Evaluation of an accelerometer for at-home monitoring of spontaneous activity in dogs

OBJECTIVE:To determine the correlation between activity as measured by an accelerometer and videographic measurements of movement and mobility in healthy dogs. ANIMALS: 4 healthy dogs. PROCEDURES: After determination that accelerometers had good agreement, 5 identical accelerometers were used simultaneously to test their output at 8 locations (rotated among collar, vest, and forelimb stocking locations) on each dog. Movement and mobility for each dog were recorded continuously with a computerized videography system for 7-hour sessions on 4 consecutive days. Accelerometer values were combined into 439 fifteen-minute intervals and compared with 3 videographic measurements of movement and mobility (distance traveled, time spent walking > 20 cm/s, and time spent changing position by > 12% of 2-dimensional surface area during 1.5 seconds). RESULTS: 96% of values compared between the most discordant pair of accelerometers were within 2 SDs of the mean value from all 5 accelerometers. All mounting locations provided acceptable correlation with videographic measurements of movement and mobility, and the ventral portion of the collar was determined to be the most convenient location. CONCLUSIONS AND CLINICAL RELEVANCE: Use of an accelerometer was adequate for at-home activity monitoring, an important end point in clinical trials of treatment for chronic disease, and provided information about daily activity that is unattainable by other methods.     

Accelerometer validity and placement for detection of changes in physical activity in dogs under controlled conditions on a treadmill

The objective of the research was to determine the optimal location and method of attachment for accelerometer-based motion sensors, and to validate their ability to differentiate rest and increases in speed in healthy dogs moving on a treadmill. Two accelerometers were placed on a harness between the scapulae of dogs with one in a pouch and one directly attached to the harness. Two additional accelerometers were placed (pouched and not pouched) ventrally on the dog's collar. Data were recorded in 1s epochs with dogs moving in stages lasting 3 min each on a treadmill: (1) at rest, lateral recumbency, (2) treadmill at 0% slope, 3 km/h, (3) treadmill at 0% slope, 5 km/h, (4) treadmill at 0% slope, 7 km/h, (5) treadmill at 5% slope, 5 km/h, and (6) treadmill at 5% slope, 7 km/h. Only the harness with the accelerometer in a pouch along the dorsal midline yielded statistically significant increases (P<0.05) in vector magnitude as walking speed of the dogs increased (5-7 km/h) while on the treadmill. Statistically significant increases in vector magnitude were detected in the dogs as the walking speed increased from 5 to 7 km/h, however, changes in vector magnitude were not detected when activity intensity was increased as a result of walking up a 5% grade. Accelerometers are a valid and objective tool able to discriminate between and monitor different levels of activity in dogs in terms of speed of movement but not in energy expenditure that occurs with movement up hill.     

Evaluation of a Commercial Activity Monitor for Determining Step Counts in Horses

Monitoring activity level has become popular in people and animals. In the horse, these monitors may be helpful for the detection of disease, monitor limb loading after surgery, and assist in rehabilitation. The objective of this study was to evaluate the accuracy of a commercial activity monitor (AM) (FitBit Zip) in horses. In Part 1, four stalled horses had five AMs placed (head, chest, withers, and left forelimb and hindlimbs) with stride length setting of 60.96 cm and were monitored for 24 hours with AM and video. In Part 2, four stalled horses had two AMs placed (left forelimb and hindlimbs) with stride length setting of 30.48 cm and were monitored for 24 hours with AM and video. In Part 3, three horses with two AMs (left forelimb and hindlimbs) had step data collected at the walk and trot in hand by AM and video. AM and video data were compared using Pearson’s correlation coefficients and by calculating AM to video step count ratios. In Part 1, there was considerable movement of AMs at the chest and withers, but head and limb mounted AMs were more secure. In Part 2, video and AM activity counts were moderate to high for forelimb and hindlimbs with R² values of 0.82 and 0.74, respectively. From Part 3, AMs mounted on either forelimb or hindlimbs approximately doubled the step counts compared to the video. While this AM did not accurately count steps, it may be able to provide general information on activity level in the stalled horses.     

A comparison of uniaxial and triaxial accelerometers for the assessment of physical activity in dogs

The present study compares the outputs of uniaxial accelerometer (UA) and triaxial accelerometer (TA) to determine whether UAs can be used instead of TAs in estimating physical activity (PA) in domestic dogs (N = 79). The PA of the dogs was measured simultaneously by a UA and a TA attached to regular collars under 3 different conditions: unstructured activity in the kennels (kennel activity); and 2 structured on-lead activities of different intensities on a designated pathway (walking and trotting). The study finds that UA consistently detected significantly more steps. Kennel activity showed the largest differences between the accelerometers, and trotting showed the least. Dogs in the heaviest body weight category showed the best correlation between the devices and the least differences between the accelerometers across the 3 activities. The limits of agreement were wide in all activities. Significantly higher agreements were associated with lower step counts in kennel activity and higher step counts in walking and trotting. The results show that these 2 types of accelerometers cannot be used interchangeably. Confounding factors, such as body weight, must be considered in future analysis of accelerometer outputs and selection of devices for different contexts. Optimal interpretation of objectively measured PA is paramount in supporting future dog fitness, health, and welfare studies.     

Monitoring distances travelled by horses using GPS tracking collars

Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8–16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled.     

Dairy cattle behavior classifications based on decision tree learning using 3‐axis neck‐mounted accelerometers

Demand has been increasing recently for an automated monitoring system of animal behavior as a tool for the management of livestock animals. This study investigated the association between the behavior of dairy cattle and the acceleration data collected using three‐axis neck‐mounted accelerometers, as well as the feasibility of improving the precision of behavior classifications through machine learning. In total 38 Holstein dairy cows were used, and kept in four different farms. A logger was mounted to each collar to obtain acceleration data for calculating the activity level and variations. At the same time the behavior of the cattle was observed visually. Characteristic acceleration waves were recorded for eating, rumination, and lying, respectively; and the activity level and variations were significantly different among these behaviors (p < 0.01). Decision tree learning was performed on the data set from Farm A and validated its precision; which proved to be 99.2% in cross‐validation, and 100% in test data sets from Farms B to D. This study showed that highly precise classifications for eating, rumination, and lying is possible by using decision tree learning to calculate the activity level and variations of cattle based on the data obtained by three‐axis accelerometers mounted to a collar.     

Validity, practical utility and reliability of Actigraph accelerometry for the measurement of habitual physical activity in dogs

Objectives : To test the validity, practical utility, and reliability of the Actigraph GT3‐X accelerometer for measurement of habitual physical activity in pet dogs. Methods : In the validation study, 30 dogs wore the accelerometer for 1 day while being filmed. Accelerometer and film were synchronised and 10‐minute periods of the filmed records were extracted with dogs in continuous periods of sedentary behaviour, light intensity physical activity indoors, light to moderate intensity physical activity outdoors and vigorous physical activity outdoors. For the ‐practical utility and reliability studies, 20 dogs wore the GT3‐X accelerometers for 1 week: practical utility was quantified as data loss and was also assessed by owner questionnaire; reliability was ‐determined by 2 to 7 days of monitoring using the Spearman–Brown prophecy formula. Results : In the validation study, accelerometry output differed significantly between activity intensities (Friedman test, P<0·01). In the practical utility study, no data were lost from any dogs and dog ‐owners reported that accelerometry was well tolerated. Reliability of accelerometry output was high: for 3 days of wear, it was 91% [95% confidence interval (CI) 82 to 96] and for 7 days of wear, it was 94% (CI 88 to 97). Clinical Significance : The GT3‐X accelerometer is valid, practical and reliable for the measurement of habitual physical activity in dogs.     

Use and perception of collars for companion cats in New Zealand

AIMS: To investigate the use and utility of collars for companion cats in New Zealand, and to explore public perception of collar use.

METHODS: An online questionnaire was distributed using emails and social media to members of the general public in New Zealand. The questionnaire collected details of respondents, cat ownership status, and responses to a number of questions regarding collar use in cats.

RESULTS: A total of 511 responses were collected. Of these, 393/511 (76.9%) reported owning ≥1 cat at the time of the survey, and 141/393 (35.9%) stated that ≥1 of their cats wore collars and 211/393 (53.7%) had ≥1 of their cats micro-chipped. Of the respondents with a pet cat, 351/393 (89.3%) allowed their cats some outdoor access. Respondents mainly used collars for identification and to reduce predation. Reasons for not using collars included cat intolerance of collars, repeated collar loss and concern over collar safety. Differences were found between cat owners and non-owners regarding whether they agreed that cats were important for pest control (43 vs. 25%, p<0.001); that not all cats will tolerate collars (81 vs. 64%, p<0.001); that cats should be kept indoors at night (37 vs. 58%, p<0.001); or disagreed that well fed cats will not catch birds (60 vs. 70%, p=0.04); and disagreed that a cat without a collar was likely to be a stray (85 vs. 76%, p<0.001). Respondents most trusted veterinarians and the Society for the Prevention of Cruelty to Animals as sources of pet care information.

CONCLUSIONS: Collar use within this sample of cat owners in New Zealand appeared to be low, with more using microchips for identification. The majority of cat owners in this study indicated their cats had some outdoor access, with collars being used for cat identification and to reduce hunting behaviour. Significant differences existed in opinions on cat management between cat owners and non-owners in this study. It should be noted that this preliminary exploration was based on a self-selected group of respondents and so results and conclusions cannot be extrapolated to the wider population.

RELEVANCE: As the most trusted source of information about pet care, an enhanced understanding of cat ownership and management may be of use to veterinarians to promote responsible pet ownership and to develop national policies and practices to improve cat welfare.     

Effective treatment and control of biting lice, Felicola subrostratus (Nitzsch in Burmeister, 1838), on cats using fipronil formulations

The efficacy of 0.25% fipronil spray (Frontline Spray, Merial), 10% fipronil spot-on (Frontline Spot-on for Cats, Merial) and 10% fipronil/12% (S)-methoprene (Frontline Plus for Cats, Merial) against the biting louse Felicola subrostratus on cats was assessed and confirmed under laboratory conditions. A field study evaluated the efficacy of a single topical application of Frontline Spray, and spot-on against the parasite on cats. In the laboratory studies, animals were allocated based on pre-treatment louse counts to the treatment groups: (1) untreated control and (2) 10% fipronil spot-on in the exploratory study or (1) untreated control, (2) 0.25% fipronil spray, at 6 ml/kg; (3) 10% fipronil spot-on as per label and (4) 10% fipronil/12% (S)-methoprene as per label in the confirmation study. Cats in treatment groups 2-4 were treated twice topically on Days 0 and 28. No live F. subrostratus were found on cats treated with fipronil formulations at any post-treatment examination. The difference from controls was significant (P < 0.01) for each product at each examination. Based on whole body counts at Day 42, the efficacy of each product was determined to be 100%. In the field study, cats were allocated in strict order of presentation. Cats were randomly allocated to one of the three treatment groups: (1) propoxur collar (Bolfo, Bayer); (2) 0.25% fipronil spray, at 6 ml/kg and (3) 10% fipronil spot-on as per label. Cats were treated once topically on Day 0. Louse counts of cats treated with fipronil formulations were not different than those of cats receiving the propoxur collar. The efficacy was determined to be > 98% on Day 2 and 100% on Days 28 and 42 in all treatment groups. The results of these studies demonstrate that fipronil in topical formulations is effective for treatment and control of biting lice (F. subrostratus) infestations on cats.     

Effects of the application of neck pressure by a collar or harness on intraocular pressure in dogs

The effect on intraocular pressure (IOP) from dogs pulling against a collar or a harness was evaluated in 51 eyes of 26 dogs. The force each dog generated while pulling against a collar or a harness was measured. Intraocular pressure measurements were obtained during application of corresponding pressures via collars or harnesses. Intraocular pressure increased significantly from baseline when pressure was applied via a collar but not via a harness. Based on the results of the study, dogs with weak or thin corneas, glaucoma, or conditions for which an increase in IOP could be harmful should wear a harness instead of a collar, especially during exercise or activity.     

The use of accelerometer to measure sleeping posture of beef cows

Sleep is one of the essential behaviors for mammals. The aims of this study were to validate the use of accelerometer for measuring sleeping posture of cattle. Duration of sleeping posture of seven Japanese Black cows from 19.00 to 07.00 hours was measured by both accelerometer and video, and a total of 67 accelerometer and video measurement sets were collected. We calculated Cohen's κ coefficient between accelerometer and video measurements and 91.5% of the κ‐values were >0.80. Intra‐ and inter‐observer coefficient of variance showed that specific acceleration waveform patterns of sleeping posture could be easily and accurately detected by independent observers. There were no significant differences in the frequency of sleeping posture occurrences between accelerometer and video measurements. We compared averaged sleeping posture bout, and the total sleeping posture time between accelerometer and video measurements using regression. In each trait, the slope was close to 1 and the intercept was not different from 0, which showed a strong agreement between accelerometer and video measurements. This shows that an accelerometer could accurately detect sleeping postures of cattle. We conclude that adequate measurements of sleeping postures can be made using an accelerometer.     

The Effect of Laparoscopic Versus Open Ovariectomy on Postsurgical Activity in Small Dogs

Objective— To describe a technique for laparoscopic ovariectomy (LapOVE) in small dogs, and compare the surgical time, complications, and postoperative activity of dogs undergoing LapOVE to those undergoing conventional traditional open ovariectomy (OOVE).
Study Design— A randomized, controlled clinical trial.
Animals— Intact small breed (<10 kg) female dogs (n=20).
Methods— Ventral median celiotomy was performed for OOVE. A 2-midline portal technique using a 3.5 mm laparoscope port and a 6 mm instrument portal was used for LapOVE. An accelerometer was attached to the collar of each dog to record 24-hour preoperative and 48-hour postoperative activity. Total activity counts recorded before surgery were compared with total counts recorded after surgery. The percent change in counts after surgery was compared between OOVE- and LapOVE-treated dogs.
Results— No major complications occurred and surgical time for LapOVE was significantly longer than for OOVE cases ( P =.005). Dogs in the LapOVE group had a 25% decrease in total activity counts after surgery (95% confidence interval [CI]: 11–38%), whereas dogs in the OOVE group had a 62% decrease in total activity counts after surgery (95% CI: 48–76%).
Conclusions— Both procedures were performed with reasonable surgical times and without major complication. Postoperative activity, as measured by accelerometry, was significantly different between the 2 groups.
Clinical Relevance— Laparoscopy is a safe method for ovariectomy in small dogs and results in increased postoperative activity counts when compared with an open technique.     

Evaluation of client-specific outcome measures and activity monitoring to measure pain relief in cats with osteoarthritis

BACKGROUND: There are no validated systems for measuring pain from osteoarthritis in cats. HYPOTHESIS: Owner subjective assessments and an activity monitor (AM) can be used to detect pain in cats with osteoarthritis and to assess efficacy of treatments. ANIMALS: Thirteen cats older than 10 years old, with owner-assessed decreases in activity, painful arthritic joints, and clinically normal blood work were included and evaluated for 3 weeks. METHODS: A collar-mounted AM measured activity and a client-specific outcome measure (CSOM) questionnaire characterized the severity of impairment. Overall global quality of life was also evaluated for each treatment. In weeks 2 and 3, meloxicam (0.1 mg/kg, day 1; 0.05 mg/kg, days 2-5) or a placebo was administered in a blinded, randomized, cross-over manner to test the assessment systems. RESULTS: The cats had a median of 4 arthritic appendicular joints. Activity counts for the week when cats (complete data on activity; n=9) were administered meloxicam were significantly higher than at baseline (P = .02) but not after placebo (P = .06). Baseline activity counts were not significantly different from placebo (P = .6). The CSOM data (n=13) showed that owners considered their cats to be more active on meloxicam compared with baseline (P = .001) and placebo (P < .004), and more active on placebo than at baseline (P < .01). Global quality of life improved significantly with meloxicam (P < .042). CONCLUSIONS AND CLINICAL IMPORTANCE: Both an AM and a CSOM system can detect behavior associated with pain relief in cats that are arthritic. Objective activity data might allow subjective assessment systems to be validated for use in clinical studies.     

Dilated cardiomyopathy in cats: survey of veterinary cardiologists and retrospective evaluation of a possible association with diet

Introduction/objectivesThe objectives were to conduct a survey of cardiologists on their recent experiences with cats that have dilated cardiomyopathy (DCM) and to retrospectively review individual cases of feline DCM.Animals, materials and methodsPart one: A survey was distributed to cardiologists with questions regarding caseload and clinical management of cats with DCM diagnosed over the past two years. Part two: Cardiologists completing the survey were invited to submit data from cats recently diagnosed with DCM. Data on signalment, clinical signs, diet, echocardiographic measurements and outcome were recorded.ResultsPart one: From 52 completed surveys, many cardiologists responded that measuring and supplementing taurine and recommending a diet change in cats with DCM are common practices. Few (15%) cardiologists reported an increase in the number of feline DCM cases over the past two years, although some had cases that improved even if taurine deficiency was not present. Part two: Twenty of 37 (54%) cats ate low pea/lentil (low PL) diets, and 14/37 (38%) ate high PL diets at the time of diagnosis; three had incomplete diet information. Two of 13 cats (15%) in which taurine was measured had levels below the reference range. After adjusting for other variables, cats eating high PL diets that changed diets after diagnosis had a significantly longer survival time than that of cats eating high PL diets that did not change diets after diagnosis (P = 0.025).ConclusionsAdditional research is warranted to determine whether there could be a possible association between diet and DCM in cats.     

Data-loggers carried on a harness do not adversely affect sheep locomotion

The use of externally fitted motion sensors to animal subjects has the potential for allowing researchers to investigate subtle changes in animal movement that may occur with the onset of specific diseases. However, it is crucial to consider whether or not the use of such technology has an effect on the variables measured. Here, we examine the effect of a body harness data logging device on the locomotive patterns of female Merino sheep, Ovis aries. We extracted locomotion variables typical of motion sensor data (stride frequency, stride length, gait type, speed, and limb velocity) from high-definition video collected under controlled conditions. We found no significant difference between the variables measured in the harnessed and unharnessed conditions. Overall, our experiment demonstrates that data-loggers carried on a harness do not adversely affect sheep locomotion, and extended periods of habituation post-instalment of devices should ensure consistency and accuracy of data in future experiments.     

Relationships between fore- and hindlimb ground reaction force and hoof deceleration patterns in trotting horses

REASONS FOR PERFORMING STUDY: The transmission of shockwaves following hoof impact is proposed to be one major source of stress to the limb. In the forelimb, there are indications that the period of horizontal deceleration of the hoof is related to the attenuation of shockwaves. In the hindlimb, information about the hoof deceleration has been lacking. OBJECTIVE: To compare hoof deceleration patterns between the fore- and hindlimbs. METHODS: Seven Standardbreds were trotted by hand over a force plate covered with sand, with triaxial accelerometers mounted on the fore and hind hooves. Variables representative of decelerations (first 2 main vertical deceleration peaks; characteristic minimum and maximum values in the craniocaudal deceleration; hoof braking time) and ground reaction forces (vertical loading rates; maximum and the following local minimum of the craniocaudal force) of the initial part of the stance phase, and the differences between individual fore- and hindlimb time and amplitude variables were used for statistical analyses. RESULTS: Force plate data showed significantly greater vertical loading rate (mean +/- s.d. 6.5 +/- 5.9 N/sec) and horizontal loads (190.4 +/- 110.2 N) in the forelimb than the hindlimb, but the parameters from accelerometer data showed no significant differences. CONCLUSIONS: No significant difference was found in the hoof deceleration, but the deceleration curves displayed a common pattern that described in detail the kinematics of the fore and hind hooves during the initial period of hoof braking. POTENTIAL RELEVANCE: These results contribute to further knowledge about the characteristics of these potential risk factors in the development of subchondral bone damage in the horse. Further studies are required on the influence of hoof braking pattern at higher speed, different shoeing and ground surfaces with different properties.     

Control of cyathostome infections in mares treated at parturition with ivermectin

Six mares were treated on the day of parturition with an intramuscular injection of 0.2 mg kg-1 ivermectin and placed in a pasture free of equine parasites as soon as possible after foaling. The mares and their foals were compared with a similar group of untreated mares and foals on an adjoining pasture. The experimental data was derived from mare and foal fecal egg counts, foal necropsies and pasture larval counts. Ivermectin administered to mares on the day of parturition, when combined with movement to parasite-free pastures, significantly lowered the cyathostome (small strongyle) egg production for 4 months. This reduced cyathostome exposure was reflected in lower worm-burdens in their foals for 5 months. The results indicate that ivermectin will effectively control equine strongyles when mares and their foals are moved to parasite-free pastures.     

Spontaneous retrograde movement of ureteroliths in two dogs and five cats

CASE DESCRIPTION: 2 dogs and 5 cats were evaluated for treatment of ureteroliths. CLINICAL FINDINGS: Spontaneous retrograde movement of 1 or more ureteroliths was detected by radiography, ultrasonography, fluoroscopy, and a combination of fluoroscopy and ultrasonography. The ureteroliths moved retrograde up to 4 centimeters. Retrograde movement of ureteroliths into the renal pelvis resulted in improved renal function in some patients but made complete surgical removal of all uroliths more difficult. TREATMENT AND OUTCOME: Medical management was not successful, and ureteroliths were surgically removed. Surgical management of ureteroliths was complicated by retrograde movement of ureteroliths in the perioperative period. CLINICAL RELEVANCE: Ureteroliths can move retrograde within the ureter and even back into the renal pelvis. Retrograde movement of ureteroliths may make surgical planning more difficult.     

Red cell morphologic alterations in cats with hepatic disease

Medical records from 39 cats with hepatic disease, examined at the Veterinary Medical Teaching Hospital, University of Florida, between 1987 and 1992 were retrospectively evaluated for alterations in red blood cell (RBC) morphology. Diagnoses included: hepatic lipidosis, neoplasia, cholangiohepatitis, hepatitis/hepatopathy, systemic histoplasmosis, and portocaval shunt. A total of 56 laboratory data sets were studied which included complete blood counts and serum chemistry results. Stained blood smears were evaluated from 51 of the data sets. Twenty-two cats (56%) were determined to have poikilocytosis on the basis of blood smear evaluation. Eleven (28%) cats had moderate to marked poikilocytosis (2+ to 4+). Acanthocytes accounted for 62.6 -/+ 22.1% of morphologically abnormal RBC and were observed in blood smears from 100% of cats with poikilocytosis. Elliptocytes (ovalocytes) comprised 19.5 -/+ 15.8% of poikilocytes and were found in smears from 82% of cats with poikilocytosis. Keratocytes (7.0 -/+ 6.8%), schistocytes (3.6 -/+ 4.4%), and blister cells (2.6 -/+ 6.4%) were present in lower numbers and in fewer cats. Serum total cholesterol values were significantly greater (p < 0.05) in cats with moderate to marked alterations in RBC morphology. Cats with hepatic lipidosis were significantly (p < 0.04) more likely to have poikilocytosis than cats with other types of hepatic disease.