Comparison of two methods for presurgical disinfection of the equine hoof

A novel transcoronal surgical technique for the treatment of cystic lesions of the distal phalanx: A cadaveric study

OBJECTIVE

To assess the feasibility of a novel transcoronal approach for the treatment of axial type 3 cysts of the palmar/plantar aspect of the distal phalanx (P3).

STUDY DESIGN

Ex vivo, experimental study.

SAMPLE POPULATION

Ten cadaveric specimens, four forelimbs and six hindlimbs.

METHODS

All cadaveric specimens underwent radiographically guided drilling, followed by cortical screw placement. The cartilage was macroscopically assessed after disarticulation of the distal interphalangeal joint. The entry point and trajectory were evaluated with computed tomography. Results were categorized as: axial, near-axial and abaxial. The minimal distance from the outer margin of the drill hole and the proximal border of the subchondral bone plate was measured using frontal computed tomographic slices.

RESULTS

Eight of the 10 screws were in an axial to near-axial position and nine followed the desired axial to near-axial trajectory. One screw was inserted axially but continued in an abaxial trajectory. Iatrogenic damage to the joint cartilage, flexor cortex and solar canal of P3 was not observed. All cortical screws were placed close to the proximal subchondral bone-plate of P3.

CONCLUSION

The desired axial/near-axial drilling and screw placement, under radiographic guidance, was achieved in nine out of 10 specimens.

CLINICAL SIGNIFICANCE

This novel technique seems promising for the treatment of inaccessible P3 cysts. Additional studies are required to investigate its feasibility in clinical cases, and the long-term outcome following transcystic screw placement of type 3 P3 cysts.

Computed tomographic guidance for internal fixation of type II distal phalangeal fractures in 51 horses

BACKGROUND

Type II distal phalanx (P3) fractures are a well-described cause of lameness in horses. Reports on outcome following internal fixation of type II P3 fractures are lacking, and with little emphasis on complications.

OBJECTIVE

To describe a technique for internal fixation of type II P3 fractures, and evaluate whether specific variables influenced post-operative complications or a horse's ability to return to work.

STUDY DESIGN

Retrospective case series.

METHODS

Medical records of 51 horses with CT-guided internal fixation of type II P3 fractures were reviewed. Outcome data were acquired from race records and telephone interviews. Associations between independent variables and outcome were analysed using multivariable logistic regression.

RESULTS

Eighty-six per cent (95% CI 74%-94%; n = 44) successfully returned to work. Implant infection (n = 15) and distal interphalangeal joint osteoarthritis (n = 9) were the most common complications, with the latter reducing the likelihood of success (OR = 0.09, 95% CI 0.01-0.7, P = .02). Implant infection increased the time to return to work (HR = 0.5, 95% CI 0.2-0.9, P = .03). The odds of delayed infection decreased by filling the hoof defect with acrylic hoof adhesive rather than poly(methyl methacrylate) and deeply countersinking the screw head (OR = 0.08, 95% CI 0.02-0.38, P = .001); the individual effect of each treatment is unknown. Radiographic healing was not associated with likelihood of success.

MAIN LIMITATIONS

Study limitations included variation in follow-up methods, lack of control population for comparison and lack of randomisation of treatment protocols.

CONCLUSIONS

Internal fixation of type II P3 fractures is an effective treatment that allows horses to return to athletic use, with similar improved success rates as those reported for conservative management. Infection rates were reduced by deeply countersinking the screw head and filling the hoof defect with an acrylic that mimics hoof wall flexibility and provides a secure seal. Recommencement of training should be based on clinical rather than strictly radiographic findings.

Colloidal Iron Oxide Formulation for Equine Hoof Disinfection

The presence of bacteria of various origins on horse hoofs enables the onset of infections following trauma or even post-surgical wounds. Thus, the analysis of new antibacterial substances is of fundamental importance. In this study, the antibacterial efficacy of Iron Animals (IA), a stable colloidal suspension of iron oxide, organic acids, and detergents, was tested in vitro and in vivo. In vitro assays were performed to test the unspecific inhibitory effect of IA on both gram-positive and gram-negative bacteria monitoring the microorganism growth by spectrophotometry (optical density OD600) at 37 °C for 24 h. In vivo test consists on the quantification of the bacterial load in colony forming units per gram (CFU/g) of specimens collected from the frog region of the anterior hooves of 11 horses. Sampling followed the application of four disinfectant protocols consisting of two consecutive 3 min scrubs with 50 mL of 10% Povidone-iodine (PI) or 4% Chlorhexidine (CHx), with or without an additional application for 15 min of 10 mL of Iron Animals (PI+IA and CHx+IA). In vitro, IA completely suppressed the bacterial growth of all the tested microorganisms, resulting in effectiveness also against CHx-resistant bacteria, such as Staphylococcus aureus. In vivo, PI emerged as an ineffective protocol; CHx was effective in 18% of cases, but with the addition of IA (CHx + IA) its use emerged as the best disinfectant protocol for horse hoof, achieving the lowest bacterial load in 55% of cases. The addition of IA, after PI or CHx, improves the effectiveness of both disinfectants leading to the highest bactericidal activity in 82% of cases.

Intrigues of biofilm: A perspective in veterinary medicine

Biofilm has a tremendous impact in the field of veterinary medicine, especially the livestock industry, leading to a serious economic loss. Over the years, little attention has been given to biofilm in animals with most of the research geared toward human biofilm diseases. The greatest challenge posed by biofilm is in its incredible ability to resist most of the currently existing antibiotics. This mystery can best be demystified through understanding the mechanism of the quorum sensing which regulate the pathophysiology of biofilm. Ability of biofilm formation in a variety of inanimate surfaces such as animal food contact surfaces is responsible for a host of biofilm diseases affecting animals and humans. In this review, we highlighted some of the challenges of biofilm in livestock and food industries. Also highlighted are; mechanisms of biofilm development, best diagnostic approach and possible novel therapeutic measures needed to combat the menace of biofilm in veterinary medicine.

Effect of Presurgical Iodine-Based Disinfection on Bacterial Colonization of the Equine Peripodal Region

OBJECTIVE

To compare bacterial colonization after diluted iodine tincture or povidone iodine solution for presurgical disinfection of the equine peripodal region.

STUDY DESIGN

Complete block design.

ANIMALS

Five horses.

METHODS

Disinfection protocols using iodine tincture or povidone iodine solutions were tested on 5 pairs (n = 10) equine front feet. Iodine tincture was applied to the left feet and povidone iodine to the right feet. Fixed surfaces of the sole, frog, hoof wall, and peripodal skin were swabbed pre-preparation (T0), after a standard pre-disinfection step (T1), after short disinfection with a 4-minute application of 0.5% iodine tincture or povidone iodine (T2), and after long disinfection with 12-hour soaking in 0.25% iodine tincture or povidone iodine (T3). Quantitative bacteriology was performed on each swab.

RESULTS

The frog and sole were the most contaminated sites compared to hoof wall and skin at T0. Bacterial counts were significantly decreased at T2 for both solutions. Bacterial counts did not change significantly with iodine tincture at T3 but increased with povidone iodine compared to T2. Skin abrasions were detected on almost all feet but were subjectively more severe on iodine tincture-treated feet.

CONCLUSION

Soaking for 12 hours with either iodine tincture or povidone iodine is not recommended as these solutions damaged the skin and bacterial recolonization was noted with povidone iodine. Four-minute disinfection using either iodine tincture or povidone iodine (0.5% available iodine) is appropriate for presurgical preparation of the equine peripodal region.

Septic osteitis of the distal phalanx in foals: 22 cases (1995–2002)

OBJECTIVE

To determine the clinical characteristics and outcome of foals with septic osteitis of the distal phalanx.

DESIGN

Retrospective case series.

ANIMALS

22 foals.

PROCEDURES

Information obtained from medical records included signalment; clinical, laboratory, and radiographic findings; treatment method; and outcome. Foals included in the study had lameness referable to the foot, radiographic evidence of localized lysis or focal loss of bone density of the distal phalanx, and suppurative discharge or necrosis of the affected bone evident at surgery. Foals with a history or evidence of penetrating wounds or subsolar abscessation were excluded.

RESULTS

Mean age of foals at initial evaluation was 40.8 days (range, 3 to 122 days). Twenty-one (95%) foals had lameness as the primary complaint. Lesions consistent with septic osteitis of the distal phalanx localized to specific areas of the bone on the basis of radiographic and surgical findings were located on the solar margin or toe (14/22 [64%]), extensor process (5/22 [23%]), and palmar or plantar process (3/22 [13%]). Hind limbs (18/26 [69%] affected limbs) were more frequently affected. Two foals had > 1 affected limb, 2 had additional sites of osteomyelitis, and 4 had concurrent septic arthritis. Surgical debridement and regional antimicrobial perfusion were performed during general anesthesia. Extensor process lesions were not debrided. Nineteen of 22 (86%) foals survived to be discharged from hospital, and 16 horses reached racing age. Eleven of 16 had race starts, of which 8 had official race starts and 3 had unofficial race starts.

CONCLUSIONS AND CLINICAL RELEVANCE

Septic osteitis of the distal phalanx should be considered as a source of lameness in foals with signs referable to the foot and does not necessarily preclude a career in racing. Although infection may occur secondary to bacterial penetration of the hoof or sole, the distal phalanx should also be considered as a potential site for hematogenous septic arthritis or osteomyelitis in foals.

Biofilms and their relevance to veterinary medicine

Bacteria are renowned for their ability to tolerate and adapt to a wide range of adverse environmental conditions. The primary mechanism that facilitates these adaptations is thought to be the capacity to form and maintain biofilms. Within a biofilm, bacteria become attached to a surface where they exist in complex communities which are able to interact with each other through intracellular communication and thus rapidly adapt to changing environments. The organisms within biofilms are notorious for their resistance towards the host immune response and antibacterial agents compared to their free-living planktonic counterparts. Consequently, biofilms are of significant importance to both clinical and veterinary science. However, although bacterial infections are widely reported in animals their association with biofilms is rarely discussed. The aim of this review is to look at the characteristics of biofilm infections in humans and to relate this knowledge to veterinary science in order to assess their relevance in this area.

Management of equine hoof injuries

Hoof injuries are common in horses. Some wounds can pose diagnostic and treatment challenges because of the rigid nature of horn,the tissue involved, the deeper underlying structures eventually invaded, or the pattern of healing. By combining knowledge about the anatomy and biomechanical properties of the foot and healing characteristics of the hoof with adapted general principles of wound management, satisfactory clinical outcomes usually result.