Botox For Horse Lameness?

Hello Summarians!

Wow! Sometimes, the more clarity we have with clinical studies, the more confusing the issues become. Here are some reports that discuss valid and timely issues, but also bring up questions as to how to best apply them.

A true byproduct of the information age that we are living in…

Obesity And Neutering By Breed

Gonadectomy (spay/neuter) is a common and widely accepted procedure in the U.S. that prevents unwanted litters and reduces the risk of certain health issues, including pyometra, mammary neoplasia in females, and benign prostatic hyperplasia and perianal adenomas in males. However, research has shown that gonadectomy can also lead to certain adverse health outcomes, particularly canine obesity (OvOb). Obesity in dogs is associated with various physical, behavioral, and quality-of-life issues. Several studies have identified gonadectomy as a risk factor for obesity, though results vary depending on the breed and age at which the surgery is performed. Most studies report similar obesity rates in gonadectomized dogs of both sexes, but some studies have shown differing results, with male dogs having a higher risk in certain cases, while in others, the opposite is true. 

A foundational study by Banfield Pet Hospital examined the relationship between gonadectomy and obesity in dogs, categorizing them by size group to address previous limitations of breed-based analysis. This study found that gonadectomy increased the risk of obesity across all ages, with toy/small dogs having the highest obesity rates, followed by large breeds. Interestingly, for medium, standard, and giant breeds, gonadectomy was associated with lower obesity rates compared to smaller and larger dogs. 

The study also revealed unexpected findings regarding the timing of gonadectomy. For toy/small, medium, standard, and giant breeds, early gonadectomy (at 3 or 6 months) was associated with equal or lower obesity rates compared to surgery performed at 1 year old. However, for large breeds, early gonadectomy was linked to higher obesity rates. These findings raised questions about the influence of individual breeds within these size categories. 

The present analysis focused on the 10 most recorded toy/small breeds and 5 large breeds in the Banfield data set. It found that gonadectomy generally increased obesity rates in these breeds, but the risk varied by breed and age at surgery. For toy/small breeds, gonadectomy at 3 or 6 months posed less risk or no significant difference compared to gonadectomy at 1 year or older. The results for large breeds were more variable, with breeds such as Labrador Retrievers and Golden Retrievers showing increased obesity rates when gonadectomy was performed at 3 or 6 months. Other large breeds like German Shepherds and Boxers showed different outcomes depending on the timing of the surgery. 

One notable finding was that certain breeds, such as Pugs, had the highest overall rates of obesity regardless of whether they were gonadectomized or intact, highlighting their genetic predisposition to weight issues. In general, male dogs exhibited higher obesity rates than females across most breeds, though this trend was not universal. 

Several factors contribute to obesity in dogs beyond reproductive status, including environmental influences, such as diet and physical activity. Studies have shown that human behaviors, such as feeding practices and exercise routines, significantly impact pet obesity outcomes. Moreover, genetic factors, such as mutations in the POMC gene, have been linked to obesity in certain breeds like Labrador Retrievers. 

While this study provided valuable insights, it also had limitations, such as not accounting for factors like feeding practices and exercise, and it did not exclude dogs with conditions that could influence obesity risk. The sample was also not fully representative of the broader population, as toy/small breeds were overrepresented. Furthermore, the breed designation used in this study relied on medical records, which may not always accurately reflect a dog’s true breed, particularly for mixed breeds. 

Ultimately, these findings underscore the complexity of the decision to spay or neuter a dog. While gonadectomy provides significant health benefits, including the prevention of unwanted litters and the reduction of certain health risks, the increased risk of obesity in some breeds, especially when performed at an early age, should be considered in decision-making. Veterinarians, dog owners, and shelters should be proactive in addressing obesity risks through management strategies such as proper diet, exercise, and weight monitoring, particularly for breeds predisposed to obesity regardless of their reproductive status. 

Benka, V. A., Sahrmann, J. M., Rieke, K., Briggs, J. R., Spofford, N., Zawistowski, S., Ruple, A., Romagnoli, S., & Morrison, J. A. (2025). Gonadectomy status and age are associated with variable risk of overweight or obese outcomes in 15 dog breeds: a retrospective cohort study using data from primary care veterinary clinics. Journal of the American Veterinary Medical Association https://doi.org/10.2460/javma.24.12.0834 

Bottom line — Shows the complexity of advising on neutering.

Efficacy of Alcohol Hand Scrubs

Hand preparation with aseptic technique is a critical factor in reducing surgical site infections and improving patient outcomes. Traditional methods have included a 5-minute scrub with chlorhexidine or povidone iodine-based detergents, which aim to reduce bacterial growth on the surgeon's hands. However, studies have shown that these detergents are equally effective at reducing bacterial counts following a 5-minute scrub. Recent research has shifted toward alcohol-based antiseptics, as recommended by the WHO and CDC, for their efficacy in preoperative hand antisepsis. 

A study by Chou et al. compared different alcohol-based hand rubs, including a combination of 61% ethanol and 1% chlorhexidine gluconate, a 30% 1-propanol and 45% 2-propanol solution, and a 70% 2-propanol solution, alongside a traditional 5-minute chlorhexidine scrub. They found that both the ethanol-chlorhexidine product and the 5-minute scrub were most effective in reducing bacterial counts. However, the results for other alcohol-based solutions were less effective. 

The efficacy of commonly used products like Sterillium, an 80% ethanol-based solution, and Avagard, a 61% ethanol and 1% chlorhexidine gluconate product, has been compared in previous studies with mixed outcomes. Kampf and Ostermeyer found that the 80% ethanol solution effectively reduced bacterial counts, while Chou et al. showed that the ethanol-chlorhexidine combination was equally effective. The discrepancies in findings between these studies were attributed to differences in the methods used to test bacterial reduction. Kampf and Ostermeyer employed fingertip sampling, which focuses on the high bacterial density of the fingertips, while Chou et al. used the glove-juice method, which samples the entire hand. This discrepancy highlights that different testing methods may yield varying results for different products. 

The current study aimed to evaluate the efficacy of two alcohol-based hand rubs—one containing 61% ethanol and 1% chlorhexidine gluconate and the other containing 85% ethanol—using the glove-juice method. Both products were found to significantly reduce bacterial counts immediately after application, with a reduction of at least one Log10 as required by the US standard. Interestingly, only the ethanol-chlorhexidine combination was effective at maintaining reduced bacterial counts one hour after application, suggesting that it may be more suitable for longer surgeries. These findings contradict those of Kampf and Ostermeyer, where the 61% ethanol and 1% chlorhexidine combination was not as effective. 

While this study supports the efficacy of both products for surgical hand antisepsis, it acknowledges several limitations, such as the lack of clinical testing and the low sample size. The study also did not account for potential contamination during routine activities between the application and the one-hour mark. Future research in clinical surgical settings is needed to further validate these findings, especially in terms of product longevity and real-world applicability. 

Whisenant, K. D., Stewart, H. L., Kelly, D., Barnhart, D., Rossney, V., Richardson, D. W., & Levine, D. (2025). Short-term bactericidal properties differ between 2 alcohol-based surgical antiseptic products using the glove-juice technique. Journal of the American Veterinary Medical Association https://doi.org/10.2460/javma.25.02.0093 

Bottom line — Supports efficacy with caveats.

Botox For Horse Lameness

The management of equine osteoarthritis has significantly advanced over the past few decades, with joint pain being a major factor leading to lameness, affecting both performance and animal welfare. Pain stimuli in osteoarthritis can result from direct tissue damage and inflammatory processes, which are detected by various receptors in the joint tissues and relayed to the brain for processing. Medications such as systemic NSAIDs and intra-articular corticosteroid injections have been used to manage pain and inflammation. However, these treatments can cause side effects like chondrocyte necrosis and reduced proteoglycan synthesis, and some horses may not respond well to these drugs, necessitating additional therapies. 

One promising alternative is botulinum toxin type A (BoNT-A), a neurotoxin known for its ability to block the release of acetylcholine and neurotransmitters involved in nociceptive pathways. This property has been explored in human medicine and more recently in veterinary medicine. BoNT-A has shown promise in relieving pain associated with various conditions in humans and animals, including joint pain. Initial studies in dogs and horses have indicated that BoNT-A could provide pain relief with minimal side effects. For instance, a small pilot study in horses suggested that BoNT-A could reduce lameness associated with experimentally induced synovitis, while a more recent study found that it was safe for intra-articular use in horses, producing no local or systemic adverse effects. 

The objective of the study in question was to assess the efficacy of a single intra-articular injection of BoNT-A in horses with naturally occurring chronic distal tarsal osteoarthritis. The results demonstrated that a 50 U injection of BoNT-A alleviated pain related to the tarsometatarsal (TMT) and calcaneocuboid (CD) joints, with significant improvement in lameness observed up to 180 days after treatment. Early responses were evident as well, with two horses showing complete lameness relief within 24 hours of treatment. This study marks the first investigation into the use of BoNT-A for osteoarthritis pain management in horses and highlights the potential long-lasting antinociceptive effects of the neurotoxin, which were superior to those observed with placebo and comparable to other clinical trials in humans and dogs. 

While the study provided promising results, it also had some limitations. The sample size was small, and only the TMT and CD joints were tested. Further studies are needed with larger sample sizes and a broader range of joint types, particularly high-motion joints. The lack of radiographic confirmation of needle placement in some horses and the potential for misdiagnosis at the time of study enrollment were also recognized as limitations. Nonetheless, this study opens new avenues for managing chronic osteoarthritis in horses, particularly those who are retired or have refractory joint pain, without the need for more invasive treatments like surgical arthrodesis. 

In conclusion, BoNT-A showed significant potential as a safe and effective treatment for pain relief in horses with distal tarsal osteoarthritis. While the findings are promising, further research is necessary to refine the treatment and explore its full potential in veterinary medicine. 

Beck, A. A., Jr, Paz, L. B., Frank, M. I., Pereira, R. C. F., & De La Côrte, F. D. (2025). Lameness improvement in horses with distal tarsal pain after intra-articular injection of botulinum neurotoxin type A. American Journal of Veterinary Research https://doi.org/10.2460/ajvr.24.10.0294 

Bottom line — Potentially useful for therapy protocol

Just putting things in perspective …