Darryl L. Millis

Objective: To identify the effects of incline and decline treadmill trotting on forelimb muscle activity in dogs using electromyography (EMG). Methods: Data were collected for a prospective within-subject, repeated-measures study in January and February of 2025 where subjects were trotted on a level treadmill, 5% incline, 10% incline, 5% decline, and 10% decline. Surface EMG data were collected bilaterally from the scapular portion of the deltoideus, lateral head of the triceps brachii, and biceps brachii, and fine-wire EMG data were collected from the supraspinatus muscle. Repeated-measures ANOVA tests were conducted followed by post hoc pairwise comparisons when significant main effects were seen ( P < .05). Results: Data were collected from 12 adult large-breed dogs. Peak supraspinatus activity increased by 6.5% (95% CI, 0.1% to 11.8%) from 0% to 5% incline and by 5.7% (95% CI, 1.6% to 15.5%) from 5% to 10% incline. Average triceps muscle activity increased by 17.9% (95% CI, 0.6% to 3.7%) from 0% to 10% incline, by 12.5% (95% CI, 1.2% to 5.9%) from 5% to 10% incline, and by 9.3% (95% CI, 1.1% to 1.7%) from 5% to 10% decline. Peak triceps and average deltoideus activity followed similar trends. Biceps brachii activity showed no significant changes. Conclusions: Muscle activities of the supraspinatus, triceps, and deltoideus all exhibited significant changes during incline and/or decline treadmill trotting. The biceps brachii was not significantly affected by any condition tested. Clinical Relevance: The findings support the use of incrementally increasing or decreasing levels of treadmill trotting to progressively load specific forelimb musculature in canine rehabilitation.

Objective: The objective of this study was to determine the prevalence of radiographic osteoarthritis (OA) and the joints affected in medium to large dogs undergoing dental prophylaxis. We hypothesized that up to 50% of dogs in the study population would have radiographic OA. Methods: This was a prospective observational study. Dogs admitted for dental prophylaxis at the University of Tennessee College of Veterinary Medicine from May 2013 to February 2014, > 11 kg, and 4 to 10 years of age without a previous diagnosis of OA were studied. Orthopedic examinations and ground reaction force measurements were performed. Radiographs of the major joints were obtained under sedation and evaluated for the presence and severity of OA. Results: 18 of 30 dogs (60%) had 1 or more joints with radiographic OA. The number of dogs with affected joints included coxofemoral (n = 11), tarsus (10), antebrachiocarpal (4), stifle (4), glenohumeral (3), and elbow (1). Dogs with OA had an average of 3 joints affected (range, 1 to 8 joints). Returned owner questionnaires indicated that 10 of 14 dogs with OA had no clinical signs, whereas 6 of 7 dogs without OA had no signs. Conclusions: OA was common in dogs. Most owners did not realize their dog had OA. An optimal time to screen for radiographic OA is during procedures requiring sedation. Clinical Relevance: Radiographic OA occurred in 60% of dogs, suggesting that dogs be screened for OA. Most owners did not suspect their dogs had OA, but questions regarding mobility may direct further screening.

End-stage masticatory muscle fibrosis may occur following trauma, resulting in the inability to open the mouth for eating, drinking, panting and vomiting. Following MRI and EMG confirmation of end-stage muscle fibrosis, a bilateral wedge ostectomy was performed of the mandibles, leaving a permanent mouth opening of 3.5 cm. The osteotomies were stabilized with 6-hole dynamic compression plates and screws. A temporary percutaneous endoscopic gastrotomy tube was placed while the dog underwent rehabilitation and reconditioning. The dog was able to eat, drink, and pant after recovery, which allowed the dog to live a relatively normal and good quality life. Wedge osteotomies of the mandibles with bone plate stabilization may allow dogs with permanent restrictive mouth opening due to fibrosis of the masticatory muscles to live a relatively normal life.

Background: Use of kinesiology taping has increased in veterinary medicine, yet there are few studies of its effects. The purpose of this study was to evaluate the effect of kinesiology tape placed on the dorsal surface of the tarsus on kinetic and kinematic gait characteristics while performing selected exercises in dogs using 3D motion capture and force platform analysis of gait. Methods: Ten clinically normal, healthy, adult mixed-breed dogs were recruited for this study. Reflective markers were applied to the skin of the left and right pelvic limbs of each dog. Eight infrared cameras were positioned around a 13 m platform containing a force platform. Dogs were walked, trotted, and led over cavaletti rails with and without kinesiology tape extending from the distal tibia, crossing the cranial surface of the tarsus, and extending to the dorsal surface of the metatarsals. The evaluations were repeated 2 h later. Maximum flexion and extension in the sagittal plane and maximum angular acceleration and velocity were measured at the tarsus and stifle for each dog. Peak vertical (Z_Peak), braking (Y_A), and propulsion (Y_B) forces were determined as a percentage of body weight while walking and trotting. Results: Ground-reaction forces were greater at the trot compared to the walk, and stifle and tarsal flexion were greater with stepping over cavaletti rails as compared to walking and trotting. There were no differences in kinematic or kinetic measurements related to the kinesiology tape application, time, or exercise being performed. Conclusions: Kinesiology tape had no effect on tarsal joint gait characteristics while walking, trotting, or stepping over cavaletti rails when applied to the dorsal tarsus of normal dogs.

Background: Use of kinesiology taping has increased in veterinary medicine, yet there are few studies of its effects. The purpose of this study was to evaluate the effect of kinesiology taping of the tarsus on kinetic and kinematic gait characteristics while performing selected exercises in dogs using 3D motion capture and force platform analysis of gait. Methods: Ten clinically normal, healthy, adult mixed-breed dogs were recruited for this study. Reflective markers were applied to the skin of the left and right pelvic limbs if each dog. Eight infrared cameras were positioned around a 13 m platform containing a force platform. Dogs were walked, trotted and led over cavaletti rails with and without kinesiology tape extending from the distal tibia, crossing the cranial surface of the tarsus, and extending to the dorsal surface of the metatarsals. The trial was repeated 2 hours later. Maximum flexion and extension in the sagittal plane, and maximum angular acceleration and velocity were measured at the tarsus and stifle for each dog. Peak vertical (ZPeak), braking (YA) and propulsion (YB) forces were determined as a percent of body weight while walking and trotting. Results: Ground reaction forces were greater at the trot compared to the walk, and stifle and tarsal flexion were greater with stepping over cavaletti rails as compared to walking and trotting. There were no differences in kinematic or kinetic measurements related to the kinesiology tape application, time or exercise being performed. Conclusions: Kinesiology tape had no effect on tarsal joint gait characteristics while walking, trotting, or stepping over cavaletti rails when applied to the dorsal tarsus of normal dogs.

In allogeneic MSC implantation, the cells are isolated from a donor different from the recipient. When tested, allogeneic MSCs have several advantages over autologous ones: faster cell growth, sufficient cell concentration, and readily available cells for clinics. To ensure the safe and efficient use of allogeneic MSCs in clinics, the MSCs need to be first tested in vitro. With this study, we paved the way by addressing the in vitro aspects of canine adipose-derived MSCs, considering the limited studies on the clinical use of canine cells. We isolated cAD-MSCs from canine falciform ligament fat and evaluated their viability and proliferation using an MTS assay. Then, we characterized the MSC-specific antigens using immunophenotyping and immunofluorescence and demonstrated their potential for in vitro differentiation. Moreover, we established shipping and cryobanking procedures to lead the study to become an off-the-shelf therapy. During expansion, the cells demonstrated a linear increase in cell numbers, confirming their proliferation quantitatively. The cells showed viability before and after cryopreservation, demonstrating that cell viability can be preserved. From a clinical perspective, the established shipping conditions demonstrated that the cells retain their viability for up to 48 h. This study lays the groundwork for the potential use of allogeneic cAD-MSCs in clinical applications.

The presence of potentially pathogenic bacteria on veterinary clinic surfaces may be problematic. In this study, we collected swab samples (Fisherbrand, double transport swabs with Stuart’s liquid medium) and water samples from five veterinary rehabilitation clinics. Swabs and water samples were transported to a microbiology lab for processing. At the lab, swabs were used to inoculate Hardy’s Cdiff Banana Broth (for Clostridium difficile [Cdiff]) and five different types of bacterial growth media, including Hardy CHROM MRSA agar (methicillin-resistant Staphylococcus aureus [MRSA] and S. pseudintermedius [SIM]), mannitol salt agar (S. aureus [SA]), eosin methylene blue agar (enterics [ENT]), Pseudomonas isolation agar (Pseudomonas spp. [PS]), and tryptic soy agar [TSA] (non-specific). The most prominent presumptive species cultured was Cdiff (on nearly 55% of swabs). Bacillus spp. and enteric bacteria were encountered on nearly 35% of swabs, with MRSA and SIM on just over 10% of swabs. The most contaminated sample site was harnesses/life jackets used with the underwater treadmill (33% of swabs). The underwater treadmill water had total bacterial counts from 1,600 to 2,800 cfu/mL. Of all presumptive bacterial species detected, SIM tends to be more pathogenic for dogs. Targeted cleaning/disinfecting in these clinics could help reduce risks for both animals and caregivers utilizing these clinics.

The presence of potentially pathogenic bacteria on veterinary clinic surfaces may be problematic. In this study we collected swab samples (Fisherbrand, double transport swabs with Stuart’s liquid medium) and water samples from five veterinary rehabilitation clinics. Swabs and water samples were transported to a microbiology lab for processing. At the lab swabs were used to inoculated Hardy’s Cdiff Banana broth (for Clostridium difficile [Cdiff]), and five different types of bacterial growth media, including: Hardy CHROM MRSA agar (methicillin resistant Staphylococcus aureus [MRSA], and S. pseudintermedius [SIM]), Mannitol Salt Agar (S. aureus), Eosin Methylene Blue agar (enterics [ENT]), Pseudomonas Isolation agar (Pseudomonas sp.), and Tryptic Soy Agar [TSA] (non-specific). The most prominent species cultured was Cdiff (on nearly 55% of swabs). Bacillus sp. and Enterics were encountered on nearly 35% of swabs, with MRSA and SIM on just over 10% of swabs. The most contaminated sample site was harnesses/life jackets used with the underwater treadmill (33% of swabs). Underwater treadmill water had total bacterial counts from 1.6 to 2.7 e3 cfu/ml. Of all bacterial species detected SIM tends to be more pathogenic for dogs. Targeted cleaning/disinfecting in these clinics could help reduce risks for both animals and caregivers utilizing these clinics.

OBJECTIVE: Patient factors may alter laser photon attenuation, but these factors have not been adequately evaluated in live dogs. Our objective was to evaluate class IV laser beam attenuation (LBA) by canine tissues using a colorimeter to evaluate melanin and erythema indices. We hypothesized that greater melanin and erythema indices and unclipped hair would increase LBA, and these properties would vary among tissues. ANIMALS: 20 client-owned dogs. PROCEDURES: Between October 1 and December 1, 2017, colorimeter measurements and LBA in various tissues before and after clipping overlying hair were evaluated. Data were analyzed using generalized linear mixed models. Statistical significance was set at P < .05. RESULTS: LBA was greater in unclipped (98.6 ± 0.4%) than clipped hair (94.6 ± 0.4%). The least LBA occurred in the pinna (93%) while the greatest occurred in the caudal vertebra (100%) and caudal semitendinosis muscles (100%). Each mm of tissue thickness resulted in LBA of 11.6%. Each unit increase in melanin index resulted in a 3.3% increase in LBA. There was no association of LBA with erythema index. CLINICAL RELEVANCE: To our knowledge, this is the first study that evaluated LBA by different tissues in live dogs using a colorimeter to evaluate melanin and erythema indices. We recommend clipping hair prior to photobiomodulation to decrease laser beam attenuation and using increased laser doses in thicker tissues and dogs with high melanin content. The colorimeter may be helpful in customizing patient treatment dosimetry. Future studies are necessary to determine therapeutic laser doses for adequate photobiomodulation effects.

Light therapy, or photobiomodulation, is a collective name for methods where tissue is irradiated with different types of light, with the aim of stimulating healing. Despite being frequently used, there is no consensus regarding the optimal treatment protocols for light therapy, nor its clinical efficacy. A systematic literature review was conducted, searching the relevant literature regarding light therapy in three databases, published between 1980–2020. The risk of bias in each article was evaluated. Forty-five articles met the inclusion criteria; 24 articles were regarding dogs, 1 was regarding cats, and the rest were regarding horses. The indications for treatment were musculoskeletal and neurologic conditions, skin disease and wounds, and pain. The literature review showed conflicting study results and unclear application for clinical use. This can be explained by the wide variety of treatment parameters used in the searched studies, such as wavelength, laser class, dose, and effect, as well as the frequency and duration of treatment. Although some beneficial effects were reported for light therapy, the studies also had limited scientific quality regarding these therapies, with a high or moderate risk of bias.