Acute pain responses in dairy calves undergoing cornual nerve blocks with or without topical anesthetic

Abstract

Dairy calves are routinely administered medicines, vaccines, and anesthesia via injection. Although injections are painful, little is known about methods to alleviate this pain. The aim of this study was to determine whether lidocaine-prilocaine cream, a topical anesthetic, reduced calves' pain response to a subcutaneous injection around the cornual nerve. Calves were assigned 1 of 2 treatments: lidocaine-prilocaine cream at the sites of injection (n = 10) or no cream (n = 9). Thirty minutes after treatment, calves received a subcutaneous injection of 2% buffered lidocaine hydrochloride around the left and right cornual nerves. Contrary to our hypothesis, calves that received anesthetic cream beforehand displayed more escape behaviors during the injections than control calves. Both treatments had similarly low amounts of head-related behaviors afterward. Maximum eye temperature did not differ between the calves that received anesthetic cream and control calves, although eye temperature increased over time for both treatments. Heart rate increased during the 30 s following the first injection in both treatments. There were no treatment differences for any heart rate measures over the 5-min period after the first injection (mean heart rate, root mean square of successive differences, high-frequency power, and the ratio of low-frequency power to high-frequency power). These results suggest that cornual nerve blocks with buffered lidocaine are painful and that a lidocaine-prilocaine cream was not only ineffective in reducing this pain but that it may also worsen it.

Conditioned place preference reveals ongoing pain in calves 3 weeks after disbudding

“…We took steps to reduce this aversiveness by buffering the lidocaine with sodium bicarbonate to decrease its acidity and by applying a topical anesthetic to numb the skin before injection. Unfortunately, we have since found that the anesthetic cream we used may worsen injection pain rather than alleviate it 19 . However, the cream was used for both lidocaine and saline injections and so cannot explain the sham calves' aversion to lidocaine.…”

“…Body weights were similar among treatment groups the day before disbudding (mean ± SD; Day 0 Sham: 44 ± 6 kg; Day 0 Disbud: 45 ± 7 kg; Day 20 Sham: 43 ± 7 kg; Day 20 Disbud: 43 ± 5 kg). On the day of disbudding, the calf was restrained in a head device in her home enclosure, as previously depicted 19 . A 5 ×5 cm patch of hair was clipped with a size 40 electric razor blade on each side of the head to locate the horn bud.…”

Iron and laterality effects on healing of cautery disbudding wounds in dairy calves

“…The side (left vs. right) that each iron was applied to was alternated and balanced between calves. On the day of disbudding, the calf was restrained in a head device in her home pen (Jimenez et al, 2019) and a 5 × 5 cm patch was clipped on each side of the head to locate the horn bud. The calf received a cornual nerve block of 5 mL 2% lidocaine hydrochloride injected on each side with a 20-gauge × 25-mm needle.…”

“…A measuring tape was placed to the right of the wound and included in the photographs to evaluate wound size. During photography, the calf was restrained and blindfolded in a head device in her home pen (Jimenez et al, 2019).…”

Body expressions of emotions: does animals have it?

“…The percentage of eye white area (ocular sclera) in the eye of cattle has been measured as an indicator of emotional state in some studies (Sandem et al 2006;Proctor and Carder 2015;Lambert and Carder 2017;Gómez et al 2018;Jimenez et al 2019) and was associated with a strong emotional response in dairy cows (Sandem and Braastad 2005). The percentage of the visible white area increases when the upper eyelid is lifted.…”