Osteoarthritic Dogs Research Articles

Spatial working memory in a disappearing object task is impaired in female but not male dogs with chronic osteoarthritis

Chronic pain in humans is associated with impaired working memory but it is not known whether this is the case in long-lived companion animals, such as dogs, who are especially vulnerable to developing age-related chronic pain conditions. Pain-related impairment of cognitive function could have detrimental effects on an animal’s ability to engage with its owners and environment or to respond to training or novel situations, which may in turn affect its quality of life. This study compared the performance of 20 dogs with chronic pain from osteoarthritis and 21 healthy control dogs in a disappearing object task of spatial working memory. Female neutered osteoarthritic dogs, but not male neutered osteoarthritic dogs, were found to have lower predicted probabilities of successfully performing the task compared to control dogs of the same sex. In addition, as memory retention interval in the task increased, osteoarthritic dogs showed a steeper decline in working memory performance than control dogs. This suggests that the effects of osteoarthritis, and potentially other pain-related conditions, on cognitive function are more clearly revealed in tasks that present a greater cognitive load. Our finding that chronic pain from osteoarthritis may be associated with impaired working memory in dogs parallels results from studies of human chronic pain disorders. That female dogs may be particularly prone to these effects warrants further investigation.

Initial exploration of the discriminatory ability of the PetPace collar to detect differences in activity and physiological variables between healthy and osteoarthritic dogs

BackgroundAccelerometry has been used to evaluate activity in dogs with osteoarthritis (OA) pain, especially in relation to effect of treatment; however no studies have compared accelerometry-measured activity in dogs with OA-pain and healthy dogs. The aims of this study were to (1) compare activity output from the PetPace collar with the validated Actical monitor and (2) determine if PetPace collar outputs (overall activity, activity levels, body position, and vital signs) differed between healthy dogs and dogs with OA-pain.MethodsThis was an observational, non-interventional study in healthy dogs and dogs with OA-pain. All dogs were outfitted with the PetPace collar and the Actical monitor simultaneously for 14 days. Output from these devices was compared (correlations), and output from the PetPace device was used to explore differences between groups across the activity and vital sign outputs (including calculated heart rate variability indices).ResultsThere was moderate correlation between the PetPace collar and Actical monitor output (R2 = 0.56, p < 0.001). Using data generated by the PetPace collar, OA-pain dogs had lower overall activity counts and spent less time standing than healthy dogs. Healthy dogs spent more time at higher activity levels than OA-pain dogs. Certain heart rate variability indices in OA-pain dogs were lower than in healthy dogs.Conclusions and clinical relevanceThe results of this study suggest that the PetPace collar can detect differences between healthy dogs and those with OA-pain, and that OA-pain negatively impacts overall activity levels in dogs, and especially higher intensity activity.

The expression of nerve growth factor in healthy and inflamed equine chondrocytes analysed by capillary western immunoassay

Nerve Growth Factor (NGF) is a signalling molecule for pain and inflammation. NGF is increased in synovial fluid from osteoarthritic humans and animals, compared to healthy controls. Monoclonal antibody therapy directed against NGF has been approved to treat pain in osteoarthritic dogs but despite many years of trialling, therapy has not been approved for human use. One reason for this is that adverse reactions with rapidly progressing osteoarthritis has occurred in some individuals. More detailed knowledge of NGF expression in joints is needed. In this study, capillary-based Simple Western was used to analyse NGF in cultured equine chondrocytes. Chondrocytes were collected post mortem from three macroscopically healthy intercarpal joints and three intercarpal joints with mild osteoarthritic changes. The chondrocytes were expanded to passage one and seeded in chondrogenic medium to maintain the phenotype. On day four, cells were either stimulated with LPS or kept untreated in medium. All cells were harvested on day five. Wes analysis of lysates did not show mature NGF but two proforms, 40 and 45 kDa, were identified. Results were confirmed with western blot. The same proforms were expressed in chondrocytes from healthy and osteoarthritic joints. Acute inflammation induced by LPS stimulation did not change the forms of expressed NGF. Capillary Simple Western offers a sensitive and sample-sparing alternative to traditional western blot. However, confirmation of peaks is imperative in order to avoid misinterpretation of findings. In addition, in this case the method did not offer the possibility of quantification advertised by the manufacturers.

Evaluation of clinical efficacy of undenatured type II collagen supplementation compared to cimicoxib and their association in dogs affected by natural occurring osteoarthritis

The aim of the study was to evaluate the clinical efficacy of 30 days treatment of undenatured type II collagen(UC-II®), compared to cimicoxib and to their combination, in osteoarthritic dogs. Client-owned dogs were enrolled in a clinical, randomized, controlled and prospective study. Posture, lameness, pain, range of motion and x-ray of affected joint(s) were evaluated and scored based on severity (CLINICAL score). The Liverpool Osteoarthritis in Dogs survey was used to score the owner evaluation of dog's mobility (LOAD score and MOBILITY score). Osteoarthritis (OA) stage was defined through the Canine Osteoarthritis Staging tool (COAST). After diagnosis (T0), all patients were randomly assigned to different treatment groups: C group = cimicoxib 2 mg/kg/day orally OS, F group = UC-II® 1 tablet per day OS; C + F group = cimicoxib-UC-II® at the same previous dosages; CTR group = dogs who didn't received any treatment. All treatments were administered for 30 days. Seventy-six dogs completed the study. LOAD score was recorded significant lower after treatment for each group, with a reduction in percentage of 29.5% for C, 31.4% for F, 21.1% for C + F. LOAD score was lower in C(P = 0.04), F(P = 0.001) and C + F(P = 0.009) group at T30 than CTR group. MOBILITY and CLINICAL scores were significantly lower in all groups at T30, when compared to T0. MOBILITY score was lower than CTR in C(P = 0.02) and F(P = 0.01); CLINICAL score was lower in C + F(P = 0.016). The present findings prove that the treatment with UC-II®, cimicoxib and their combination provide significant reduction in clinical signs associated with OA.

Associations between osteoarthritis and duration and quality of night-time rest in dogs

Human patients with chronic pain from osteoarthritis often report impaired sleep, but it is not yet known if sleep is also impaired in dogs with osteoarthritis. This study aimed to compare the night-time sleep behaviour of osteoarthritic (N = 20) and healthy control (N = 21) dogs over a 28-day period, using an actigraphic device (the FitBark activity monitor) and an owner questionnaire designed to measure sleep quality (the SNoRE). Actigraphic data were aggregated to estimate the time each dog spent resting each night, and questionnaires were completed every 7 days. Data were analysed using robust mixed-effects linear regression. The presence of clinical signs of osteoarthritis had a significant effect on actigraphic recordings, with osteoarthritic dogs spending lower proportions of the night period resting (and therefore higher proportions of the night period active) compared to control dogs (z = 2.21; P = 0.0268). However, there was no significant difference between the SNoRE scores of osteoarthritic and control dogs (z = −1.01, p = 0.312). The actigraphic findings of this study suggest that dogs with osteoarthritis may experience impaired sleep, which could have important welfare implications and merits further study.

Initial exploration of the discriminatory ability of the PetPace collar to detect differences in activity and physiological variables between healthy and osteoarthritic dogs

Initial exploration of the discriminatory ability of the PetPace collar to detect differences in activity and physiological variables between healthy and osteoarthritic dogs

Could it be osteoarthritis? How dog owners and veterinary surgeons describe identifying canine osteoarthritis in a general practice setting

Canine osteoarthritis is a common, painful condition that is typically managed in a general practice setting. Osteoarthritis may have significant negative impacts on the welfare of both dogs and their owners. Anticipated early clinical signs of canine osteoarthritis and the preferred route to its diagnosis are well described by veterinary subject experts in published literature. However, little is known about changes owners first recognise in a dog ultimately diagnosed with osteoarthritis, how they make decisions about when to present that dog to a general practitioner, or whether the described diagnostic pathways are followed by general practitioners. The aim of this research was to investigate how dog owners and veterinary surgeons describe identifying and diagnosing canine osteoarthritis.Owners of osteoarthritic dogs were recruited for semi-structured interview, and veterinary surgeons working in general practice were invited to take part in practice-based focus groups. Transcripts from both datasets were thematically analysed using a contextualist epistemology with an ontology based on critical realism to construct convergent themes from latent and semantic codes. Thirty-two interviews were completed with 40 owners from 32 households who discussed 35 dogs with osteoarthritis, and 26 veterinary surgeons engaged in four practice-based focus groups.Owners described identifying a wide range of acute and chronic, typically subtle and intermittent, behavioural and demeanour changes prior to their dogs’ osteoarthritis diagnosis. Few attributed these changes to canine osteoarthritis, and some waited many months before presenting their dog to a veterinary practice. Veterinary surgeons described a consistent ‘typical osteoarthritis’ presentation that they recognised through history taking and clinical examination. Their diagnostic work-up rarely followed that advocated by subject experts for reasons including lack of time and perceptions that it would not change the outcome. Many veterinary surgeons described frustration that some owners did not accept their recommendations to provide analgesia for affected dogs. Short consultation lengths, poor awareness of owner knowledge levels, and lack of recognition of the importance of owners’ prior knowledge, beliefs and assumptions may contribute to these consultations being perceived as challenging by some veterinary surgeons and owners.This research demonstrates that veterinary surgeons and owners want dogs with clinical signs of osteoarthritis to be happy and comfortable, but that ineffective communication and lack of trust in the consulting room may be a barrier. Our data identifies many new avenues for future research and improved communication strategies that could facilitate earlier identification and treatment of canine osteoarthritis in general practice.

\u201cYou can be blind because of loving them so much\u201d: the impact on owners in the United Kingdom of living with a dog with osteoarthritis

BackgroundThere is growing awareness that caring for a chronically ill pet may have a detrimental impact on their owner’s quality of life. Companion animal orthopaedic disease has received little research interest in this context. Canine osteoarthritis is known to negatively affect the welfare of many dogs in the United Kingdom, but its consequences for their owners has not previously been described. The aim of this study was to use a qualitative methodology to explore the impacts on a dog owner that occur following their dog’s diagnosis with osteoarthritis. Owners of osteoarthritic dogs based in the United Kingdom (UK) were recruited through veterinary practices to participate in semi-structured interview about life with their dog. Interviews were transcribed verbatim and thematic analysis was used to construct key themes. This publication describes the theme that focused on the impact(s) that the dog’s condition had had on the life of their owner.ResultsForty owners of 35 dogs of a range of breeds and ages were interviewed. A wide range of negative impacts on the physical, mental and financial health of owners were described. Few had any prior experience of canine osteoarthritis, and owners of young dogs appeared to be particularly affected by the diagnosis. Owners detailed increasing worry over time about their pet’s condition, frequently combined with a growing need to physically assist their dog. Sometimes this led them to seek information about, and purchase, adjunctive therapies and products. The dog’s reduced mobility and need for medications progressively limited their own lifestyles and ability to have time away from their pet. Owners typically described a strong bond with their dog as a motivator to provide ongoing care.ConclusionsThe negative impacts on owners of caring for an osteoarthritic dog appear multi-faceted and may be sustained over many years, particularly if the dog is young at diagnosis. Owners may be highly motivated to improve their dog’s mobility and to reduce the impact the condition has on their own lives, yet they may be unsure how to achieve this. Veterinary professionals should inform and support these owners as much as possible.

Slower, shorter, sadder: a qualitative study exploring how dog walks change when the canine participant develops osteoarthritis

BackgroundDog walking may have multiple physical and mental health advantages, but not all dog owners appear to benefit. Dog health is a described barrier to dog walking activity, but specific causes and impacts of reduced exercise in owners of dogs with health problems have not previously been reported. The current study used a qualitative methodology to explore the impact of canine osteoarthritis on dog walking activity.MethodsOwners of dogs with osteoarthritis living in the United Kingdom (UK) were recruited through veterinary practices for semi-structured interview about life with an osteoarthritic dog. Participants were asked to reflect on walks that they had taken with their dog before he/she developed osteoarthritis, and to describe how those walks had changed. Interviews were transcribed verbatim and thematic analysis was used to construct key themes.ResultsForty owners of 35 osteoarthritic dogs were interviewed. Prior to their dog’s development of osteoarthritis, dog walking distance, speed and location were usually decided by the owner to satisfy the needs and enjoyment of dog and walker. A diagnosis of canine osteoarthritis led to both dogs and their owners altering the walks undertaken. Walks were typically slower, shorter and limited to locations where physical infrastructure, underfoot surface and gradients were perceived by the owner to be navigable by their dog. Most owners did not go on additional walks without their dog due to feelings of guilt and because walking without a dog was less enjoyable. Many owners described negative effects on their own physical health and diminished enjoyment of walking as a result of their dog’s condition.ConclusionOur research suggests that osteoarthritic dogs may reduce the walking exercise their owners are able or willing to undertake. Since osteoarthritis is a common condition in older dogs, this is an important finding for those advocating dog ownership as a positive public health intervention. Strategies may be needed to ensure that owners of dogs that develop physical incapacities can continue to enjoy the health benefits they previously associated with dog walking. Future studies investigating dog walking activity should ensure that the health status of the dog has been considered.

The effect of spontaneous osteoarthritis on conditioned pain modulation in the canine model

Endogenous Pain Modulation (EPM) impairment is a significant contributor to chronic pain. Conditioned pain modulation (CPM) testing assesses EPM function. Osteoarthritic (OA) dogs are good translational models, but CPM has not been explored. Our aim was to assess EPM impairment in OA dogs compared to controls using CPM. We hypothesized that CPM testing would demonstrate EPM impairment in OA dogs compared to controls. Dogs with stifle/hip OA and demographically-matched controls were recruited. The pre-conditioning test stimulus, using mechanical/thermal quantitative sensory testing (MQST or TQST), were performed at the metatarsus. A 22N blunt probe (conditioning stimulus) was applied to the contralateral antebrachium for 2 minutes, followed by MQST or TQST (post-conditioning test stimulus). The threshold changes from pre to post-conditioning (∆MQST and ∆TQST) were compared between OA and control dogs. Twenty-four client-owned dogs (OA, n = 11; controls, n = 13) were recruited. The ∆MQST(p < 0.001) and ∆TQST(p < 0.001) increased in control dogs but not OA dogs (∆MQST p = 0.65; ∆TQST p = 0.76). Both ∆MQST(p < 0.001) and ∆TQST(p < 0.001) were different between the OA and control groups. These are the first data showing that EPM impairment is associated with canine OA pain. The spontaneous OA dog model may be used to test drugs that normalize EPM function.

Treatment of canine osteoarthritis with allogeneic platelet-rich plasma: review of five cases.

Background:Osteoarthritis (OA) is a major cause of chronic pain and lameness in dogs. Platelet-rich plasma (PRP) is a concentrate of growth and differentiation factors from the blood, which can be used in regenerative medicine strategies.Aim:The main aim of this study was to evaluate the effect of allogeneic PRP on the treatment of canine OA.Methods:Five dogs from several breeds, between 6 and 12 years old, and from both genders were studied. Clinical and imageological examinations diagnosed OA in the knee, tibiotarsal, elbow, and intercarpal joints. These dogs were refractory to medical therapy and to physical rehabilitation protocols that included shockwave therapy, laser therapy, electrostimulation, hydrotherapy, and diathermy.Animals were treated with allogeneic PRP obtained from the blood of the five dogs, which was processed in a pool. Echoguided intra-articular PRP injection was administered under sedation and after aseptic field preparation. Lameness at walk and trot (five grades) and pain (five scores) were evaluated before treatment and 30, 60, and 90 days post-treatment. Results:All animals presented improvements at 30 and 60 days in both parameters. Four dogs showed a decrease of three grades of lameness after 90 days and there was complete absence of lameness in 2 days. Pain was reduced from severe and moderate to mild in all the dogs after 30 days, and among them, three revealed no pain after 90 days.Conclusion:This study sheds light on the applicability and safety of a single administration of allogeneic PRP in osteoarthritic dogs.

Functional linear modeling of activity data shows analgesic-mediated improved sleep in dogs with spontaneous osteoarthritis pain

In humans, pain due to osteoarthritis has been demonstrated to be associated with insomnia and sleep disturbances that affect perception of pain, productivity, and quality of life. Dogs, which develop spontaneous osteoarthritis and represent an increasingly used model for human osteoarthritis, would be expected to show similar sleep disturbances. Further, these sleep disturbances should be mitigated by analgesic therapy. Previous efforts to quantify sleep in osteoarthritic dogs using accelerometry have not demonstrated a beneficial effect of analgesic therapy; this is despite owner-reported improvements in dogs’ sleep quality. However, analytic techniques for time-series accelerometry data have advanced with the development of functional linear modeling. Our aim was to apply functional linear modeling to accelerometry data from osteoarthritic dogs participating in a cross-over non-steroidal anti-inflammatory (meloxicam) drug trial. Significant differences in activity patterns were seen dogs receiving drug (meloxicam) vs. placebo, suggestive of improved nighttime resting (sleep) and increased daytime activity. These results align with owner-reported outcome assessments of sleep quality and further support dogs as an important translational model with benefits for both veterinary and human health.

Correlation of serum and synovial leptin concentrations with body condition scores in healthy and osteoarthritic dogs.

To evaluate the relationship between serum and synovial fluid (SF) leptin concentrations and body condition score (BCS) in healthy and osteoarthritic dogs. Controlled, prospective, clinical study. Nineteen healthy dogs and 29 dogs with osteoarthritis (OA) secondary to cranial cruciate ligament injury. Synovial fluid was obtained from the femorotibial joint under sedation (healthy dogs) or during surgery (OA dogs). Serum and SF leptin and interleukin (IL)-1β concentrations were measured via enzyme-linked immunosorbent assay. Dogs were classified as optimal weight (BCS 4-5/9) or overweight (BCS >5/9). Radiographs were scored for OA severity by a radiologist. Owners completed the Liverpool Osteoarthritis in Dogs (LOAD) questionnaire. Mean (± SD) SF leptin (4.09 ± 4 ng/mL) was lower than serum leptin (6.88 ± 5.52 ng/mL, P < .0001). Synovial fluid leptin was higher in overweight (5.28 ± 4.21) than in optimal body weight dogs (1.54 ± 1.72 ng/mL, P < .0001). Serum (P < .001) and SF leptin (P = .004) concentrations were associated with BCS. Concentration of SF leptin did not differ between healthy (2.4 ± 2.04 ng/mL) and OA (4.9 ± 4.3 ng/mL, P = .25) dogs. Synovial fluid leptin and LOAD scores were weakly associated (P = .03). No association was detected between SF leptin and radiographic score or IL-1β (P = .73). Serum and SF leptin correlated with BCS in this population. Synovial fluid leptin was weakly associated with LOAD scores but not with radiographic severity of OA or IL-1β. Serum and SF leptin concentrations do not predict radiographic severity of canine OA but contribute to joint pain and dysfunction.

Evaluation of the effect of signalment and owner-reported impairment level on accelerometer-measured changes in activity in osteoarthritic dogs receiving a non-steroidal anti-inflammatory

In veterinary medicine, evaluation of osteoarthritis (OA) treatment efficacy remains challenging. Measurement of activity, utilizing accelerometers, provides a surrogate measure of pain through measuring effects on activity, and the objective data collected can be used to assess the efficacy of treatments. However, little is known about how dog characteristics impact the accelerometry-measured response to treatment. The objectives of this study were to evaluate the effect of signalment and initial impairment level on accelerometer-measured changes in activity in osteoarthritic dogs after receiving a non-steroidal anti-inflammatory (NSAID). Fifty-seven client-owned dogs with OA-associated pain and mobility impairment were administered meloxicam for 2 weeks, following a 2-week baseline, and spontaneous activity was measured using an Actical accelerometer unit. Signalment factors and disease variables were recorded (age, sex, weight, impairment level, forelimb or hindlimb pain).Initial degree of impairment had a significant effect on changes in weekly (P=0.009), weekday (P=0.044) activity following NSAID treatment. Greater initial impairment was associated with larger positive changes in activity. Degree of impairment should be taken into consideration during the development of a clinical trial. Appropriate selection of candidates based on initial degree of impairment may permit a greater treatment effect, therefore increasing the power of the study.

Pharmacokinetics, Safety, and Clinical Efficacy of Cannabidiol Treatment in Osteoarthritic Dogs.

Objectives: The objectives of this study were to determine basic oral pharmacokinetics, and assess safety and analgesic efficacy of a cannabidiol (CBD) based oil in dogs with osteoarthritis (OA).Methods: Single-dose pharmacokinetics was performed using two different doses of CBD enriched (2 and 8 mg/kg) oil. Thereafter, a randomized placebo-controlled, veterinarian, and owner blinded, cross-over study was conducted. Dogs received each of two treatments: CBD oil (2 mg/kg) or placebo oil every 12 h. Each treatment lasted for 4 weeks with a 2-week washout period. Baseline veterinary assessment and owner questionnaires were completed before initiating each treatment and at weeks 2 and 4. Hematology, serum chemistry and physical examinations were performed at each visit. A mixed model analysis, analyzing the change from enrollment baseline for all other time points was utilized for all variables of interest, with a p ≤ 0.05 defined as significant.Results: Pharmacokinetics revealed an elimination half-life of 4.2 h at both doses and no observable side effects. Clinically, canine brief pain inventory and Hudson activity scores showed a significant decrease in pain and increase in activity (p < 0.01) with CBD oil. Veterinary assessment showed decreased pain during CBD treatment (p < 0.02). No side effects were reported by owners, however, serum chemistry showed an increase in alkaline phosphatase during CBD treatment (p < 0.01).Clinical significance: This pharmacokinetic and clinical study suggests that 2 mg/kg of CBD twice daily can help increase comfort and activity in dogs with OA.

220 Crude fiber and total dietary fiber concentrations of popular, premium, and clinical canine diets fed to client-owned osteoarthritic dogs

220 Crude fiber and total dietary fiber concentrations of popular, premium, and clinical canine diets fed to client-owned osteoarthritic dogs

233 Variation in macronutrient composition of popular, premium, and clinical canine diets fed to client-owned osteoarthritic dogs

233 Variation in macronutrient composition of popular, premium, and clinical canine diets fed to client-owned osteoarthritic dogs

Effects of dietary calcium fructoborate supplementation on joint comfort and flexibility and serum inflammatory markers in dogs with osteoarthritis.

Our objective was to evaluate the short-term effects of calcium fructoborate (CFB) on gait, joint range of motion, serum inflammatory markers, and owner perception of pain in client-owned dogs. We used 59 osteoarthritic dogs with impairment, with dogs being randomly assigned to 4 treatments: placebo (60 mg fructose; = 15), low dose (69 mg CFB; = 14), high dose (127 mg CFB; = 14), or combination (69 mg CFB, 500 mg glucosamine hydrochloride and 200 mg chondroitin sulfate; = 16). Dogs up to 22.9 kg received 1 capsule/d, while dogs weighing 23 to 50 kg received 2 capsules/d. A physical examination, radiographs, goniometry measurements, gait analysis, blood sample collection, and a canine brief pain inventory questionnaire were performed on d 0 and 28. Change from baseline values were statistically analyzed among groups. After 28 d, dogs fed the low and high doses had an improved ( < 0.05) ability to rise from a lying position compared to placebo. Dogs fed the high dose also had a greater ( = 0.05) increase in soluble receptor for advanced glycation end products concentration than dogs fed the placebo. Sub-analysis of only large dogs (> 23 kg) showed that dogs fed the low dose had decreased ( < 0.05) pain severity score and pain at its worst compared to dogs fed the placebo. Large dogs fed the low dose also were shown to improve ( < 0.05) in their ability to rise from a lying position compared to dogs fed the placebo. Overall, CFB supplementation was well-tolerated and may aid in mitigating joint discomfort in dogs.

The effect of intra-articular botulinum toxin A on substance P, prostaglandin E2, and tumor necrosis factor alpha in the canine osteoarthritic joint

BackgroundRecently, intra-articular botulinum toxin A (IA BoNT A) has been shown to reduce joint pain in osteoarthritic dogs. Similar results have been reported in human patients with arthritis. However, the mechanism of the antinociceptive action of IA BoNT A is currently not known. The aim of this study was to explore this mechanism of action by investigating the effect of IA BoNT A on synovial fluid (SF) and serum substance P (SP), prostaglandin E2 (PGE2), and tumor necrosis factor alpha (TNF-α) in osteoarthritic dogs. Additionally, the aim was to compare SF SP and PGE2 between osteoarthritic and non-osteoarthritic joints, and investigate associations between SP, PGE2, osteoarthritic pain, and the signalment of dogs. Thirty-five dogs with chronic naturally occurring osteoarthritis and 13 non-osteoarthritic control dogs were included in the study. Osteoarthritic dogs received either IA BoNT A (n = 19) or IA placebo (n = 16). Serum and SF samples were collected and osteoarthritic pain was evaluated before (baseline) and 2 and 8 weeks after treatment. Osteoarthritic pain was assessed with force platform, Helsinki Chronic Pain Index, and joint palpation. Synovial fluid samples were obtained from control dogs after euthanasia. The change from baseline in SP and PGE2 concentration was compared between the IA BoNT A and placebo groups. The synovial fluid SP and PGE2 concentration was compared between osteoarthritic and control joints. Associations between SP, PGE2, osteoarthritic pain, and the signalment of dogs were evaluated.ResultsThere was no significant change from baseline in SP or PGE2 after IA BoNT A. Synovial fluid PGE2 was significantly higher in osteoarthritic compared to control joints. Synovial fluid PGE2 correlated with osteoarthritic pain. No associations were found between SP or PGE2 and the signalment of dogs. The concentration of TNF-α remained under the detection limit of the assay in all samples.ConclusionsThe results suggest that the antinociceptive effect of IA BoNT A in the joint might not be related to the inhibition of SP nor PGE2. Synovial fluid PGE2, but not SP, could be a marker for chronic osteoarthritis and pain in dogs.

The Effectiveness of Specific Collagen Peptides on Osteoarthritis in Dogs-Impact on Metabolic Processes in Canine Chondrocytes

In clinical trials over the past decade, the beneficial effect of orally administered collagen peptides in osteoarthritic dogs has been clearly demonstrated [1] [2] [3]. Although a statistically significant improvement in the lameness and vitality of dogs in general has been documented, the mode of action of the collagen peptide treatment is still under discussion. A previous study [3] indicated that the reduction in lameness and increased mobility in dogs after collagen peptide treatment were associated with a statistically significantly lowered plasma content of MMP-3, which is involved in collagen degradation. In addition, the content of the MMP-antagonist TIMP-1 increased slightly after collagen peptide supplementation, suggesting a direct impact on the cartilage metabolism, particularly on the decrease of extracellular matrix degradation. Based on these findings, the impact of specific collagen peptides (PETA-GILE?) on cartilage metabolism was tested in canine chondrocytes in the current investigation. In addition to the biosynthesis of various matrix molecules (type II collagen, aggrecan and elastin), the RNA profile of inflammatory cytokines and degenerative matrix molecules was investigated. The results showed clearly that the supplementation of specific collagen peptides reduced catabolic processes, as indicated by a statistically significant decrease in inflammatory cytokines and proteases in canine chondrocytes compared with untreated control experiments. In addition, a statistically significantly enhanced biosynthesis of type II collagen, elastin, and aggrecan was observed. Hence, the current data supports the suggested anti-inflammatory effect of specific collagen peptides, but also clearly demonstrates a pronounced stimulatory impact on matrix molecule synthesis. A combination of both observed effects might help to explain the previously reported clinical improvements after collagen peptide supplementation. Furthermore, the beneficial effect of the specific collagen peptides was also confirmed in case reports on osteoarthritic dogs that demonstrated decreased lameness and increased vitality in the affected animals after PETAGILE treatment.