OBJECTIVE To assess the repeatability and accuracy of polymer replicas of small, medium, and large long bones of small animals fabricated by use of 2 low-end and 2 high-end 3-D printers. SAMPLE Polymer replicas of a cat femur, dog radius, and dog tibia were fabricated in triplicate by use of each of four 3-D printing methods. PROCEDURES 3-D renderings of the 3 bones reconstructed from CT images were prepared, and length, width of the proximal aspect, and width of the distal aspect of each CT image were measured in triplicate. Polymer replicas were fabricated by use of a high-end system that relied on jetting of curable liquid photopolymer, a high-end system that relied on polymer extrusion, a triple-nozzle polymer extrusion low-end system, and a dual-nozzle polymer extrusion low-end system. Polymer replicas were scanned by use of a laser-based coordinate measurement machine. Length, width of the proximal aspect, and width of the distal aspect of the scans of replicas were measured and compared with measurements for the 3-D renderings. RESULTS 129 measurements were collected for 34 replicas (fabrication of 1 large long-bone replica was unsuccessful on each of the 2 low-end printers). Replicas were highly repeatable for all 3-D printers. The 3-D printers overestimated dimensions of large replicas by approximately 1%. CONCLUSIONS AND CLINICAL RELEVANCE Low-end and high-end 3-D printers fabricated CT-derived replicas of bones of small animals with high repeatability. Replicas were slightly larger than the original bones.

Bacterial biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that is attached to a surface. Biofilms protect and allow bacteria to survive and thrive in hostile environments. Bacteria within biofilms can withstand host immune responses, and are much less susceptible to antibiotics and disinfectants when compared to their planktonic counterparts. The ability to form biofilms is now considered an attribute of many microorganisms. Diseases associated with biofilms require novel methods for their prevention, diagnosis and treatment; this is largely due to the properties of biofilms. Furthermore, the presence of biofilms on surfaces found at farms, slaughterhouses or food processing plants will have an impact on the efficacy of disinfection protocols. Surprisingly, biofilm formation by bacterial pathogens of veterinary or zoonotic importance has received relatively little attention. The objective of this brief Review article is to bring awareness about the importance of biofilms to animal health stakeholders.

Epiglottic augmentation was evaluated in 7 horses, using 7 ml of polytetrafluoroethylene (polytef) paste injected submucosally on the ventral surface of the epiglottis. In 6 horses, an Arnold-Bruning intracordal injection syringe, specifically designed to inject polytef into paralyzed vocal folds in human beings, was used. At necropsy 60 days after surgery, group mean thickness measurement 20 mm from the epiglottic tip was 40% greater (P < 0.01) and, at the epiglottic attachment of the aryepiglottic fold, was 29% greater (P < 0.01) in the 6 polytef-augmented horses than in clinically normal nonsurgically treated controls. At necropsy, extensive epiglottic thickening was seen. This thickening was exclusively attributable to distention of submucosal areas in the ventral aspect of the epiglottis, with foreign body granulomata surrounded by fibrous connective tissue. In 1 horse, polytef paste was injected by use of a disposable syringe and needle. Excess ventral epiglottic swelling and exposed epiglottic cartilage was seen during subsequent endoscopy. At necropsy 60 days after surgery, the epiglottic contour remained deformed and a large deep mucosal ulcer was observed at the injection site. Histologic examination revealed necrotizing suppurative inflammation that extended into the epiglottic cartilage. Surgery was not technically difficult to perform through a laryngotomy, and all horses tolerated the procedure without apparent discomfort. Endoscopy performed after surgery revealed unremarkable and uniform response to the polytef paste in 4 horses, and in 3 horses, revealed excess swelling and inflammation of the ventral epiglottic tissue that resolved over time. Overdistention of the submucosal space with polytef may have accounted for the undesirable tissue responses that developed, including excess inflammation in the ventral epiglottic tissue in 3 horses, migration of polytef in 4 horses, and ventral mucosal ulceration in 3 horses. Thickening of the ventral epiglottic surface that was readily apparent in all horses at necropsy could not be reliably distinguished endoscopically in conscious horses. Qualitative changes in epiglottic thickness and contour could be distinguished on lateral-view laryngeal radiographs; however, thickness measurements made from radiographs did not correlate accurately with actual thickness measurements made at necropsy.

Cartilage retention strengths of laryngoplasty prostheses were compared in larynges of 2-, 3-, and 4-year-old horses, using doubled polyester and expanded polytetrafluoroethylene prostheses. Bilateral laryngoplasties were performed on each of 15 (seven 2-year-old, two 3-year-old, and six 4-year-old) larynges, which were collected at an abbatoir. Prostheses were secured to a mechanical testing machine, and tension causing arytenoid cartilage abduction was applied, until total failure of the cartilage or prosthesis resulted. Tension caused cricoid cartilage failure in 1 specimen, and muscular process cartilage failure in the remainder. There was no significant effect of age, prosthetic material, or side of prosthesis placement on cartilage retention of the prostheses. Additionally, frequency of multiple load-displacement peaks, indicating partial muscular process failure, was not affected by age or prosthetic material variables.

In addition to its well-known physicochemical properties, hyaluronate (HA) has recently been shown to have important biological and pathophysiologic regulatory effects on granulocytes, monocytes, fibroblasts, and endothelial cells, as well as on the healing of wounds and various joint disorders. Many of these effects depend on or are reflected in the concentration and degree of polymerization of HA. Therefore, high-performance liquid chromatography with size-exclusion column was used to characterize the concentration and degree of polymerization of HA in equine synovial fluid (SF). The mean (+/-SD) HA concentration was 0.47 +/- 0.19 mg/ml and there was no difference between control joints and those with positive response to local anesthetic administration (0.61 +/- 0.20 mg/ml vs 0.42 +/-0.17 mg/ml), suggesting that in horses with acute traumatic synovitis causing lameness, HA concentration in SF cannot be used as a marker for the condition. High-performance liquid chromatograms disclosed considerable variation between horses in the degree of polymerization reflected in the peak area to height ratio (mean +/-SD, 3.207 +/- 0.447; range, 2.229 to 3.915), indicating differences in local synthesis, degradation, or mobilization into lymph of SF HA. In addition, the correlation between SF HA concentration and degree of polymerization was 0.760 (P < 0.01; linear regression analysis) suggesting that HA concentration and chain length are independently regulated.