Table 5.
Normal swallow metrics by age (median ± IQR)
| Juvenile (0.1 ± 0.6 years) | Adult (4.9 ± 0.93 years) | Geriatric (11.3 ± 3.55 years) | P value | |
|---|---|---|---|---|
| Liquid | ||||
| Interswallow interval (ISI) | 1.51 ± 1.97 | 1.14 ± 0.53 | 1.19 ± 0.69 | .215 |
| Swallow rate | 1.65 ± 1.20 | 2.65 ± 0.7 | 2.35 ± 0.65 | .670 |
| Jaw cycles per swallow ratio | 2.70 ± 2.68 | 2.85 ± 1.15 | 3.00 ± 1.25 | .847 |
| Time to proximal esophageal sphincter opening (PESO) | 0.04 ± 0.02 | 0.05 ± 0.03 | 0.03 ± 0.02 | .463 |
| Time to maximum laryngeal excursion (MLE) | 0.07 ± 0.03 | 0.08 ± 0.04 | 0.10 ± 0.06 | .254 |
| Time to maximum pharyngeal constriction (MPC) | 0.11 ± 0.06 | 0.12 ± 0.04 | 0.11 ± 0.02 | .834 |
| Time to air column reopening (AIR) | 0.28 ± 0.03 | 0.26 ± 0.06 | 0.30 ± 0.05 | .389 |
| Time to proximal esophageal sphincter closure (PESC) | 0.33 ± 0.03 | 0.31 ± 0.06 | 0.35 ± 0.06 | .743 |
| Pharyngeal constriction ratio | – | – | – | – |
| Esophageal transit time (ETT) | 3.1 ± 6.0 | 4.64 ± 1.13 | 4.5 ± 0.1 | .969 |
| Proximal esophageal bolus area | – | – | – | – |
| Puree | ||||
| Interswallow interval (ISI) | 2.53 ± 0.4 | 3.14 ± 1.49 | 4.04 ± 1.75 | .193 |
| Swallow rate | 2.0 ± 0.08 | 1.50 ± 1.0 | 1.25 ± 0.65 | .211 |
| Jaw cycles per swallow ratio | 7.7 ± 2.3 | 8.0 ± 5.7 | 9.35 ± 5.68 | .861 |
| Time to proximal esophageal sphincter opening (PESO) | 0.03 ± 0.02 | 0.06 ± 0.03 | 0.09 ± 0.04 | .385 |
| Time to maximum laryngeal excursion (MLE) | 0.07 ± 0.02 | 0.14 ± 0.04 | 0.09 ± 0.03 | .206 |
| Time to maximum pharyngeal constriction (MPC) | 0.11 ± 0.03 | 0.12 ± 0.02 | 0.12 ± 0.02 | .609 |
| Time to air column reopening (AIR) | 0.27 ± 0.04 | 0.30 ± 0.08 | 0.28 ± 0.08 | .732 |
| Time to proximal esophageal sphincter closure (PESC) | 0.34 ± 0.02 | 0.39 ± 0.05 | 0.37 ± 0.05 | .088 |
| Pharyngeal constriction ratio | 0.04 ± 0.01 | 0.05 ± 0.04 | 0.02 ± 0.01 | .083 |
| Esophageal transit time (ETT) | 4.74 ± 0.02 | 4.6 ± 0.09 | 4.62 ± 1.04 | .965 |
| Proximal esophageal bolus area | 2.96 ± 0.55 | 4.44 ± 5.69 | 3.44 ± 1.08 | .875 |
| Kibble | ||||
| Interswallow interval (ISI) | 6.61 ± 3.44 | 5.25 ± 2.90 | 6.43 ± 3.65 | .345 |
| Swallow rate | 1.25 ± 0.63 | 1.30 ± 0.70 | 1.0 ± 0.0 | .140 |
| Jaw cycles per swallow ratio | 15.5 ± 6.5 | 12.0 ± 9.3 | 10.0 ± 4.5 | .513 |
| Time to proximal esophageal sphincter opening (PESO) | 0.08 ± 0.05 | 0.12 ± 0.11 | 0.09 ± 0.04 | .265 |
| Time to maximum laryngeal excursion (MLE) | 0.14 ± 0.12 | 0.24 ± 0.05 | 0.14 ± 0.12 | .145 |
| Time to maximum pharyngeal constriction (MPC) | N/A | N/A | N/A | – |
| Time to air column reopening (AIR) | 0.37 ± 0.17 | 0.56 ± 0.27 | 0.53 ± 0.10 | .122 |
| Time to proximal esophageal sphincter closure (PESC) | 0.43 ± 0.44 | 1.02 ± 0.62 | 0.65 ± 0.12 | .116 |
| Pharyngeal constriction ratio | – | – | – | – |
| Esophageal transit time (ETT) | 4.95 ± 0.02 | 5.84 ± 3.78 | 5.9 ± 0.53 | .101 |
| Proximal esophageal bolus area | – | – | – | – |
| Other | ||||
| Proximal esophageal retention | 1/5 | 0/12 | 2/7 | .282 |
| Distal esophageal retention | 0/5 | 2/12 | 1/7 | |
| Distal and proximal esophageal retention | 3/5 | 10/12 | 4/7 | |
| Gastric reflux | 3/5 | 4/12 | 4/7 | .709 |
| Retrograde flow | 2/5 | 8/12 | 3/7 | .579 |
| Bolus discohesion | 4/5 | 11/12 | 5/7 | .675 |
| Aspiration | 0/5 | 0/12 | 0/7 | 1.00 |
Median ± IQR for objective swallow metrics for liquid, kibble, and puree for dogs stratified by age. Bolus area was calculated for pureed food only. Animals were evaluated for the presence of proximal and distal esophageal retention, gastric reflux, retrograde flow, and bolus discohesion and aspiration regardless of consistency. N/A indicates that sufficient data could not be collected for this metric due to movement out of frame or instrument limitations leading to delay in video capture and data clipping.