Mechanical/thermal sensitivity and superficial temperature in the stump of long-term tail-docked dairy cows

Abstract

BackgroundTail docking of dairy cows is a painful procedure that affects animal welfare level. The aims of this study were first to evaluate the response to mechanical and thermal stimulation, and second to determine the superficial temperature of the stump of tail-docked dairy cows.MethodsOne hundred and sixty-four dairy cows were enrolled. From these, 133 cows were assigned to the tail-docked (TD) group and 31 cows were selected as control animals. The following sensory assessments to evaluate pain in tail-docked cows were performed. Sensitivity of the tail region in both groups of animals was evaluated using a portable algometer. Cold and heat sensitivity assessment was performed using a frozen pack (0 °C) and warm water (45 °C), respectively. Pinprick sensitivity was evaluated using a Wartenberg neurological pinwheel. Superficial temperature was evaluated using a thermographic camera. All sensory assessments and superficial temperature were evaluated in the ventral surface of the tail stump (TD) and tail (C).ResultsPressure pain threshold was lower in TD cows (5.97 ± 0.19 kg) compared to control cows (11.75 ± 0.43 kg). Heat and cold sensitivity was higher in the TD cows compared to control cows with 29% and 23% of TD cows responding positively, respectively. Similarly, after pinprick sensitivity test was performed, 93% of TD cows elicited a positive response to stimulation. Tail-docked cows had lower superficial temperature (26.4 ± 0.27 °C) compared to control cows (29.9 ± 0.62 °C).DiscussionPressure pain threshold values in both groups of animals were higher than those previously reported for TD pigs, sows and cows. In contrast, pinprick stimulation evaluates the presence of punctate mechanical hyperalgesia/allodynia, usually related to traumatic nerve injury, and this association may reveal that it is possible that these animals developed a disorder associated to the development of a tail stump neuroma and concurrent neuropathic pain, previously reported in TD lambs, pigs and dogs. Thermal sensitivity showed that TD cows responded positively to heat and cold stimulation. These findings suggest that long-term TD cows could be suffering hyperalgesia/allodynia, which may be indicative of chronic pain. Lower superficial temperature in the stump may be associated to sympathetic fiber sprouting in the distal stump, which can lead to vasoconstriction and lower surface temperatures. Further studies are needed in order to confirm neuroma development and adrenergic sprouting.

Animal models of chronic pain. Are naturally occurring diseases a potential model for translational research?

“…Nonetheless, scientific evidence discussing how these conditions could represent a translational approach has only been reported for feline interstitial cystitis (Buffington 2001), feline diabetes mellitus (Mizisin et al 2002), osteoarthritis (McCoy 2015) and various tumours in dogs (Peña et al 2003, Brown et al 2009 and cats (Pérez-Alenza et al 2004), lameness in dairy cattle and horses (Bustamante et al 2015, Rodriguez et al 2018, Herzberg et al 2019, tail docking in dairy cows (Troncoso et al 2018). According to Klinck et al (2017), this relatively limited evidence could be indicative of the complexity in the design and interpretation of studies in which the number of recruited subjects is reduced.…”

“…Interestingly, the vast majority of the test used in experimental models have been evaluated in naturally occurring models, including thermal and mechanical thresholds, activity monitoring, operant testing, fMRI, PET and electroencephalography. Troncoso et al (2018) used a QST battery in order to confirm the presence of chronic pain in long-term tail docked dairy cows. Probably the most studied and well-defined translational model of chronic pain is companion animals' osteoarthritis.…”

Verhaltensassoziierte und physiologische Indikatoren für Schmerz und Unwohlsein bei Kälbern nach Schwanzamputation

“…In Bezug auf chronischen Schmerz nach Schwanzamputation beim Rind, ver gleichbar mit Phantom und Stumpfschmerzen, ergaben sich eben falls bereits Hinweise auf ein solches Geschehen. Analog zu Men schen mit amputierten Gliedmaßen, die unter chronischen Ampu tationsschmerzen leiden, zeigten schwanzamputierte Kalbinnen und Kühe eine erhöhte Temperaturempfindlichkeit am Amputati onsstumpf [36] [37]. Stumpfschmerzen entstehen u. a. durch Bil dung von Neuromen im Amputationsstumpf [38].…”

Diagnostic Value and Application of Infrared Thermography in the Analysis of Circumanal Gland Tumors

“…Medically, the use of thermal imaging is not limited to oncology and has been applied in sports medicine, orthopedics, neurology, anesthesiology and pain management, angiology, and animal and human plastic reconstructive surgery (25)(26)(27)(28)(29)(30).…”