3D Gait Analysis in Dogs

Hello, Summarians!

Is technology ready to replace the human eye, experience, and a hands-on physical exam? I’ll let you be the judge…

Also, an interesting study about magnesium and renal disease. Enjoy. 🙂 

Please give me feedback on ways I can make it more useful to you.

If it is valuable to you please consider sending it on to a friend 😄 

3D Gait Analysis in Dogs

In veterinary practice, diagnosing gait abnormalities in dogs often relies on subjective observation, which can be less accurate compared to objective methods. Kinematic data, which offer a more objective view, can help veterinarians diagnose musculoskeletal and neurological disorders and monitor treatment progress. While 3-D kinematic gait analysis is considered the gold standard, it is often limited to research settings due to its high cost and complexity. Recent studies suggest that 2-D kinematic gait analysis might also be effective in detecting abnormal limb movements and has become more accessible due to advances in technology. 

Kinovea, a free and open-source software for 2-D kinematic motion analysis, has been increasingly used in veterinary research. It allows for the analysis of video recordings with minimal technical effort and has been employed in various studies, including those on canine sports medicine, aquatic motion analysis, and the impact of harnesses on working dogs. However, Kinovea has not yet been validated for kinematic gait analysis in dogs. 

This study aimed to evaluate Kinovea’s accuracy in 2-D kinematic gait analysis of healthy dogs walking on a treadmill, comparing it with a 3-D motion analysis system. Healthy large-breed dogs were used, and both systems recorded kinematic data at different frequencies and setups. Kinovea provided acceptable accuracy for most forelimb joints but had limitations with the carpal joint and hindlimb joints due to perspective distortion and recording angles. Despite these limitations, Kinovea’s joint angle measurements were generally considered acceptable for most joints and gait cycle increments. 

The study highlighted that while Kinovea offers a cost-effective alternative to 3-D systems, it has specific limitations, including issues with perspective distortion and tracking accuracy, particularly in varying lighting conditions and with different coat colors. Future studies should address these limitations and explore Kinovea’s accuracy in dogs with musculoskeletal disorders and different sizes. 

Winkler, E. V., Lauer, S. K., Steigmeier-Raith, S. I., Zablotski, Y., & Mille, M. A. (2024). Accuracy of Kinovea-based kinematic gait analysis compared to a three-dimensional motion analysis system in healthy dogs. American Journal of Veterinary Research https://doi.org/10.2460/ajvr.24.05.0128 

Bottom line — Shows some early promise with limitations.

US Staging After Splenic Rupture.

The study aimed to assess the reliability of preoperative abdominal ultrasonography for staging dogs with hemoperitoneum due to presumed splenic tumor rupture, specifically focusing on liver metastases. 

Ninety-nine dogs from 20 hospitals across the US, enrolled in a prospective trial, were included. The study found that preoperative ultrasonography identified liver lesions in 20% of cases, but these findings were not consistently associated with liver lesions observed during surgery. Notably, 22% of liver lesions detected during surgery were not seen on preoperative ultrasonography. The sensitivity of ultrasonography for detecting metastatic disease in the liver was low, at 19%, with a specificity of 82%. 

The presence of liver lesions on ultrasonography was linked to a higher likelihood of a benign splenic tumor diagnosis rather than metastatic disease. Furthermore, ultrasonography had poor sensitivity in detecting intra-abdominal lesions beyond the liver and spleen, missing 82% of these lesions. 

The study challenges the effectiveness of ultrasonography as a preoperative staging tool and suggests that more comprehensive imaging methods like CT or MRI might be more reliable for assessing metastasis. This is particularly relevant given the low sensitivity of ultrasonography in detecting metastatic lesions and the significant prevalence of benign lesions mistaken for malignant ones. 

Overall, the findings indicate that ultrasonography alone may not be sufficient for accurate staging and surgical decision-making, advocating for more advanced imaging techniques to improve diagnostic accuracy. 

Ramirez, A. R., Stewart, S. D., & Khanna, C. (2024). Ultrasonographic liver nodules are more often benign lesions in dogs with hemoperitoneum secondary to splenic tumor rupture. Journal of the American Veterinary Medical Association https://doi.org/10.2460/javma.24.04.0254 

Bottom line — US alone for staging may not be enough.

Magnesium Affects the Progression of Kidney Disease

Increasing evidence in both human and veterinary medicine suggests that magnesium influences disease progression and mortality in patients with chronic kidney disease (CKD). Hypomagnesemia is a common electrolyte abnormality among CKD patients and is associated with vascular calcification (VC) and increased cardiovascular risk. Magnesium supplementation has shown benefits, such as preventing VC in rat models and reducing mortality in hemodialysis patients. 

Magnesium plays a role in regulating calcium and fibroblast growth factor-23 (FGF23). Studies in rats and humans have demonstrated that magnesium deficiency leads to lower serum magnesium levels and higher serum calcium and FGF23 levels. Similar findings were observed in cats with azotemic CKD, where hypomagnesemia was linked to an increased risk of death. Oral magnesium administration significantly reduces serum FGF23 and calcium concentrations in human CKD patients, but its effects on CKD-related mineral and bone disorder (CKD-MBD) in cats have not been evaluated. 

A prospective randomized controlled trial was conducted to assess the effects of dietary magnesium supplementation on plasma total magnesium concentration (tMg) and CKD-MBD variables in cats with azotemic CKD. The study found that magnesium-enriched diets increased plasma tMg and venous bicarbonate (HCO3−) concentration. Cats fed magnesium-enriched diets showed greater stability in plasma FGF23 and ionized calcium (iCa) levels, indicating potential benefits in managing CKD-MBD. Some cats developed moderate hypermagnesemia, which normalized after switching back to a standard diet. 

The trial highlighted the calcium-lowering effect of magnesium, which might be due to decreased intestinal calcium absorption or increased urinary excretion. The study also pointed out that dietary phosphate restriction, a common CKD management strategy, could lead to hypercalcemia in some cats. Magnesium-enriched diets might counteract this effect without compromising phosphate restriction. 

Significant reductions in plasma FGF23, phosphate, and parathyroid hormone (PTH) levels were observed in CKD cats fed a magnesium-enriched diet. Increased venous HCO3− concentrations suggested that magnesium supplementation might prevent metabolic acidosis, a common CKD complication, thus stabilizing the disease. Body weight decreased in all enrolled cats over the study period, with no significant difference between diet groups. 

The study faced limitations such as protocol amendments and dietary nonadherence in some cats. Despite these challenges, the trial provided evidence that magnesium-enriched diets can increase tMg and stabilize calcium and FGF23 levels in CKD cats. Future long-term studies are needed to evaluate the effects on CKD progression and survival outcomes in cats with CKD. 

Tang P-K, van den Broek DHN, Jepson RE, et al. Dietary magnesium supplementation in cats with chronic kidney disease: A prospective double-blind randomized controlled trial. J Vet Intern Med. 2024; 38(4): 2180-2195. doi:10.1111/jvim.17134 

Bottom line — Magnesium enrichment seems to be useful.

Just putting things in perspective …