Introduction: In determining the proper size of an equine nasal strip (FLAIR™ strip, CNS, Inc) a range of equine nasal dimensions was needed. The strip consists of three polyester springs sandwiched between two layers of non-woven material and adheres to the animal’s nose via a rubber based adhesive. The springs act to support the soft tissue between the nasal and incisive bone rostral to the nasoincisive notch. Positioning of the springs across the soft tissue area is critical to the proper functioning of the strip and having one size for all horses was desirable. This anatomic dimensional study was performed to determine the optimal shape and size of the equine nasal strip.
Materials/Methods: An equal mix of thoroughbreds (TB), quarterhorses (QH), arabians (AR) and standardbreds (STB) were sought for the study with a distribution of stallions (St), mares (Ma) and geldings (Ge). Measurements were made in the rostral portion of the head (see figure 1) using a flexible tape measure. The measurement of the bone included the cartilage but not soft tissue, eg, the width of nasal bone at the rostral end. Measurements were made to the nearest 0.25 inch.
Measurements were made of both the width and the height of the opening of the nostril which were then combined to create a cross sectional area of the nostril opening. An ellipse was used to model the nostril opening with the formula: area = X (width / 2) X (height / 2).
General descriptive statistics were developed. When comparisons were made an ANOVA technique was used followed by Tukey’s Multiple Comparison to determine statistical significance. A p value of less than 0.05 was used to indicate significance.
Fig 1. Flattened view of nasal region from above.
Results: A total of 154 horses (36 St, 53 Ma, 65 Ge) with an average age of 4 years (1 SD = 2.1, range of 2 to 13 years) were measured for the study. There were 31 TB (5 St, 9 Ma, 17 Ge), 32 QH (12 Ma, 20 Ge), 48 AR (18 St, 18 Ma, 12 Ge) and 43 STB (13 St, 14 Ma, 16 Ge).