Feline musculoskeletal ageing: How are we diagnosing and treating musculoskeletal impairment?

Paw pressure and gait in middle-aged client-owned cats with and without naturally-occurring musculoskeletal disease

Musculoskeletal disease (MSD) is common in ageing cats, resulting in chronic pain and mobility impairment, but diagnosis can be challenging. We hypothesised that there would be differences between cats with and without MSD in paw pressure and spatiotemporal and kinetic gait metrics. A cohort of 53 cats, aged between 7 and 10 years from the North West of the United Kingdom, underwent an orthopaedic examination and walked on a pressure sensitive walkway. Thirty-one of the cats (58%) were determined to be apparently-healthy, based on a normal orthopaedic examination and having no history of MSD, whilst the remaining 22 cats (42%) had findings consistent with MSD; 13/22 cats (59%) had multiple limb involvement, 7/22 (32%) had forelimb involvement and 2/22 (9%) had hindlimb involvement. Bodyweight (P = 0.048) and body condition score (BCS; P = 0.015) were both greater in cats with MSD (mean bodyweight 5.4 ± 1.35 kg; median BCS 6, IQR 6-7.75) compared with apparently-healthy cats (mean bodyweight 4.7 ± 0.94 kg; median BCS 5, IQR 4.5-6.5). There was a relatively large intra-cat variation in spatiotemporal and kinetic gait variables (coefficient of variation >3.0%), whilst a linear mixed-effects model suggested no significant difference in spatiotemporal or kinetic gait variables between apparently-healthy cats and those with MSD. Palmar and plantar pressure asymmetry was assessed by pedobarographic statistical parametric mapping (pSPM) within each individual cat, with no significant difference (P = 0.353) between the apparently heathy cats and those with MSD as to the presence or absence of asymmetry. Given the marked intra-cat variation and the 'multi-limb' nature of MSD in this cohort, it was not possible to differentiate healthy cats from those with MSD based on spatiotemporal and kinetic gait metrics or paw pressure asymmetry. Future work should examine gait in cats with defined musculoskeletal disorders (e.g. hip dysplasia) and also to track longitudinal changes within individual cats to better establish age-related trends.

Evaluation of stem-cell therapies in companion animal disease models: a concise review (2015-2023)

Companion animals in veterinary medicine develop multiple naturally occurring diseases analogous to human conditions. We previously reported a comprehensive review on the feasibility, safety, and biologic activity of using novel stem cell therapies to treat a variety of inflammatory conditions in dogs and cats (2008-2015) [Hoffman AM, Dow SW. Concise review: stem cell trials using companion animal disease models. Stem Cells. 2016;34(7):1709-1729. https://doi.org/10.1002/stem.2377]. The purpose of this review is to provide an updated summary of current studies in companion animal disease models that have evaluated stem cell therapeutics that are relevant to human disease. Here we have reviewed the literature from 2015 to 2023 for publications on stem cell therapies that have been evaluated in companion animals, including dogs, cats, and horses. The review excluded case reports or studies performed in experimentally induced models of disease, studies involving cancer, or studies in purpose-bred laboratory species such as rodents. We identified 45 manuscripts meeting these criteria, an increase from 19 that were described in the previous review [Hoffman AM, Dow SW. Concise review: stem cell trials using companion animal disease models. Stem Cells. 2016;34(7):1709-1729. https://doi.org/10.1002/stem.2377]. The majority of studies were performed in dogs (n = 28), with additional studies in horses (n = 9) and cats (n = 8). Disease models included those related to musculoskeletal disease (osteoarthritis and tendon/ligament injury), neurologic disease (canine cognitive dysfunction, intervertebral disc disease, spinal cord injury) gingival/dental disease (gingivostomatitis), dermatologic disease (atopic dermatitis), chronic multi-drug resistant infections, ophthalmic disease (keratoconjunctivitis sicca, eosinophilic keratitis, immune-mediated keratitis), cardiopulmonary disease (asthma, degenerative valve disease, dilated cardiomyopathy), gastrointestinal disease (inflammatory bowel disease, chronic enteropathy), and renal disease (chronic kidney disease). The majority of studies reported beneficial responses to stem cell treatment, with the exception of those related to more chronic processes such as spinal cord injury and chronic kidney disease. However, it should also be noted that 22 studies were open-label, baseline-controlled trials and only 12 studies were randomized and controlled, making overall study interpretation difficult. As noted in the previous review, improved regulatory oversight and consistency in manufacturing of stem cell therapies are needed. Enhanced understanding of the temporal course of disease processes using advanced-omics approaches may further inform mechanisms of action and help define appropriate timing of interventions. Future directions of stem-cell-based therapies could include use of stem-cell-derived extracellular vesicles, or cell conditioning approaches to direct cells to specific pathways that are tailored to individual disease processes and stages of illness.

The potential for senotherapy as a novel approach to extend life quality in veterinary medicine

Cellular senescence, a condition where cells undergo arrest and can assume an inflammatory phenotype, has been associated with initiation and perpetuation of inflammation driving multiple disease processes in rodent models and humans. Senescent cells secrete inflammatory cytokines, proteins, and matrix metalloproteinases, termed the senescence associated secretory phenotype (SASP), which accelerates the aging processes. In preclinical models, drug interventions termed "senotherapeutics" selectively clear senescent cells and represent a promising strategy to prevent or treat multiple age-related conditions in humans and veterinary species. In this review, we summarize the current available literature describing in vitro evidence for senotheraputic activity, preclinical models of disease, ongoing human clinical trials, and potential clinical applications in veterinary medicine. These promising data to date provide further justification for future studies identifying the most active senotherapeutic combinations, dosages, and routes of administration for use in veterinary medicine.

Nutraceutical supplementation increases mobility in aged captive non-domesticated felids

BACKGROUND

Musculoskeletal diseases (MSDs) are an increasing issue as the lifespan of captive animals increases. Extracts of green-lipped mussels have been linked to alleviation of MSDs in domestic carnivores. Understanding their efficacy in non-domestic felids could provide another tool to improve the welfare of aged individuals in collections.

METHODS

A within-subject study design quantified steps per minute in each of 18 cats of 13 species before and after the addition of a nutraceutical containing green-lipped mussel extract (Antinol) to their diets. The age structure of four commonly kept subspecies of non-domestic cats was quantified to provide a demographic context to the need for managing aged individuals.

RESULTS

Each of the 18 cats exhibited a higher number of steps per minute after the addition of Antinol to their diet. At the group level, a paired t-test showed that the step rate was significantly increased after the addition of Antinol to the diet.

LIMITATIONS

While our results showed a strong significant increase in step rate following Antinol supplementation, further studies that incorporate a placebo, more individuals and more detailed metrics of mobility would provide a more detailed evidence base for practitioners.

CONCLUSION

Nutraceuticals may yield benefits to aged individual felids, including species kept widely in European collections. Their use warrants further, detailed research in collections.

Technology-enhanced weight-loss program in multiple-cat households: a randomized controlled trial

OBJECTIVES

The objectives of this study were to determine whether a technology-enhanced weight-loss program, using a home pet health technology ecosystem, is an effective tool in feline weight-loss management in multiple-cat households and to evaluate its impact on cat behavior.

METHODS

The study was a prospective parallel unmasked block-randomized controlled trial comparing two weight loss intervention groups: (1) traditional group with dietary restriction alone (n = 9); (2) technology group that used dietary restriction, digital scales, smart feeders, activity monitors and pet treat cameras (n = 6). A 12-week weight-loss program of client-owned indoor-only two- or three-cat households with at least one overweight cat was conducted in Canada and the USA. Owner impressions of the technology, weight loss rates, smart feeder data, activity monitor data and health-related quality of life (HRQoL) were assessed.

RESULTS

The study was completed by 9/15 traditional group and 6/10 technology group cats. Dropouts were mainly due to owner issues unrelated to the study. The pet health technology ecosystem received favorable reviews (six responders). Smart feeders and home scales were perceived as valuable additions, while activity monitors and pet treat cameras were valued lower. The average weekly weight-loss rate (percent loss of initial body weight) was higher (P = 0.036) in the technology group (0.694%) than in the traditional group (0.175%). Although not associated with weight-loss rates, technology group cats trended toward grazing feeding patterns and decreased daily activity counts, while HRQoL increased, on average, for all cats.

CONCLUSIONS AND RELEVANCE

This introductory investigation suggests that a technology-enhanced weight-loss program would be accepted by cat owners and may deliver advantageous outcomes in multiple-cat households, providing an effective and practical tool in feline weight-loss strategies that will continue to evolve as new technologies become available. It also illustrates the potential value of data gathered from home monitoring devices and digital diaries, providing deeper insights into pet behavior.