Botox For Laminitis?

Hello Summarians!

Although it is usually recognized as the plastic surgeon’s best friend, Botox was originally approved for use in eye muscle disorders. It blocks the transmission of nerve signals, making it useful for a variety of applications. This study talks about one of those applications.

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Post Op Regurgitation Therapy In Dogs

This prospective, randomized, blinded clinical trial evaluated whether intraoral administration of a lignocaine–phenylephrine spray could reduce opioid requirements and postoperative complications in brachycephalic dogs undergoing surgery for brachycephalic obstructive airway syndrome (BOAS). Ninety-eight client-owned dogs were enrolled and randomly assigned to receive either the active spray or a placebo prior to surgery, alongside a standardized anesthetic and perioperative protocol. The study aimed to determine whether this locoregional vasoconstrictive anesthesia technique could reduce reliance on opioids and improve postoperative outcomes. 

The results showed that the spray did not significantly reduce intraoperative or postoperative opioid requirements. Rates of rescue methadone administration and other anesthetic interventions were similar between treatment and placebo groups, indicating no measurable antinociceptive benefit in terms of opioid sparing. However, a substantial difference was observed in postoperative complications, particularly regurgitation. Dogs in the placebo group had significantly higher odds of regurgitation compared to those receiving lignocaine–phenylephrine, with an odds ratio of 8.1. Overall complication rates were also higher in the placebo group. 

The authors propose that the beneficial effect on regurgitation may be related to improved airway comfort during recovery, reduced stress and respiratory effort, and possibly decreased aspiration of blood due to vasoconstriction. These factors may help prevent the cascade of increased negative intrathoracic pressure and gastrointestinal reflux that commonly affects brachycephalic dogs. The effect appeared consistent even in dogs with preexisting risk factors, such as a history of regurgitation or mild laryngeal collapse. 

Despite these promising findings, the study had limitations, including variability in surgical procedures, clinician decision-making, and a lack of objective pain scoring. Additionally, the mechanism of action and pharmacokinetics of the spray in dogs remain incompletely understood. 

In conclusion, while intraoral lignocaine–phenylephrine did not reduce opioid use, it significantly decreased postoperative regurgitation and overall complications. This technique may serve as a simple, low-risk adjunct within multimodal anesthesia protocols for BOAS surgery. 

Graham, M., King, J., Atkinson, P., & Corfield, G. (2026). Lignocaine and phenylephrine spray prior to brachycephalic obstructive airway syndrome surgery in dogs reduces postoperative regurgitation: a prospective, randomized, controlled trial. Journal of the American Veterinary Medical Association https://doi.org/10.2460/javma.25.12.0853 

Bottom line — Low-risk intervention may be useful.

Hypoxemia And Heart Disease

This retrospective study evaluated whether arterial blood gas analysis (ABGA) can detect clinically meaningful changes in oxygenation in dogs with myxomatous mitral valve disease (MMVD), and how these changes relate to echocardiographic and radiographic findings. The authors compared dogs without significant cardiac disease (control/B1) to dogs with stage B2 and stage C MMVD, and further stratified disease severity using echocardiographic markers (left atrium-to-aorta ratio and E-wave velocity). 

The key finding was that dogs with more advanced MMVD (stages B2 and C) had significantly lower arterial oxygen levels (Pao₂) compared to controls, despite the absence of radiographic evidence of pulmonary edema. The degree of hypoxemia worsened as echocardiographic indicators of disease severity increased, particularly in dogs with both elevated E-wave velocity and enlarged left atria. Notably, a substantial proportion of dogs exhibited moderate to severe hypoxemia, suggesting impaired pulmonary gas exchange even when standard imaging appeared normal. 

The study also highlighted that concurrent respiratory disease, such as bronchomalacia and tracheal collapse, was common across all groups and may contribute to reduced oxygenation. However, the worsening hypoxemia seen with increasing cardiac severity—even when airway disease prevalence was similar—suggests that progression of MMVD itself plays a central role. The elevated alveolar-arterial oxygen gradient further supports the presence of gas exchange abnormalities, likely due to subtle or early pulmonary changes not detectable on radiographs. 

These findings have important clinical implications. Traditional diagnostic tools like thoracic radiography and echocardiography may fail to identify early pulmonary dysfunction in MMVD. ABGA, by directly measuring arterial oxygenation, can detect hypoxemia earlier and may provide a more sensitive assessment of disease impact on pulmonary function. When combined with echocardiographic parameters, especially those reflecting left atrial pressure and volume overload, ABGA may improve staging accuracy, guide treatment decisions, and help assess prognosis. 

The study is limited by its retrospective design, small sample size, and inclusion of dogs with concurrent respiratory disease, which may confound interpretation. Nonetheless, it provides evidence that hypoxemia is present in preclinical and clinical MMVD and is associated with disease severity, supporting the use of ABGA as an adjunctive diagnostic tool in affected dogs. 

Seki, D., Goya, S., Teshima, K., & Yamaya, Y. (2026). Incidence of hypoxemia is associated with echocardiographic findings in dogs with advanced myxomatous mitral valve disease. Journal of the American Veterinary Medical Association https://doi.org/10.2460/javma.25.11.0726 

Bottom line — It is useful to be aware of potential implications

Botox For Laminitis Therapy

This study evaluated the biomechanical effects of injecting botulinum toxin into the deep digital flexor (DDF) muscle of healthy horses, with the goal of understanding its potential role in managing laminitis. Six horses received a unilateral injection, with the opposite limb serving as a control. Ground reaction forces (GRF) and center of pressure (COP) were measured over time during both standing and walking. 

The results showed that botulinum toxin produced a transient but measurable shift in hoof biomechanics. At seven days post-injection, peak GRF at the toe decreased by approximately 20%, while forces in the heel region increased significantly. This redistribution of load indicates that weight-bearing shifted away from the toe toward the palmar aspect of the foot. In parallel, the COP moved palmarly by about 10 mm during standing and 6 mm during walking, suggesting a reduction in the mechanical moment acting on the distal phalanx. These effects were temporary, largely resolving by 14 days after injection. 

The findings support the hypothesis that reducing DDF muscle activity decreases rotational forces on the distal phalanx, thereby potentially lowering strain on the dorsal lamellae. This is clinically relevant because excessive tension from the DDF tendon contributes to lamellar damage and distal phalangeal rotation in laminitis. Unlike orthotic interventions that alter hoof-ground contact, botulinum toxin appears to reduce these forces intrinsically without changing hoof orientation. 

However, the magnitude of biomechanical change was smaller than that achieved with orthotic devices, which produced greater reductions in toe forces. The study also highlights limitations, including small sample size, use of healthy rather than laminitic horses, and indirect assessment of lamellar stress. 

Overall, botulinum toxin injection into the DDF muscle appears to be a safe, short-acting intervention that can temporarily redistribute hoof loading and reduce forces associated with lamellar injury. It may serve as a useful adjunct therapy in acute laminitis, particularly during the early phase when preventing distal phalangeal rotation is critical. 

Slavik, K., Underwood, C., Lowndes, C., Skelton, G., & van Eps, A. (2026). The effect of botulinum toxin injection into the deep digital flexor muscle on foot biomechanics in healthy horses. American Journal of Veterinary Research https://doi.org/10.2460/ajvr.25.12.0452 

Bottom line — May be useful adjunct therapy

Just putting things in perspective …