The mission of the AJVR is to publish, in a timely manner, peer-reviewed reports of the highest-quality research that has the clear potential to enhance the health, welfare, and performance of animals and humans. The AJVR is an on-line only, fully Open Access journal.
This month’s cover image displays a multi-omics approach for machine learning (ML) in veterinary medicine. The last decade has brought tremendous growth in the use of artificial intelligence (AI) in veterinary medicine. This has been accompanied by rapid evolution in -omics technologies in veterinary practice. With the use of ML technologies, the combination of these disparate -omics datatypes, like genomics, image features (radiomics), and radiation dose distribution features (dosiomics), offers the potential for a deeper understanding of diseases, their detection and expression, and better treatments for them. This image was obtained as part of the “Currents in One Health Study.” Am J Vet Res. 2022;83(5):385–392. DOI: 10.2460/ajvr.22.03.0038
The cover illustration depicts the oromaxillofacial region as a potential and promising model for a ‘One Health’ global approach in regenerative medicine and tissue engineering. Translating discoveries of regenerative therapeutics in veterinary species to novel, effective human therapies using a One Health approach provides a fundamental link between basic biomedical research and medical clinical practice, with the goal of developing strategies for curing or preventing disease and ameliorating pain and suffering in companion animals and humans alike. Am J Vet Res. 2022;83(4):291–297. DOI: 10.2460/ajvr.21.12.0208
This month’s cover images show blood smears from a Jack Russell Terrier presented with very severe pulmonic stenosis (peak systolic trans-stenotic = 340 mmHg). On the blood smear before valvuloplasty (A), severe schistocytosis (arrowheads) and polychromasia (asterisk) are present, suggestive of regenerative hemolytic anemia due to abnormal blood flow. The schistocytosis completely resolved 2 months after pulmonary balloon valvuloplasty (B). This study concluded that poikilocytosis (schistocytosis, acanthocytosis, keratocytosis) is common in dogs with congenital ventricular outflow tract obstruction associated with hemolytic anemia in a few cases with severe or very severe pulmonic stenosis. These results indicate the importance of serial blood smear analysis from canine patients with severe or very severe ventricular outflow tract obstruction. The images were obtained as part of the following study: Passavin P, Chetboul V, Poissonnier C, et al. Red-blood cell abnormalities occur in dogs with congenital ventricular outflow tract obstruction. Am J Vet Res. 2022;83(3):198–204. DOI: 10.2460/ajvr.21.11.0188
This month's cover image shows the bacterial pathobiome map of canine oral health and disease. Dogs were assigned to one of four different stages of periodontal disease and their microbiome was analyzed. Several bacterial species were identified that were significantly associated with the different stages of periodontitis. This pathobiome map can provide a guidance to veterinarians to understand their patient’s periodontal microbiome and health status. The image was obtained as part of the following study: Niemiec BA, Gawor J, Tang S, Prem A, Krumbeck JK. The bacteriome of the oral cavity in healthy dogs and dogs with periodontal disease. Am J Vet Res. 2022;83(1):50–58. DOI: 10.2460/ajvr.21.02.0027
This month's cover images are shear-wave elastographic images of the color map and propagation map of the mandibular lymph node from a healthy adult beagle to measure shear-wave velocities (SWVs). This study concluded that SWE could be used to non¬invasively evaluate changes in the elastic properties of lymphatic tissues. Ultimately, SWE could be applied to increase the diagnostic accuracy of tumor staging. Intra- and interobserver reliability were excellent suggesting that SWV of lymph nodes could be used in practice settings.
The images were obtained as part of the following study: Kang YR, Lee SH, Seo IM, et al. Comparison of shear-wave velocities obtained with shear-wave elastography of various peripheral lymph nodes in healthy Beagles. Am J Vet Res. 2021;82(12):981–987. DOI: 10.2460/ajvr.82.12.981
This month's cover (top photomontage) depicts a series of sodium fluorescein angiographic images exhibiting various degrees of vascular abnormalities (dye leakage) present within the iris of diabetic canines. A standard color, near-infrared, indocyanine green and sodium fluorescein angiographic image of an age-matched control is also shown below. Venular dilation, in the absence of dye leakage, is illustrated. The presence and severity of vascular changes (dye leakage) noted in diabetic canines appear to be associated with disease duration and blood glucose regulation. Anterior segment angiography could be employed to identify the severity of these vascular disruptions present, in addition to, monitoring disease progression and potential response to therapeutic interventions. These images were obtained as part of the following study: Pirie CG, Shelnutt LM, Langlois DK. Assessment of iris vasculature abnormalities in dogs with diabetes mellitus. Am J Vet Res 2021;82(10):829–839. doi: 10.2460/ajvr.82.10.829
This month's cover images are micro-CT and photomicrographs of proximal sesamoid bones (PSB) of Thoroughbred racehorses following catastrophic PSB fracture. Osteophyte size at the apical and basilar margins was scored and found to positively correlate with accrued total career high-speed furlongs and with catastrophic PSB fracture. The image was obtained as part of the following study: Cresswell EN, Ruspi BD, Wollman CW, et al. Determination of correlation of proximal sesamoid bone osteoarthritis with high-speed furlong exercise and catastrophic sesamoid bone fracture in Thoroughbred racehorses. Am J Vet Res 2021;82:467–477.
This month's cover image is a photograph of multiple cross sections of the prostate gland from a canine cadaver in which microwave ablation with cooling urethral perfusion was performed in 2 zones (white outline and arrow). The median percentage of prostate gland ablation for this and 7 other cadavers in this group was 73%, and urethral mucosal injury was limited. The image was obtained as part of the following study: Traverson M, Lin S, Kendall A, et al. Investigation of the use of microwave ablation with and without cooling urethral perfusion for thermal ablation of the prostate gland in canine cadavers. Am J Vet Res 2021;82:395–404.
This month's cover image is a composite photograph of the bottom of an equine foot that was shod with 5 different types of shoes to determine which one provided the best hoof protection and traction for horses on paved surfaces. Results suggest that shoes coated with a thin layer of tungsten carbide (Panel E), and plastic-steel composite shoes (Panel F) offered the best protection and traction. The image was obtained as part of the following study: Wang P, Takawira C, Taguchi T, et al. Assessment of the effect of horseshoes with and without traction adaptations on the gait kinetics on nonlame horses during a trot on a concrete runway. Am J Vet Res 2021;82:292–301.
Echocardiographic image obtained from a modified apical 4-chamber view used to measure right atrial longitudinal strain (RALS) indices (left), and curves obtained from 120 healthy dogs (right). The right atrial wall is divided into 6 color-coded segments, and the colors correspond to the strain curves, with the average color in white.The authors concluded that age should be considered in the interpretation of RALS indices in clinical settings. Morita T, Nakamura K, Osuga T, et al. Repeatability, reproducibility, and reference intervals for indices of right atrial longitudinal strain derived from speckle-tracking echocardiography in healthy dogs. Am J Vet Res 2021;82:274–279.
This month's cover image is a photograph of a mature (> 18 months old) domestic laying hen (Gallus domesticus) during ovariectomy performed with a vessel and tissue–sealing device through a left lateral celiotomy. Notice the ovary with multiple follicles and yolks of various sizes. The image was obtained as part of the following study: Sullivan JL, Wakamatsu N, Yin J-H et al. Assessment of a vessel and tissue–sealing device for ovariectomy in chickens to evaluate the potential application of the procedure to other avian species. Am J Vet Res 2021;82:310–317.
This month's cover image is a photograph depicting explants harvested from fibrocartilage on the dorsal surface of the deep digital flexor tendon of the forelimb of a horse. To obtain these explants, the navicular bone was dissected from the foot en bloc, and the deep digital flexor tendon segment directly opposing the navicular bone was harvested with aseptic technique. The explants were obtained with a 4-mm biopsy punch. The image was obtained as part of the following study: Sullivan SN, Cole SL, Stewart MC, et al. Ex vivo effects of corticosteroids on equine deep digital flexor and navicular fibrocartilage explant cell viability. Am J Vet Res 2021;82:125–131.
This month's cover image is a photomicrograph depicting the results of immunohistochemical staining for insulin expression in isolated canine insulinoma cells after 48 hours of culture. Insulin content (red stain) varies among individual insulinoma cells (arrowheads). Intact insulinoma cells approximately 10 µm in diameter are enlarged after processing with the cytocentrifuge. The image was obtained as part of the following study: Suwitheechon O, Schermerhorn T. Evaluation of the expression of hexokinase I, glucokinase, and insulin by canine insulinoma cells maintained in short-term culture. Am J Vet Res 2021;82:110–117.
This month's cover image is a photomicrograph of a section of placentome obtained at 80 days of gestation from a pregnant yearling Katahdin ewe that was experimentally inoculated with 4 X 107 TCID50 of a noncytopathic bovine viral diarrhea virus type lb isolate (NY-I strain), intranasally, at 65 days of gestation. The chorioallantois is lined by plump trophoblastic epithelium that contains multifocal areas of intracytoplasmic immunoreactivity for bovine viral diarrhea virus antigen (red-stained tissue). The image was obtained as part of the following study: Lear A, Pohler K, Sula M-JM, et al. Alterations in pregnancy-associated glycoprotein concentrations of pregnant sheep experimentally infected with bovine viral diarrhea virus. Am J Vet Res 2021;82:63–70.
This month's cover image is a photomicrograph of a section of liver tissue from a dog that was euthanized because of development of clinical signs of liver failure 12 weeks after being treated with lomustine (75 mg/m2, PO, q 21 d for 5 doses). Notice that the portal vein profiles are diminished, prominent pigmented macrophages are present in the portal tract and adjacent parenchyma, and persistent biliary hyperplasia is evident. The image was obtained as part of the following study: Dedeaux AM, Flesner BK, Reinhart JM, et al. Biochemical, functional, and histopathologic characterization of lomustine-induced liver injury in dogs. Am J Vet Res 2020;81:810–820.
This month's cover image is a laparoscopic image obtained during microwave ablation of the ovary in a healthy dog. The dog was positioned in dorsolateral recumbency for the procedure, and laparoscopic forceps were used to grasp the proper ligament and elevate and stabilize the ovary. The microwave ablation probe was placed percutaneously through the ventrolateral aspect of the abdominal wall at an orientation parallel to the long axis of the ovary after complete dissection of the ovarian bursa. Notice how dissection of the ovarian bursa improved the visibility of the ovary and facilitated correct positioning of the probe in the central longitudinal axis of the ovary. The image was obtained as part of the following study: Verpaalen VD, Case JB, Dark MJ, et al. Feasibility and efficacy of ultrasonographic and laparoscopic guidance for microwave ablation of clinically normal canine ovaries. Am J Vet Res 2020;81:747–754.
This month's cover features color-coded transverse abdominal MRI images illustrating hepatic apparent diffusion coefficient and hepatic fat fraction in a healthy neutered male cat (top) and a neutered male cat that underwent 40 weeks of dietary intervention to achieve and maintain a body condition score of 7/9 (bottom). Notice the bright violet component in the liver and increased subcutaneous and visceral fat tissue in the bottom cat. The color scale bar depicts approximate percentage fat. The image was obtained as part of the following study: Steger G-L, Salesov E, Richter H, et al. Evaluation of the changes in hepatic apparent diffusion coefficient and hepatic fat fraction in healthy cats during body weight gain. Am J Vet Res 2020;81:796–803.
This months cover image is a perfusion CT image of the abdomen of a healthy Beagle. A region of interest (dotted circle) has been placed over the body of the pancreas, and blood flow is expressed as a color map. The image was obtained as part of the following study: Park S, Jung J-W, Je H, et al. Effect of slice thickness on computed tomographic perfusion analysis of the pancreas in healthy dogs. Am J Vet Res 2020;81:732–738.
This month's cover image is a photomicrograph of a section of neoplastic lymph node from a dog illustrating expression of luteinizing hormone receptors, as determined with an immunohistochemical, LH receptor–specific stain and hematoxylin counterstain. The image was obtained as part of the following study: Ettinger AM, Gust SK, Kutzler MA. Luteinizing hormone receptor expression by nonneoplastic and neoplastic canine lymphocytes. Am J Vet Res 2019;80:572–577.
This month's cover image consists of a series of median plane T2-weighted spin-echo magnetic resonance images and corresponding anatomic sections of cervical intervertebral disks in cadaveric cats. From left to right, the images illustrate increasing stages of intervertebral disk degeneration. The images were obtained as part of the following study: Alisauskaite N, Bitterli T, Kircher PR, et al. Evaluation of agreement and correlation of results obtained with MRI-based and macroscopic observation-based grading schemes when used to assess intervertebral disk degeneration in cats. Am J Vet Res 2020;81:309–316.
This month's cover image is a photomicrograph depicting qualitative histologic scoring of neutrophil infiltration (in this instance, rare neutrophils, or a score of 1 on a scale from 1 to 5) at local injection sites in equids after SC administration of ReqIL-4, ReqIL-8, or a negative control solution, each mixed with a biopolymer carrier. A 6-mm-diameter biopsy punch was used to collect cutaneous and subcutaneous tissues, including the biopolymer plug, at the injection sites. The biopolymer is pink, and the host tissue is saffron-yellow to orange. The image was obtained as part of the following study: Godbout M, Vargas A, Hélie P, et al. Use of a biopolymer delivery system to investigate the influence of interleukin-4 on recruitment of neutrophils in equids. Am J Vet Res 2020;81:344–354.
This month's cover image is a lateromedial radiographic view illustrating locations of soft tissue attachments in the tarsal region of horses. Illustrated locations represent composite findings based on dissection and radiographic imaging of 8 hind limbs from healthy adult horses. The image was obtained as part of the following study: Casillas JM, Jacobs CC, Manfredi JM. Radiographic localization of the attachments of soft tissue structures in the tarsal region of horses. Am J Vet Res 2020;81:406–415.
This month's cover features an endoscopic image of the coelomic cavity in a male bearded dragon (Pogona vitticeps). The endoscope was inserted in a cranial direction through an incision just lateral to the umbilicus. In this image, the gallbladder can be seen between lobes of the liver. The location of the skin incision for the ventral approach was chosen to avoid the ventral abdominal vein and pelvic veins. The image was obtained as part of the following study: Frei S, Sanchez-Migallon Guzman D, Kass PH, et al. Evaluation of a ventral and a left lateral approach to coelioscopy in bearded dragons (Pogona vitticeps). Am J Vet Res 2020;81:267–275.
This month's cover image is a transverse computed tomographic image of the cranial abdominal region in a healthy dog showing placement of regions of interest for evaluation of perfusion of the pancreas (T1 and T2) and liver (T3 and T4). Colors indicate the scale from the lowest (blue) to highest (red) amount of perfusion. The image was obtained as part of the following study: Kloer TB, Rao S, Twedt DC, et al. Computed tomographic evaluation of pancreatic perfusion in healthy dogs. Am J Vet Res 2020;81:131–138.
This month's cover image is a 5-chamber view obtained by use of multidetector computed tomography of the left side of the heart in a healthy adult hound-type dog. The lumen of the left atrium is shaded pink. The image was obtained as part of the following study: Owens EJ, LeBlanc NL, Scollan KF. Comparison of left and right atrial volumes determined by two- and three-dimensional echocardiography with those determined by multidetector computed tomography for healthy dogs. Am J Vet Res 2020;81:33–40.
This month's cover image is an endoscopic image (with the endoscope positioned in a caudal-to-cranial direction) of the abdomen of a rabbit obtained during evaluation of working space achieved with CO2 insufflation to an intra-abdominal pressure of 8 mm Hg. The diaphragm and liver are shown. The image was obtained as part of the following study: Kabakchiev CM, zur Linden AR, Singh A, et al. Effects of intra-abdominal pressure on laparoscopic working space in domestic rabbits (Oryctolagus cuniculus). Am J Vet Res 2020;81:77–83.
This month's cover image is a contrast-enhanced ultrasonographic image of the left kidney of a Beagle obtained at the time of peak enhancement. Notice the placement of 3 regions of interest (black circles) in the renal cortex and 2 regions of interest (white circles) in the renal medulla. Each region of interest area was 0.11 cm2. The image was obtained as part of the following study: Hwang J, Kang K, Kang J, et al. Effect of catheter diameter and injection rate of flush solution on renal contrast-enhanced ultrasonography with perfluorobutane in dogs. Am J Vet Res 2019;80:825–831.
This month's cover image is a dorsal-plane, maximum-intensity CT image, displayed in a bone window, of a cat after injection of contrast medium into a popliteal lymph node. Notice the caudal extent of thoracic duct branching. No other abnormalities were identified during evaluation of baseline CT lymphangiography images. The image was obtained as part of the following study: Dickerson VM, Grimes JA, Secrest SA, et al. Abdominal lymphatic drainage after thoracic duct ligation and cisterna chyli ablation in clinically normal cats. Am J Vet Res 2019;80:885–890.
This month's cover image consists of a 3-D model (left) and a heat map (right) illustrating deviations from the articular surface of the radius of a feline cadaver. The 3-D model illustrates positive differences between models created by use of laser-scanned images and images obtained with CT in a transverse orientation. For the heat map, negative deviations (light to dark blue) indicate that the CT model overestimated the articular surface, and positive deviations (yellow, orange, or red) indicate that the CT model underestimated the articular surface. The image was part of the following study: Webster CE, Marcellin-Little DJ, Koballa EM, et al. Evaluation of the geometric accuracy of computed tomography and microcomputed tomography of the articular surface of the distal portion of the radius of cats. Am J Vet Res 2019;80:976–984.
This month's cover image is a photograph of the ground surface of a bovine hind foot with toe-tip necrosis. The photograph was obtained during application of a static load of 3 kN, and a region-growing technique involving a stylus and tablet was used to process the image to highlight regions of white line separation (yellow areas). The image was part of the following study: Johnston JD, Eichhorn DJR, Kontulainen SA, et al. Investigation of white line separation under load in bovine claws with and without toe-tip necrosis. Am J Vet Res 2019;80:736–742.
This month's cover image is a photomicrograph of a section of neoplastic lymph node from a dog illustrating expression of luteinizing hormone receptors, as determined with an immunohistochemical, LH receptor–specific stain and hematoxylin counterstain. The image was obtained as part of the following: Ettinger AM, Gust SK, Kutzler MA. Luteinizing hormone receptor expression by nonneoplastic and neoplastic canine lymphocytes. Am J Vet Res 2019;80:572–577.
This month's cover image is a volume rendering of the intracranial arteries in a 21-month-old 5-kg mixed-breed dog with idiopathic epilepsy; the image was obtained in the dorsal plane by use of 1.5-T, 3-D, time-of-flight magnetic resonance angiography. Bilaterally, the caudal communicating artery (green) and rostral cerebellar artery (pink) overlap the internal carotid artery (blue), which is located ventral to the caudal communicating artery. The image was obtained as part of the following study: Ishikawa C, Ito D, Tanaka N, et al. Use of three-dimensional time-of-flight magnetic resonance angiography at 1.5 Tesla to evaluate the intracranial arteries of 39 dogs with idiopathic epilepsy. Am J Vet Res 2019;80:480–489.
This month's cover features an echocardiographic image obtained during longitudinal strain analysis in a dog with tricuspid valve dysplasia. The image shows a left apical 4-chamber image that was analyzed with 2-D speckle tracking echocardiography software. The left ventricle is outlined in red by the software. The image was obtained as part of the following study: Santarelli G, Toaldo MB, Bouvard J, et al. Variability among strain variables derived from two-dimensional speckle tracking echocardiography in dogs by use of various software. Am J Vet Res 2019;80:347–357.
This month's cover image represents a propagation map of the right liver lobe of a healthy dog obtained by means of 2-D shear wave elastography in elasticity mode. Notice the consistent parallel contour lines. The image was obtained as part of the following study: Tamura M, Ohta H, Nisa K, et al. Evaluation of liver and spleen stiffness of healthy dogs by use of two-dimensional shear wave elastography. Am J Vet Res 2019;80:378–384.
This month's cover image is a photomicrograph of a skin sample obtained from the incision site of a koi 2 weeks after coelioscopy. The image depicts poor healing; the epithelium is incomplete, and the wound surface is partially covered by a layer of serofibrinous crust and cellular debris. The sides of the incision have separated, and severe pyogranulomatous inflammation extends transmurally through the section, which severely disrupts the normal tissue architecture. Suture material is visible. The image was obtained as part of the following study: Stevens BN, Sanchez-Migallon Guzman D, Phillips KL, et al. Evaluation of diagnostic coelioscopy in koi (Cyprinus carpio). Am J Vet Res 2019;80:221–229.
This month's cover image is a photomicrograph of a portal region in a section of a hepatic biopsy sample from a cat with lymphocytic cholangitis. Bile duct proliferation has been made obvious through immunohistochemical staining of proliferative epithelial progenitors. The image was obtained as part of the following study: Chandler AM, Center SA, Randolph JF, et al. Reference limits for hepatic bile duct-to-arteriole and bile duct-to-portal tract ratios in healthy cats. Am J Vet Res 2019;80:15–23.
This month's cover image is a representative 3-D reconstruction of the entire renal volume in a healthy dog. The image was created by combining CT attenuation values of the entire renal volume (including renal parenchyma) in all transverse planes. The image was obtained as part of the following study: Wallimann M, Richter H, Sieber-Ruckstuhl NS, et al. Influence of injection protocol and measurement technique on computed tomographic assessment of glomerular filtration rate in healthy Beagles. Am J Vet Res 2018;79:1298–1305.
This month's cover image was generated during finite element modeling depicting the minimum principal strain at the bone-pin interface for a 2 transfixation pin–cast construct applied to an equine forelimb. The insert represents a higher magnification of the bone-pin interface outlined by the white line in the main image. Notice that local bone strain at the bone-pin interface was quite high, reaching approximately –15,000 microstrain. The image was obtained as part of the following study: Thomas KL, Carmalt JL, Burnett WD, et al. In vitro mechanical evaluation of three transfixation pin–cast constructs applied to equine forelimbs. Am J Vet Res 2018;79:1287–1297.
This month's cover image is a photomicrograph of equine lamellar tissue following extracorporeal perfusion of the limb with lipopolysaccharide. The section was immunostained for total (active and latent) matrix metalloproteinase-9 (brown). Notice the moderate reaction in fibroblasts, endothelial cells, and suprabasal epidermal cells and intense reaction in basal epidermal cells. The image was obtained as part of the following study: Patan-Zugaj B, Gauff FC, Egerbacher M, et al. Endotoxin-induced changes of type VII collagen–cleaving matrix metalloproteinases in lamellar tissue of extracorporeally perfused equine limbs. Am J Vet Res 2018;79:986–994.
This month's cover image is a scanning electron micrograph of the surface of a cast stainless steel tibial plateau leveling osteotomy plate that had been explanted from a dog. Notice the circular areas of corrosion that can be seen between scratches on the surface of the plate. The image was part of the following study: Sprecher CM, Milz S, Suter T, et al. Retrospective analysis of corrosion and ion release from retrieved cast stainless steel tibia plateau leveling osteotomy plates in dogs with and without peri-implant osteosarcoma. Am J Vet Res 2018;79:970–979.
This month's cover image is a sagittal proton-density fast spin echo image of the supraspinatus tendon of a nonlame 2-year-old sexuallty intact male Beagle. Notice that the collagen-dense fibers of the superficial and deep margins of the supraspinatus tendon have a hypointense signal, whereas the thick water-rich central substance has a hyperintense signal. The image was obtained as part of the following study: Pownder SL, Caserto BG, Hayashi K, et al. Magnetic resonance imaging and histologic features of the supraspinatus tendon in nonlame dogs. Am J Vet Res 2018;79:836–844.
This month's cover image is a photomicrograph of cultured primary canine aortic endothelial cells. Endothelial cells were grown to confluency and fixed in 4% paraformaldehyde, then stained for vascular endothelial–cadherin with rabbit polyclonal anti-CD144 antibody. Fluorescent-labeled goat anti-rabbit lgG was used as the secondary antibody, and cell nuclei were stained with blue fluorescent bisbenzimide stain. The image was obtained as part of the following study: König ML, Lettry SC, Marti E, et al. Validation of a human angiopoietin-2 ELISA for measurement of angiopoietin-2 concentrations in canine plasma samples and supernatant of primary canine aortic endothelial cell cultures. Am J Vet Res 2018;79:803–810.
This month's cover image is a photograph of the left eye of a 24-year-old female horse that was obtained during anterior segment indocyanine green angiography. The image was obtained 18 seconds after injection of indocyanine green and illustrates filling of the radial iris veins. The image was part of the following study: Pirie CG, LoPinto AJ, Tenney WA. Comparison of angiographic dyes and injection techniques for ocular anterior segment angiography in horses. Am J Vet Res 2018;79:562–567.
This month's cover image is a color-coded map created by postprocessing of delayed gadolinium-enhanced magnetic resonance images of the distal sagittal medial midcondylar region of the second phalanx of a horse obtained after injection of gadolinium into the dorsal recess of the distal interphalangeal joint. Different colors represent different cartilage relaxation times, with light green and blue pixels representing articular cartilage. The image was obtained as part of the following study: Bischofberger AS, Fürst AE, Torgerson PR, et al. Use of a 3-Telsa magnet to perform delayed gadolinium-enhanced magnetic resonance imaging of the distal interphalangeal joint of horses with and without naturally occurring osteoarthritis. Am J Vet Res 2018;79:287–298.
This month's cover image consists of photomicrographs of representative cytologic preparations of neutrophils isolated from equine blood samples and cultured for 12 hours with (top) and without (bottom) lipopolysaccharide (1 µg/mL). Treatment with LPS delayed apoptosis of neutrophils for up to 24 hours. The image was obtained as part of the following study: Anderson SL, Townsend HGG, Singh B. Role of toll-like receptor 4 and caspase-3, -8, and -9 in lipopolysaccharide-induced delay of apoptosis in equine neutrophils. Am J Vet Res 2018;79:424–432.
This month's cover image is a transverse CT image of a clinically normal Holstein calf. The calf was anesthetized and received an IV injection of iodinated contrast medium, with dynamic CT scanning of the head initiated at the time of contrast medium injection. The image was created by merging a perfusion CT color map of cerebral blood flow with a conventional CT image of the same slice, and was obtained as part of the following study: Kishimoto M, Kushida K, Yamada K. Perfusion computed tomographic measurements of cerebral blood flow variables in live Holstein calves. Am J Vet Res 2018;79:177–180.
This month's cover image is a photomicrograph depicting the distribution of Helicobacter-like organisms on the mucosal surface of the gastric antrum in a healthy dog. The image was obtained as part of the following study: Suárez-Esquivel M, Alfaro-Alarcón A, Guzmán-Verri C, et al. Analysis of the association between density of Helicobacter spp and gastric lesions in dogs. Am J Vet Res 2017;78:1414–1420.
This month's cover image is a photograph from the caudal aspect of a canine cadaver larynx after bilateral ventriculocordectomy performed via ventral laryngotomy. The image was obtained as part of the following study: Regier PJ, McCarthy TC, Monnet E. Effect of bilateral ventriculocordectomy via ventral laryngotomy on laryngeal airway resistance in larynges of canine cadavers. Am J Vet Res 2017;78:1444–1448.
This month's cover image is a photomicrograph of a tissue section obtained from a horse 120 days after unicortical ostectomy of the third metacarpal bone and filling of the defect with a castor oil polyurethane polymer containing calcium carbonate. There is a degenerating clot on the bone tissue in a pore of the polymer and focal areas of bone matrix. The image was obtained as part of the following study: Nóbrega FS, Selim MB, Arana-Chavez VE, et al. Histologic and immunohistochemical evaluation of biocompatibility of castor oil polyurethane polymer with calcium carbonate in equine bone tissue. Am J Vet Res 2017;78:1210–1214.
This month's cover image is a photomicrograph of equine hematopoietic cells after culturing for B-cell differentiation and immunostaining with antibodies against B-cell signature transcription factor E2A/TCF3 (green) and cell surface molecule CD19 (red); nuclei were stained blue with 4',6-diamidino-2-phenylindole. The image was obtained as part of the following study: Schwab UE, Tallmadge RL, Matychak MB, et al. Effects of autologous stromal cells and cytokines on differentiation of equine bone marrow–derived progenitor cells. Am J Vet Res 2017;78:1215–1228.
This month's cover features an endoscopic image of the upper respiratory tract of a horse after nasopharyngeal administration of contrast medium. The contrast medium is visible on the surfaces of the nasopharynx, laryngopharynx, and larynx. The image was obtained as part of the following study: Colbath AC, Valdés-Martinez A, Leise BS, et al. Evaluation of two methods for topical application of contrast medium to the pharyngeal and laryngeal region of horses. Am J Vet Res 2017;78:1098–1103.
This month's cover features a photomicrograph of a cytologic preparation of bone marrow from a healthy juvenile female New Zealand White rabbit showing large granulocyte precursor cells. The myeloid precursor cells are 2 to 3 times the diameter of mature heterophils. The image was obtained as part of the following study: Riedel RM, de Matos R, Schaefer DMW. Bone marrow cell composition and morphology in healthy juvenile female New Zealand White rabbits (Oryctolagus cuniculus). Am J Vet Res 2017;78:910–918.
The American Journal of Veterinary Research is a fully open access, peer-reviewed, veterinary medical journal owned by the American Veterinary Medical Association that publishes reports of original research and review articles in the general area of veterinary medical research.
The mission of the American Journal of Veterinary Research is to publish, in a timely manner, peer-reviewed reports of the highest-quality research that has the clear potential to enhance the health, welfare, and performance of animals and humans. The journal will maintain the highest ethical standards of scientific journalism and promote such standards among its contributors. In addition, the journal will foster global interdisciplinary cooperation in veterinary medical research.
The American Journal of Veterinary Research supports the collaborative exchange of information between researchers and clinicians by publishing novel research findings that bridge the gulf between basic research and clinical practice or that help to translate laboratory research and preclinical studies to the development of clinical trials and clinical practice. The journal welcomes submission of high-quality original studies and review articles in a wide range of scientific fields, including anatomy, anesthesiology, animal welfare, behavior, clinical pathology, epidemiology, genetics, infectious disease, microbiology, molecular biology, oncology, pharmacology, pathogenic mechanisms, physiology, surgery, theriogenology, toxicology, and vaccinology. Species of interest include production animals, companion animals, equids, exotic animals, birds, reptiles, and wild and marine animals. Reports of laboratory animal studies and studies involving the use of animals as experimental models of human diseases are considered only when the study results are of demonstrable benefit to the species used in the research or to another species of veterinary interest. Other fields of interest or animal species are not necessarily excluded from consideration, but such reports must focus on novel research findings. Submitted papers must make an original and substantial contribution to the veterinary medicine knowledge base; preliminary or pilot studies are not appropriate.