Sensory perception in horses involves the processing and interpretation of sensory stimuli from the environment through various sensory modalities. Horses rely on their senses, including vision, hearing, touch, taste, and smell, to interact with their surroundings and respond to potential threats or opportunities. Vision in horses is adapted for detecting movement and changes in light, with a wide field of view due to the lateral placement of their eyes. Their hearing is sensitive to a range of frequencies, allowing them to detect sounds over long distances. The tactile sense is facilitated by whiskers and sensitive skin, particularly around the muzzle, aiding in exploration and communication. Taste and smell play roles in feeding behavior and social interactions. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomical structures, physiological mechanisms, and behavioral implications of sensory perception in equine species.
Roberts SM.Vision is a marvelous sense, critical to the well-being and functional use of horses. Anatomic, optical, and visual acuity generalities are presented. The constituents of unsoundness due to equine ocular disease are discussed, and recommendations are made.
Timney B, Keil K.We assessed the ease with which horses could learn visual discriminations and measured their resolution acuity. We trained three horses to press their noses against one of two large wooden panels to receive a small food reward. Following training on a series of two-choice discrimination tasks, resolution acuity was measured. Although there was some variability between animals, the best acuity obtained was 23.3 c deg-1. Within the margin of error imposed by limited anatomical data, the obtained values are consistent with predictions based on retinal ganglion cell density estimates and posterior...
Dougherty DM, Lewis P.Using horses, we investigated three aspects of the stimulus control of lever-pressing behavior: stimulus generalization, discrimination learning, and peak shift. Nine solid black circles, ranging in size from 0.5 in. to 4.5 in. (1.3 cm to 11.4 cm) served as stimuli. Each horse was shaped, using successive approximations, to press a rat lever with its lip in the presence of a positive stimulus, the 2.5-in. (6.4-cm) circle. Shaping proceeded quickly and was comparable to that of other laboratory organisms. After responding was maintained on a variable-interval 30-s schedule, stimulus generalizat...
Wheeler SJ.This study aimed to establish a clinically reproducible method of evaluation of sensory nerve conduction in the horse and to provide reference values in a group of normal horses. Age-related changes in the sensory nerve conduction velocity were of particular interest. Sensory nerve conduction was performed in the lateral palmar nerve. The results revealed an increase in velocity over the first year of life and a subsequent decrease in velocity in older horses. The effect of age must be considered if results from horses in which peripheral nerve disease is suspected are to be interpreted correc...
Palmieri G, Sanna L, Asole A, Farina V, Bo Minelli L.The origin and course of the collateral sesamoidean (suspensory navicular) ligament of the horse and ass and its attachment to the distal sesamoid bone were studied by means of dissection. Particular attention was given to the topographic relations between this ligament and the deep digital flexor tendon. Numerous sensitive nerve endings are present in this anatomical district. The free and encapsulated nerve endings, displayed by impregnating techniques, are mostly concentrated in the ligament tract connected to the above-named tendon and close to its attachment to the distal sesamoid angle. ...
Schatzmann U, Gugelmann M, Von Cranach J, Ludwig BM, Rehm WF.Carprofen, flunixin meglumine and placebo in the form of a physiological solution of sodium chloride were tested in an open randomised cross-over trial for analgesic efficacy in horses with two external skin-stimulation systems. Both systems, the withers model and the "heating element" model, were compared in order to find an optimal way to measure pain perception after stimulating the skin with high temperature. No analgesic effect of flunixin or carprofen could be demonstrated when using the withers model. In the "heating element" model, a 1.1 mg/kg i.v. dose of flunixin meglumine failed to ...
Wheeler SJ.Sensory nerve conduction velocity was measured in the lateral palmar nerve of 8 horses. The limb temperature was manipulated by external means and monitored. Alterations in the nerve conduction velocity related to limb temperature variation were identified at both increased and decreased temperatures. These were quantified and a mean value of 2.15 +/- 0.2 m/s/degree Celsius was determined. The effect of altered limb temperature should be considered in nerve conduction velocity determinations.
Heffner RS, Heffner HE.The ability of horses to use binaural time and intensity difference cues to localize sound was assessed in free-field localization tests by using pure tones. The animals were required to discriminate the locus of a single tone pip ranging in frequency from 250 Hz to 25 kHz emitted by loudspeakers located 30 degrees to the left and right of the animals' midline (60 degrees total separation). Three animals were tested with a two-choice procedure; 2 additional animals were tested with a conditioned avoidance procedure. All 5 animals were able to localize 250 Hz, 500 Hz, and 1 kHz but were complet...
Kamerling SG, Dequick DJ, Weckman TJ, Sprinkle FP, Tobin T.The effects of procaine, mepivacaine and phenylbutazone on pain perception in the equine were studied using two behavioral assays of nociception; the thermal evoked hoof withdrawal reflex and skin twitch reflex. Pain perception threshold was measured as the latency from onset of thermal stimuli to reflex withdrawal of the forelimb or contraction of the cutaneous musculature. Procaine 2% and mepivacaine 2% prolonged the hoof withdrawal reflex latency when administered locally by producing a block of the palmar and metacarpal nerves. Significant analgesia lasted 90 min and 210 min for procaine a...
Heffner HE, Heffner RS.The idea that large mammals localize sounds more accurately than small mammals has been noted frequently and is usually explained by reference to their large interaural distance and the correspondingly broad binaural time (delta t) and spectral (delta fi) differences between their two ears. Sound-localization thresholds for single clicks and 100-ms noise bursts were determined for horses, and the magnitude of the binaural time (delta t) and spectral (delta fi) cues for sound direction were measured on a horse. Although horses have relatively large interaural distances and physically broad bina...
Erickson HH, Kitchell RL.In the last 2 decades there have been substantial advances in our knowledge of the scientific basis of the mechanisms of pain. Nociceptors or pain receptors are widespread in the skin and tissues of animals; chemical mediation of nociceptor excitation may provide a key for understanding the peripheral phenomena related to pain. The expression of pain in animals involves multiple ascending and descending branches, as well as specialized pain-signaling mechanisms in the spinal cord. The importance of these different pathways varies with species and circumstances. Endogenous neural systems in the...
Palmieri G, Asole A, Panu R, Farina V, Sanna L.A vegetative innervation is described for the first time in this district. On the contrary, the finding of Pacini and pacini-like corpuscles, of Golgi Mazzoni's receptors, of muscle spindles and Golgi's tendon-organs testifies the existence of a sensitive innervation in this anatomical territory. According to Karamanlidis free nervous endings are not present. All the above recorded receptors show the typical structure and can be found isolated, grouped to constitute flower-sprays, organized to form opposito-polar corpuscles or associated to originate pecilomorphic fibers. These two last findin...
Klein L, Hopkins J.4-Aminopyridine was administered in incremental IV doses to healthy horses to evaluate cardiorespiratory and behavioral effects. Doses of 100 micrograms/kg produced apparent sensory discomfort, manifested by wiggling or curling of the lips and tongue, arching or stretching the neck, snorting, squealing, and coughing. At cumulative dosages of 300 to 500 micrograms/kg, muscle tremors, a stilted gait, and signs of excitement occurred. Once signs of excitement occurred, additional administration of 4-aminopyridine resulted in prolonged excitement consisting of severe muscle tremors and exaggerated...
Randall RP, Schurg WA, Church DC.The two-choice preference test was used to
characterize the test reactions of five immature
horses to sweet, salty, sour and bitter tasting
solutions. Sucrose was preferred ('>60% of total
fluid as test solution) to tap water by the foals at
concentrations ranging from 1.25 to 10 g/100 ml.
Concentrations above and below this range result-
ed in indifference (40 to 60% of fluid consumed as
test solution). The horses were indifferent to NaCI
until a concentration of.63 g/100 ml was reached.
At this level the mean response changed to
rejection (<40% of total fluid as test solution).
F...
Eagle RC, Font RL, Swerczek TW.An 18-month-old Standardbred filly had a large intraocular tumor involving the optic nerve. The tumor was a malignant medulloepithelioma, a rare intraocular neoplasm derived from the primitive medullary epithelium. By light microscopy the tumor had cords and lobules of primitive neuroepithelial cells that formed clefts and true rosettes. Electron microscopy of the rosettes showed a girdle of zonulae adherentes joining the apices of the cells as well as several basal bodies. This is the sixth report of equine intraocular medulloepithelioma, and, to the best of our knowledge, the first intraocul...
Odberg FO.The ability of 10 horses to hear frequencies between 14 and 25 Kc/s was tested. The horses appeared to perceive ultrasounds by showing either fright reactions or Pryer reflexes to all of the 12 frequencies. The highest frequencies were heard less by older animals, and elicited more reactions in geldings than in mares.
Tauffkirchen E.Neurodevelopmental treatment according to Dr. K. and B. Bobath can be supplemented by hippotherapy. At proper control and guidance, an improvement in posture tone, inhibition of pathological movement patterns, facilitation of normal automatical reactions and the promotion of sensorimotor perceptions is achieved. By adjustment to the swaying movements of the horse, the child feels how to retain straightening alignment, symmetry and balance. By pleasure in this therapy, the child can be motivated to satisfactory cooperation and accepts the therapy horse as its friend. The results of hippotherapy...
VOR DER DOMESTIKATION HING DAS ÜBERLEBEN DER EQUIDEN VON DER FäHIGKEIT AB, SICH IHRER UMGEBUNG UND MIT IHR VERBUNDENEN GEFAHREN ANZUPASSEN. DIES BETRAF V. A. RAUBTIERE, AUF DIE DIE PFERDE SCHNELL REAGIEREN MUSSTEN. MODERNE PFERDE UNTERSCHEIDEN SICH VON IHREN VORFAHREN U. A. IN IHRER REAKTION AUF STRESSOREN. SIE WURDEN üBER JAHRHUNDERTE HINWEG SO GEZüCHTET, DASS EIN FüR MENSCHEN SICHERER UMGANG MIT IHNEN MöGLICH IST. DIES REDUZIERTE AUCH IHRE REAKTIONEN AUF ANGSTERZEUGENDE FAKTOREN. DIE STUDIE UNTERSUCHTE, OB PFERDE NOCH IMMER DIE FäHIGKEIT BESITZEN, RECHTZEITIG AUF GEFAHREN DURCH RAUBTI...
Palmieri G, Sanna L, Asole A, Farina V, Bo Minelli L.The origin and course of the collateral sesamoidean (suspensory navicular) ligament of the horse and ass and its attachment to the distal sesamoid bone were studied by means of dissection. Particular attention was given to the topographic relations between this ligament and the deep digital flexor tendon. Numerous sensitive nerve endings are present in this anatomical district. The free and encapsulated nerve endings, displayed by impregnating techniques, are mostly concentrated in the ligament tract connected to the above-named tendon and close to its attachment to the distal sesamoid angle. ...
Forino S, Cameron L, Stones N, Freeman M.The ideal equestrian body image (BI) is a smaller physique and riders feel body shape (BS) influences subjective judge scoring within dressage competitions. The aims were to identify perceptions of equestrian coaches and dressage judges of rider body shape (BS), identify perceptions of appropriate horse-rider matching and establish the impact of BS on perceived rider ability. An online survey (GoogleFormsTM) was shared, respondents (n = 265, coaches = 174 judges = 91) viewed images of twelve riders of different BS (Ectomorph, Mesomorph, and Endomorph) mounted on three horses of different...
Zachar EK, Burgess HJ, Wobeser BK.Fine-needle aspiration (FNA) is commonly used to diagnose skin disease in companion animals, but its use in horses appears to be infrequent. Equine veterinarians in western Canada were surveyed to determine their opinions about FNA and 15 years of diagnostic submissions were used to compare the perceived to actual value of FNA in the diagnosis of skin disease in horses. Practitioners viewed FNA as quick, easy, economical, and minimally invasive. However, most veterinarians rarely chose to use FNA due to a perception that sample quality and diagnostic yield were poor and there was a narrow rang...
Spaas J, Helsen WF, Adriaenssens M, Broeckx S, Duchateau L, Spaas JH.There is general agreement that horses have dichromatic colour vision with similar capabilities to human beings with red-green colour deficiencies. However, whether colour perception has an impact on equine jumping performance and how pronounced the colour stimulus might be for a horse is unknown. The present study investigated the relationship between the colour of the fences (blue or green) and the show jumping performance of 20 horses ridden by two riders using an indoor and outdoor set of green and blue fences. In the indoor arena, significantly more touches and faults were made on blue fe...
Walker N, Cater M, Bourg B, Devall H, Sarver M.Due to the increased awareness of animal welfare issues and sensitized attitudes throughout society, youth animal projects provide a unique opportunity to assess and impact youth understanding and attitudes regarding animal welfare. Animal ethics training is not an uncommon requirement for participants in 4-H livestock programs. However, participants in 4-H horse projects are not universally held to the same standard. The purpose of this study was to assess youth knowledge, attitudes, and confidence in understanding of equine welfare at the 4-H state horse show, as well as to determine the bel...
Ross C, Haussler KK, Kenney JD, Marks D, Bertone JJ, Henneman K, May KJ.Vigorous and prolonged effort is required to gain true mastery of the healing arts. Conventional and complementary medicine have complementary strengths and weaknesses. Like the yin and yang of traditional Chinese medicine, they naturally flow into one another by a process of induction, creating balance. Integrative medicine is the frontier; it is the future. If we are to progress beyond our current understanding and ability to heal, we must work with theoretic models that allow us and our perception to operate "outside the box." For some, this understanding is intuitive. It is through coopera...
Mattila M, Honkanen S, Sjögren T, Piirainen A, Aartolahti E.Interaction has a multidimensional role in equine-facilitated rehabilitation. Unassigned: The aim of this study was to understand rehabilitees' experiences of interaction during equine-facilitated rehabilitation. Unassigned: Six children and four adults with individual diagnoses or reasons to participate in equine-facilitated rehabilitation were included in this qualitative study. Data were collected by interviewing individually the rehabilitees. A phenomenological Spiegelberg's seven-phase meaning analysis was performed to reveal the meanings. Unassigned: Seven meanings were identified: 1) Tr...
Wickens C, Arias Esquivel AM, Hendricks C, Heleski C.Several studies have indicated higher incidence of stereotypic behaviors (STBs) in Thoroughbreds. The aftercare of Off-the-Track Thoroughbreds (OTTBs) has received increased attention in the last decade; however, research on the impact of STBs on placement of OTTBs after their racing career is limited. Thoroughbred Aftercare Alliance (TAA) accredits centers throughout North America that work to rehome OTTBs in a safe, welfare-friendly manner. Although the authors have suspected that having an STB would make OTTBs more challenging to rehome, this hypothesis remains to be empirically tested. The...
McCarthy PH.A description is given of 75 features present in the normal tarsus of the standing horse which are apparent due to visible skin contours overlying them. Depending on whether or not the pelvic limb is supporting full weight or resting, some contours alter their configuration. Therefore the contour of each underlying feature is described separately for each stance of the limb. It is considered that visual inspection and identification of the apparent superficial features of the normal equine tarsus form the basis of orientation and clinical inspection. Furthermore, these features provide referen...
Tauffkirchen E.Neurodevelopmental treatment according to Dr. K. and B. Bobath can be supplemented by hippotherapy. At proper control and guidance, an improvement in posture tone, inhibition of pathological movement patterns, facilitation of normal automatical reactions and the promotion of sensorimotor perceptions is achieved. By adjustment to the swaying movements of the horse, the child feels how to retain straightening alignment, symmetry and balance. By pleasure in this therapy, the child can be motivated to satisfactory cooperation and accepts the therapy horse as its friend. The results of hippotherapy...
Keller P, Hudders L, Decloedt A.Complementary and alternative veterinary medicine (CAVM) is increasingly popular in horses. As CAVM usage could have risks, client-veterinarian communication about CAVM is crucial. Objective: Evaluating equine veterinarians' attitude towards CAVM, their CAVM usage and veterinarian-client communication about CAVM. Methods: Cross-sectional study. Methods: A telephone survey was conducted among equine veterinarians providing ambulatory care on a daily or weekly basis. The first section of the survey included questions about the veterinarians' attitude towards CAVM and their CAVM usage. The second...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the roots of (Rupr. & Maxim.) Maxim. (taiga root tincture) when used as a sensory additive in feed for dogs, cats and horses. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive is safe for dogs, cats and horses at the maximum proposed use level of 460.7, 489.5 and 140.7 mg/kg complete feed, respectively. The additive was considered safe for consumers when used at the proposed conditions of us...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of an essential oil obtained from the oleoresin of Aiton (pine white oil, also known as turpentine oil), when used as a sensory additive in feed and water for drinking for all animal species. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the essential oil under assessment is safe up to the maximum proposed use levels of 35 mg/kg for laying hens, piglets, pigs for fattening, sows, rabbits, salmonids, 50 mg/kg for veal ca...
Ekiri AB, House AM, Krueger TM, Hernandez JA.To assess awareness, perceived relevance, and acceptance of surveillance and infection control practices at a large animal referral hospital among referring veterinarians and clients who sent horses to the facility for veterinary care. Methods: Survey. Methods: 57 referring veterinarians and 594 clients. Methods: A 15-question survey targeting Salmonella enterica as an important pathogen of interest in horses was sent to clients who sent ≥ 1 horse to the University of Florida Large Animal Hospital for veterinary care during July 1, 2007, through July 1, 2011, and to veterinarians who had ref...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Fašmon Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the fruit (pericarps and seeds) of Hook f. (star anise tincture) when used as a sensory feed additive for all animal species. The product is a ■■■■■solution, with a dry matter content of approximately 1.86%. The product contained on average 0.2588% polyphenols (of which 0.0229% were flavonoids, including 0.0036% rutin), anethole (0.018%) and estragole (0.00039%). The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)...
Walker NL, Patout AR, Cater M.Hereditary equine regional derma asthenia (HERDA), an autosomal-recessive trait, found in Quarter Horses, causes abnormal collagen structure. Owing to current breeding practices, 3.5% of registered quarter horses and 28.3% of the cow horse population are heterozygote carriers. Research demonstrated homozygote horses develop hyperextensible skin susceptible to injury and other abnormal tissues containing high fibrillar collagen content. No research exists determining the effects of the disease in heterozygote carriers. Currently, 30% of cutting sires are HERDA carriers, potentially increasing t...
Starke SD, May SA.A large number of lameness indicators have been suggested for the visual equine lameness assessment. However, it remains unknown which of these are commonly used by experts. Twenty-four expert lameness assessors from 10 leading UK institutions viewed 28 video clips of sound and mildly lame horses (median score 2/10). Horses were shown at trot in a straight line (rear and front view) and circle (side view, left and right rein). Eye tracking data were collected at 60Â Hz while participants evaluated each clip. A questionnaire captured contextual information. During assessment on the straight lin...
Harkins JD, Tobin T.Fentanyl and other opioid drugs have their effect in the central nervous system; however, activity at peripheral sites has also been demonstrated. Pain-suppression activity at peripheral sites raises the possibility of skilled individuals producing local anaesthetic effects with small doses of opioid drugs that would be difficult to detect forensically and could be used to affect the outcome of a race. Therefore, the local pain-suppression effect (peripheral nerve inhibition) of fentanyl was tested using an abaxial sesamoid block/hoof withdrawal model. With this model, fentanyl did not produce...
McTigue FE, Mansbridge SC, Pyatt AZ.Equine anthelmintic resistance poses a threat to the health and welfare of horses worldwide. With no new imminent anthelmintic classes, it is vital to decrease the resistance rate and preserve available classes. Traditional indiscriminate anthelmintic use is not synonymous with a strategic control ideology; however, many continue to implement outdated practices. In comparison to livestock farmers, there have been few social science studies examining horse owner behaviours. This study aimed to understand the perceived barriers faced by horse owners and yard managers to adopting a strategic appr...
Palmieri G, Asole A, Panu R, Farina V, Sanna L.A vegetative innervation is described for the first time in this district. On the contrary, the finding of Pacini and pacini-like corpuscles, of Golgi Mazzoni's receptors, of muscle spindles and Golgi's tendon-organs testifies the existence of a sensitive innervation in this anatomical territory. According to Karamanlidis free nervous endings are not present. All the above recorded receptors show the typical structure and can be found isolated, grouped to constitute flower-sprays, organized to form opposito-polar corpuscles or associated to originate pecilomorphic fibers. These two last findin...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of 4-methyl-5-vinylthiazole [15.018] belonging to chemical group 29 (thiazoles, thiophene and thiazoline), when used as sensory additive (flavourings) in feed for all animal species. The FEEDAP Panel concluded that 4-methyl-5-vinylthiazole [15.018] was safe at the maximum proposed use level of 0.5 mg/kg complete feed for veal calves (milk replacer), dogs, salmonids and ornamental fish. For the other species, the calculated safe concentrations in complete feed are: 0.4â€...
