Left Forelimb Research Articles

Preserved intersegmental coordination during locomotion after cervical spinal cord injury in common marmosets

It is known that primates including human regain some locomotor function after a partial spinal cord injury, but the locomotor pattern is different from before the injury. Although these observations have many implications for improving rehabilitative strategies, these mechanisms are not well understood. In this study, we used a common marmoset hemisection SCI model to examine temporal changes in locomotor pattern, in particular, intersegmental coordination of left hindlimb. Marmoset showed loss of detectable function in the left forelimb and hindlimb after left unilateral hemisection of cervical spinal cord. At two weeks after injury, weight-bearing of the left forelimb during locomotion was limited, but the left hindlimb was able to plantar step. Then marmosets showed gradual recovery in walking ability, but kinematics analysis showed differences in the endpoint trajectory and joint angle movement. Furthermore, intersegmental coordination in left hindlimb represented by planar covariation was preserved over time after the injury. Previous studies have reported that planar covariance is disrupted in patients with stroke or SCI, and that improvement in planarity correlates with recovery in walking ability after rehabilitation. In this study, quadrupedal marmosets were able to walk without loss of balance even after SCI; the different balance needs of bipedal and quadrupedal walkers may lead to differences in planar covariation. Our results show that planar covariation was preserved at all time points after the cervical unilateral hemisection.

Transplantation of feces from mice with Alzheimer's disease promoted lung cancer growth

BackgroundAlzheimer's disease (AD) is a progressive neurologic disorder that causes the brain to shrink and brain cells to die. Lung cancer is characterized by high morbidity and mortality, late diagnosis and poor prognosis. And there is no specific mechanism to explain the epidemiological correlation between AD and lung cancer. Materials and methodsLewis lung cancer cells (LLC) were injected into the left forelimb armpit of APP/PS1 mice to establish a tumor-bearing model. After remodeling the gut microbiota by fecal microbiota transplantation (FMT), the tumor were collected and analyzed for tumor size, Western blotting, and 16S rRNA gene sequencing. ResultsCompared with the control group, the AD FMT group showed larger tumors, while C57 FMT group showed smaller tumors. The former group showed the inhibition of AKT/Bax/Bcl-2 pathway, while the latter showed promotion of Caspase-1/IL-1β and AKT/Bax/Bcl-2 pathway, which induced changes in tumor size. And Prevotella, Prevotella, Mucispirillum and Halomonas in the gut lumen of LLC tumor-bearing mice are increased, and Bacteroides, Coprobacillus, Bifidobacterium, Faecalibacterium and Aggregatiacter are decreased significantly. ConclusionAD and lung cancer showed a positive correlation in APP expression, which proposed a different view from epidemiology on the correlation between AD and lung cancer.

Supracutaneous locking compression plating for the management of humerus fracture in a dog

A dog was presented to the University Veterinary Hospital, Kokkalai with a history of nonweight bearing lameness on left forelimb and was diagnosed as humerus fracture. Supracutaneous locking compression plating was carried out after open reduction under general anaesthesia. Periodic clinical and radiographic evaluations were conducted at two weeks interval for a period of six weeks until the plate removal. Physiological and haematological parameters were within the normal range. The serum alkaline phosphatase level was high at the time of presentation and decreased progressively. The dog returned to sound gait, normal weight bearing and satisfactory functional limb usage by sixth post operative week. The fracture healed with periosteal and endosteal callus. The implant was intact and patient acceptance was satisfactory throughout the observation period.

Effects of MCC950 on nerve injury in rats with intracerebral hemorrhage

Objective: To investigate the effects of the pyrin domain-containing protein 3 (NLRP3) inflammasome inhibitor MCC950 on nerve injury in rats with intracerebral hemorrhage(ICH). Methods: Seventy-two SD rats were randomly divided into three groups (n=24): Sham group, ICH group and MCC950 group. ICH group and MCC950 group rats were injected with autogenous non-anticoagulant blood to establish ICH model, and then the rats in MCC950 group were intraperitoneally injected with MCC950 at the dose of 10 mg/kg(2 mg/ml) for 3 days after ICH model was established. Seventy-two hours after the establishment of the model, the forelimb placement test, the corner test and mNSS score were performed to observe the neurological function of the rats with ICH. The volume of hematoma was observed in fresh brain tissue sections. HE staining was used to observe the pathological changes of brain tissue. The dry-wet weight ratio was calculated to evaluate the changes of brain tissue edema. The degeneration of neurons was observed by FJC staining. The neuronal apoptosis was observed by TUNEL staining. The protein expression and activation levels of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD were determined by Western blot. Results: Compared with sham group, the percentage of successful placement of left forelimb and left turn was decreased significantly (P＜0.01, P＜0.05), mNSS score was increased significantly (P＜0.01) in ICH group. Hematoma volume was increased significantly, the number of microglial cells around the hematoma was increased, the number of neurons was decreased, nerve cell swelled, some cells showed pyknotic necrosis, and the staining was deepened. The water content of the right base was increased significantly (P＜0.05). The number of FJC positive and TUNEL positive cells around the hematoma was increased significantly (P＜0.05). The levels of NLRP3, ASC, caspase-1, pro-caspase-1, caspase-1/pro-caspase-1 ratio, GSDMD-N, GSDMD, GSDMD-N/GSDMD ratio, IL-1β and IL-18 were increased significantly (P＜0.01, P＜ 0.05). Compared with ICH group, the percentage of successful placement of left forelimb and left turn was increased significantly in MCC950 group (P＜0.05), while the mNSS score and the volume of hematoma were decreased significantly (P＜0.01), the swelling degree of nerve cells around the hematoma was reduced significantly, and the number of pyrotic necrotic cells was decreased. The water content of the right base was decreased significantly (P＜0.05), and the number of FJC positive and TUNEL positive cells around the hematoma was decreased significantly (P＜0.05). The levels of NLRP3, ASC, caspase-1, pro-caspase-1, caspase-1/pro-caspase-1 ratio, GSDMD-N, GSDMD, GSDMD-N/GSDMD ratio, IL-1β and IL-18 were decreased significantly (P＜0.05). Conclusion: MCC950 can ameliorate nerve injury after ICH by inhibiting NLRP3 inflammasome mediated inflammation and pyroptosis.

Remote conditioning as protective strategy influencing ubiquitin-mediated stress response in the rabbit spinal cord after ischemia/reperfusion.

The aim of presented study was to investigate the model of non-invasive method of remote conditioning induced by compression of left forelimb with a tourniquet in three cycles of 2 min of ischemia each followed by 2 min of reperfusion and its influence on the rabbit spinal cord ischemia/reperfusion injury via ubiquitin-mediated stress response. Ubiquitin immunoreaction in spinal cord motor neurons as well as detection of neuronal survival in ventral horns of spinal cord were evaluated. Significantly increased (p < 0.001) number of ubiquitin positive neurons was registered in all remote conditioned groups versus both spinal cord ischemia (SC-ischemia) groups. Our results indicate that remote conditioning significantly attenuated degeneration of motor neurons in all conditioned groups versus SC-ischemia groups in each time point. According to our results, we concluded that the remote conditioning induced by transient limb ischemia is relevant stimulus that provides potent neuroprotection in a model of spinal cord ischemia/ reperfusion injury.

Acoustic Myography: Its Assessment of Ground Reaction Forces as Measured through Forelimb and Hind Limb of the Horse during Mild Exercise

Background: Fractures in the limbs of racehorses are common, resulting among other factors, as the result of repeated ground reaction forces on bones and joints, leading to catastrophic failure. Aim: To quantify ground impact transmission through the limb bones of un-shod healthy horses using the non-invasive technique of acoustic myography (AMG). Methods: Four sites were selected for AMG measurements at the walk and trot, hoof wall (site 1) and sites 2 - 4, metacarpal 3, carpals and the radius of the left forelimb of two healthy horses. Measurements were on both rubber and concrete. AMG of the equine hind limb suspensory system was made and analyzed (amplitude and timing) for the proximal suspensory ligament (PSL) and the SDFT/DDFT. Results: AMG signal amplitude at site 1 (1.5 ± 0.2 versus 1.1 ± 1.5) was not found to be significantly different at the trot compared to the walk; however, sites 2, 3 and 4 were all significantly different when compared between the two gaits; site 2 P = 0.008; site 3 P = 0.006; site 4 P = 0.005. AMG signals recorded on the rubber surface had smaller amplitude than the equivalent signal and site on the concrete surface. Ground Reaction Force (GRF) transmission in the equine forelimb was 22 m/sec, whilst that of the hind limb suspensory system was 25 m/sec. Conclusion: Findings indicate that GRFs are transmitted proximally along the limb at considerable speeds, that they are dampened by tissues and structures in the limb, and that the GRFs are present and detectable proximal to the fetlock joint.

Fatal cerebral cuterebrosis in a dog.

A 4-year-old intact female Yorkshire Terrier presented an acute onset of hypersalivation and depressed mentation. The owner reported that the dog displayed tremors, right-sided torticollis, right-sided head tilt, and lifting of the left forelimb. The dog appeared restless and confused, and the condition progressed to lethargy and death on the way to an emergency hospital. At necropsy, a single 10mm long x 1mm wide, pale gray, botfly larva with black spines was found along the cerebral meninges. Areas of hemorrhage were noted in the right cerebral hemisphere. Microscopically, these areas also had evidence of necrosis and inflammation. Morphology of the larva allowed confirmation of subfamily-level identification as Cuterebrinae, and presumed genus-level identification of Cuterebra. Species-level identification of the larva as C. abdominalis was achieved through DNA extraction, PCR and sequencing at the cytochrome oxidase subunits 1 and 2 (COI and COII), followed by phylogenetic analysis. Aberrant cuterebrosis is a poorly documented condition in dogs that may cause neurologic signs and lead to death.

Effects of forelimb instrumentation on lameness detection in horses using a portable inertial sensor-based system.

To investigate the effects of a small sensor attached to the pastern region of a forelimb on lameness detection and quantification with a portable inertial sensor-based system (PISBS) for lameness detection and quantification in horses. 20 adult horses (body weight, 410 to 650 kg) with no visible lameness at the walk. In a crossover study design, horses were evaluated at the trot twice using the PISBS with the gyroscope alternately attached to the right forelimb pastern region (as recommended by the manufacturer) or to the left forelimb pastern region (with the sensor flipped 180° on the frontal plane relative to the standard position). Agreement between the 2 instrumentation approaches was investigated graphically and by repeated-measures ANOVA, Pearson correlation analysis, and Bland-Altman analysis. No effects of instrumentation of a forelimb with the gyroscope were detected on the lame limb or limbs or on lameness severity. Attachment of the gyroscope to a forelimb had no effect on forelimb or hind limb lameness (ie, did not cause or mask lameness) as measured with the PISBS. Instrumentation of a forelimb with a lightweight gyroscope for lameness evaluations with a PISBS had no effects on lameness measurements in horses. Results suggested that, when indicated, the gyroscope can be attached (while flipped 180° on the frontal plane relative to the standard position) to the left forelimb (rather than the right forelimb).

Partial rupture of the biceps tendon with concurrent septic arthritis of the shoulder joint in a dog

AbstractA 7‐year‐old, male‐neutered, Cockapoo presented for rapidly deteriorating non‐weight bearing (5/5) left thoracic lameness with poorly localised severe pain. Based on physical examination, advanced diagnostic imaging and cytology of joint fluid, a diagnosis was made of left partial biceps tendon rupture with presumptive secondary bacterial infectious arthritis of the left shoulder. No obvious source of bacteraemia was found. Initial treatment with intravenous antibiotics and multimodal analgesia for 48 hours led to rapid improvement of the clinical signs. Following seven weeks of oral antibiotic therapy, at clinical reassessment, the clinical signs had steadily improved with persistent mild left forelimb lameness (1/5). Ultrasound examination revealed signs of left biceps tendon healing. Fifteen weeks after initial presentation, the patient had no lameness or pain and had returned to normal exercise levels as reported by the owner.

English

The present study was conducted to identify morphometric values and to reveal differences between sexes through three-dimensional modeling of digit bones (ossa phalanges) of gazella by using computed tomography images. A total of 14 (7 female, 7 male) adult gazella (Gazella subgutturosa) cadavers were used in the study. The images were extracted by scanning acropodium bones of gazella at 64-detector Multi Detector Computed Tomography (MDCT) in cross section thickness of 0.625mm. Using MIMICS 20.1 program, three-dimensional models of these images were prepared and morphometric measurements were taken. In GLpe and Bd measurements of Phalanx proximalis, a statistically significant difference was established between females and males in terms of the left forelimb internal, the right forelimb internal, the right forelimb external, and the right hindlimb external bones (P&lt;0.05). There was a statistically significant difference between females and males in terms of volume of phalanx proximalis and surface area of the right forelimb internal phalanx proximalis (P&lt;0.001). In GLpe measurements, a statistically significant difference was determined between females and males in terms of the left forelimb internal, the right forelimb internal, the right hindlimb internal, the left forelimb external, the right forelimb external, and the right hindlimb external phalanx media (P&lt;0.05). A statistically significant difference was determined between females and males in terms of the data related to volume and surface areas of the left hindlimb internal the right hindlimb internal, the left hindlimb external, and the right hindlimb external phalanx distalis (P&lt;0.05).

Lameness and Radial Nerve Neuropathy Caused By Chondroma Tumor in a Male Dog

A 5-year-old mongrel male dog with severe left forelimb lameness was referred to the veterinary clinic of Urmia University. On initial physical examination, vital signs were normal. However, a firm swelling with a history of one year progressive increasing in size was observed on the caudolateral aspect of the left shoulder. Pedal reflex was negative. On radiographic examination, a large mass with abnormal radiodensity was seen in the caudal humerus. Hypodermic needle aspiration specimen were unremarkable except large number of normal blood cells. Under general anesthesia, the tumoral mass was surgically removed via a caudolateral approach to the humerus. Pathological assessments corroborated the lobular pattern with the presence of tumor cells similar to normal chondrocytes in an amorphous, basophilic matrix that confirmed the chondroma tumor. In the postoperative follow-up, normal nerve function was returned and lameness was disappeared. Chondroma tumors should be considered in the differential diagnosis of dogs with persistent lameness and neuropathies.

Systemic mucoid degeneration of the arterial tunica intima in a young dog.

A 27-mo-old, spayed female mixed-breed dog was presented with left forelimb pain, which progressed to full thickness necrosis of the soft tissues of multiple limbs. Clinical imaging and postmortem examination suggested multiple large arterial thromboemboli. Histologic examination of vascular lesions revealed markedly thickened tunica intima with polypoid intraluminal projections, which partially to entirely occluded the arterial lumen. The expanded tunica intima was comprised of intimal accumulation of Alcian blue-positive matrix with scattered spindle-to-satellite cells. These cells were positive for von Willebrand factor and vimentin but negative for α-smooth muscle actin, suggesting endothelial origin. Deposition of the intimal mucoid matrix was observed in the elastic and muscular arteries associated with regional ischemic changes. Mucoid emboli, likely from fragmentation of proliferative intimal tissue, were identified in smaller vessels supplied by affected arteries. Based on these findings, we diagnosed systemic mucoid degeneration of the arterial tunica intima. Such systemic arterial degeneration characterized by deposition of mucoid matrix in the tunica intima has not been reported previously in dogs, to our knowledge, and should be distinguished from thromboembolism and other degenerative vascular diseases.

The influence of equine limb conformation on the biomechanical responses of the hoof: An in vivo and finite element study

Hoof conformation plays a key role in equine locomotion. Toe-in conformation is an abnormal condition characterized by inward deviation of the limb from its frontal axis. Several studies have documented differences in hoof deformation and hoof kinematics in horses with toe-in and normal hoof conformations. However, the reason behind this has yet to be understood. The present study hypothesizes that a different center of pressure (COP) path underneath the hoof is the cause of different deformation patterns and hoof kinematics in toe-in hooves. In vivo measurements and finite element (FE) analysis were conducted to test the hypothesis. A normal and a toe-in limb were considered for in vivo strain measurements. Strains were measured at three different sites on the hoof wall, and the stride characteristics were investigated using video recording. The magnitude of the minimum principal strain measured at the medial aspect of the toe-in hoof was much lower relative to the normal hoof. Furthermore, the toe-in hoof had a different movement pattern (plaiting) compared to the normal hoof. In the second study, an entire hoof model was simulated from computed tomography (CT) scans of an equine left forelimb. The Neo-Hookean hyperelastic material model was used, and the hoof was under dynamic loading over a complete stride at the trot. Two different COP paths associated with normal and toe-in conformations were assigned to the model. The FE model produced the same in vivo minimum principal strain distributions and successfully showed the different kinematics of the toe-in and normal hooves.

Induction of ischemic tolerance by remote perconditioning or postconditioning as neuroprotective strategy for spinal cord motor neurons

AimsThe study is focused on the investigation of the mechanisms leading to ischemic tolerance acquisition in the spinal cord neurons via application of non-invasive method of remote conditioning. Material and methodsWe have verified the possibility of neuroprotection of spinal cord in rabbit by using remote perconditioning (PerC) applied during last 12 min of spinal cord ischemia (SC-ischemia) or postconditioning (PostC) applied after 1st (early) or 3rd (late) h of reperfusion. Spinal cord ischemia was induced by occlusion of the aorta below the left renal artery for 20 min. Reperfusion period was 24 or 72 h. Remote conditioning was induced by compression of left forelimb with a tourniquet in 3 cycles of 2 min of ischemia, each followed by 2 min of reperfusion. Damaged neurons were detected by Fluoro Jade B method and the modified Tarlov score was used for functional assessment. Key findingsThe remote conditioning significantly attenuated degeneration of motor neurons in all remote conditioned groups versus both SC-ischemia groups. We detected significant changes in number of Hsp70 positive motor neurons. At 72time point, in the group with remote late PostC we observed significant increase (p < 0.001) of Hsp70 positive motor neurons versus SC- ischemia group and sham control. There was a trend towards improvement of hindlimbs movement. SignificanceThis study showed the effectiveness of remote conditioning as a neuroprotective strategy, evidenced by induction of ischemic tolerance leading to decrease of motor neuron degeneration.

Degloving wound management by second-intention healing in a dog: a case report

A degloving wound is a minimal to extensive loss of skin with variable amounts of deep tissues loss through trauma. The occurrence of degloving injuries has been reported to affect different body parts. This article presents a left forelimb degloving wound that was successfully managed via second intention following a failed first intention management in a 2-year-old German shepherd bitch. Keywords: Degloving wound, dog, forelimb, second intention

2 yaşlı melez ırk bir köpekte ektrodaktili olgusu

Ectrodactyly is a rare anomaly seen in the appendicular skeleton and characterized by a cleft or split between bone and soft tissue in the distal regions of the extremities. Ectrodactyly may be associated with the absence and hypoplasia of several carpal-metacarpal bones, phalanx duplication, or metacarpal synostosis. In this case report, a 2-years-old mixed breed male dog was presented withhold up the left forelimb and inspectional abnormality with a cleft. In the radiographic images, it was observed that the fourth phalanx and the fourth distal carpal bone were absent in the related extremity, the cleft extended up to the carpal joint and there was an incongruity between the radius and ulna. The cleft between the metacarpal bones was stabilized using 2 lag screws and corticocancellous bone graft. The incongruity between the carpal joints was eliminated by pancarpal arthrodesis and ulna ostectomy was performed for the incongruity between radius and ulna. It has been observed that postoperative physical therapy exercises with correlated methods have positive long-term results in the related extremity.

Effect of fatigue loading and rest on impact strength of rat ulna

Stress fracture is a common injury among athletes and military personnel and is associated with fatigue-initiated damage and impact loading. The recovery of bending strength has been shown to be a function of the rest days allowed after fatigue loading in rodents and the aim of this study was to investigate if similar results would occur under impact conditions. In this study, cyclic axial compression load was applied in vivo on the right forelimbs while left forelimbs served as controls. Two rest groups were used: one day of rest and seven days of rest. Afterwards, all ulnae were scanned using micro-Computed Tomography followed by impact testing. The micro-CT scan confirmed the formation of woven bone on loaded ulnae after seven days rest. The peak impact force was 37.5% higher in the control (mean = 174.96 ± 33.25 N) specimens compared to the loaded bones (mean = 130.34 ± 22.37 N). Fourier-transformed infrared spectroscopy analyses suggested no significant change of chemical composition in the cortical region between the loaded and control ulnae, but woven bone region had lower carbonate and amide I content than contralateral controls (p < 0.05). We find that cyclic fatigue loading had a negative effect on bone’s impact response. Bones that experienced fatigue loading became less stiff, weaker, and more prone to fracture when subjected to impact. The formation of woven bone after seven days of rest did not restore the stiffness upon impact and confirm that rest time is crucial to the recovery of fatigue damage.

32 Maturation of proximal sesamoid bones in Thoroughbred horses

Proximal sesamoid bone (PSB) injuries account for approximately 50% of fatal catastrophic musculoskeletal injuries in Thoroughbred racehorses. In addition, PSB fractures are not uncommon in Thoroughbred foals and yearlings as a result of energetic or intense free exercise. The ability to interpret some PSB pathology assessments, however, is more difficult given the limited information published on the normal development and maturation of these paired sesamoid bones. Further, information on the level of normal variation in PSB morphological and structural parameters within the Thoroughbred population as a function of age, body size, gender, and inter-animal differences generally are not well documented. This project aims to address these knowledge gaps through analyses of PSB anatomy from 18 Thoroughbreds obtained on postmortem examination representing an age range from birth to skeletal maturity using micro–CT Bone Morphometry Evaluation (μCT BME, n = 8 horses) and clinical CT evaluation (n = 10 horses). The μCT BME was performed on the left front medial PSB in 8 horses ranging from 4 d to 5 years of age. When graphed, the following were observed: 2nd order polynomic relationships with a positive trend between age and bone volume fraction (R 2 = 0.8125), trabecular thickness (R 2 = 0.8084), and degree of anisotropy (R 2 = 0.914); a 2nd order polynomic relationship with a negative trend between age and trabecular number (R 2 = 0.9242); a negative logarithmic relationship between age and connectivity density (R 2 = 0.9439); and a positive exponential relationship between age and trabecular spacing (R 2 = 0.7818). Clinical CT evaluations were performed on medial and lateral PSBs from the respective right and left forelimbs in 10 horses ranging in age from 2 to 5 years of age utilizing Mindways CT Bone Investigational Toolkit for bone mineral density (BMD) analysis. A one-way ANOVA indicates no significant differences ( P = 0.755) in BMD between the 20 PSB in the left forelimb and the contralateral 20 PSB in the right forelimb. However, significant differences, measured though one-way ANOVA, existed between the 20 lateral PSB (10 from the left forelimb and 10 from the right forelimb) and the 20 medial PSB ( P = 0.006). These findings provide a first of its type reference on the development and maturation timeline of equine PSBs, as well as confirming structural differences between lateral and medial PSBs. The data also document rapid PSB changes between birth and 18 mo of age. The long-term objective of this project is to define normal structural and morphological characteristics of Thoroughbred PSBs as a basis for comparison to PSB pathologies.

Immunolocalization of decorin, a small leucin-rich proteoglycan, in the normal and injured horse tendon

The aim of this study was to evaluate the intensity of decorin in normal and the injured equine cadaver limbs. The study was carried out using superficial digital flexor tendon (SDFT) samples harvested from equine cadaver limbs. Randomly assigned left or right equine distal forelimbs were collected in normal (7 - 14 years old ± 2.86 SD) and injured (6 - 16 years old ± 3.64 SD) SDFT. Small pieces of approximately 5 x 5 x 3 mm were collected from normal and the injured areas at the mid-most metacarpal regions and fixed in 4% paraformaldehyde at room temperature. They were routinely prepared for H&E staining in order to confirm whether they were normal or injured. Then they were prepared for immunological assay, the primary and the secondary antibodies were prepared in a standard ratio. The results showed that the distribution of decorin was varied between fascicles and the interfascicular matrix (IFM), and the latter showed greater intensity than the fascicles. The injured tendons showed up-regulation of decorin, it was intensively expressed in all the cases of injured tendon, particularly fascicles showed significant up-regulation when compared to the normal tendon. It was concluded that decorin was varied regionally, and the injured tendons presented a significant up-regulation.

Digit ratio in the common toad Bufo bufo: the effects of reduced fingers and of age dependency

IntroductionDespite the growing number of studies describing digit ratio patterns in tetrapods, knowledge concerning certain basic issues is still scarce. In lower vertebrates such as tailless amphibians (Anura), the numbering of individual fingers on the forelimbs and their homology with the fingers of other vertebrates pose an unsolved problem. Based on reviewed data on anuran limb development, we argue that the correct finger numbering scheme should be based on the assumption that the first finger, not the fifth finger, was reduced on the forelimbs. We analyzed the digit ratio in the common toad (Bufo bufo, Bufonidae), a species characterized by well-developed sexual dimorphism whereby females are larger than males, using both numbering schemes present in the literature.ResultsWe found that the digit ratio on hindlimbs differed significantly between the sexes only in the cases of left 2D:3D, with lower digit ratios in females, and of left 3D:4D, with lower digit ratios in males. We found that sex was the only significant variable for forelimbs, differentiating 2D:3D on the left forelimb, with lower digit ratios in females; 2D:4D on the right forelimb, with lower digit ratios in males; and 3D:4D on both forelimbs, with lower digit ratios in males. These results relate to variant II reflecting the hypothesis that the first digit was reduced during phylogenesis. There was no relationship between the body size (SVL) of individuals and any digit ratio, excluding 2D:4D on the right forelimbs in models with age variables. Additionally, for a subset of data where individual age was known, the models indicated that age was linked to significant differences in 2D:4D and 3D:4D on the left hindlimbs, while age, SVL, and sex influenced 2D:4D on the right forelimbs.ConclusionWe emphasize the importance of the problem of the correct numbering of forelimb digits in Anura and, under the assumption that it was the fifth digit that was reduced, argue that earlier results on digit ratio in this group should be interpreted with caution. The detected relationship between digit ratio and age in amphibians expands our knowledge, indicating that the age of individuals should be included in future digit ratio studies. This relationship may also apply to studies using digit ratio as a noninvasive indicator of endocrine disruption in amphibians.