Obesity can induce cardiovascular diseases in both humans and animals. Heart rate variability (HRV) is an indicator of sympathovagal balance and is used to identify cardiovascular diseases in humans. However, HRV and cardiac function have rarely been investigated in obese dogs. This study investigated the effect of obesity on oxidative stress, HRV, and cardiac function in obese and non-obese dogs. The nine-scale body condition score (BCS) system was used to determine obesity. Thirty small breed dogs were divided into a normal weight group (n = 15) and an obese group (n = 15). All dogs underwent physical examination, plasma malondialdehyde (MDA) measurement, electrocardiography, echocardiography, and two hours of Holter monitoring. This study found that obese dogs had increased plasma MDA and sympathovagal imbalance, which was indicated by impaired time and frequency domains compared to normal weight dogs. Although cardiac function was within normal limits, the echocardiographic study found that the obese dogs had reduced cardiac wall thickness and lower systolic function, as indicated by a reduction in %ejection fraction, %fractional shortening, increased left ventricular (LV) internal diameter during systole, and LV end-systolic volume compared to normal weight dogs. This study concluded that obesity in dogs can induce increased plasma oxidative stress, impaired HRV, and reduced cardiac systolic function compared to non-obese dogs.

Pathological mandibular fracture after dental extraction usually occurs in dogs with moderate to severe periodontitis. A nanohydroxyapatite-based hydrogel (HAP hydrogel) was developed to diminish the limitations of hydroxyapatite for post-extraction socket preservation (PSP). However, the effect of the HAP hydrogel in dogs has still not been widely investigated. Moreover, there are few studies on PSP in dogs suffering from clinical periodontitis. The purpose of this study was to evaluate the effectiveness of the HAP hydrogel for PSP in dogs with periodontitis. In five dogs with periodontitis, the first molar (309 and 409) of each hemimandible was extracted. Consequently, all the ten sockets were filled with HAP-hydrogel. Intraoral radiography was performed on the day of operation and 2, 4, 8 and 12 weeks post operation. The Kruskal–Wallis test and paired t-test were adopted for alveolar bone regeneration analysis. The results demonstrated that the radiographic grading, bone height measurement, and bone regeneration analysis were positively significant at all follow-up times compared to the day of operation. Moreover, the scanning electron microscopy with energy-dispersive X-ray spectroscopy imaging after immersion showed a homogeneous distribution of apatite formation on the hydrogel surface. Our investigation suggested that the HAP hydrogel effectively enhances socket regeneration in dogs with periodontitis and can be applied as a bone substitute for PSP in veterinary dentistry.

Among the respiratory disorders in dogs from small breeds, tracheal collapse is one of the most commonly found in clinical practice. Presently, acupuncture is widely used as an alternative treatment which was shown to bring about positive effects in the treatment of human respiratory diseases. The present study demonstrated the effect of acupuncture on tracheal collapse dogs. We hypothesized that acupuncture can help dogs suffering from tracheal collapse by improving various parameters including heart rate variability, serum biomarkers for oxidative stress, exercise performance, and quality of life. Twenty client-owned dogs from small breeds with tracheal collapse disease were enrolled. The study was divided into two 5-week periods. During the first period, the dogs received normal veterinary care but received no acupuncture treatment (NAC). After completing that period, all forms of treatment were withheld for one week before the beginning of the second period. In the second period, all dogs restarted normal veterinary care and underwent acupuncture treatment (AC) once a week for five consecutive weeks. Blood was collected at the beginning and end of each of the two periods for malondialdehyde (MDA) level measurement. Heart rate variability (HRV) was recorded at the 1st, 3rd and 5th weeks of both periods. Exercise tests were performed at the beginning and end of AC period and questionnaire interviews with the owners were accomplished at the end of each period. The results showed that acupuncture can alleviate clinical signs of tracheal collapse, reduce MDA level, and improve sympathovagal balance. We suggest that acupuncture treatment could be used as an adjunct treatment for canine tracheal collapse.

Cardiac wall stress and high oxidative stress are often found in cases of myxomatous mitral valve degenerative (MMVD) disease and can lead to myocardial injuries and cardiac dysfunction. Melatonin, an antioxidant, has been shown to exert cardioprotection in laboratory animal models. However, its effect on metabolic parameters and left ventricular (LV) adaptation in MMVD dogs has rarely been investigated. This clinical trial hypothesized that a melatonin supplement for 4 weeks would improve metabolic parameters, LV structure (diameters and wall thickness), and LV function in MMVD dogs. Blood profiles, echocardiograms, and oxidative stress levels were obtained from 18 dogs with MMVD stage B2 and C at baseline and after prescribed Melatonin (2 mg/kg) for 4 weeks. Eleven dogs with MMVD stage B2 and C, which received a placebo, were evaluated as a control group. In this clinical trial, the baseline plasma malondialdehyde (MDA) was no different between the treatment and placebo groups. The post-treatment plasma MDA levels (4.50 ± 0.63 mg/mL) in the treatment group was significantly decreased after 4 weeks of melatonin supplementation compared to pre-treatment levels (7.51 ± 1.11 mg/mL) (P = 0.038). However, blood profiles and LV structure and function investigated using echocardiography were found not to different between pre-and post-treatment in each group. No adverse effects were observed following melatonin supplementation. This clinical trial demonstrated that a melatonin supplement for 4 weeks can attenuate oxidative stress levels in MMVD dogs, especially in MMVD stage C, but does not result in LV structural changes or LV function in MMVD dogs of either stage B2 or stage C.

Myxomatous mitral valve disease (MMVD) is the most common heart disease in small-breed dogs, often leading to heart failure. Oxidative stress in MMVD can harm mitochondria, decreasing their DNA content. This study assesses dogs’ oxidative stress and mitochondrial DNA at different MMVD stages. Fifty-five small-breed dogs were categorized into four groups, including: A—healthy (n = 15); B—subclinical (n = 15); C—heart failure (n = 15); and D—end-stage MMVD (n = 10). Serum malondialdehyde (MDA) and mitochondrial DNA in peripheral blood were analyzed. Quantitative real-time PCR measured mitochondrial DNA, and PCR data were analyzed via the fold-change Ct method. Serum MDA levels were assessed using competitive high-performance liquid chromatography (HPLC). Mitochondrial DNA was significantly lower in group B (−0.89 ± 2.82) than in group A (1.50 ± 2.01), but significantly higher in groups C (2.02 ± 1.44) and D (2.77 ± 1.76) than B. MDA levels were notably elevated in groups B (19.07 ± 11.87 µg/mL), C (23.41 ± 12.87 μg/mL), and D (19.72 ± 16.81 μg/mL) in comparison to group A (9.37 ± 4.67 μg/mL). Nevertheless, this observed difference did not reach statistical significance. It is noteworthy that mitochondrial DNA content experiences a decline during the subclinical stage but undergoes an increase in cases of heart failure. Concurrently, oxidative stress exhibits an upward trend in dogs with MMVD. These findings collectively suggest a potential association between mitochondrial DNA, oxidative stress, and the progression of MMVD in small-breed dogs.