Hoof Temperature Research Articles

Evaluation ofthe hoof's temperature variations depending onlesion presence, measurement points and leg position.

Inorder todetermine the possibility ofusing infrared thermography (IRT) inpreventing lameness indairy cows, the aim ofthis study was toevaluate temperature variations depending onthe lesion presence, measurement points and leg position. The study used about 3000IRT records from 60Holstein cows housed inafree-stall barn. Surface temperature measurements were taken attwo regions ofthe hooves: the region ofthecoronary band, and the region ofthe skin up to2cm above the coronary band. Ahighly significant (P=0.004; 0.006, P<0.01) difference intemperature was observed between healthy and diseased legs atboth measurement points. Additionally, asignificant (P=0.029; 0.037; 0.045; 0.012; 0.018, P<0.05) orhighly significant (P=0.004; 0.006, P<0.01) difference intemperature values between the front and rear legs was established for both measurement points, i.e., the coronary band and the skin. Despite confirming the potential applicability ofinfrared thermography inthedetection oflameness, itis crucial toconsider the significant influences ofthe environmental factors, impurities, and animal-related factors.

Integrated infrared thermography and accelerometer-based behavior logger as a hoof lesion identification tool in dairy cows with various foot diseases under subtropical climates.

Infrared thermography (IRT) can measure a temperature change on the surface of objects, and is widely used as an inflammation or fever detection tool. The objective of this longitudinal study was to investigate the feasibility of detecting hoof lesion cattle using IRT under subtropical climate conditions. The experiment was conducted in two free-stall commercial dairy farms and 502 dairy cows participated between August 2020 and March 2022. Before hoof trimming, the portable IRT was used to measure the maximum temperature of each hoof from three shooting directions, including anterior (hoof coronary band), lateral (hoof lateral coronary band), and posterior (skin between heel and bulbs). In order to evaluate the effect of hoof lesions on the behavior of dairy cows, we also collected behavior data by automated accelerometers. The results indicated that the temperature of hooves with lesions was significantly higher than that of sound hooves in hot environments regardless of the shooting directions (P < 0.0001). In all of three shooting directions, the maximum temperature of feet with severe lesion was significantly higher than those of feet with mild lesion and sound feet (P < 0.05). Cows with lesion feet had lower daily activity and feeding time than sound cows before clinical diagnosis (P < 0.05). Furthermore, we used thresholds of both anterior hoof temperature at 32.05 °C and average daily activity at 410.5 (arbitrary unit/d) as a lame cow detecting tool. The agreement of this integrated tool reached 75% with clinical diagnosis, indicating that this integrated approach may be feasible for practice in dairy farm. In conclusion, IRT has the potential to be used as a hoof lesion detecting tool under subtropical climate conditions when using sound hoof temperature as reference points, and detection precision can be improved when IRT integrated with automated accelerometers as a lame cow detecting tool.

Seasonal Variations of Haematological and Biochemical Parameters Associated with Potential Laminitis in Apparently Healthy Horses

Early detection of laminitis in horses is valuable as it provides information that can be used as a basis for advice to trainers of race and performance horses. The study was aimed to determine the seasonal variations in haematological and biochemical parameters of horses developing laminitis at Polo Club Port Harcourt, River State, Nigeria. A total of 18 horses were sampled during the dry season (February) and rainy season (July). The horses sampled were aged between 3 and 8 years. The hoof temperature, weight, packed cell volume (PCV), red blood cell (RBC) count, hemoglobin (Hb) concentration, total and differential leucocyte counts, glucose level and fibrinogen concentration were determined using standard methods. The mean hoof temperature of the horses was 36.1± 0.11oC and 35.6 ± 0.2 oC during the dry and rainy season respectively. The mean body weight of the horses was 323 ± 8.90 kg in dry season while that of rainy season was 330 ± 11.0 kg. Glucose concentration during the dry season (71.6 ± 1.5 dl/mg) was significantly lower (P ˂ 0.05) than that obtained during the rainy season (91.7 ± 1.9 dl/mg). Furthermore, the PCV, RBC count and Hb concentration were significantly higher (P ˂ 0.05) in the rainy season than the corresponding parameters in the dry season. Similarly, the total leucocyte, neutrophil and lymphocyte counts were significantly higher (P ˂ 0.05) during the rainy season than the dry season. It was concluded that variations on the parameters determined may aid to identify early warning signs of laminitis.

РАЗРАБОТКА МАТЕМАТИЧЕСКОЙ МОДЕЛИ ОПРЕДЕЛЕНИЯ СОСТОЯНИЯ КОПЫТ КРУПНОГО РОГАТОГО СКОТА НА ОСНОВЕ ПРОФИЛЕЙ ТЕРМОГРАММ

Inflammation in the cow hooves leads to a decrease in milk yield and may cause early culling of animals. Early diagnosis of the disease provides a reduction in the cost of treatment, allows maintaining the health and milk production of animals. The use of infrared thermography to determine the temperature of cattle limbs is a fast and non-invasive way to obtain reliable information about the animal’s health. To develop a mathematical model for determining the state of cattle limbs based on the profiles of hoof thermograms, the authors processed the data of 20 cows of the Yaroslavl breed, which are on the 2nd-4th lactation, with a lactation period ranging between months 1 and 7. The data array was formed using a Guide C400M thermal imager in the IR range. Data on the physiological state of cattle were entered into the Matlab R2019b program. For color gradation, the RGB color space was selected. The presented mathematical model for processing the profile of thermograms makes it possible to collect information on the spatial and temporal dynamics of cattle hoof temperatures by thermophysiological categories. When determining the state of the limbs, the areas of spatio-temporal distribution of temperature in the hoof are identified in the form of a transformed segmentation profile of the thermogram into a matrix, where RGB is assigned to the pixels from each fragment of the area, indicating a certain temperature. Exceeding the values R &gt; 230, G &gt; 103, B &lt; 0 symbolizes a temperature above 40°C and means the presence of inflammation in the hoof. The developed algorithm will allow a farm veterinarian to automatically receive information about the state of the hooves of each cow, determine the focus of inflammation, its location, and diagnose the disease.

The Effect of Horse Shoeing with Egg Bar Shoes and Shoes with Wedge Pads on the Results of Thermal Imaging of the Equine Distal Limb.

Simple SummaryThermography is a non-invasive and contact-free imaging method that measures temperature on the surface of the body and determines temperature distribution across the examined surface. The aim of this study was to determine the effect of horse shoeing with egg bar shoes and shoes with wedge pads on hoof temperature measured by thermography. The authors decided to use egg bar shoes and shoes with wedge pads as they are commonly used in the treatment of navicular syndrome in horses. This study was conducted on 16 client-owned warmblood horses. The horses were directed for magnetic resonance imaging (MRI) according to unilateral front limb lameness, specifically associated with the hoof. For thermographic analysis, we took into consideration only one limb that was not lame and that showed no radiological changes. After the application of egg bar shoes, the temperature decreased on the palmar surface of the hoof. After shoeing with wedge pads, the temperature decreased in the dorsal and palmar views. Thermography, despite its great usefulness, is only an indirect method of assessing the blood supply in a given area, so we cannot uncritically conclude about the harmfulness of shoeing.The presented manuscript provides reference for practitioners when measuring normal hoof temperature, as well as controlling the temperature after shoeing with particular shoes. The aim of this study was to determine the effect of horse shoeing with egg bar shoes and shoes with wedge pads on hoof temperature measured by thermography. This was a prospective study conducted on 16 horses. The horses were divided into two groups: horses from group 1 were shod with egg bar shoes, while horses from group 2 were shod with shoes with wedge pads. Thermographic examination was performed below the metacarpophalangeal joint before and one month after shoeing. After shoeing with egg bar shoes, there was a decrease in the median of the minimal temperature in the palmar view. After shoeing with wedge pads, thermography revealed decreased hoof temperature in the dorsal and palmar views. Horse shoes may have a negative impact on the blood circulation and metabolism within the distal part of the limb; however, our study found this only to a minor extent.

Relationship between management practices and calf welfare in mid- country dairy farms in Sri Lanka

There is an emerging trend towards appreciating welfare of farm animals in Sri Lanka. A survey was conducted covering 182 farms in Mid-Country, Sri Lanka to identify management-related risk factors that may affect welfare of dairy calves. A total of 217 calves were monitored where majority were Jersey (54.4%) and Friesian (43.9%) crosses. The management-related risk factors identified include, not practicing naval disinfection for new-borns (100%), not using calving pens (100%), absence of calf pen (96.2%), dam-fed colostrum (99.5%), high mortality (28.0%), high prevalence of hock wounds (83.4%) and diseases (80.2%). Concrete/cement was the prominent flooring category (90.1%) which causes unfriendly footing as indicated by hoof damageable (45.6%), slippery (75.8%), and unclean (40.7%) floor conditions. The hoof damageable floors considerably increased hoof temperature (P 65 years). Welfare of male calves was satisfied with appropriate weaning age (3.8+1.4 months), concentrate supplement (0.55+0.25 kg), attending to health problems (96.5%) and selling after six months of age (89.6%). However, both female and male calves were under weight for their corresponding age. The findings emphasized that increasing the awareness on appropriate calf management practices is needed for achieving better results in raising calves into well-grown cattle.

PSIII-14 Infrared thermography as a tool to detect inflammation in feedlot lambs with footrot

Abstract Infrared thermography (IRT) has been used as a non-invasive tool to detect inflammatory processes associated with disease in livestock. The aim of this study was to evaluate IRT as a tool to compare healthy and footrot (FR) affected hooves in feedlot lambs with varying degrees of lameness over two seasons. A total of 106 lame lambs with footrot from a feedlot in Alberta were individually categorized according to a 3-point locomotion scale [1 = mild (n = 7), 2 = moderate (n = 46) and 3 = severe lameness (n = 53)] during the summer (n = 39) and fall (n = 68) of 2018. All lambs were physically examined once by two experienced observers to determine if the lamb had footrot. IRT images of the interdigital space were used to obtain the maximum hoof temperature (MHT) of both FR affected as well as healthy (CT) hooves within the same animal. Generalized linear mixed models (SAS PROC GLIMMIX) were performed separately for each season and diagnosis and included locomotion score as a fixed effect and ambient temperature as a co-variate. Predicted means were compared using the limits at 95% of confidence. Overall, greater MHT (P &amp;lt; 0.05) were observed for FR affected compared to unaffected hooves for lambs categorized as moderately and severely lame, within each season. However, no differences (P &amp;gt; 0.05) in MHT were observed for lambs categorized as mildly lame, likely due to the small number of lambs having a locomotion score of 1. Under the conditions of this study, thermal images can be effectively used as a tool to distinguish footrot affected hooves in feedlot lambs with moderate and severe lameness. Further studies should be conducted with more lambs with a locomotion score of 1 to assess the relationship between mild lameness, IRT, and footrot diagnosis.

Can changes in hoof wall temperature and digital pulse pressure be used to predict laminitis onset?

PICO question&#x0D; In horses and ponies at risk of laminitis, does the use of hoof wall temperature and digital pulse pressure as diagnostic techniques for acute laminitis provide a method of detecting acute laminitis in the prodromal stage?&#x0D; Clinical bottom line&#x0D; &#x0D; A palpable bilateral increase in forelimb hoof temperature maintained for longer than half a day may indicate that the horse is 18–­24 hours from acute laminitis onset.&#x0D; A period of increased digital pulse may also be expected up to 11 hours prior to onset.&#x0D; Further studies using larger and more representative cohorts are required to confirm the accuracy of the times at which such changes can be expected.&#x0D; &#x0D; &#x0D;

Influence of trimming and shoeing on hoof temperature and digital cushion thickness in mature horses

Influence of trimming and shoeing on hoof temperature and digital cushion thickness in mature horses

Infrared thermography as a tool to detect hoof lesions in sheep

Lameness has a major negative impact on sheep production. The objective of this study was to 1) quantify the repeatability of sheep hoof temperatures estimated using infrared thermography (IRT); 2) determine the relationship between ambient temperature, sheep hoof temperature, and sheep hoof health status; and 3) validate the use of IRT to detect infection in sheep hooves. Three experiments (a repeatability, exploratory, and validation experiment) were conducted over 10 distinct nonconsecutive days. In the repeatability experiment, 30 replicate thermal images were captured from each of the front and back hooves of nine ewes on a single day. In the exploratory experiment, hoof lesion scores, locomotion scores, and hoof thermal images were recorded every day from the same cohort of 18 healthy ewes in addition to a group of lame ewes, which ranged from one to nine ewes on each day. Hoof lesion and locomotion scores were blindly recorded by three independent operators. In the validation experiment, all of the same procedures from the exploratory experiment were applied to a new cohort of 40 ewes across 2 d. The maximum and average temperature of each hoof was extracted from the thermal images. Repeatability of IRT measurements was assessed by partitioning the variance because of ewe and error using mixed models. The relationship between ambient temperature, hoof temperature, and hoof health status was quantified using mixed models. The percentage of hooves correctly classified as healthy (i.e., specificity) and infected (i.e., sensitivity) was calculated for a range of temperature thresholds. Results showed that a small-to-moderate proportion of the IRT-estimated temperature variability in a given hoof was due to error (1.6% to 20.7%). A large temperature difference (8.5 °C) between healthy and infected hooves was also detected. The maximum temperature of infected hooves was unaffected by ambient temperature (P > 0.05), whereas the temperature of healthy hooves was associated with ambient temperature. The best sensitivity (92%) and specificity (91%) results in the exploratory experiment were observed when infected hooves were defined as having a maximum hoof temperature ≥9 °C above the average of the five coldest hooves in the flock on that day. When the same threshold was applied to the validation dataset, a sensitivity of 77% and specificity of 78% was achieved, indicating that IRT could have the potential to detect infection in sheep hooves.

The Effects of Hydroponic Wheat Fodder on Fecal Metabolites in Equines

There are currently no published data on the effects of fodder in horses. Eight Quarter Horse mares were randomly assigned to one of two diets: control horses received 2% of their body weight (BW) in hay (dry matter [DM]); treatment (TRT) horses received 1% of their BW in hay (DM) and 2% of BW in fresh wheat fodder (as fed [AF]) divided into two equal feedings offered at 0600 and 1800 for 5 weeks. Body weight, hoof temperature, and fecal samples were collected once weekly and orts were collected after every meal. Fecal samples were analyzed for pH, ammonia, volatile fatty acid, DM, ash, neutral detergent fiber, acid detergent fiber, nitrogen, crude protein, and ether extract values. Data were analyzed as a completely randomized design comparing weekly means using PROC MIXED of SAS (v. 9.4) and significance was established at P < .05. There was no effect of TRT on BW or hoof temperatures (P > .05). Fecal pH was lower (P ≤ .01) and isobutyric acid was higher (P ≤ .05) for horses receiving fodder and hay as compared with horses receiving hay alone. Dry matter intake (DMI) was also significantly higher (P < .0001) for horses consuming hay alone as compared with horses on the fodder with hay diet. These results indicate that using fodder affects fecal metabolites associated with digestion, and horses were able to maintain BW even with lower DMI.

The effects of parity and stage of lactation on hoof temperature of dairy cows using a thermovision camera

The aim of the study was to determine the effects of the parity and stage of lactation on tissue changes of the dairy cows’ hooves (Holstein; n = 130) and their early detection using the thermovision camera. The parity did not have a significant impact on temperature of the coronary band (CB) for the cows with lesions, although the stage of lactation did (P<0.0001) between first and second parity. For the cows without lesions the parity and stage of lactation had a significant (P<0.01; P<0.0001) influence on the temperature of the CB. The obtained results indicate that stage of lactation has a stronger influence on temperature of coronary band than parity. This knowledge is crucial when using thermovision cameras for detection of the cows which are at risk of lameness.

The impact of floor type on lameness and hoof health of dairy origin bulls

This study aimed to evaluate the effect of using different floor types to accommodate growing and finishing beef cattle on lameness. In all, 80 dairy origin bulls were blocked according to live weight and breed into 20 groups, and randomly allocated within groups to one of four treatments. The floor types studied were fully slatted flooring throughout the entire experimental period (CS); fully slatted flooring covered with rubber strips throughout the entire experimental period (RS); fully slatted flooring during the growing period and then moved to a solid floor covered with straw bedding during the finishing period (CS-S) and fully slatted flooring during the growing period and then moved to fully slatted flooring covered with rubber strips during the finishing period (CS-RS). The total duration of the study was 204 days. The first 101 days was defined as the growing period, with the remainder of the study defined as the finishing period. During the growing period, there was a tendency for bulls accommodated on CS to have a higher locomotion score compared with those accommodated on RS (P=0.059). However, floor type had no significant effect on locomotion score during the finishing period. There was also no significant effect of floor type on digital dermatitis during both the growing or finishing period. Floor type had no significant effect on swelling at the leg joints at the end of the finishing period. Bulls accommodated on RS had the least probability of bruised soles during both the growing and finishing period (P<0.01). Growing bulls accommodated on CS had significantly greater front heel height net growth compared with those accommodated on RS (P<0.05). However, bulls accommodated on RS had a tendency to have greater front toe net growth compared with those accommodated on CS (P=0.087). Finishing bulls accommodated on CS-RS had the greatest front toe net growth (P<0.001). Heel height net growth was greatest in bulls accommodated on CS-S (P<0.001). Floor type had no significant effect on mean maximum hoof temperature during the growing period. Finishing bulls accommodated on CS-S had a significantly lower mean maximum hoof temperature compared with those accommodated on any other floor type (P<0.001). The study concluded that rubber flooring is a suitable alternative to fully slatted flooring, reducing the prevalence of bruised soles. Despite greater toe net growth in bulls accommodated on rubber flooring, there was no effect of floor type on locomotion score, suggesting that increased toe net growth does not adversely affect walking ability. In addition, although mean maximum hoof temperature was lowest in bulls accommodated on straw bedding, there was no evidence to suggest this is indicative of improved hoof health.

Assessment of horse owners' ability to recognise equine laminitis: A cross-sectional study of 93 veterinary diagnosed cases in Great Britain.

Use of owner-reported data could further epidemiological knowledge of equine laminitis. However, owner recognition of laminitis has not previously been assessed. The primary objective was to establish whether cases of owner-suspected laminitis would be confirmed as laminitis by the attending veterinary surgeon. Secondary objectives were to compare owner- and veterinary-reported information from veterinary-confirmed cases of equine laminitis. Cross-sectional study. Twenty-five British veterinary practices were invited to submit laminitis reporting forms (LRFs) for active laminitis cases attended between January 2014 and October 2015; detailing 27 clinical signs, 5 underlying conditions and 7 risk factors associated with laminitis. Owners were invited to independently complete a modified LRF if reason for the veterinary visit was suspicion of laminitis. Differences between paired veterinary and owner LRFs, and between cases where owners did and did not recognise laminitis, were assessed using McNemar's and Fisher's Exact tests, respectively. Veterinary LRFs were received for 93 veterinary-diagnosed laminitis cases. All 51 owner-suspected cases were confirmed by veterinary diagnosis, with the remaining 42 (45.2%) not recognised as laminitis by owners. Undefined lameness, foot abscesses, colic and stiffness were common reasons for owner-requested veterinary visits in owner-unrecognised cases. 'Divergent growth rings' (prevalence difference: +27.3%, P=0.01) and 'breed type' (prevalence difference: +21.2%, P=0.04) were more commonly reported by veterinary surgeons in owner-recognised compared to owner-unrecognised cases. 'Difficulty turning', 'shifting weight' and risk factor 'body condition' were more frequently reported by veterinary surgeons whilst 'increased hoof temperature' was reported more frequently by owners. The limited clinical data restricted statistical inferences regarding the secondary objectives. All owner-suspected laminitis cases were confirmed upon veterinary examination, showing validity for the inclusion of owner-reported cases in future epidemiological studies. However, failure of laminitis recognition by owners highlights further need for evidence-based education to ensure early disease detection.

Temporal, spatial, inter-, and intra-cow repeatability of thermal imaging.

The objective of the present study was to quantify the within- and between-cow, operator, and day variances of various descriptive temperature parameters from different anatomical areas captured using thermal images on Holstein-Friesian cows. Three experiments were undertaken. In Exp. 1, 30 images were captured by a single operator of each of the eye, hoof, and udder from each of 45 cows; in Exp. 2, three different operators captured eye and hoof images from 12 cows; and in Exp. 3, eye and hoof images were captured by a single operator from 8 cows over a 5-d period. Maximum, minimum, and average descriptive temperature parameters were manually extracted from all thermal images within the study. The repeatability of thermal imaging and the number of replicates required to obtain a certain level of precision was evaluated. Precision was defined as the 95% CI range within which the (average of the) measured temperature(s) was expected to lie relative to the gold standard; the gold standard temperature of an entity in this study was the average of 30 temperature measurements. The partitioning of the variance into error, cow, operator, and day variances was undertaken using mixed models. Results show that the most repeatable anatomical area was the hoof, with the total proportion of variation attributed to the cow ranging from 91.37 to 99.28%. The descriptive temperature parameter with the lowest error variance was the maximum temperature for the eye (0.11°C) and udder (0.03°C) images, whereas the average temperature was the most precise descriptive temperature parameter for hoof (0.08°C) images. Additionally, no significant between-day variance was detected for maximum hoof temperatures. Results from the present study indicate that when the most precise descriptive temperature parameter is used, measurements made using infrared thermography can achieve a high level of precision in an agricultural environment if at least 3 replicate images of the eye, udder, or hooves of cows are captured and averaged. Additionally, when multiple operators capture thermal images in an agricultural environment, a standard operating procedure should be put in place to minimize the variance between operators.

Thermographic assessment of hoof temperature in dairy cows with different mobility scores

The aim of this study was to determine if temperature varies in hooves of cows with different mobility scores (MS) using infrared thermography. A total of 120 Friesian, Kiwi cross and Jersey cows were used, which were grouped according to their mobility scores (MS 0–3: n=30 in each MS group). Animals were introduced in a crush for clinical examination and then thermograms from the anterior, posterior, lateral and sole views were taken. Thermogram analysis of different anatomical hoof zones was performed. The temperatures obtained for different views were: anterior (20.8°C–24.7°C), posterior (20.7°C–25.9°C), lateral (19.2°C–22.4°C) and sole (16.5°C–20.1°C). The observed zonal temperature for each view was independent and similar for all MS, however significant differences between cows with MS 0 and MS 3 are described. For this purpose, a threshold temperature for the sole view>16.6°C was set allowing the identification of 83% cows with MS 1 and 60% those cows with MS 0. The best trade off was obtained for the posterior view, with a threshold temperature>23.5°C, allowing the identification ~70% of both cows with MS 0 and MS 3. Using IRT we were able to show that cows with MS 3 had higher hoof temperatures compared to cows with MS 0 in the anterior, posterior and sole views. None of the evaluated thermographic views showed significant temperatures changes for cows with MS 1 and MS 2. IRT is not a practical method to be used on farm and does not contribute to early lameness detection.

Assessing the Association Between Hoof Thermography and Hoof Doppler Ultrasonography for the Diagnosis of Lameness in Horses

The objectives of this study were to assess the correlation between hoof surface temperature and ultrasonographic measurements of digital blood vessels in horses and to evaluate the measurements' potential as predictors for clinical lameness. Twelve 3-year-old American Quarter Horses, 6 geldings and 6 mares, with average initial body weight of 459 ± 31 kg were used. On days 0, 30, 60, and 90 of the study, horses were weighed and subjected to clinical lameness examinations. Doppler ultrasonography was used to measure diameter of the medial palmar artery in the distal left forelimb and velocity of blood flow through that artery, starting at 60 minutes after morning feeding and repeated at 30-minute intervals. Temperature measurements on the hoof were collected at 15-minute intervals beginning 75 minutes after feeding, using a digital thermographic camera. A series of bivariate linear mixed models were fitted to estimate the correlation between Doppler and temperature measurements. The within-horse and between-horse correlations between hoof surface temperature and velocity of blood flow in the distal limb through the medial palmar artery was estimated at 0.40 (P > .50) and 0.99 (P < .001), respectively. These results indicate that at the horse level, the correlation between hoof temperature and velocity of blood flow in the distal limb was very high but that the within-horse correlation was not significantly different from 0. Velocity of blood flow at 60 minutes after feeding improved model fit to the lameness data, so it was included as a model predictor for lameness.

The impact of endophyte-infected fescue consumption on digital circulation and lameness in the distal thoracic limb of the horse12

This experiment was conducted to evaluate if consumption of endophyte-infected fescue alters digital circulation in the distal thoracic limb of the horse and to assess if soundness of the hooves of horses is affected by consumption of endophyte-infected fescue. Twelve American Quarter Horses (mean initial BW 459 ± 31 kg), 6 mares and 6 geldings, were used in this 90-d study that comprised high-endophyte (E+) and low-endophyte (E-) treatment groups. Fescue seed was integrated into the E+ diet at a rate sufficient to bring total ergovaline to 200 μg/kg, and endophyte-free fescue seed was incorporated into the E- diet from d 0 to 90. From d 30 to 60, native prairie hay was replaced with high- or low-endophyte fescue hay, bringing total dietary ergovaline to 280 μg/kg (E+) and 18 μg/kg (E-). From d 61 to 90, fescue seed was ground to decrease particle size. On d 0, 30, 60, and 90, Doppler ultrasonography and thermographic imaging were used to measure the diam. of the medial palmar artery, velocity of blood flow, and surface temperature of the hoof as indicators of digital circulation. Lameness examinations were conducted on the same days. There were no consistent treatment differences observed when evaluating measurements of digital circulation. On d 60, horses in the E+ treatment group showed increased hoof sensitivity in the left limb (P = 0.02). These horses tended to have increased hoof sensitivity when both thoracic limbs were averaged (P = 0.06), and they demonstrated increased lameness during longeing (P = 0.08). Data indicated that mares may have increased digital circulation, regardless of treatment, compared with geldings (P ≤ 0.05). Heavier horses also had greater arterial diam., velocity of blood flow, and hoof temperature than lighter BW horses (P ≤ 0.05) on d 30, 60, and 90 at time points that ranged from 90 to 180 min after feeding. Although horses consuming the E+ diet demonstrated increased lameness, especially on d 60, compared with horses consuming the E- diet, the measures of digital circulation did not support the hypothesis that digital circulation was reduced. Because of observed lameness issues, limiting the access of horses to endophyte-infected fescue may be prudent.

THE INFLUENCE OF TEMPERATURE AND AGE ON THE T1 RELAXATION TIME OF THE EQUINE DISTAL LIMB

The extent of fat suppression using short tau inversion recovery (STIR) imaging is variable between horses. Our aim was to determine if patient's age and/or hoof temperature have an influence on the T(1) relaxation time of bone marrow in the equine distal limb, thereby affecting the suppression of fat signal. Magnetic resonance imaging was conducted on standing horses and cadaver samples using a low-field magnet (0.27 T). The hoof temperature was measured at the lateral side of the coronary band. A modified inversion recovery fast spin-echo (IR-FSE) sequence was used to measure the signal intensity for a range of inversion times (TIs) at six different regions of interest (ROI): (1) distal aspect of the proximal phalanx, (2) proximal aspect of the middle phalanx, (3) distal aspect of the middle phalanx, (4) navicular bone, (5) proximal aspect of the distal phalanx, and (6) distal aspect of the distal phalanx. The T(1) of the bone marrow in the equine distal limb was calculated from the results and was found to increase by 3.13 ± 0.08 (SE) ms/°C. There was no significant effect of age (2-16 years) but the T(1) values measured from the limbs of young (< 1 year) animals were considerably longer (32.6 ± 1.7 (SE) ms). Similar effects of temperature and age were found for all measured ROIs but there were significant differences in the mean values of T(1) , ranging from +7.7 (distal aspect of the distal phalanx) to -13.2 ms (distal aspect of the proximal phalanx).

Normal variation in thermal radiated temperature in cattle: implications for foot-and-mouth disease detection

BackgroundThermal imagers have been used in a number of disciplines to record animal surface temperatures and as a result detect temperature distributions and abnormalities requiring a particular course of action. Some work, with animals infected with foot-and-mouth disease virus, has suggested that the technique might be used to identify animals in the early stages of disease. In this study, images of 19 healthy cattle have been taken over an extended period to determine hoof and especially coronary band temperatures (a common site for the development of FMD lesions) and eye temperatures (as a surrogate for core body temperature) and to examine how these vary with time and ambient conditions.ResultsThe results showed that under UK conditions an animal's hoof temperature varied from 10°C to 36°C and was primarily influenced by the ambient temperature and the animal's activity immediately prior to measurement. Eye temperatures were not affected by ambient temperature and are a useful indicator of core body temperature.ConclusionsGiven the variation in temperature of the hooves of normal animals under various environmental conditions the use of a single threshold hoof temperature will be at best a modest predictive indicator of early FMD, even if ambient temperature is factored into the evaluation.