Feline Degenerative Joint Disease

The use of platelet rich plasma in the treatment of degenerative joint disease in cats: an exploratory case series

Objective

To evaluate the effectiveness of intra-articular autologous Platelet Rich Plasma (PRP) in managing Degenerative Joint Disease (DJD) in cats.

Design

Prospective pilot clinical trial.

Methods

Six domestic cats with clinically and radiographically diagnosed DJD received intra-articular injections of autologous PRP. Clinical assessments pre and post intra-articular injections were conducted using the Feline Musculoskeletal Pain Index (FMPI, owner assessed) and Visual Analog Scale (VAS, clinician assessed) at baseline, Day 14, Day 28, and Day 42-45.

Results

Significant improvements were noted in both FMPI and VAS scores at the end of the study period, indicating enhanced joint function and reduced pain.

Conclusion and clinical relevance

The study suggests the potential of PRP therapy as a safe and effective treatment for feline DJD, warranting further research with larger cohorts and longer follow-up to establish comprehensive treatment guidelines.

Functions and Metabolism of Amino Acids in Bones and Joints of Cats and Dogs

The bone is a large and complex organ (12-15% of body weight) consisting of specialized connective tissues (bone matrix and bone marrow), whereas joints are composed of cartilage, tendons, ligaments, synovial joint capsules and membranes, and a synovial joint cavity filled with synovial fluid. Maintaining healthy bones and joints is a dynamic and complex process, as bone deposition (formation of new bone materials) and resorption (breakdown of the bone matrix to release calcium and phosphorus) are the continuous processes to determine bone balance. Bones are required for locomotion, protection of internal organs, and have endocrine functions to maintain mineral homeostasis. Joints are responsible for resisting mechanical stress/trauma, aiding in locomotion, and supporting the overall musculoskeletal system. Amino acids have multiple regulatory, compositional, metabolic, and functional roles in maintaining the health of bones and joints. Their disorders are prevalent in mammals and significantly reduce the quality of life. These abnormalities in companion animals, specifically cats and dogs, commonly lead to elective euthanasia due to the poor quality of life. Multiple disorders of bones and joints result from genetic predisposition and are heritable, but other factors such as nutrition, growth rate, trauma, and physical activity affect how the disorder manifests. Treatments for cats and dogs are primarily to slow the progression of these disorders and assist in pain management. Therapeutic supplements such as Cosequin and formulated diets rich in amino acids are used commonly as treatments for companion animals to reduce pain and slow the progression of those diseases. Also, amino acids (e.g., taurine, arginine, glycine, proline, and 4-hydroxyproline), and glucosamine reduce inflammation and pain in animals with bone and joint disorders. Gaining insight into how amino acids function in maintaining bone and joint health can aid in developing preventative diets and therapeutic supplementations of amino acids to improve the quality of life in companion animals.

A case report of CBD and THC as analgesic therapy in a cat with chronic osteoarthritic pain

A 10-year-old mixed breed male cat presented with clinical signs related to chronic orthopaedic pain. Upon physical examination, pain was noted, based on the feline Musculoskeletal Pain Index (FMPI). An analgesic treatment with a full spectrum cannabis oil (1.8% CBD and 0.8% THC) was proposed for 30 days (0,5 mg/kg based on CBD). The FMPI scale score decreased more than 50%. This case reported a satisfactory outcome for the patient and the owner, although this medication could increase ALT. Given the paucity of literature published to date on the treatment of veterinary species with cannabis-based medications, further clinical and pharmacokinetic studies are necessary to study the safety and efficacy of its use.

Conservative nonsurgical treatment for cranial cruciate ligament disease can be an effective management strategy in cats based on validated owner-based subjective assessment in some cases

OBJECTIVE

To describe long-term outcomes of cats managed medically for cranial cruciate ligament disease (CCLD) via a validated owner-based questionnaire.

ANIMALS

18 client-owned cats.

PROCEDURES

Retrospective review of medical records at 2 tertiary referral hospitals was conducted for records of cats diagnosed with CCLD for which medical management was pursued. History, physical examination findings, and medical management strategies were recorded. Owner follow-up was obtained via phone call or an email correspondence interview using a 2-part questionnaire. Part 1 consisted of 5 multiple-choice questions evaluating short-term outcomes following initiation of medical management. Part 2 assessed long-term outcomes via the validated Feline Musculoskeletal Pain Index—short form metrology instrument.

RESULTS

Mean follow-up time was 66.5 ± 46.7 months (range, 7 to 154 months). Medical management included oral analgesics, activity restriction, and joint supplements. Of the 18 cats, 13 (72%) were always able to bear weight or became weight bearing within a week following initiation of medical management, and 15 (83%) were reportedly clinically normal within 3 months of initiating medical management, with complete resolution of lameness occurring in less than 2 months in 12 of those cats. Long term, 17 of the 18 (94%) owners reported they felt that their cat had a good to excellent outcome with medical management. The mean Feline Musculoskeletal Pain Index—short form score of all cats was 0.29 ± 0.53 (range, 0 to 2.13).

CLINICAL RELEVANCE

Based on owner follow-up, conservative, nonsurgical management of CCLD can be an effective and appropriate management strategy for some cats; however, some may be best treated with surgical stabilization.

Refinement of the Feline Musculoskeletal Pain Index (FMPI) and development of the short-form FMPI

OBJECTIVES

The aim of this study was to investigate the reliability and responsiveness of the Feline Musculoskeletal Pain Index (FMPI) using the collective results of multiple clinical studies and iteratively refine the FMPI for future use.

METHODS

Data were compiled from previously conducted studies involving client-owned cats with degenerative joint disease (DJD) and which used the FMPI. The reliability of the FMPI was assessed using the data from the initial visits of those studies. For the assessment of responsiveness of the FMPI, only placebo-controlled studies that used analgesic treatments were included. Treatment groups from each study were combined and categorized as 'placebo' group and 'analgesic' group. Then, the mean change from baseline in score of each FMPI item and across all items within and between these groups were assessed. Based on the results of the reliability and responsiveness of the FMPI, stepwise elimination was used to remove the items that were least able to distinguish between the placebo and analgesic groups. Finally, after the stepwise elimination, a proposed new FMPI-short form (FMPI-sf) was constructed and its reliability was reassessed using the data sets described above. Individual and combined data sets of the studies were also used to compare the responsiveness of the original FMPI and the FMPI-sf.

RESULTS

The data from 180 cats from four studies were included. The original FMPI had a reasonable reliability, but low/no responsiveness. The elimination process of FMPI items refined the responsiveness of the instrument while maintaining its reliability. When the responsiveness was compared between the original FMPI (17 items) and the FMPI-sf (nine items), the treatment effect between groups was always greater when the FMPI-sf was used.

CONCLUSIONS AND RELEVANCE

The proposed FMPI-sf may be able to better distinguish between placebo and analgesic effects in cats with DJD.

Complications associated with total hip arthroplasty in four large nondomestic felids

CASE DESCRIPTION

A 9-year-old 37-kg sexually intact male snow leopard (Panthera uncia) with no history of lameness but radiographic evidence of right femoral subluxation and flattening of both femoral heads, 2 juvenile (< 1 year old) 25-kg sexually intact male cheetahs (Acinoynx jubatus) with unilateral hind limb lameness resulting from trauma, and an 11-year-old 110-kg sexually intact female Amur tiger (Panthera tigris altaica) with a 2-year history of left hip joint osteoarthritis were examined.

CLINICAL FINDINGS

No clinically relevant clinical findings other than hip joint problems were identified. All 4 felids underwent staged bilateral (snow leopard) or unilateral (cheetahs and tiger [Panthera tigris]) total hip arthroplasty (THA).

TREATMENT AND OUTCOME

In the snow leopard, both femoral THA components were found to be luxated 1 year after surgery. Treatment consisted of autogenous corticocancellous rib graft augmentation of the dorsal acetabular rims and synthetic suture capsulorrhaphies. The snow leopard lived for an additional 4 years with no additional THA-related complications. In the other 3 animals, catastrophic complications (luxation in the cheetahs and femoral fracture in the tiger) occurred shortly after THA. The THA implants were removed, and excision arthroplasty was performed. Long-term outcomes were good in all 3.

CLINICAL RELEVANCE

Findings underscore the challenges associated with THA in large nondomestic felids. Given the high risk for early catastrophic failure as a result of luxation or fracture, plans must be made and resources must be available in case revision surgery or implant removal with excision arthroplasty becomes necessary.

Indicators of Health-Related Quality of Life in Cats With Degenerative Joint Disease: Systematic Review and Proposal of a Conceptual Framework

Objectives: The assessment of health-related quality of life (HRQoL) is becoming increasingly important in companion animals. This study describes a systematic review and development of a proposed conceptual framework to assess HRQoL in cats with osteoarthritis (OA). Methods: The conceptual framework was developed according to published guidelines. A comprehensive search of the CAB Direct, Scopus, PubMed, and Web of Science databases was carried out for publications in English from inception to November 12, 2019. Search words used were "cat", "feline", "chronic pain", "pain", and "quality of life". Publications were selected if they were full-text and peer-reviewed, based on primary data, and identified or measured behavioral symptoms of chronic musculoskeletal pain in cats. A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A data extraction form was developed from categories identified in the literature review and piloted on a small number of studies to ascertain the appropriateness for relevant data extraction. Categories were then finalized, and key domains were identified. The domains were then synthesized to develop a conceptual framework. Results: A total of 454 studies were identified, of which 14 met the eligibility criteria and were included in the meta-synthesis. All 14 were assessed to be of good quality. Seven domains related to HRQoL in cats with OA were thematically identified from the data: mobility, physical appearance, energy and vitality, mood, pain expression, sociability, and physical and mental wellbeing. The three main HRQoL domains were pain expression, mobility, and physical and mental wellbeing, which impacted all the others. Pain and mobility impacted all six other domains, with increased pain and decreased mobility negatively impacting physical appearance, energy and vitality, mood, sociability, and physical and mental wellbeing. Conclusions and Relevance: This is the first study to develop an evidence-based conceptual framework for the assessment of HRQoL in cats with OA. The proposed conceptual framework suggests that effective management of chronic pain in cats may improve their overall HRQoL.

Computed tomography reveals hip dysplasia in the extinct Pleistocene saber-tooth cat Smilodon

Reconstructing the behavior of extinct species is challenging, particularly for those with no living analogues. However, damage preserved as paleopathologies on bone can record how an animal moved in life, potentially reflecting behavioral patterns. Here, we assess hypothesized etiologies of pathology in a pelvis and associated right femur of a Smilodon fatalis saber-toothed cat, one of the best-studied species from the Pleistocene-age Rancho La Brea asphalt seeps, California, USA, using visualization by computed tomography (CT). The pelvis exhibits massive destruction of the right hip socket that was interpreted, for nearly a century, to have developed from trauma and infection. CT imaging reveals instead that the pathological distortions characterize chronic remodeling that began at birth and led to degeneration of the joint over the animal's life. These results suggest that this individual suffered from hip dysplasia, a congenital condition common in domestic dogs and cats. This individual reached adulthood but could not have hunted properly nor defended territory on its own, likely relying on a social group for feeding and protection. While extant social felids are rare, these fossils and others with similar pathologies are consistent with a spectrum of social strategies in Smilodon supported by a predominance of previous studies.

Computed tomography is superior to radiography for detection of feline elbow osteoarthritis

Elbow osteoarthritis (OA) is common in cats and radiography is typically used for diagnosis. However computed tomography (CT), with its multiplanar three-dimensional characteristics, could have significant advantages for assessment of OA compared to radiography, particularly early in the disease process. The study objectives were to compare radiography and CT to histologic OA changes, investigate the stage of OA that radiography and CT detect, and search for specific changes in CT images strongly predictive for feline elbow OA. Right elbows from 29 cats were evaluated by radiography and CT, and articular cartilage lesions graded histologically and macroscopically. Three further joints were sampled to specifically evaluate the morphology of the anconeal process. Macroscopic, radiographic and CT OA diagnosis were compared to the reference standard histologic OA that was divided into mild, moderate and severe. Osteophytic spurs on the lateral margin of the anconeal process could be reliably measured in CT images (intra-class correlation 0.79) and when ≥0.5 mm had high sensitivity for moderate/severe histologic OA, moderate sensitivity for mild histologic OA and high specificity for all stages of OA. In moderate/severe histologic OA both radiography and CT subjective OA diagnosis had moderate to very high sensitivity. However, in mild histologic OA CT grading had low sensitivity and radiography did not detect OA. In conclusion, CT of the feline elbow including measurement of osteophytes on the anconeal process lateral margin is superior to radiography for OA detection and should be considered for OA diagnosis, particularly when mild OA changes are of interest.

Traumatic stifle injury in 72 cats: a multicentre retrospective study

OBJECTIVES

The aim of the study was to describe traumatic stifle injury in cats and report complications and long-term outcome.

METHODS

The medical records from seven veterinary hospitals of cats treated for traumatic stifle injury were reviewed. Long-term follow-up data were collected from referring veterinarians and using the Feline Musculoskeletal Pain Index, collected from owners.

RESULTS

Seventy-two cats were included in the study. The most common combination of ligament injury involved both cruciate ligaments and the lateral collateral ligament (25.4%). Medial meniscal injury was more common (66.2%) than lateral meniscal injury (59.4%). A temporary transarticular pin was used intraoperatively to aid reduction in 23/73 (31.5%) surgeries. Postoperative immobilisation was applied in 41/72 (56.9%) cats with a mean duration of 4.8 weeks. Short-term complications occurred in 40/64 (62.5%) cats. Long-term complications occurred in seven (17.5%) cats. Overall outcome was excellent in 25/61 (41%) cats, good in 13/61 (21.3%) cats, fair in 11/61 (18%) cats and poor in 12/61 (19.7%) cats. Mean length of follow-up was 29.6 months (range 0.5-204). A significantly poorer outcome was observed in cats with medial meniscal injury and those undergoing revision surgery. Use of a transarticular pin when left in situ for postoperative immobilisation was associated with a poorer outcome (P = 0.043) and a higher risk of complications (P = 0.018). Postoperative immobilisation was not related to outcome.

CONCLUSIONS AND RELEVANCE

Traumatic stifle injury in cats can lead to rupture of multiple ligaments causing significant instability of the joint. Surgical treatment is associated with a high rate of short-term complications, although long-term outcome may still be good to excellent in the majority of cats (62.3%). In cats where follow-up was available, postoperative immobilisation had no positive effect on outcome and may not be required. Leaving a transarticular pin for postoperative immobilisation is not recommended as it was significantly associated with a poorer outcome and a higher complication rate.

Associations between early neutering, obesity, outdoor access, trauma and feline degenerative joint disease

OBJECTIVES

The aim of this case-control study was to identify early-life risk factors associated with the occurrence of owner-reported mobility changes in 6-year-old cats by examining prospective data from a longitudinal cohort study of pet cats, the Bristol Cats study.

METHODS

Data on potential risk factors were obtained from seven sequential questionnaires completed between the ages of 2-4 months and 5 years. Mobility-related questions from the study questionnaire distributed at the age of 6 years were used to calculate each cat's mobility score. Cats with mobility scores of ⩾2 and 0 were allocated to the case and control groups, respectively, and the cat's status was the outcome variable.

RESULTS

Of the 799 cats included for analysis, 238 (29.8%) had owner-reported mobility changes. Binomial logistic regression using backwards elimination identified four risk factors for owner-reported mobility changes at 6 years of age: entire neuter status at 6 months of age (odds ratio [OR] 1.97; 95% confidence interval [CI] 1.26-3.07), sustained trauma before 6 years of age (OR 1.85; 95% CI 1.30-2.60), outdoor access at 6 years of age (OR 1.67; 95% CI 0.96-2.90) and overweight/obese status at 6 years of age (OR 1.62; 95% CI 1.13-2.33).

CONCLUSIONS AND RELEVANCE

Risk factor analysis demonstrated that obesity, outdoor access and a history of trauma may predispose cats to developing owner-reported mobility changes associated with degenerative joint disease, whereas neutering before 6 months of age appears to decrease that risk.

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

PRACTICAL RELEVANCE

An understanding of the process of musculoskeletal ageing - which all senior and geriatric cats will experience - is vital to maintaining the health and welfare of our ageing cat population.

CLINICAL CHALLENGES

Assessment of the feline musculoskeletal system is not always straightforward. Diagnosis of impairment relies on input from owners and veterinarians in terms of visual observation, and clinical and orthopaedic examination, in addition to diagnostic imaging.

AUDIENCE

This review is written for the primary care veterinary team.

AIMS

The goals are to raise awareness and improve clinical diagnosis of musculoskeletal impairment as a result of ageing. The article also reviews therapeutic options and considers the evidence available for the prevention/deceleration of musculoskeletal ageing and impairment.

EVIDENCE BASE

There is good evidence of a high prevalence of osteoarthritis (OA) and degenerative joint disease (DJD) in older cats. There is also good evidence to indicate that functional impairment and chronic pain are sequelae of musculoskeletal disease. However, there is a paucity of information for what is best practice for the management and treatment of musculoskeletal impairment in a clinical situation. There is also a lack of evidence on how prevention of central stimulation of the nervous system caused by musculoskeletal impairment and, in turn the development of chronic pain, can be avoided.

Novel use of an activity monitor to model jumping behaviors in cats

OBJECTIVE

To develop methods to identify and characterize activity monitor (AM) data signatures for jumps performed by cats.

ANIMALS

13 healthy, client-owned cats without evidence of osteoarthritis or degenerative joint disease.

PROCEDURES

Each cat was fitted with the same AM, individually placed in an observation room, then simultaneously recorded by 3 video cameras during the observation period (5 to 8 hours). Each cat was encouraged to jump up (JU), jump down (JD), and jump across (JA) during the observation period. Output from the AM was manually annotated for jumping events, each of which was characterized by functional data analysis yielding relevant coefficients. The coefficients were then used in linear discriminant analysis to differentiate recorded jumps as JUs, JDs, or JAs. To assess the model's ability to distinguish among the 3 jump types, a leave-one-out cross-validation method was used, and the misclassification error rate of the overall categorization of the model was calculated.

RESULTS

Of 731 jumping events, 29 were misclassified. Overall, the mean misclassification error rate per cat was 5.4% (range, 0% to 12.5%), conversely indicating a correct classification rate per cat of 94.6%.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the model was successful in correctly identifying JUs, JDs, and JAs in healthy cats. With advancements in AM technology and data processing, there is potential for the model to be applied in clinical settings as a means to obtain objective outcome measures.

Potential Causes of Increased Vocalisation in Elderly Cats with Cognitive Dysfunction Syndrome as Assessed by Their Owners

The objectives of this study were to explore owner perception of the causes of increased vocalisation in cats diagnosed with cognitive dysfunction syndrome (CDS) and consider what impact this vocalisation may have on the cat's household. Owners of cats diagnosed with CDS that presented with increased vocalisation were invited to complete an online survey. The survey consisted of 28 questions including the cat's signalment, its medical history, and questions pertaining to the owner's perception of what motivated their cat´s increased vocalisation. This was determined by looking at the cat's behaviour when vocalising, where it was looking when it was vocalising, and if the vocalisation stopped when the owner interacted with it, e.g., petting or feeding it. The owners were also asked how stressful they found their cat's vocalisation. There were 37 responses. The majority of owners reported that the main cause of their cat's vocalisation appeared to be disorientation (40.5%) or attention seeking (40.5%). Seeking a resource such as food was reported in 16.2%, and pain was perceived to be the cause in only 2.7% of cats. However, the majority of owners (64.8%) believed there was >1 cause of their cat's increased vocalisation. Importantly, when owners were asked how stressful they found their cat's increased vocalisation, 40.5% scored ≥3 (where 1 = not stressful; 5 = significantly stressful). This study provides novel insight into owner perception of feline CDS, as well as potential causes for increased vocalisation; this will allow veterinarians to better advise owners on how to manage their cat with CDS.

Feline Chronic Pain and Osteoarthritis

This article reviews the current knowledge regarding osteoarthritis-related pain in cats as a structure in which to discuss the assessment of chronic pain in the research and clinical settings. The scientific evidence available for current and emerging drug therapies is described. The importance of environmental enrichment and positive emotions to reduce pain, stress, and anxiety as means to promote feline welfare and human-pet bond is discussed.

Undenatured Type II Collagen (UC-II) in Joint Health and Disease: A Review on the Current Knowledge of Companion Animals

OA is quite common in companion animals, especially in large breed dogs and horses. Collagen, the most abundant protein of mammals, has specific connective tissue types for skin, bones, reticulate, basal lamina, bones, cell surfaces, while type II collagen (UC-II) forms the main structure of cartilage tissue. Even at the smaller dosages, UC-II has also been reported to be more effective than the glucosamine and chondroitin sulfate supplements, which are the supplements most frequently used in the market. In this review, we summarize the effects of UC-II on joint health and function in health and disease conditions in companion animals.

Retrospective Radiographic Study of Degenerative Joint Disease in Cats: Prevalence Based on Orthogonal Radiographs

Feline degenerative joint disease (DJD) has been reported worldwide. Radiographic evidence, including that from single-plane radiographs, has been used for diagnosis in these reports, though orthogonal radiographs are generally required to diagnose DJD. However, more orthogonal radiographs are required for diagnosis. In this study, we investigated how many orthogonal radiographs are necessary to diagnose feline DJD among domestic short-haired cats. We analyzed the data from 101 cats for which the owners requested screening for arthritis. Orthogonal radiographs of appendicular and intervertebral joints were taken from the chest to the caudal side. Radiographs were then reviewed and graded by severity of DJD in each joint. Radiographic evidence of appendicular DJD was detected in 74.26% of 101 cats, of which 40.59% had intervertebral DJD (typically of the lumbosacral joint). Appendicular DJD was most common in elbow joints. Lameness was recognized by an owner of two cats and was diagnosed by a veterinarian in two cats. No obvious pain was detected on palpation in any cats with appendicular osteoarthritis, but lumbosacral DJD was associated with back pain in seven cases. Aging was associated with radiographic evidence of DJD: radiographic evidence of DJD was observed in most older domestic short-haired cats. Most cases without lumbosacral DJD had no obvious symptoms. As the lifespan of cats increases due to better lifestyles, diet, and medical treatment, lumbosacral DJD, which is more likely in older cats, may become an increasingly important clinical problem. In addition, orthogonal radiograph must be taken to make diagnosis for appendicular joint DJD especially hip and stifle joint.

Development of a checklist for the detection of degenerative joint disease-associated pain in cats

OBJECTIVES

The aim of this study was to develop an evidence-based, clinically expedient checklist to identify cats likely to have degenerative joint disease (DJD)-associated pain.

METHODS

Data were compiled from previously conducted studies that employed a standardized subjective outcome measure consisting of a series of questions. These studies included a prevalence study (with DJD non-informed owners) and therapeutic trials (with DJD-informed owners). For each cat, and each question, response scores were converted to 'impaired' and 'unimpaired'. Cats were categorized as 'DJD pain' and 'non-DJD' based on orthopedic pain and radiographic DJD scores. These binary data were compared between cat phenotypes (non-DJD and DJD pain) for each question. Sensitivity and specificity of each question were calculated using the binary data; based on this, potential questions for the checklist were selected. Sensitivity and specificity across this group of questions were calculated, and questions sequentially removed to optimize length, sensitivity and specificity. Finally, the proposed checklist was applied to a novel data set to evaluate its ability to identify cats with DJD pain.

RESULTS

In total, 249 DJD pain cats and 53 non-DJD cats from five studies were included. Nine questions with adequate sensitivity and specificity were initially identified. Following sequential removal of questions, a checklist with six binary questions was proposed. Based on the data from the cohorts of DJD-informed and DJD non-informed owners, the sensitivity and specificity of the proposed checklist were approximately 99% and 100%, and 55% and 97%, respectively.

CONCLUSIONS AND RELEVANCE

The proposed checklist represents a data-driven approach to construct a screening checklist for DJD pain in cats. This checklist provides a clinically expedient tool likely to increase veterinarians' ability to screen for DJD pain in cats. The identified behaviors comprising the checklist may further provide a foundation for increasing awareness of DJD pain among cat owners.

Anatomic Study of the Elbow Joint in a Bengal Tiger (Panthera tigris tigris) Using Magnetic Resonance Imaging and Gross Dissections

The objective of our research was to describe the normal appearance of the bony and soft tissue structures of the elbow joint in a cadaver of a male mature Bengal tiger (Panthera tigris tigris) scanned via MRI. Using a 0.2 Tesla magnet, Spin-echo (SE) T1-weighting, and Gradient-echo short tau inversion recovery (GE-STIR), T2-weighting pulse sequences were selected to generate sagittal, transverse, and dorsal planes. In addition, gross dissections of the forelimb and its elbow joint were made. On anatomic dissections, all bony, articular, and muscular structures could be identified. The MRI images allowed us to observe the bony and many soft tissues of the tiger elbow joint. The SE T1-weighted MR images provided good anatomic detail of this joint, whereas the GE-STIR T2-weighted MR pulse sequence was best for synovial cavities. Detailed information is provided that may be used as initial anatomic reference for interpretation of MR images of the Bengal tiger (Panthera tigris tigris) elbow joint and in the diagnosis of disorders of this region.

Demography, heritability and genetic correlation of feline hip dysplasia and response to selection in a health screening programme

Feline hip dysplasia (FHD) is a debilitating condition affecting the hip joints of millions of domestic cats worldwide. Despite this, little is known about FHD except that it is relatively common in the large breed Maine Coon. We used 20 years of data from 5038 pedigree-registered Maine Coon cats in a radiographic health screening programme for FHD to determine, for the first time, its heritability, genetic correlation to body mass and response to selection. FHD prevalence was 37.4%, with no sex predilection; however, FHD severity increased with age and body mass. Heritability of the radiographic categories used to classify FHD severity was 0.36 (95%CI: 0.30–0.43). The severity of FHD symptoms was also genetically correlated with body mass (0.285), suggesting that selection for a large body type in this breed concurrently selects for FHD. Support for this was found by following generational responses to selective breeding against FHD. Not only did selective breeding successfully reduce the severity of FHD symptoms in descendants, but these cats were also smaller than their ancestors (−33g per generation). This study highlights the value of breeding programmes against FHD and cautions against breed standards that actively encourage large bodied cats.

Postcranial axial skeletal pathology in Commerson's dolphins Cephalorhynchus c. commersonii from Tierra del Fuego, Argentina

Commerson's dolphins Cephalorhynchus c. commersonii are the small cetacean most frequently found stranded along the coast of Tierra del Fuego, Argentina, but little is known about their pathologies. We examined the postcranial axial skeleton of 425 Commerson's dolphins collected in the period 1974-2011 for the presence of pathologies. Miscellaneous lesions were detected in 107 (25.2%) of the specimens. Among them, idiopathic hyperostosis was the most frequent pathology (73.8%), followed by spondyloarthropathy (40.2%). Traumata (25.2%), spondylitis (10.3%) and osteoarthritis (11.2%) occurred less frequently. The type of lesion was statistically associated with the region of the vertebral column. Idiopathic hyperostosis occurred significantly more frequently in the lumbar vertebrae than in other parts of the vertebral column, while spondyloarthropathy was more frequent in the thoracic and caudal vertebrae. Both conditions were predominantly seen in mature dolphins. Osteoarthritis affected the transverse processes of the thoracic vertebrae of 6 males, 3 females and 3 individuals of undetermined sex, all mature. Healed and unhealed fractures were observed in the ribs of 27 specimens and in the transverse processes of 3 others. Spondylitis of various degrees of severity affected the cervical, thoracic, lumbar and caudal regions of 11 individuals. Together these data indicate that bone lesions and traumata commonly occur in Commerson's dolphins, likely causing pain and morbidity in severe cases.

Characterization of gene expression in naturally occurring feline degenerative joint disease-associated pain

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Nervous system tissue from cats with painful degenerative joint disease (DJD) was analyzed.

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Gene expression was determined to investigate the neurobiological signature of DJD pain.

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There was decreased NGF and increased CX3CL1 expression in the spinal cord in DJD-affected cats compared to healthy controls.

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There was increased expression of ATF3 and CX3CL1 in dorsal root ganglia, in DJD-affected cats compared to healthy controls.

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Such studies have the potential to inform about relevant targets for the control of chronic feline pain.

Degenerative joint disease (DJD) associated-pain is a clinically relevant and common condition affecting domesticated cats and other species including humans. Identification of the neurobiological signature of pain is well developed in rodent pain models, however such information is lacking from animals or humans with naturally occurring painful conditions. In this study, identification of housekeeping genes (HKG) for neuronal tissue and expression levels of genes considered associated with chronic pain in rodent models were explored in cats with naturally occurring osteoarthritic pain. Fourteen adult cats were evaluated — seven without clinical signs of osteoarthritic pain, and seven with hind limb radiographic DJD and pain. Expression of an investigator-selected set of pain signaling genes (including ASIC3, ATF3, COX2, CX3CL1, NAV1.7, NAV1.8, NAV1.9, NGF, NK1R, TNFα, TRKA) in lumbar spinal cord dorsal horn and lumbar dorsal root ganglia tissues from clinically healthy cats and cats with DJD were studied using quantitative RT-PCR (qPCR).

HKG identified as the most stable across all tissue samples were many of the ribosomal protein genes, such as RPL30 and RPS19. qPCR results showed ATF3 and CX3CL1 up-regulated in DJD-affected dorsal root ganglia compared to clinically healthy controls. In spinal cord, CX3CL1 was up-regulated and NGF was down-regulated when DJD-affected samples were compared to healthy samples. Further work is needed to understand the neurobiology of pain in naturally occurring disease and what rodent models are predictive of these changes in more heterogeneous populations such as domestic cats.

Anti-nerve growth factor monoclonal antibodies for the control of pain in dogs and cats

Nerve growth factor (NGF) is essential for the survival of sensory and sympathetic neurons during development. However, in the adult, NGF and its interaction with tropomyosin receptor kinase A receptor (TrkA) has been found to play a critical role in nociception and nervous system plasticity in pain conditions. Thus, various monoclonal antibody (mAb) therapies targeting this pathway have been investigated in the development of new pharmacotherapies for chronic pain. Although none of the mAbs against NGF are yet approved for use in humans, they look very promising for the effective control of pain. Recently, species-specific anti-NGF mAbs for the management of osteoarthritis (OA)-associated pain in dogs and cats has been developed, and early clinical trials have been conducted. Anti-NGF therapy looks to be both very effective and very promising as a novel therapy against chronic pain in dogs and cats. This review outlines the mechanism of action of NGF, the role of NGF in osteoarthritis, research in rodent OA models and the current status of the development of anti-NGF mAbs in humans. Furthermore, we describe and discuss the recent development of species-specific anti-NGF mAbs for the treatment of OA-associated pain in veterinary medicine.

Refinement of the Montreal Instrument for Cat Arthritis Testing, for Use by Veterinarians: detection of naturally occurring osteoarthritis in laboratory cats

Objectives Feline osteoarthritis causes pain and disability. Detection and measurement is challenging, relying heavily on owner report. This study describes refinement of the Montreal Instrument for Cat Arthritis Testing, for Use by Veterinarians. Methods A video analysis of osteoarthritic (n = 6) and non-osteoarthritic (n = 4) cats facilitated expansion of scale items. Three successive therapeutic trials (using gabapentin, tramadol and oral transmucosal meloxicam spray) in laboratory cats with and without natural osteoarthritis (n = 12-20) permitted construct validation (assessments of disease status sensitivity and therapeutic responsiveness) and further scale refinements based on performance. Results Scale osteoarthritic sensitivity improved from phase I to phase III; phase III scale total score ( P = 0.0001) and 4/5 subcategories - body posture ( P = 0.0006), gait ( P = 0.0031), jumping (0.0824) and global distance examination ( P = 0.0001) - detected osteoarthritic cats. Total score inter-rater (intra-class correlation coefficients [ICC] = 0.64-0.75), intra-rater (ICC = 0.90-0.91) and overall internal consistency (Cronbach's alpha = 0.85) reliability were good to excellent. von Frey anesthesiometer-induced paw withdrawal threshold increased with gabapentin in phase I, in osteoarthritic cats ( P <0.001) but not in non-osteoarthritic cats ( P = 0.075). Night-time activity increased during gabapentin treatment. Objective measures also detected tramadol and/or meloxicam treatment effects in osteoarthritic cats in phases II and III. There was some treatment responsiveness: in phase I, 3/10 subcategory scores improved ( P <0.09) in treated osteoarthritic cats; in phase II, 3/8 subcategories improved; and in phase III, 1/5 subcategories improved ( P <0.096). Conclusions and relevance The revised scale detected naturally occurring osteoarthritis, but not treatment effects, in laboratory cats, suggesting future potential for screening of at-risk cats. Further study is needed to confirm reliability, validity (disease sensitivity and treatment responsiveness) and clinical feasibility, as well as cut-off scores for osteoarthritic vs non-osteoarthritic status, in client-owned cats.

Vertical or Horizontal? Diagnosing and Treating Cats Who Urinate Outside the Box

Feline elimination problems are commonly presented to general practitioners and behavioral medicine specialists. The correct diagnosis is often missed by veterinarians owing to individual variation and multifactorial cases. Three diagnostic umbrellas need to be considered: medical problems, toileting behavior outside of the litter box, and urine marking. The treatment plan for most cases, regardless of etiology, involves optimum litter box management, fulfilling cats' environmental needs, stress reduction, behavior therapy techniques, and trigger removal. Medical management with psychoactive medication might be necessary in cases where chronic stress, fear, and anxiety play a role in the feline patient's symptomatology.

Use of greater omentum in the surgical treatment of a synovial cyst in a cat

A 13-year-old cat was diagnosed with a synovial cyst originating from the glenohumeral joint. The cat presented with severe front limb lameness and a non-painful fluctuating swelling on the medial aspect of the humerus. Radiographic examination showed severe bilateral shoulder osteoarthritis with osteophyte formation. The mass was surgically resected and histopathology confirmed the diagnosis of a synovial cyst. Three weeks postoperatively the cyst recurred. Surgical resection was repeated followed by omentalisation of the defect. Throughout the following 3 months the cyst did not recur. Unfortunately, for reasons unrelated to the presented disease, the cat was euthanized shortly afterwards, therefore making a long-term follow-up impossible.

Prevalence of spondylosis deformans in the feline spine and correlation with owner-perceived behavioural changes

Objectives: The primary objective was to determine the prevalence, spinal distribution, and association with the signalment of cats suffering from different grades of feline spondylosis deformans (spondylosis). The secondary objective was to document behavioural changes associated with spondylosis by owner observation.

Methods: A cross-sectional study was performed to determine the prevalence of feline spondylosis (group 1). A prospective study was performed to determine the association between radiographic abnormalities of the lumbosacral region (L3-S1) and owner perceived behavioural changes based on a completed questionnaire (group 2). The radiographs were reviewed using a grading system (0–3) for spondylosis.

Results: The prevalence of spondylosis in group 1 was 39.4% (158/402). Cats with spondylosis were significantly older than cats without spondylosis (p <0.001). The thoracic (T) vertebrae T4-T10 were most often affected by spondylosis, but spondylosis was most severe in the T10-S1 vertebrae. In group 2, spondylosis of the lumbosacral region was significantly correlated with owner-reported behavioural changes, such as a decreased willingness to greet people and to being petted, increased aggressiveness, and a poor perceived quality of life (p = 0.037).

Clinical significance: This study found that feline spondylosis is common and that spondylosis of the lumbosacral region may be accompanied by behavioural changes.

Comparison of meloxicam and a glucosamine-chondroitin supplement in management of feline osteoarthritis

Objectives: To compare the efficacy of meloxicam and a glucosamine-chondroitin (Glu-Ch) supplement in the management of feline osteoarthritis (OA).

Methods: Prospective, blinded, randomized clinical trial. Cats over eight years of age with clinical signs of chronic OA were assigned to one of two groups and Glu-Ch or meloxicam was administered orally for 70 days, followed by a placebo until day 98. Cats were assessed by a veterinarian on five occasions and the owner completed an assessment form at the same time.

Results: Data were collected from thirty cats. Pre-treatment disease scores were significantly higher in the meloxicam group for owner mobility (p = 0.01) and veterinary lameness (p = 0.02). Owner mobility scores at day 14 (p = 0.01) and day 42 (p = 0.002) were significantly improved compared to pre-treatment scores for the meloxicam group. When meloxicam and Glu-Ch were discontinued and the placebo commenced, a significant proportion of the meloxicam group showed worsening of all the ownerassessed scores between day 70 and day 98, when compared to the Glu-Ch group (mobility p = 0.01; activity p = 0.02; temperament p = 0.04; lifestyle p = 0.01).

Clinical significance: Treatment with meloxicam resulted in a significant improvement in mobility and activity levels of cats with OA until the placebo was introduced. A greater proportion of cats receiving meloxicam medication showed a significant worsening of owner assessment scores once the placed was introduced, when compared to the Glu-Ch group.

Evaluation of the transarticular external skeletal fixator for the treatment of tarsocrural instability in 32 cats

The medical records of all cats with tarsocrural joint instability that were treated between June 2002 and December 2008 at the Royal Veterinary College were retrospectively reviewed. A total of 32 cats were identified. Information gathered included signalment, type of injury (subluxation or luxation), concurrent fractures, presence of soft tissue wounds, transarticular external skeletal fixation (TESF) type, configuration of TESF (number of pins proximal and distal to the joint), duration of hospitalisation, duration of TESF prior to removal, complications and cost. A significant association was identified between the length of hospitalisation and the presence of wounds. Similarly a significant association was present between wounds and final cost of treatment. Additionally, the authors found that a high number of implant related complications were present when only two pins were used proximal and distal to the tarsocrural joint, but this association was not significant.

Chronic diseases in cats from the medieval site of Qalhât (Oman)

Paleopathological information observed in cats (Felis catus, L. 1758) is rarely described in zooarcheological assemblages. This article is intended to present different bone diseases (infections, degenerative and traumatic lesions) affecting several bones (i.e. femur, hip bone, skull, etc.) of at least two cats from the medieval harbor site of Qalhât (Oman) and to inform us about the health status of these felines.

Retrospective Case—Control Study of the Effects of Long-Term Dosing with Meloxicam on Renal Function in Aged Cats with Degenerative Joint Disease

Medical records (2005–2009) of a feline-only practice were searched for cats with degenerative joint disease (DJD) treated using meloxicam. DJD was diagnosed by the presence of at least two of the following: (i) altered mobility (observed by the owner), (ii) abnormal physical findings, (iii) characteristic radiographic changes. The primary study cohort consisted of cats older than 7 years that had received meloxicam for variable intervals in excess of 6 months, and for which complete records were available. These cats were subdivided according to whether detectable chronic kidney disease (CKD) was present (‘renal group’), or not (‘non-renal group’), and, for the ‘renal group’, according to the cat's IRIS category. Serum biochemistry, urinalysis (including urine specific gravity [USG]), body mass and condition score were monitored regularly. Progression of CKD in the ‘renal group’ and ‘non-renal group’ of cats was compared to two groups of age- and IRIS-matched control cats not receiving meloxicam (from the same clinic, over the same time period). The study was thus a case—control design, with two study groups. Thirty-eight cats with DJD receiving long-term meloxicam therapy met the inclusion criteria. Of these, 22 cats had stable CKD at the start of treatment (stage 1, eight cats; stage 2, 13 cats; stage 3, one cat). No cats initially had an elevated urinary protein to creatinine ratio. The remaining 16 cats initially had normal renal analytes and adequately concentrated urine. The median age of the ‘renal’ and ‘non-renal’ meloxicam groups was 15.5 and 13.4 years, respectively. The median treatment duration was 467 days in the ‘renal group’ and 327 days in the ‘non-renal group’. After titration (to the lowest effective dose), the median maintenance dose was 0.02 mg/kg/day in both groups (range 0.015–0.033 mg/kg/day). There was no difference in sequential serum creatinine concentration or USG measurements between the ‘non-renal group’ treated with meloxicam compared to control cats not treated with meloxicam. There was less progression of renal disease in the ‘renal group’ treated with meloxicam compared to the age- and IRIS-matched cats with CKD not given meloxicam. These results suggest that a long-term maintenance dose of 0.02 mg/kg of meloxicam can be safely administered to cats older than 7 years even if they have CKD, provided their overall clinical status is stable. Long-term meloxicam therapy may slow the progression of renal disease in some cats suffering from both CKD and DJD. Prospective studies are required to confirm these findings.

Repeatability of quantitative sensory testing in healthy cats in a clinical setting with comparison to cats with osteoarthritis

Objectives

The aim of this study was to evaluate the repeatability of quantitative sensory tests (QSTs) in a group of healthy untrained cats (n = 14) and to compare the results with those from cats with osteoarthritis (n = 7).

Methods

Peak vertical force (PVF) and vertical impulse were measured on a pressure plate system. Thermal sensitivity was assessed using a temperature-controlled plate at 7°C and 40°C. Individual paw lifts and overall duration of paw lifts were counted and measured for each limb. Paw withdrawal thresholds were measured using manual and electronic von Frey monofilaments (MVF and EVF, respectively) applied to the metacarpal or metatarsal pads. All measurements were repeated twice to assess repeatability of the tests.

Results

In healthy cats all tests were moderately repeatable. When compared with cats with osteoarthritis the PVF was significantly higher in healthy hindlimbs in repeat 1 but not in repeat 2. Cats with osteoarthritis of the forelimbs showed a decrease in the frequency of paw lifts on the 7°C plate compared with cats with healthy forelimbs, and the duration of paw lifts was significantly less than healthy forelimbs in the first repeat but not in the second repeat. Osteoarthritic limbs had significantly lower paw withdrawal thresholds with both MVF and EVF than healthy limbs.

Conclusions and relevance

QSTs are moderately repeatable in untrained cats. Kinetic gait analysis did not permit differentiation between healthy limbs and those with osteoarthritis, but thermal sensitivity testing (cold) does. Sensory threshold testing can differentiate osteoarthritic and healthy limbs, and may be useful in the diagnosis and monitoring of this condition in cats in the clinical setting.

Evaluation of serum cytokines in cats with and without degenerative joint disease and associated pain

Degenerative joint disease is common in cats, with signs of pain frequently found on orthopedic examination and radiographs often showing evidence of disease. However, understanding of the pathophysiology of degenerative joint disease and associated pain remains limited. Several cytokines have been identified as having a role in pain in humans, but this has not been investigated in cats. The present study was performed to use a multiplex platform to evaluate the concentration of 19 cytokines and chemokines in serum samples obtained from cats with and without degenerative joint disease and associated pain. Samples from a total of 186 cats were analyzed, with cats representing a range of severity on radiographic and orthopedic evaluations and categorized by degenerative joint disease scores and pain scores. Results showed that cats with higher radiographic degenerative joint disease scores have higher serum concentrations of IL-4 and IL-8, while cats with higher orthopedic exam pain scores have higher concentrations of IL-8, IL-2, and TNF-α; increased concentration of IL-8 in degenerative joint disease and pain may be confounded by the association with age. Discriminant analysis was unable to identify one or more cytokines that distinguish between groups of cats classified based on degenerative joint disease score category or pain score category. Finally, cluster analysis driven by analyte concentrations shows separation of groups of cats, but features defining the groups remain unknown. Further studies are warranted to investigate any changes in cytokine concentrations in response to analgesic therapies, and further evaluate the elevations in cytokine concentrations found here, particularly focused on studies of local cytokines present in synovial fluid.

Do cats with a cranial cruciate ligament injury and osteoarthritis demonstrate a different gait pattern and behaviour compared to sound cats?

Background

Osteoarthritis (OA) is a common cause of chronic pain and dysfunction in older cats. The majority of cats with OA do not show signs of overt lameness, yet cats with orthopaedic disease are known to redistribute their body weight from the affected limb. OA can cause changes in the cat’s behaviour, which is often misinterpreted as signs of aging. The aim of the present study was to investigate if cats with a previous cranial cruciate ligament (CCL) injury perform differently on the pressure mat and exhibit different behaviour compared to sound cats according to the owner´s subjective assessment. Ten cats with a previous CCL injury were assessed with a pressure mat system and their owners were asked to complete an assessment questionnaire. The results were compared to those of 15 sound cats, matched to have the same weight and body condition score.

Results

The front/hind limb index for peak vertical force (PVF) was significantly higher for CCL cats, and there was a decreased PVF and vertical impulse (VI) on the affected hindlimb compared to the unaffected one. The results indicate that cats with a previous CCL injury put less weight, on the affected hindlimb but for a longer time. There was a significantly higher owner assessment questionnaire score for the group of cats with CCL injury compared to sound cats.

Conclusions

Cats with a previous CCL injury have a different gait pattern compared to sound cats and a different behaviour according to owner subjective assessment. It is of great importance that further studies are performed to investigate the long term effects of CCL injury as a cause of pain and physical dysfunction, and its role in the development of OA in cats. Improved assessment tools for chronic pain caused by OA in cats are needed, both to facilitate diagnosis and to evaluate pain-relieving treatment.

Tibial plateau levelling osteotomy in eleven cats with cranial cruciate ligament rupture

OBJECTIVE

To report the surgical procedure, intra- and postoperative complications, and short-term follow-up of tibial plateau levelling osteotomy (TPLO) in feline patients with cranial cruciate ligament (CrCL) rupture using a 2.0 or 2.4 mm Synthes^® TPLO plate.

STUDY DESIGN

Prospective study.

MATERIAL AND METHODS

Eleven cats with a CrCL rupture were included in the study. Inspection of intra-articular structures was carried out via arthroscopy or arthrotomy. Each patient was re-examined one and 10 days after surgery. Orthopaedic examination and follow-up radiographs were obtained four to 12 weeks postoperatively.

RESULTS

Two meniscopathies and one partial CrCL rupture were detected. Minor intra-operative complications occurred in five cats (suboptimal positioning of the plate [n = 3], proximal fibular fracture [n = 1], a visible osteotomy gap [n = 1]). Postoperatively, minor complications were detected in three cats (mild patellar desmitis [n = 2], superficial wound infection [n = 1]). No additional surgical reintervention, graded as major complication, was necessary. Four to eight weeks postoperatively, all cats showed no to mild intermittent lameness. Complete bone union was apparent within four to 12 weeks. Owners reported a high level of comfort and mobility during the last follow-up.

CONCLUSION

The preliminary results of this study support the use of TPLO in cats, but larger case numbers are needed to evaluate its practicability, as well as long-term outcome (>1 year), especially evaluating the development and the clinical relevance of osteoarthritis.

Preliminary Validation and Reliability Testing of the Montreal Instrument for Cat Arthritis Testing, for Use by Veterinarians, in a Colony of Laboratory Cats

Simple Summary

Feline osteoarthritis (OA) is challenging to diagnose. A pain scale was developed for use by veterinarians, in association with their physical examination, and tested for reliability and validity. The scale items were: Interaction with the examiner, Exploration of the room, Body Posture, Gait, Body Condition, condition of Coat and Claws, and abnormal Findings or Cat Reaction upon joint Palpation. Expert review supported the scale content. Two studies using laboratory-housed cats found the most promising results for Gait and Body Posture, in terms of distinguishing between OA and non-OA cats, repeatability of results, and correlations with objectively measured kinetics (weight-bearing).

Abstract

Subtle signs and conflicting physical and radiographic findings make feline osteoarthritis (OA) challenging to diagnose. A physical examination-based assessment was developed, consisting of eight items: Interaction, Exploration, Posture, Gait, Body Condition, Coat and Claws, (joint) Palpation–Findings, and Palpation–Cat Reaction. Content (experts) and face (veterinary students) validity were excellent. Construct validity, internal consistency, and intra- and inter-rater reliability were assessed via a pilot and main study, using laboratory-housed cats with and without OA. Gait distinguished OA status in the pilot (p = 0.05) study. In the main study, no scale item achieved statistically significant OA detection. Forelimb peak vertical ground reaction force (PVF) correlated inversely with Gait (Rho_s = −0.38 (p = 0.03) to −0.41 (p = 0.02)). Body Posture correlated with Gait, and inversely with forelimb PVF at two of three time points (Rho_s = −0.38 (p = 0.03) to −0.43 (p = 0.01)). Palpation (Findings, Cat Reaction) did not distinguish OA from non-OA cats. Palpation—Cat Reaction (Forelimbs) correlated inversely with forelimb PVF at two time points (Rho_s = −0.41 (p = 0.02) to −0.41 (p = 0.01)), but scores were highly variable, and poorly reliable. Gait and Posture require improved sensitivity, and Palpation should be interpreted cautiously, in diagnosing feline OA.

Thoracic limb morphology of the red panda (Ailurus fulgens) evidenced by osteology and radiography

The red panda (Ailurus fulgens) is distributed primarily in the Himalayas and southern China. It is classified as a vulnerable species by the International Union for Conservation of Nature. The aim of this study was to describe the normal osteology and radiographic anatomy of the thoracic limb of the red panda. Radiography of the right thoracic limb was performed in seven captive adult red pandas. Radiographic findings were correlated with bone specimens from three adult animals. The scapula was wide craniocaudally and presented with a large area for the origin of the teres major muscle. The square-shaped major tubercle did not extend proximal to the head of the humerus. The medial epicondyle was prominent. A supracondylar foramen was present. The radial tuberosity and sesamoid bone for the abductor digiti I longus were prominent. The accessory carpal bone was directed palmarolaterally. Metacarpal bones were widely spread. The thoracic limb morphology of the red panda evidenced by osteology and radiography indicated flexibility of the thoracic limb joints and well-developed flexor and supinator muscles, which are important in arboreal quadrupedal locomotion. Knowledge gained during this study may prove useful in identifying skeletal material or remains and diagnosing musculoskeletal diseases and injuries of the thoracic limb.

Criterion Validation Testing of Clinical Metrology Instruments for Measuring Degenerative Joint Disease Associated Mobility Impairment in Cats

Introduction

Degenerative joint disease and associated pain are common in cats, particularly in older cats. There is a need for treatment options, however evaluation of putative therapies is limited by a lack of suitable, validated outcome measures that can be used in the target population of client owned cats. The objectives of this study were to evaluate low-dose daily meloxicam for the treatment of pain associated with degenerative joint disease in cats, and further validate two clinical metrology instruments, the Feline Musculoskeletal Pain Index (FMPI) and the Client Specific Outcome Measures (CSOM).

Methods

Sixty-six client owned cats with degenerative joint disease and owner-reported impairments in mobility were screened and enrolled into a double-masked, placebo-controlled, randomized clinical trial. Following a run-in baseline period, cats were given either placebo or meloxicam for 21 days, then in a masked washout, cats were all given placebo for 21 days. Subsequently, cats were given the opposite treatment, placebo or meloxicam, for 21 days. Cats wore activity monitors throughout the study, owners completed clinical metrology instruments following each period.

Results

Activity counts were increased in cats during treatment with daily meloxicam (p<0.0001) compared to baseline. The FMPI results and activity count data offer concurrent validation for the FMPI, though the relationship between baseline activity counts and FMPI scores at baseline was poor (R²=0.034). The CSOM did not show responsiveness for improvement in this study, and the relationship between baseline activity counts and CSOM scores at baseline was similarly poor (R²=0.042).

Conclusions

Refinements to the FMPI, including abbreviation of the instrument and scoring as percent of possible score are recommended. This study offered further validation of the FMPI as a clinical metrology instrument for use in detecting therapeutic efficacy in cats with degenerative joint disease.

A canine-specific anti-nerve growth factor antibody alleviates pain and improves mobility and function in dogs with degenerative joint disease-associated pain

Background

There is a critical need for proven drugs other than non-steroidal anti-inflammatory drugs for treatment of degenerative joint disease (DJD) pain in dogs. Antibodies against nerve growth factor (NGF) are analgesic in rodent models and in humans with DJD. This pilot study aimed to evaluate the efficacy of a novel caninised anti-NGF antibody (NV-01) for the treatment of DJD pain in dogs. In a randomized, parallel group, stratified, double masked, placebo controlled, proof of principle clinical pilot study design, 26 dogs with DJD received NV-01 (200 mcg/kg IV) or placebo on day 0 (D0). In addition to objective accelerometry measures, owners completed clinical metrology instruments (Client-Specific Outcome Measures [CSOM], Canine Brief Pain Inventory [CBPI] and Liverpool Osteoarthritis in Dogs Index [LOAD]) on D0, D14 and D28. CBPI subscales (pain severity [PS] and pain interference [PI]), CSOM and LOAD scores were evaluated within and between groups for change over time. Recognized success/failure criteria were applied and success compared between groups.

Results

CBPI PS and PI scores significantly improved in the NV-01 group (PS: D0-14, P = 0.012 and D0-28, P = 0.019; PI: D0-14, P = 0.012 and D0-28, P = 0.032) but not in the placebo group. CSOM scores showed similar patterns with a significant difference between within-group changes at D14 and D28 (P = 0.038 and P = 0.009, respectively), and significantly more successes at D28 (P = 0.047). LOAD scores significantly improved in the NV-01 group (D0-14, P = 0.004 and D0-28, P = 0.002) but not in the placebo group. There were significant differences between the groups for change in LOAD score at D14 (P = 0.014) and D28 (P = 0.033). No side effects were noted. Activity in the NV-01 group increased over the study period compared to placebo (P = 0.063) and the difference between the groups for change in activity over the time period 9am-5pm (8 hours) was significant (P = 0.006).

Conclusions

These pilot data demonstrate a positive analgesic effect of anti-NGF antibody in dogs suffering from chronic pain. The magnitude of the effect appeared identical to that expected with an NSAID.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0413-x) contains supplementary material, which is available to authorized users.

Relationship between degenerative joint disease, pain, and Bartonella spp. seroreactivity in domesticated cats

Background

Recently, a potential association was identified between Bartonella exposure and arthritides in mammalian species other than cats.

Hypothesis/Objectives

We hypothesized that Bartonella exposure is associated with more severe degenerative joint disease (DJD) and a greater burden of DJD‐associated pain in client‐owned cats.

Animals

Ninety‐four client‐owned cats (6 months to 20 years old), ranging from clinically unaffected to severely lame because of DJD.

Methods

Using physical examination and radiography, pain and radiographic scores were assigned to each part of the bony skeleton. Sera were tested for Bartonella henselae, B. koehlerae, and B. vinsonii subsp. berkhoffii (genotypes I, II, and III) antibodies using immunofluorescence antibody assays. Variables were categorized and logistic regression used to explore associations.

Results

Seropositivity to Bartonella was identified in 33 (35.1%) cats. After multivariate analysis controlling for age, total DJD score (OR, 0.51; 95% CI, 0.26–0.97; P = .042), appendicular pain score (OR, 0.33; 95% CI, 0.17–0.65; P = .0011), and total pain score (OR, 0.35; 95% CI, 0.17–0.72; P = .0045) were significantly inversely associated with Bartonella seroreactivity status, indicating that cats with higher DJD and pain scores were less likely to be Bartonella seropositive.

Conclusions and Clinical Importance

Based upon this preliminary study, Bartonella spp. seropositivity was associated with decreased severity of DJD and decreased DJD‐associated pain in cats. Additional studies are needed to verify these findings, and if verified, to explore potential mechanisms.

Morphology of the pelvis and hind limb of the red panda (Ailurus fulgens) evidenced by gross osteology, radiography and computed tomography

The red panda (Ailurus fulgens) is a quadrupedal arboreal animal primarily distributed in the Himalayas and southern China. It is a species commonly kept in zoological collections. This study was carried out to describe the morphology of the pelvis and hind limb of the red panda evidenced by gross osteology, radiography and computed tomography as a reference for clinical use and identification of skeletons. Radiography of the pelvis and right hind limb was performed in nine and seven animals, respectively. Radiographic findings were correlated with bone specimens from three adult animals. Computed tomography of the torso and hind limb was performed in one animal. The pelvic bone had a wide ventromedial surface of the ilium. The trochlea of the femur was wide and shallow. The patella was similar to that seen in feline species. The medial fabella was not seen radiographically in any animal. The cochlea grooves of the tibia were shallow with a poorly defined intermediate ridge. The trochlea of the talus was shallow and presented with an almost flattened medial ridge. The tarsal sesamoid bone was always present. The lateral process of the base of the fifth metatarsal (MT) bone was directed laterally. The MT bones were widely spaced. The morphology of the pelvis and hind limb of the red panda indicated flexibility of the pelvis and hind limb joints as an adaptation to an arboreal quadrupedal lifestyle.

Gait and jump analysis in healthy cats using a pressure mat system

Physical orthopaedic examination in cats does not always reveal signs of lameness and no objective gait analysis method has yet been standardised for use in cats. The aims of the present study were to define appropriate parameters for pressure mat analyses during walk and jump, and to define reference values for gait parameters of healthy cats. Further, the distribution of the vertical force within the paws and the influence of a non-centred head position were investigated. The hypothesis was that cats have a symmetrical gait, a front/hindlimb asymmetry similar to dogs, and that peak vertical force (PVF) and vertical impulse (VI) have high intraclass correlation coefficients, confirming the reliability of these parameters. Data for walking (n = 46) showed gait symmetry indices of close to 1.0, besides PVF front/hind (1.3 ± 0.2). The PVF front/hind for jumping cats (n = 16) was 1.7 ± 0.6. Results from the distribution of the vertical force within the paw (n = 39) showed that the main weight during a strike is transferred from the caudal towards the craniomedial part of the paw. The findings support the hypothesis that healthy cats have similar gait symmetry to healthy dogs and that PVF and VI are reliable gait parameters. In conclusion, the present study provides a reference interval for healthy cats. Further studies are needed to investigate gait parameters in cats with orthopaedic disease.

Coxofemoral joint kinematics using video fluoroscopic images of treadmill-walking cats: development of a technique to assess osteoarthritis-associated disability

The objectives of this pilot study were to develop a video fluoroscopy kinematics method for the assessment of the coxofemoral joint in cats with and without osteoarthritis (OA)-associated disability. Two non-OA cats and four cats affected by coxofemoral OA were evaluated by video fluoroscopy. Video fluoroscopic images of the coxofemoral joints were captured at 120 frames/s using a customized C-arm X-ray system while cats walked freely on a treadmill at 0.4 m/s. The angle patterns over time of the coxofemoral joints were extracted using a graphic user interface following four steps: (i) correction for image distortion; (ii) image denoising and contrast enhancement; (iii) frame-to-frame anatomical marker identification; and (iv) statistical gait analysis. Reliability analysis was performed. The cats with OA presented greater intra-subject stride and gait cycle variability. Three cats with OA presented a left-right asymmetry in the range of movement of the coxofemoral joint angle in the sagittal plane (two with no overlap of the 95% confidence interval, and one with only a slight overlap) consistent with their painful OA joint, and a longer gait cycle duration. Reliability analysis revealed an absolute variation in the coxofemoral joint angle of 2º-6º, indicating that the two-dimensional video fluoroscopy technique provided reliable data. Improvement of this method is recommended: variability would likely be reduced if a larger field of view could be recorded, allowing the identification and tracking of each femoral axis, rather than the trochanter landmarks. The range of movement of the coxofemoral joint has the potential to be an objective marker of OA-associated disability.

Prevalence and classification of chronic kidney disease in cats randomly selected from four age groups and in cats recruited for degenerative joint disease studies

Chronic kidney disease (CKD) and degenerative joint disease are both considered common in older cats. Information on the co-prevalence of these two diseases is lacking. This retrospective study was designed to determine the prevalence of CKD in two cohorts of cats: cats randomly selected from four evenly distributed age groups (RS group) and cats recruited for degenerative joint disease studies (DJD group), and to evaluate the concurrence of CKD and DJD in these cohorts. The RS group was randomly selected from four age groups from 6 months to 20 years, and the DJD group comprised cats recruited to four previous DJD studies, with the DJD group excluding cats with a blood urea nitrogen and/or serum creatinine concentration >20% (the upper end of normal) for two studies and cats with CKD stages 3 and 4 for the other two studies. The prevalence of CKD in the RS and DJD groups was higher than expected at 50% and 68.8%, respectively. CKD was common in cats between 1 and 15 years of age, with a similar prevalence of CKD stages 1 and 2 across age groups in both the RS and DJD cats, respectively. We found significant concurrence between CKD and DJD in cats of all ages, indicating the need for increased screening for CKD when selecting DJD treatments. Additionally, this study offers the idea of a relationship and causal commonality between CKD and DJD owing to the striking concurrence across age groups and life stages.

Evoked temporal summation in cats to highlight central sensitization related to osteoarthritis-associated chronic pain: a preliminary study

In cats, osteoarthritis causes significant chronic pain. Chronicity of pain is associated with changes in the central nervous system related to central sensitization, which have to be quantified. Our objectives were 1) to develop a quantitative sensory testing device in cats for applying repetitive mechanical stimuli that would evoke temporal summation; 2) to determine the sensitivity of this test to osteoarthritis-associated pain, and 3) to examine the possible correlation between the quantitative sensory testing and assessment using other pain evaluation methods. We hypothesized that mechanical sub-threshold repetitive stimuli would evoke temporal summation, and that cats with osteoarthritis would show a faster response. A blinded longitudinal study was performed in 4 non-osteoarthritis cats and 10 cats with naturally occurring osteoarthritis. Quantification of chronic osteoarthritis pain-related disability was performed over a two week period using peak vertical force kinetic measurement, motor activity intensity assessment and von Frey anesthesiometer-induced paw withdrawal threshold testing. The cats afflicted with osteoarthritis demonstrated characteristic findings consistent with osteoarthritis-associated chronic pain. After a 14-day acclimation period, repetitive mechanical sub-threshold stimuli were applied using a purpose-developed device. Four stimulation profiles of predetermined intensity, duration and time interval were applied randomly four times during a four-day period. The stimulation profiles were different (P<0.001): the higher the intensity of the stimulus, the sooner it produced a consistent painful response. The cats afflicted with osteoarthritis responded more rapidly than cats osteoarthritis free (P = 0.019). There was a positive correlation between the von Frey anesthesiometer-induced paw withdrawal threshold and the response to stimulation profiles #2 (2N/0.4 Hz) and #4 (2N/0.4 Hz): Rhos = 0.64 (P = 0.01) and 0.63 (P = 0.02) respectively. This study is the first report of mechanical temporal summation in awake cats. Our results suggest that central sensitization develops in cats with naturally occurring osteoarthritis, providing an opportunity to improve translational research in osteoarthritis-associated chronic pain.