Table 2.
Univariable logistic regression analysis of historical and admission variables and survival in adult horses diagnosed with botulism. Only variables with P < .20 that were considered for inclusion in the final model are listed
| Variable | Nonsurvivors (n = 48) n (%) Median (IQR) | Survivors (n = 44) n (%) Median (IQR) | Crude OR | 95% CI | P‐Value |
|---|---|---|---|---|---|
| Signalment | |||||
| Weight (kg) | 377 (295–436) | 448 (394–495) | 1.01 | 1.00–1.01 | .120 |
| Age (years) | 7 (3–12) | 3.5 (2–8) | 0.93 | 0.86–1.01 | .089 |
| Breed | |||||
| Thoroughbred | 20 (42.6) | 24 (54.6) | Reference | NA | |
| Standardbred | 4 (8.5) | 6 (13.6) | 1.25 | 0.31–5.06 | .754 |
| Warmblood | 3 (6.4) | 1 (2.3) | 0.28 | 0.03–2.88 | .283 |
| Quarter Horse | 8 (17.0) | 2 (4.6) | 0.21 | 0.04–1.10 | .064 |
| Arabian | 1 (2.1) | 2 (4.6) | 1.67 | 0.14–19.76 | .686 |
| Miniature/pony | 6 (12.8) | 2 (4.6) | 0.28 | 0.05–1.53 | .141 |
| Other light breed | 1 (2.1) | 3 (6.8) | 2.50 | 0.24–25.95 | .443 |
| Draft | 4 (8.5) | 4 (9.1) | 0.83 | 0.19–3.76 | .813 |
| Historical signs | |||||
| Colic | |||||
| No | 36 (75) | 39 (88.6) | Reference | NA | |
| Yes | 12 (25) | 5 (11.4) | 0.39 | 0.12–1.23 | .094 |
| Sustained recumbency | |||||
| No | 39 (81.3) | 42 (95.5) | Reference | NA | |
| Yes | 9 (18.8) | 2 (4.6) | 0.21 | 0.04–1.07 | .037 |
| Weak tail/eyelid | |||||
| No | 39 (81.3) | 40 (90.9) | Reference | NA | |
| Yes | 9 (18.8) | 4 (9.1) | 0.43 | 0.12–1.55 | .186 |
| Nasal discharge | |||||
| No | 43 (89.6) | 43 (97.7) | Reference | NA | |
| Yes | 5 (10.4) | 1 (2.3) | 0.20 | 0.02–1.86 | .116 |
| Reason for admit | |||||
| Botulism suspect | |||||
| No | 23 (48.9) | 15 (34.9) | Reference | NA | |
| Yes | 24 (51.1) | 28 (65.1) | 1.79 | 0.76–4.24 | .180 |
| Colic | |||||
| No | 35 (74.5) | 37 (86.1) | Reference | NA | |
| Yes | 12 (25.5) | 6 (14.0) | 0.47 | 0.16–1.42 | .173 |
| Clinical signs | |||||
| Temperature | 100.2 (99.1–101.4) | 101.2 (100.8–101.8) | 2.10 | 1.36–3.23 | .001 |
| Respiratory rate | 24 (20–32) | 24 (16–28) | 0.97 | 0.93–1.01 | .154 |
| Dysphagia | |||||
| No | 18 (37.5) | 5 (11.4) | Reference | NA | |
| Yes | 30 (62.5) | 39 (88.6) | 4.68 | 1.47–14.92 | .004 |
| Weak tongue | |||||
| No | 1 (2.1) | 6 (13.6) | Reference | NA | |
| Yes | 47 (97.9) | 38 (86.4) | 0.14 | 0.02–1.25 | .038 |
| Weak eyelids | |||||
| No | 6 (12.5) | 14 (31.8) | Reference | NA | |
| Yes | 42 (87.5) | 30 (68.2) | 0.31 | 0.10–0.92 | .026 |
| Weak anal tone | |||||
| No | 29 (60.4) | 33 (75) | Reference | NA | |
| Yes | 19 (39.6) | 11 (25) | 0.51 | 0.21–1.27 | .138 |
| Abnormal pupils | |||||
| No | 30 (62.5) | 36 (81.8) | Reference | NA | |
| Yes | 18 (37.5) | 8 (18.2) | 0.37 | 0.14–1.00 | .041 |
| Increased recumbency | |||||
| No | 33 (68.8) | 36 (81.8) | Reference | NA | |
| Yes | 15 (31.3) | 8 (18.2) | 0.49 | 0.18–1.32 | .150 |
| Weak tail | |||||
| No | 7 (14.6) | 13 (29.6) | Reference | NA | |
| Yes | 41 (85.4) | 31 (70.5) | 0.41 | 0.14–1.17 | .084 |
| Total recumbency | |||||
| No | 29 (60.4) | 42 (95.5) | Reference | NA | |
| Yes | 19 (39.6) | 2 (4.6) | 0.07 | 0.01–0.40 | <.001 |
| Decreased GI sounds | |||||
| No | 22 (45.8) | 29 (65.9) | Reference | NA | |
| Yes | 26 (54.2) | 15 (34.1) | 0.44 | 0.18–1.04 | .054 |
| Abnormal respiratory effort | |||||
| No | 34 (70.8) | 42 (95.5) | Reference | NA | |
| Yes | 14 (29.2) | 2 (4.6) | 0.12 | 0.02–0.60 | .002 |
| Hematology | |||||
| Hematocrit (%) | 43 (39–46) | 38 (35–47) | 0.95 | 0.89–1.02 | .151 |
| Total protein (g/dL) | 7.3 (7.0–7.8) | 7.0 (6.6–7.6) | 0.69 | 0.40–1.19 | .184 |
| WBC count (K/μL) | 10.40 (8.86–12.25) | 9.66 (8.16–10.56) | 1.00 | 1.00–1.00 | .070 |
| Neutrophil count (K/μL) | 8.74 (6.75–9.91) | 7.10 (6.31–8.60) | 1.00 | 1.00–1.00 | .044 |
| pH | 7.41 (7.36–7.43) | 7.42 (7.41–7.43) | 4043459 | 0.17–9.78e+13 | .079 |
| pCO2 (mmHg) | 47.7 (45.9–51.5) | 45.1 (43–46.8) | 0.86 | 0.74–1.00 | .043 |
| CK (U/L) | 600 (327–1,616) | 300 (174–696) | 1.00 | 0.99–1.00 | .043 |
| AST (U/L) | 476 (367–665) | 543 (389–734) | 1.00 | 0.99–1.00 | .136 |
IQR, interquartile range; OR, odds ratio; CI, confidence interval; CK, creatine kinase; AST, aspartate aminotransferase.