference in the proportion of recently (≤ 2 weeks) parturient cows between the 2 groups; 12 of 19 survivors and 20 of 32 nonsurvivors were recently parturient cows. However, among the cows that had undergone parturition within 2 weeks prior to admission, there was a significant (P = 0.01) difference in the serum phosphate concentration at admission between survivors (median, 2.7 mg/dL; range, 2.0 to 6.2 mg/dL) and nonsurvivors (median, 4.6 mg/dL; range, 1.7 to 9.8 mg/dL), whereas there was no difference (P = 0.77) in serum ionized calcium concentration at admission between survivors (median, 1.24 mmol/L; range, 0.94 to 1.78 mmol/L) and nonsurvivors (median, 1.25 mmol/L; range, 0.68 to 1.79 mmol/L).

Overall, there were no significant differences between survivors and nonsurvivors with regard to median weight at admission and at discharge from the hospital or at necropsy; age; stage of lactation cycle; duration of recumbency prior to the first flotation tank treatment at the hospital; whether manipulation to stand had been performed at the farm prior to hospitalization; number of days on which flotation tank treatment was performed or attempted; serum potassium, ionized calcium, and phosphate concentrations and CK activity at admission to the hospital; and highest and last serum CK activities. Eight cattle had abdominal surgery ≤ 3 days prior to flotation treatment; there was no significant (P = 0.70) difference between survivors and nonsurvivors. Duration of the first flotation tank treatment differed significantly (P = 0.02) between survivors (median, 24 hours; range, 1 to 68 hours) and nonsurvivors (median, 6 hours; range, 1 to 55 hours; Table 1). The longest duration of recumbency prior to flotation tank treatment was 7 days among survivors and 21 days among nonsurvivors. Although the median serum CK activity at admission was not significantly (P = 0.58) different between survivors and nonsurvivors, there were some extreme values in both groups (Figure 1). The highest serum CK activity at admission was 68,545 U/L among survivors and 97,300 U/L among nonsurvivors.

Table 1—

Median (range) of variables for 51 nonambulatory cattle that received flotation tank treatment during hospitalization and that subsequently did or did not survive to discharge from the hospital (survivors and nonsurvivors, respectively).

VariableSurvivors (n = 19)Nonsurvivors (n = 32)P value*
Age (y)5 (1–7)5 (2–11)0.60
Weight (kg)636.0 (415–800)639.5 (427–825)0.92
Duration of recumbency prior to the first flotation tank treatment (d)1 (0.5–7)2 (0.5–21)0.25
No. of days on which flotation tank treatment was performed or attempted3 (1–8)2 (1–13)0.06
Duration of the first flotation tank treatment (h)24 (1–68)6 (1–55)0.02
Serum CK activity at admission (U/L)3,144 (288–68,220)5,199 (112–97,300)0.58
Highest serum CK activity measured during hospitalization (U/L)4,936 (453–68,545)6,286 (112–97,300)0.56
Last serum CK activity measured during hospitalization (U/L)2,601 (435–68,545)5,638 (112–97,300)0.16
Serum potassium concentration at admission (mEq/L)3.60 (1.60–4.60)3.55 (1.80–5.40)0.82
Serum ionized calcium concentration at admission (mmol/L)1.25 (0.92–2.21)1.29 (0.68–1.79)0.98
Serum phosphate concentration at admission (mg/dL)3.5 (1.8–10.8)5.7 (1.7–9.8)0.06

For comparisons between groups, a value of P < 0.05 was considered significant.

To derive the weight in pounds, multiply the weight in kilograms by 2.2.

Figure 1—
Figure 1—

Box-and-whisker plots of the serum CK activity at the time of admission to the hospital in 51 nonambulatory cattle that underwent flotation tank treatment and subsequently did or did not survive to discharge from the hospital (survivors [n = 19] and nonsurvivors [32], respectively). For each box, the horizontal line represents the median, and the upper and lower boundaries represent the first and third quartiles, respectively. Whiskers represent the highest and lowest nonoutlier observations, and circles represent outlier observations.

Citation: Journal of the American Veterinary Medical Association 234, 9; 10.2460/javma.234.9.1177

Significantly (P = 0.02) more survivors (3/19 cows) than nonsurvivors (2/32 cows) had mastitis at admission, although systemic illness attributable to mastitis was not apparent in any of the affected cows. A sample of CSF was collected from 9 of 19 survivors, and results of each analysis indicated no CNS abnormalities. A sample of CSF was collected from 10 of 32 nonsurvivors, and results of analyses indicated CNS abnormalities in 2 cows.

Manipulation to stand was performed at the farm prior to hospitalization for 2 of 19 survivors and 5 of 32 nonsurvivors and did not have an effect on survival rate. After water was removed from the flotation tank following the first treatment, cattle that could walk backward out of the tank and then walk to the stall without falling were 4.8 (95% CI, 2.2 to 10.2) times as likely to survive as cattle that fell or could not stand (P < 0.001). Cattle that did not eat during flotation tank treatment were 1.9 (95% CI, 1.3 to 2.4) times as likely not to survive as those that did eat during treatment (P = 0.02). Cattle that stood apparently normally on all 4 limbs during flotation tank treatment were 2.9 (95% CI, 1.3 to 6.3) times as likely to survive as those that had an asymmetric stance or that were unable to stand (P = 0.007). There was no significant (P = 0.49) difference in stall behavior prior to flotation tank treatment between survivors and nonsurvivors.

Cattle that died and those that were euthanatized were not treated as separate outcome groups because of the small number of cattle that died (3/32 nonsurvivors). In all instances, euthanasia was performed because of a poor prognosis (determined by the clinician) and not because of financial reasons—most of the cattle were considered to be valuable by the owners.

Underlying causes for recumbency among the 19 survivors included metabolic disease (eg, hepatic lipidosis, hypokalemia, hypophosphatemia, or refractory hypocalcemia; n = 6), sciatic nerve problem (2), vagal nerve–associated gastrointestinal tract disease (1), brachial plexus or radial nerve neuropathy (2), bilateral infected carpal hygromas (1), dystocia-induced paralysis (1), arthritis (1), and epidural spinal lymphoma (1). For 5 cattle, a specific diagnosis was unknown, but these animals were unable to stand by use of their pelvic limbs and had no other sign of systemic illness. Underlying causes for recumbency among the 32 nonsurvivors included metabolic disease (n = 2), sciatic nerve problem (2), vagal nerve–associated gastrointestinal tract disease (4), brachial plexus neuropathy (1), vertebral fracture or luxation (2), septic condition (eg, peritonitis, metritis, pericarditis, or pleuritis; 6), myopathy (5), spinal cord damage (2), and femoral head fracture or luxation (including rupture of the ligaments of the head of the femur without luxation; 8).

Complications of flotation tank treatment included development of mild mastitis, superficial limb abrasions, and mild pneumonia. No thrombophlebitis developed in any of the cattle that had an IV jugular catheter in place during flotation treatment.

Discussion

In the study reported here, the rate for survival to discharge from the hospital of nonambulatory cattle following flotation tank treatment (19/51 [37%]) was lower than that determined in a prior study,1 in which the success rate in manipulating 70 nonambulatory cattle to rise and walk was 46%. The success rate in that study1 increased to 78% if only cows with dystocia-induced paralysis were considered. Differences between the cattle population used in the previous study1 (beef cattle) and the population used in the present study (dairy cattle), and thus the underlying reasons for cattle being nonambulatory, are a likely cause of the difference in success rates. In the study of this report, there was only 1 beefbreed animal and 1 case of dystocia-induced paralysis. The population of nonambulatory cattle sent to our referral hospital is mainly comprised of mature, valuable dairy cows with a variety of metabolic, infectious, musculoskeletal, or neurologic diseases that often have a guarded prognosis.

Cattle most frequently become nonambulatory during the postparturient period; in 1 study,13 58% of affected cows (incidence rate, 12.4/1,000 cow-years) became nonambulatory within 1 day of parturition and 97% (incidence rate, 20.8/1,000 cow-years) became nonambulatory within 100 days of parturition. This is not surprising because many of the initial causative factors (eg, hypocalcemia, endotoxic mastitis, and musculoskeletal injuries [especially dystocia-induced paralysis]) develop in the postparturient period. Only 32 of 51 (63%) cows in the present study became nonambulatory ≤ 2 weeks after parturition. A reason for this proportion of recently parturient cattle could be prompt management of cows with periparturient hypocalcemia and other health issues that develop as cows progress into a lactation cycle on farms that use our hospital services. In addition, there may be reluctance to send cattle with low- to mid-range market values to the hospital because of cost; subsequently, only cattle with more complicated treatment needs, high market values, or both are referred to the hospital.

Periparturient hypocalcemia is a common initiating cause of recumbency in cattle; 3.8% to 28.2% of cows with periparturient hypocalcemia become nonambulatory with a mortality rate of 20% to 67%.1 Recently, a prospective field study14 revealed that cows with periparturient hypocalcemia that had pretreatment serum ionized calcium concentrations ≥ 1.7 mmol/L were 14 times as likely to become nonambulatory as those that had serum ionized calcium concentrations < 1.7 mmol/L. The same study14 revealed that cows with periparturient hypocalcemia that had pretreatment serum phosphate concentrations ≥ 0.9 mmol/L were 12 times as likely to not become nonambulatory as those that had serum phosphate concentrations < 0.9 mmol/L.

In the present study, no significant differences in serum concentrations of ionized calcium and phosphate were evident at admission between survivors and nonsurvivors. However, in the subgroup of cows that had undergone parturition within the preceding 2 weeks, survivors had significantly lower serum phosphate concentrations, compared with serum phosphate concentrations in nonsurvivors; there was no significant difference in serum ionized calcium concentrations. The lack of difference in serum ionized calcium concentrations in the present study could be attributable to the fact that all cows had received at least 1 (usually multiple) treatment with calcium prior to admission. Therefore, unless a cow had refractory hypocalcemia, any pretreatment differences in serum ionized calcium concentration would have been masked.

In a recent study,14 cows with periparturient hypocalcemia that had hypophosphatemia were more likely to become nonambulatory, compared with cows with serum phosphate concentrations in reference limits. In the study reported here, surviving nonambulatory cattle that were recently parturient had significantly lower serum phosphate concentrations at admission, compared with findings in nonsurvivors that were recently parturient. A possible explanation for the increased survival rate of cows with hypophosphatemia may be in part attributable to the fact that hypophosphatemia is often treatable. Therefore, if hypophosphatemia is a major contributing factor for recumbency, it may be treated with supplemental phosphate administered IV, PO, or via both delivery methods, whereas other conditions (eg, luxation of the hip joint or neuropathy) are more difficult to successfully treat.

It might be expected that serum CK activity would be higher in nonsurvivors than in survivors because increased muscle damage may have developed in nonsurvivors and prevented them from recovering fully. In 1 study,5 8 of 16 healthy cattle that were anesthetized in sternal recumbency with the right pelvic limb underneath the body for 6 to 12 hours were unable to subsequently rise to a standing position. At necropsy of the 8 cattle that remained recumbent, gross swelling of the right pelvic limb, ischemic necrosis of muscles along the proximal portion of the right pelvic limb, and inflammation of the sciatic nerve in the region caudal to the proximal end of the femur were present. In those 8 nonambulatory cattle, serum CK activity increased starting at 12 hours after the start of anesthesia, continued to increase up to 48 hours, and then decreased. However, serum CK activities at 12 and 48 hours after the start of anesthesia did not differ significantly between the cows that could rise to a standing position following anesthesia and those that could not. In agreement with the results of that investigation,5 serum CK activities at admission, the highest values detected during hospitalization, or the last values measured during hospitalization did not differ significantly between surviving and nonsurviving nonambulatory cattle in the present study. There were a few survivors with extremely high serum CK activities (up to 68,545 U/L); it should be emphasized that the number of cattle that were considered outliers with regard to this variable were few, and most serum CK activities for both groups were within the range of 3,000 to 6,000 U/L.

The fact that patient behavior during and after flotation tank treatment was a prognostic indicator was not surprising. Cattle that could walk out of the tank after water was removed, that stood apparently normally on all 4 limbs during flotation tank treatment, or that ate during treatment were more likely to survive than cattle that fell or could not stand after treatment, that did not stand apparently normally on all 4 limbs during flotation tank treatment, or that did not eat during treatment. Intuitively, the former behaviors are indicative of better clinical progress. The findings of the present study are useful for ranking the relative importance of these behaviors. In addition, the ability to formulate a quantitative measure of the likelihood of success is an important tool in decision making for the clinician and owner.

The median number of days on which flotation tank treatment was performed or attempted (3 days) and the median duration of the first flotation treatment (24 hours) among survivors in the present study are useful data for estimating expected progress and may also aid in more accurately estimating cost of treatment for owners. The number of days on which flotation tank treatment was performed or attempted before recovery was less than the number previously reported.1 In that other investigation, the mean number of days of flotation tank treatment required to achieve unassisted standing among cattle that had been recumbent for ≤ 1 day was 2.8; in cattle that had been recumbent for ≥ 2 days, the number of treatment days was 5.3. It is difficult to determine whether some of the nonsurvivors in the present study may have survived if they had received flotation tank treatments for up to 5 days. The median duration of the first flotation tank treatment before removal from the tank for nonsurvivors was only 6 hours, compared with 24 hours for survivors, in the study reported here. The shorter treatment duration for nonsurvivors reflects a large proportion (17/32) of nonsurvivors that showed signs of distress (eg, repeated struggling, increased respiratory rate, and dilated pupils) during attempted flotation. All of the nonsurvivors that were unable to stand at all (n = 9) and 8 of 11 nonsurvivors that could not bear weight on 1 or more limbs during flotation tank treatment showed signs of distress. It is therefore questionable whether it is humane for these cattle to undergo repeated attempts at flotation tank treatment in the hope that after several more days, they would be able to stand, especially considering that survivors were able to stand unassisted after a median of 3 days of treatment.

The age and body weight of the cattle in the survivor and nonsurvivor groups in the present study were not significantly different. This was an interesting and useful finding because there is a tendency among clinicians to predict a poorer outcome for older, heavier nonambulatory cattle. These results concur with the findings of another study,14 in which age was not a significant risk factor for nonambulatory status among cows with periparturient hypocalcemia. Although there was no significant difference in stall behavior between the survivors and nonsurvivors in our study, cattle with fulminant signs of CNS disease or that are unable to be maintained in sternal recumbency would not be candidates for flotation tank treatment.

In the study reported here, objective clinical variables in nonambulatory cattle that can be evaluated within the first 24 hours of hospitalization and flotation tank treatment and that are associated with survival to discharge from the hospital were identified. In addition, some variables that are traditionally considered poor prognostic indicators for recovery (eg, heavy body weight) did not differ significantly between survivors and nonsurvivors, indicating that these variables should not be of primary consideration in making clinical decisions. Used in context with a patient's history, clinical picture, and financial value, these findings will assist logical decision making with respect to flotation tank treatment of nonambulatory cattle.

Abbreviations

CI

Confidence interval

CK

Creatine kinase

References

  • 1.

    Smith BP, Angelos J, George LW, et al. Down cows: causes and treatments, in Proceedings. 30th Am Assoc Bovine Pract Conv 1997;4345.

  • 2.

    Fenwick DC, Kelly WR, Daniel RC. Definition of a nonalert downer cow syndrome and some case histories. Vet Rec 1986;118:124128.

  • 3.

    Ciszewski DK, Ames NK. Disease of peripheral nerves. Vet Clin North Am Food Anim Pract 1982;3:193212.

  • 4.

    Cox VS. Nonsystemic causes of the downer cow syndrome. Vet Clin North Am Food Anim Pract 1988;4:413433.

  • 5.

    Cox VS, McGrath CJ, Jorgensen SE. The role of pressure damage in pathogenesis of the downer cow syndrome. Am J Vet Res 1982;43:2631.

  • 6.

    Guard C. Musculoskeletal disorders. In: Divers TJ, Peek SF, eds. Rebhun's diseases of dairy cattle. 2nd ed. Philadelphia: WB Saunders Co, 2007;499500.

    • Search Google Scholar
    • Export Citation
  • 7.

    Green AL, Lombard JE, Garber LP, et al. Factors associated with occurrence and recovery of nonambulatory cows in the United States. J Dairy Sci 2008;91:22752283.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Stone WC, Guard CL, Button DA. Why do cows die?, in Proceedings. 35th Cornell Fall Dairy Conf 2005;5058.

  • 9.

    Cox VS, Marion RS. Sand as a bedding for a downer cow. Vet Rec 1992;130:7475.

  • 10.

    Cox VS, Farmsworth RJ. Prevention and treatment of down cows: a continuum, in Proceedings. 31st Am Assoc Bovine Pract Conv 1998;31:167169.

    • Search Google Scholar
    • Export Citation
  • 11.

    Rosner BA. Nonparametric methods. In: Fundamentals of biostatistics. Pacific Groove, Calif: Duxbury Press, 1986;278293.

  • 12.

    Dean AG, Dean JA, Colombier D, et al. Epi Info, version 6: a word processing, database, and statistics program for epidemiology on microcomputers. Atlanta: CDC, 1994.

    • Search Google Scholar
    • Export Citation
  • 13.

    Cox VS, Marsh WE, Sterernagel GR, et al. Downer cow occurrence in Minnesota dairy herds. Prev Vet Med 1986;4:249260.

  • 14.

    Ménard L, Thompson A. Milk fever and alert downer cows: does hypophosphatemia affect treatment response? Can Vet J 2007;48:487491.

a.

Aqua Cow Rise System, Aqua Cow Rise System North America Inc, St Johnsbury, Vt.

b.

SAS, version 9.1, SAS Institute Inc, Cary, NC.

All Time Past Year Past 30 Days
Abstract Views 147 0 0
Full Text Views 742 571 180
PDF Downloads 197 67 6
Advertisement