Cachexia and sarcopenia: emerging syndromes of importance in dogs and cats

Cardiac cachexia in cats with congestive heart failure: Prevalence and clinical, laboratory, and survival findings

BACKGROUND

Cardiac cachexia is common in people and dogs with congestive heart failure (CHF). However, the prevalence and effects of cardiac cachexia in cats are unknown.

OBJECTIVES

To determine the prevalence of cachexia and its associations with clinical laboratory and survival data in cats with CHF.

ANIMALS

One hundred twenty-five cats with CHF.

METHODS

Medical records of cats evaluated during a 40-month period were retrospectively reviewed to identify cats with cardiac cachexia using 7 different definitions. Clinical, laboratory, and survival data were compared between cats with and without cachexia.

RESULTS

Prevalence of cachexia ranged from 0 to 66.7% for the 7 definitions, with a prevalence of 41.6% using muscle condition score (MCS). Cats with cachexia (determined by MCS) were older (P < .001), more likely to have pleural effusion (P = .003), had significantly higher blood urea nitrogen (P < .001) and neutrophil concentrations (P = .01), and significantly lower body condition score (P < .001), body weights (P < .001), hematocrit (P = .007), and hemoglobin concentrations (P = .009). Survival time for cats with cachexia (determined by MCS) was significantly shorter than for cats without cachexia (P = .03). Cats that were underweight (P = .002) and cats with dilated cardiomyopathy (DCM) also had shorter survival times (P = .04).

CONCLUSIONS AND CLINICAL IMPORTANCE

The association between cachexia and reduced survival time emphasizes the importance of identifying and addressing this common problem in cats with CHF.

Body weight at 10 years of age and change in body composition between 8 and 10 years of age were related to survival in a longitudinal study of 39 Labrador retriever dogs

BACKGROUND

Overweight and obesity have been adversely associated with longevity in dogs but there is scarce knowledge on the relation between body composition and lifespan. We aimed to investigate the effects of body composition, and within-dog changes over time, on survival in adult Labradors using a prospective cohort study design. The dogs had a median age of 6.5 years at study start and were kept in similar housing and management conditions throughout. The effects of the various predictors, including the effect of individual monthly-recorded change in body weight as a time varying covariate, were evaluated using survival analysis.

RESULTS

All dogs were followed to end-of-life; median age at end-of-life was 14.0 years. Body composition was measured annually with dual-energy x-ray absorptiometer (DEXA) scans between 6.2 and 17.0  years. All 39 dogs had DEXA recorded at 8, 9 and 10 years of age. During the study the mean (± SD) percent of fat (PF) and lean mass (PL) was 32.8 (± 5.6) and 64.2 (± 5.5) %, respectively, with a mean lean:fat ratio (LFR) of 2.1 (± 0.6); body weight (BW) varied from 17.5 to 44.0 kg with a mean BW change of 9.9 kg (± 3.0). There was increased hazard of dying for every kg increase in BW at 10 years of age; for each additional kg of BW at 10 years, dogs had a 19% higher hazard (HR = 1.19, P = 0.004). For the change in both lean mass (LM) and LFR variables, it was protective to have a higher lean and/or lower fat mass (FM) at 10 years of age compared to 8 years of age, although the HR for change in LM was very close to 1.0. For age at study start, older dogs had an increased hazard. There was no observed effect for the potential confounders sex, coat colour and height at shoulders, or of the time-varying covariate.

CONCLUSIONS

These results suggest that even rather late-life control efforts on body weight and the relationship between lean and fat mass may influence survival in dogs. Such "windows of opportunity" can be used to develop healthcare strategies that would help promote an increased healthspan in dogs.

Evaluation of the use of muscle condition score and ultrasonographic measurements for assessment of muscle mass in dogs

OBJECTIVE

To evaluate repeatability and reproducibility of muscle condition score (MCS) in dogs with various degrees of muscle loss; to compare MCS, muscle ultrasonographic measurements, and quantitative magnetic resonance (QMR) measurements; and to identify cutoff values for ultrasonographic measurements of muscle that can be used to identify dogs with cachexia and sarcopenia.

ANIMALS

40 dogs of various age, body condition score (BCS), and MCS.

PROCEDURES

A prospective cross-sectional study was conducted. Body weight, BCS, QMR measurements, thoracic radiographic measurements, and muscle ultrasonographic measurements were assessed once in each dog. The MCS for each dog was assessed 3 separate times by 4 separate raters.

RESULTS

For the MCS, overall κ for interrater agreement was 0.50 and overall κ for intrarater agreement ranged from 0.59 to 0.77. For both interrater and intrarater agreement, κ coefficients were higher for dogs with normal muscle mass and severe muscle loss and lower for dogs with mild and moderate muscle loss. The MCS was significantly correlated with age (r = -0.62), vertebral epaxial muscle score (VEMS; r = 0.71), forelimb epaxial muscle score (FLEMS; r = 0.58), and BCS (r = 0.73), and VEMS was significantly correlated (r = 0.84) with FLEMS. Cutoff values for identification of mild muscle loss determined by use of VEMS and FLEMS were 1.124 and 1.666, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

MCS had substantial repeatability and moderate reproducibility for assessment of muscle mass in dogs. Prospective studies of MCS, VEMS, and FLEMS for assessment of muscle mass in dogs are warranted.

Clinical and laboratory findings and survival time associated with cardiac cachexia in dogs with congestive heart failure

BACKGROUND

Cardiac cachexia, loss of muscle mass associated with congestive heart failure (CHF), is associated with increased morbidity and shorter survival times in people, but an association between cardiac cachexia and survival has not been reported in dogs.

OBJECTIVES

To determine the prevalence of cachexia and its associations with clinical, laboratory, and survival data in dogs with CHF.

ANIMALS

Two hundred sixty-nine dogs with CHF.

METHODS

Retrospective cohort study. Cachexia was defined by 1 of 2 definitions: (1) mild, moderate, or severe muscle loss or (2) weight loss of ≥5% in 12 months or less. Variables were compared between dogs with and without cachexia.

RESULTS

One hundred thirty of 269 dogs (48.3%) had cardiac cachexia based on muscle loss, whereas 67 of 159 dogs (42.1%) with pre-evaluation body weights had cachexia based on weight loss. Dogs with cachexia (based on muscle loss) were significantly older (P = .05), more likely to have a cardiac arrhythmia (P = .02), had higher chloride concentrations (P = .04), and had a lower body condition score (P < .001), hematocrit (P = .006), hemoglobin (P = .006), and albumin (P = .004) concentrations. On multivariable analysis, cachexia (P = .05), clinically important tachyarrhythmias (P < .001), azotemia (P < .001), and being under- or overweight (both P = .003) were associated with shorter survival times.

CONCLUSIONS AND CLINICAL IMPORTANCE

Cardiac cachexia in common in dogs with CHF and is associated with significantly shorter survival. This emphasizes the importance of preventing, diagnosing, and treating muscle loss in dogs with CHF.

Longevity: Lesson from Model Organisms

Research on longevity and healthy aging promises to increase our lifespan and decrease the burden of degenerative diseases with important social and economic effects. Many aging theories have been proposed, and important aging pathways have been discovered. Model organisms have had a crucial role in this process because of their short lifespan, cheap maintenance, and manipulation possibilities. Yeasts, worms, fruit flies, or mammalian models such as mice, monkeys, and recently, dogs, have helped shed light on aging processes. Genes and molecular mechanisms that were found to be critical in simple eukaryotic cells and species have been confirmed in humans mainly by the functional analysis of mammalian orthologues. Here, we review conserved aging mechanisms discovered in different model systems that are implicated in human longevity as well and that could be the target of anti-aging interventions in human.

Anorexia and the Cancer Patient

Appetite influences perceived quality of life for a dog or cat with cancer. Inappetence often is multifactorial, complicating treatment. Cancer-related anorexia/cachexia syndrome is a metabolic, paraneoplastic syndrome characterized by decreased food intake, involuntary weight loss, and loss of fat and muscle. If weight loss/cachexia has an impact on canine and feline cancer patients as in humans, management may improve survival times and quality of life. The challenge is having effective, proved therapies available for clinical use. Recent Food and Drug Administration approvals for appetite stimulation have renewed interest and discussion and has the potential to alter the course of case management.

Assessment of compounded transdermal mirtazapine as an appetite stimulant in cats with chronic kidney disease

Objectives

The aim of this study was to assess the appetite stimulation properties of compounded transdermal mirtazapine (CTM) in cats with chronic kidney disease (CKD).

Methods

Two sequential double-blind placebo-controlled crossover prospective studies were performed in client-owned cats with stable stage 2 or 3 CKD and a history of decreased appetite. In the first study nine CKD cats were randomized to receive 3.75 mg/0.1 ml CTM gel or placebo on the inner pinna every other day for 3 weeks, then, after a 4 day washout period, the cats were crossed over to the alternate 3 week treatment. In a second study, 10 CKD cats were randomized to receive 1.88 mg/0.1 ml CTM or placebo on the same schedule. Physical examination and serum biochemistry were performed before and after each treatment period, and owners kept daily logs of appetite, activity and eating behaviors. Mirtazapine concentrations in CTM gels and steady-state mirtazapine serum concentrations were measured using liquid chromatography/tandem mass spectrometry.

Results

Administration of both 3.75 mg and 1.88 mg CTM resulted in a statistically significant increase in weight (P = 0.002 for both), increase in appetite (P = 0.01 and P = 0.005, respectively), and increase in rate of food consumption (P = 0.03 and P = 0.008, respectively). No significant difference in activity or vocalization was seen at either dose; however, individual cats experienced excessive meowing. Median weight increase for the 3.75 mg arm was 0.22 kg (range 0.04–0.44 kg), while median weight increase for the 1.88 mg arm was 0.26 kg (range –0.25 to 0.5 kg). Improvement in body condition score was seen in 5/9 cats in the 3.75 mg arm (P = 0.04) and 6/10 cats in the 1.88 mg arm (P = 0.004).

Conclusions and relevance

CTM increased appetite and resulted in weight gain in CKD cats despite significant inconsistencies in compounding, and may benefit cats in countries where an approved product is not available.

ACVIM consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs

This report, issued by the ACVIM Specialty of Cardiology consensus panel, revises guidelines for the diagnosis and treatment of myxomatous mitral valve disease (MMVD, also known as endocardiosis and degenerative or chronic valvular heart disease) in dogs, originally published in 2009. Updates were made to diagnostic, as well as medical, surgical, and dietary treatment recommendations. The strength of these recommendations was based on both the quantity and quality of available evidence supporting diagnostic and therapeutic decisions. Management of MMVD before the onset of clinical signs of heart failure has changed substantially compared with the 2009 guidelines, and new strategies to diagnose and treat advanced heart failure and pulmonary hypertension are reviewed.

Integrating Genomic and Morphological Approaches in Fish Pathology Research: The Case of Turbot (Scophthalmus maximus) Enteromyxosis

Enteromyxosis, caused by Enteromyxum scophthalmi, is one of the most devastating diseases stemming from myxozoan parasites in turbot (Scophthalmus maximus L.), being a limiting factor for its production. The disease develops as a cachectic syndrome, associated to catarrhal enteritis and leukocytic depletion, with morbidity and mortality rates usually reaching 100%. To date, no effective treatment exists and there are different unknown issues concerning its pathogenesis. The gross and microscopic lesions associated to enteromyxosis have been thoroughly described, and several morphopathological studies have been carried out to elucidate the mechanisms of this host-parasite interaction. More recently, efforts have been focused on a multidisciplinary approach, combining histopathology and transcriptome analysis, which has provided significant advances in the understanding of the pathogenesis of this parasitosis. RNA-Seq technology was applied at early and advanced stages of the disease on fishes histologically evaluated and classified based on their lesional degree. In the same way, the transcriptomic data were analyzed in relation to the morphopathological picture and the course of the disease. In this paper, a comprehensive review of turbot enteromyxosis is presented, starting from the disease description up to the most novel information extracted by an integrated approach on the infection mechanisms and host response. Further, we discuss ongoing strategies toward a full understanding of host-pathogen interaction and the identification of suitable biomarkers for early diagnosis and disease management strategies.

Comparison of computed tomographic attenuation values for epaxial muscles in old and young dogs

OBJECTIVE To determine whether the degree of CT attenuation of muscle would differ between healthy old and young dogs. ANIMALS 10 healthy old (> 8 years old) and 9 healthy young (1 to 5 years old) Labrador Retrievers with a body condition score of 5 or 6 on a 9-point scale. PROCEDURES CT was performed with the dogs mildly sedated. A freehand closed polygon tool was used to define the outer margin of the left epaxial muscles on each transverse image obtained from the cranial to caudal endplates of T13. The CT attenuation values from every voxel from within these regions of interest were exported from DICOM software as a single dataset in an extensible markup language file. From these data, mean CT attenuation values were calculated for each dog and these mean values were compared between age groups. RESULTS Mean CT attenuation values for the epaxial muscles were significantly lower in old dogs than in young dogs. A significant negative correlation (r = -0.74) was identified between mean CT attenuation values and dog age. CONCLUSIONS AND CLINICAL RELEVANCE In addition to loss of skeletal muscle mass, low muscle CT attenuation values suggested that the old dogs in this study also had greater muscle fat content than did young dogs. Additional studies are warranted to evaluate qualitative and quantitative muscle changes in old dogs.

Strong associations of nine-point body condition scoring with survival and lifespan in cats

OBJECTIVES

The objective of the study was to investigate the associations of a nine-point body condition score (BCS) with survival time and lifespan in cats.

METHODS

Electronic patient records from a cat-dominant primary practice in metropolitan Sydney, Australia, where the body condition of cats was regularly recorded using a nine-point BCS scale were obtained. The maximum BCS of each cat during the visits was used as the primary exposure variable. Two survival analyses were conducted to evaluate the associations of BCS with cats' survival and lifespan.

RESULTS

In total, 2609 cats met the selection criteria from 4020 cats screened. The median of the maximum BCS was 6 (interquartile range [IQR] 5-7). Compared with cats with a maximum BCS of 6, increased hazards of death were observed in cats with a maximum BCS of 3 (hazard ratio [HR] 4.67, 95% confidence interval [CI] 3.00-7.27), 4 (HR 2.61, 95% CI 1.95-3.49), 5 (HR 1.43, 95% CI 11.5-1.76) and 9 (HR 1.80, 95% CI 1.11-2.93). Median lifespan was 15.8 (IQR 13.5-17.6) years. Compared with cats reaching a maximum BCS of 6 in the same age group, cats reaching a maximum BCS of 4 (HR 4.15, 95% CI 1.26-13.67) or 5 (HR 1.75, 95% CI 1.07-2.85) between age 1 and 3 years, and a maximum BCS of 3 (HR 6.09, 95% CI 1.47-25.25) and 9 (HR 2.27, 95% CI 1.27-4.04) between the age of 3 and 11 years had shorter lifespans.

CONCLUSIONS AND RELEVANCE

There are significant associations of nine-point body condition scoring with survival and lifespan, and BCSs <5 and of 9 were found to be negatively associated with both. The study yielded information regarding a desirable BCS for cat longevity that veterinarians could consult with.

Demographic Change Across the Lifespan of Pet Dogs and Their Impact on Health Status

Although dogs' life expectancies are six to twelve times shorter than that of humans, the demographics (e. g., living conditions) of dogs can still change considerably with aging, similarly to humans. Despite the fact that the dog is a particularly good model for human healthspan, and the number of aged dogs in the population is growing in parallel with aged humans, there has been few previous attempts to describe demographic changes statistically. We utilized an on-line questionnaire to examine the link between the age and health of the dog, and owner and dog demographics in a cross-sectional Hungarian sample. Results from univariate analyses revealed that 20 of the 27 demographic variables measured differed significantly between six dog age groups. Our results revealed that pure breed dogs suffered from health problems at a younger age, and may die at an earlier age than mixed breeds. The oldest dog group (>12 years) consisted of fewer pure breeds than mixed breeds and the mixed breeds sample was on average older than the pure breed sample. Old dogs were classified more frequently as unhealthy, less often had a “normal” body condition score, and more often received medication and supplements. They were also more often male, neutered, suffered health problems (such as sensory, joint, and/or tooth problems), received less activity/interaction/training with the owner, and were more likely to have experienced one or more traumatic events. Surprisingly, the youngest age group contained more pure breeds, were more often fed raw meat, and had owners aged under 29 years, reflecting new trends among younger owners. The high prevalence of dogs that had experienced one or more traumatic events in their lifetime (over 40% of the sample), indicates that welfare and health could be improved by informing owners of the greatest risk factors of trauma, and providing interventions to reduce their impact. Experiencing multiple life events such as spending time in a shelter, changing owners, traumatic injury/prolonged disease/surgery, getting lost, and changes in family structure increased the likelihood that owners reported that their dogs currently show behavioral signs that they attribute to the previous trauma.

Associations of body condition score with health conditions related to overweight and obesity in cats

OBJECTIVES

To explore the associations of cat body condition score with various health conditions, such as diabetes mellitus, dermatological conditions and hypertension, that have been shown to relate to overweight and/or obesity in cats, dogs or humans.

MATERIALS AND METHODS

Electronic patient records between January 3, 2005 and June 21, 2015 were obtained from a cat-focused primary accession clinic in metropolitan Sydney where the body condition score of cats was routinely evaluated. Binomial logistic regression modelling was conducted to investigate the associations, after adjusting for age, sex and breed, between 21 health conditions and body condition score recorded on a 9-point scale.

RESULTS

Fourteen of the 21 health conditions examined showed significant associations with an increased body condition score, particularly those of 7 and above. These were dermatological conditions, atopic dermatitis, musculoskeletal conditions, arthritis, hypertension, respiratory conditions, asthma, oral conditions, diarrhoea, general and lower urinary tract conditions, ophthalmic conditions, diabetes mellitus and allergic conditions. Additionally, cats with body condition score of 8 or 9 had significantly higher odds for gastrointestinal conditions and upper urinary tract conditions when compared with cats with body condition score of 5.

CLINICAL SIGNIFICANCE

As far as we know, this is the first study reporting positive associations of high body condition score with atopic dermatitis, hypertension, asthma, diarrhoea, ophthalmic conditions and allergic conditions in cats. A large number of positive associations between health conditions and high body condition score indicates that excess fat mass should be given a greater emphasis in preventive health care for cats.

Evaluation of serum insulin-like growth factor-1 and 26S proteasome concentrations in healthy dogs and dogs with chronic diseases depending on body condition score

In patients suffering from chronic diseases, the objective assessment of metabolic states could be of interest for disease prognosis and therapeutic options. Therefore, the aim of this study was to assess insulin-like growth factor-1 (IGF-1) and 26S proteasome (26SP) in healthy dogs and dogs suffering from chronic diseases depending on their body condition score (BCS) and to examine their potential for objective assessment of anabolic and catabolic states. Serum concentrations of IGF-1, an anabolic hormone, and 26SP, a multiprotein complex which is part of the ubiquitin-proteasome pathway, by which the majority of endogenous proteins including the muscle proteins are degraded, were measured in 21 healthy dogs and 20 dogs with chronic diseases by canine ELISA. The concentrations of IGF-1, 26SP and their ratio (IGF-1/26SP) were set in relationship to the BCS of the dogs. When examining healthy and chronically diseased dogs separately, a positive correlation between IGF-1 and the BCS was observed in the healthy group and a negative correlation between 26SP and the BCS was noted in dogs with chronic diseases. Further, dogs suffering from chronic diseases showed higher 26SP concentrations and lower values for IGF-1/26SP than the healthy dogs. Overall, we detected a negative correlation between 26SP and the BCS and a positive correlation between IGF-1/26SP and the BCS. The results of our study indicate usability of IGF-1 for description of anabolic states, while 26SP could be useful for detection and description of catabolic states. Finally, the ratio IGF-1/26SP seems to be promising for assessment of metabolic states.

Clinical findings and survival time in dogs with advanced heart failure

Background

Dogs with advanced heart failure are a clinical challenge for veterinarians but there are no studies reporting clinical features and outcome of this population.

Hypothesis/Objectives

To describe clinical findings and outcome of dogs with advanced heart failure caused by degenerative mitral valve disease (DMVD).

Animals

Fifty‐four dogs with advanced heart failure because of DMVD.

Methods

For study purposes, advanced heart failure was defined as recurrence of congestive heart failure signs despite receiving the initially prescribed dose of pimobendan, angiotensin‐converting‐enzyme inhibitor (ACEI), and furosemide >4 mg/kg/day. Data were collected for the time of diagnosis of Stage C heart failure and time of diagnosis of advanced heart failure. Date of death was recorded.

Results

At the diagnosis of advanced heart failure, doses of pimobendan (n = 30), furosemide (n = 28), ACEI (n = 13), and spironolactone (n = 4) were increased, with ≥1 new medications added in most dogs. After initial diagnosis of advanced heart failure, 38 (70%) dogs had additional medications adjustments (median = 2 [range, 0‐27]), with the final total medication number ranging from 2‐10 (median = 5). Median survival time after diagnosis of advanced heart failure was 281 days (range, 3‐885 days). Dogs receiving a furosemide dose >6.70 mg/kg/day had significantly longer median survival times (402 days [range, 3‐885 days] versus 129 days [range 9‐853 days]; P = .017).

Conclusions and Clinical Importance

Dogs with advanced heart failure can have relatively long survival times. Higher furosemide dose and non‐hospitalization were associated with longer survival.

Capromorelin: a ghrelin receptor agonist and novel therapy for stimulation of appetite in dogs

Ghrelin is a hormone, secreted from cells in the stomach, which is important in the regulation of appetite and food intake in mammals. It exerts its action by binding to a specific G-protein-coupled receptor, the growth hormone secretagogue receptor 1a (GHS-R1a) which is found in areas of the brain associated with the regulation of food intake. Ghrelin causes a release of growth hormone (GH) through binding to GHS-R1a in the hypothalamus and pituitary gland. A class of compounds known as growth hormone secretagogues, or ghrelin receptor agonists, were developed for therapeutic use in humans for the stimulation of GH in the frail elderly, and have subsequently been studied for their effects on increasing appetite and food intake, increasing body weight, building lean muscle mass, and treating cachexia. Subsequent research has shown that ghrelin has anti-inflammatory and immunomodulatory effects. This article reviews the basic physiology of ghrelin and the ghrelin receptor agonists, including the available evidence of these effects in vitro and in vivo in rodent models, humans, dogs and cats. One of these compounds, capromorelin, has been FDA-approved for the stimulation of appetite in dogs (ENTYCE ®). The data available on the safety and effectiveness of capromorelin is reviewed, along with a discussion of the potential clinical applications for ghrelin receptor agonists in both human and veterinary medicine.

Animal models for cancer cachexia

PURPOSE OF REVIEW

Cancer cachexia is a frequent syndrome that affects patient quality of life, anticancer treatment effectiveness, and overall survival. The lack of anticancer cachexia therapies likely relies on the complexity of the syndrome that renders difficult to design appropriate clinical trials and, conversely, on the insufficient knowledge of the underlying pathogenetic mechanisms. The aim of this review is to collect the most relevant latest information regarding cancer cachexia with a special focus on the experimental systems adopted for modeling the disease in translational studies.

RECENT FINDINGS

The scenario of preclinical models for the study of cancer cachexia is not static and is rapidly evolving in parallel with new prospective treatment options. The well established syngeneic models using rodent cancer cells injected ectopically are now used alongside new ones featuring orthotopic injection, human cancer cell or patient-derived xenograft, or spontaneous tumors in genetically engineered mice.

SUMMARY

The use of more complex animal models that better resemble cancer cachexia, ideally including also the administration of chemotherapy, will expand the understanding of the underlying mechanisms and will allow a more reliable evaluation of prospective drugs for translational purposes.

Spirocerca lupi induced oesophageal neoplasia: Predictors of surgical outcome

Canine spirocercosis is caused by the nematode Spirocerca lupi. Migration results in oesophageal fibro-inflammatory nodules that may undergo neoplastic transformation. No studies have assessed pre- or post-surgical prognostic indicators in dogs that undergo intervention for S. lupi induced oesophageal neoplasia. This observational, multi-center study aimed to assess the outcome of dogs with Spirocerca induced sarcoma undergoing endoscopic-guided ablation (n = 12) or surgery (n = 18), and identify prognostic indicators. Parameters evaluated included: age, weight, gender, presenting complaints, duration of clinical signs, complete blood count, serum biochemistry, neoplasia size, placement of percutaneous endoscopically-placed gastrostomy tube, histopathological mitotic indices, days to discharge and chemotherapy administration. Kaplan-Meier survival curves showed no difference in survival between ablation and surgery {(median: 73.5 days (range: 0-1511) vs. 108 days (range: 0-1550), respectively (p = 0.982)}. Reduced survival was documented in patients presenting with weight loss (P = 0.027), hypochromasia (MCHC <33 g/dL, P = 0.023) or leucocytosis (>15 × 10⁹/L, P = 0.017) with a hazard ratio of 2.51 (CI_95% = 1.071-6.018, P = 0.034), 2.71 (CI_95% = 1.10-6.65, P = 0.03) and 4.39 (CI_95%: 1.21-15.97, P = 0.025) respectively. In the dogs surviving more than 21 days, Ht <36% and leucocytosis >15.0 × 10⁹/L at presentation were associated with reduced survival (p = 0.016, p = 0.021 respectively) and hazard ratio of 3.29 (CI_95% = 1.18-9.2, P = 0.023) and 3.81 (CI_95% = 1.15-12.55, P = 0.028) respectively. Intra-intervention-group survival analysis identified increased survival time in dogs receiving chemotherapy, but only within the surgical group (P = 0.02).The hospitalisation time of dogs undergoing ablation (median: 0 days, range: 0-4) was significantly shorter than dogs undergoing surgery (9 days, 1-21) (P < 0.001). In this study, no clear benefit was identified for surgery, thus when ablation is technically possible it should be considered advantageous, as hospitalisation time is significantly shorter. Weight loss, hypochromasia and leucocytosis were identified as long-term prognostic indicators at presentation.

Comparison of naturally aging and D-galactose induced aging model in beagle dogs

Animal models have been used to study aging for decades. In numerous aging studies, beagles are the most commonly used breed of dog. However, few studies have compared between naturally aging models and experimentally induced aging models in beagle dogs. In the present study, a D-galactose induced aging model was compared with a naturally aging model, and young adult dogs were considered as the young control group. The level of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in serum, and brain tissue were measured. Histopathological comparisons of the liver, kidneys, heart, lungs and spleen were evaluated using hematoxylin and eosin (H&E) staining, in addition, the brain was evaluated by H&E staining, and Nissl staining. The expression levels of aging-associated factors in the hippocampus, including proliferating cell nuclear antigen (PCNA), P16 and P21 were also determined through reverse transcription quantitative-polymerase chain reaction, and western blot analysis. The results indicated that D-galactose induced aging significantly increased the MDA level, while the levels of SOD and GSH-Px were diminished when compared with the young control group, which was similar to the naturally aging group. Parallel histopathological features were observed in the D-galactose induced aging and naturally aging groups compared with the young control group. However, a reduced expression level of PCNA, and increased expression levels of P16 and P21 were observed in the naturally ageing and induced aging groups compared with the young control group. The results of the current study demonstrated that the beagle dogs in D-galactose induced aging model exhibited significant similarities with the naturally aging model, providing evidence to support that the D-galactose induced aging model may be applied to aging studies.

Evaluation of Weight Change During Carboplatin Therapy in Dogs With Appendicular Osteosarcoma

Background

The prevalence of cancer cachexia in veterinary medicine has not been studied widely, and as of yet, no definitive diagnostic criteria effectively assess this syndrome in veterinary patients.

Objectives

(1) To determine the patterns of weight change in dogs with appendicular osteosarcoma treated with amputation and single‐agent carboplatin during the course of adjuvant chemotherapy; and (2) to determine whether postoperative weight change is a negative prognostic indicator for survival time in dogs with osteosarcoma.

Animals

Eighty‐eight dogs diagnosed with appendicular osteosarcoma. Animals were accrued from 3 veterinary teaching hospitals.

Methods

Retrospective, multi‐institutional study. Dogs diagnosed with appendicular osteosarcoma and treated with limb amputation followed by a minimum of 4 doses of single‐agent carboplatin were included. Data analyzed in each patient included signalment, tumor site, preoperative serum alkaline phosphatase activity (ALP), and body weight (kg) at each carboplatin treatment.

Results

A slight increase in weight occurred over the course of chemotherapy, but this change was not statistically significant. Weight change did not have a significant effect on survival. Institution, patient sex, and serum ALP activity did not have a significant effect on survival.

Conclusions and Clinical Importance

Weight change was not a prognostic factor in these dogs, and weight loss alone may not be a suitable method of determining cancer cachexia in dogs with appendicular osteosarcoma.

Renal transitional cell carcinoma with bilateral ocular metastasis in a cat

Case summary A 4-year-old, spayed female, domestic shorthair cat was presented for evaluation due to a 4 day history of inappetence and lethargy. Physical examination revealed mild dehydration and blindness of the left eye. Abnormal imaging findings included a well-margined soft tissue mass with irregular central cavity located in the dorsal aspect of the caudal lung lobe. Cytological examination of the mass revealed chronic inflammation with hemorrhage. Tests for parasitic and fungal diseases were negative. Ophthalmic examination 17 days after the cat was initially presented revealed severe diffuse pathology of both retinas. Left renomegaly was noted 22 days after the initial presentation, and cytological examination of samples obtained from the right vitreous, left kidney and the pulmonary mass yielded atypical epithelial cells exhibiting malignant changes. Post-mortem examination following euthanasia revealed renal transitional cell carcinoma with metastasis to both eyes, lungs and skeletal muscle. Immunohistochemical evaluation of the neoplastic cells in the eye revealed moderate cytoplasmic reactivity for CK7. CK20 immunohistochemistry was negative.

Relevance and novel information To the best of our knowledge, this is the first report of renal transitional cell carcinoma with ocular metastasis in a cat. In addition, this report describes immunohistochemistry results of transitional cell carcinoma in a cat using CK7 and CK20.

Assessment of frailty in aged dogs

OBJECTIVE To define a frailty-related phenotype-a clinical syndrome associated with the aging process in humans-in aged dogs and to investigate its association with time to death. ANIMALS 116 aged guide dogs. PROCEDURES Dogs underwent a clinical geriatric assessment (CGA) and were followed to either time of death or the study cutoff date. A 5-component clinical definition of a frailty phenotype was derived from clinical items included in a geriatric health evaluation scoresheet completed by veterinarians during the CGA. Univariate (via Kaplan-Meier curves) and multivariate (via Cox proportional hazards models) survival analyses were used to investigate associations of the 5 CGA components with time to death. RESULTS 76 dogs died, and the median time from CGA to death was 4.4 years. Independent of age at the time of CGA, dogs that had ≥ 2 of the 5 components (n = 10) were more likely to die during the follow-up period, compared with those that had 1 or no components (adjusted hazard ratio, 3.9 [95% confidence interval, 1.4 to 10.9]). After further adjustments for subclinical or clinical diseases and routine biomarkers, the adjusted hazard ratio remained significant. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that signs of frailty appeared to be a risk factor for death in dogs. The concept of frailty in dogs requires further development. IMPACT FOR HUMAN MEDICINE The concept of frailty, as defined for humans, seems transposable to dogs. Given that they share humans' environments and develop several age-related diseases similar to those in humans, dogs may be useful for the study of environmental or age-related risk factors for frailty in humans.

Evaluation of Body Weight, Body Condition, and Muscle Condition in Cats with Hyperthyroidism

Background

The contribution of fat loss versus muscle wasting to the loss of body weight seen in hyperthyroid cats is unknown.

Objectives

To investigate body weight, body condition score (BCS), and muscle condition score (MCS) in hyperthyroid cats.

Animals

Four hundred sixty‐two cats with untreated hyperthyroidism, 117 of which were reevaluated after treatment.

Methods

Prospective cross‐sectional and before–after studies. Untreated hyperthyroid cats had body composition evaluated (body weight, BCS, and MCS). A subset of these cats were reevaluated 3–12 months after treatment when euthyroid.

Results

Pretreatment body weight (median, 4.36 kg; IQR, 3.5 to 5.2 kg) was lower than premorbid weight (5.45 kg; IQR, 4.6 to 6.4 kg, P < .0001) recorded 1–2 years before diagnosis. 154 (35.3%) cats were thin or emaciated; 357 (77.3%) had loss of muscle mass. Cats showed increases in body weight (median, 4.1 kg to 5.0 kg), BCS (median, 3/5 to 3.5/5), and MCS (2/3 to 3/3) after treatment (P < .001), but mild‐to‐moderate muscle wasting persisted in 45% of treated cats.

Conclusions and Clinical Importance

Most hyperthyroid cats lose body weight but maintain an ideal or overweight BCS, with only a third being underweight. As in human hyperthyroid patients, this weight loss is associated with muscle wasting, which affects >75% of hyperthyroid cats. Successful treatment leads to weight gain and increase of BCS in most cats, but almost half fail to regain normal muscle mass.

Evaluation of Weight Loss Over Time in Cats with Chronic Kidney Disease

Background

Thin body condition and weight loss are common in cats with chronic kidney disease (CKD). However, the time course and progression of weight loss before and after diagnosis have not been thoroughly evaluated.

Hypothesis/Objectives

To describe weight loss in cats with CKD before and after diagnosis and its relationship to survival.

Animals

A total of 569 cats (55.5% females and 44.5% males) with CKD from 6 US veterinary practices for which International Renal Interest Society (IRIS) stage, age, date of CKD diagnosis, and at least two body weight measurements were available.

Methods

Body weight measurements were analyzed by time windows and polynomial growth curve analysis. Survival analysis was performed by Kaplan–Meier curves and log‐rank tests.

Results

Median age at diagnosis was 14.9 years (range, 5.0–22.8 years). Cats were categorized at diagnosis as IRIS stage 1 (n = 34 [6%]), stage 2 (n = 345 [61%]), stage 3 (n = 141 [25%]), and stage 4 (n = 49 [9%]). Median body weight at diagnosis was 4.2 kg (range, 1.6–9.9 kg). Cats lost a median of 8.9% of body weight in the 12 months before diagnosis, but weight loss was already present 3 years before diagnosis and accelerated after diagnosis of CKD. Cats <4.2 kg at the time of diagnosis had significantly shorter survival time compared to cats ≥ 4.2 kg at diagnosis (P < .0001).

Conclusions and Clinical Importance

Weight loss can be detected in cats before diagnosis of CKD, accelerates after diagnosis, and is associated with shorter survival. Tracking body weight may help clinicians in earlier diagnosis of CKD.

The Effect of Moderate Dietary Protein and Phosphate Restriction on Calcium-Phosphate Homeostasis in Healthy Older Cats

Background

Dietary phosphate and protein restriction decreases plasma PTH and FGF‐23 concentrations and improves survival time in azotemic cats, but has not been examined in cats that are not azotemic.

Hypothesis

Feeding a moderately protein‐ and phosphate‐restricted diet decreases PTH and FGF‐23 in healthy older cats and thereby slows progression to azotemic CKD.

Animals

A total of 54 healthy, client‐owned cats (≥ 9 years).

Methods

Prospective double‐blinded randomized placebo‐controlled trial. Cats were assigned to test diet (protein 76 g/Mcal and phosphate 1.6 g/Mcal) or control diet (protein 86 g/Mcal and phosphate 2.6 g/Mcal) and monitored for 18 months. Changes in variables over time and effect of diet were assessed by linear mixed models.

Results

A total of 26 cats ate test diet and 28 cats ate control diet. There was a significant effect of diet on urinary fractional excretion of phosphate (P = 0.045), plasma PTH (P = 0.005), and ionized calcium concentrations (P = 0.018), but not plasma phosphate, FGF‐23, or creatinine concentrations. Plasma PTH concentrations did not significantly change in cats fed the test diet (P = 0.62) but increased over time in cats fed the control diet (P = 0.001). There was no significant treatment effect of the test diet on development of azotemic CKD (3 of 26 (12%) test versus 3 of 28 (11%) control, odds ratio 1.09 (95% CI 0.13–8.94), P = 0.92).

Conclusions and Clinical Importance

Feeding a moderately protein‐ and phosphate‐restricted diet has effects on calcium‐phosphate homeostasis in healthy older cats and is well tolerated. This might have an impact on renal function and could be useful in early chronic kidney disease.

Circumstances, Descriptive Characteristics, and Pathologic Findings in Dogs Suspected of Starving

The authors reviewed the case circumstances, population characteristics, gross, and histopathologic findings in 40 cases of emaciated dogs with a suspected diagnosis of starvation. The dogs’ estimated age ranged from 3 months to geriatric. Nineteen breeds were represented, including small-breed ( n = 11), large-breed ( n = 13), and pit bull–type ( n = 16) dogs. The median body condition score was 1 out of 9 (Purina scale). Various diseases were identified as the cause of death in 7 dogs, while the cause of death in the other 33 dogs was starvation due to exogenous causes (SEC). Circumstances associated exclusively with SEC included being found in a vacated residence and death during temperature extremes or severe weather. Dogs with SEC did not differ significantly from diseased dogs in body condition score, sex, neuter status, or breed category (small, large, or pit bull type). Gross findings associated exclusively with SEC included severe hair matting and traumatic injuries. Diseased dogs had an empty stomach significantly more often than SEC dogs, which frequently had food and/or foreign material in the stomach. In 5 of the 7 cases where disease was the cause of death, disease involved the gastrointestinal tract. Gross and histopathologic changes commonly found in SEC and diseased dogs included the following: gross loss of muscle mass and absence of subcuticular fat; serous atrophy of omental, perirenal, epicardial, and bone marrow fat; atrophy of the liver, skin, thyroid gland, and testicle; gastric mucosal petechiae and ecchymoses; melena; and splenic hemosiderophages.

Exceptional longevity and potential determinants of successful ageing in a cohort of 39 Labrador retrievers: results of a prospective longitudinal study

BACKGROUND

The aim of this study was to describe the longevity and causes of mortality in 39 (12 males, 27 females) pedigree adult neutered Labrador retrievers with a median age of 6.5 years at the start of the study and kept under similar housing and management conditions. Body condition score was maintained between two and four on a 5-point scale by varying food allowances quarterly. The impact of change in body weight (BW) and body composition on longevity was analysed using linear mixed models with random slopes and intercepts.

RESULTS

On 31 July 2014, 10 years after study start, dogs were classified into three lifespan groups: 13 (33 %) Expected (≥9 to ≤12.9 years), 15 (39 %) Long (≥13 to ≤15.5 years) and 11 (28 %) Exceptional (≥15.6 years) with five still alive. Gender and age at neutering were not associated with longevity (P ≥ 0.06). BW increased similarly for all lifespan groups up to age 9, thereafter, from 9 to 13 years, Exceptional dogs gained and Long-lifespan dogs lost weight (P = 0.007). Dual-energy x-ray absorptiometer scans revealed that absolute fat mass increase was slower to age 13 for Long compared with Expected lifespan dogs (P = 0.003) whilst all groups lost a similar amount of absolute lean mass (P > 0.05). Percent fat increase and percent lean loss were slower, whilst the change in fat:lean was smaller, in both the Exceptional and Long lifespan compared with Expected dogs to age 13 (P ≤ 0.02). Total bone mineral density was significantly lower for Expected compared to Exceptional and Long lifespan dogs (P < 0.04).

CONCLUSIONS

This study shows that life-long maintenance of lean body mass and attenuated accumulation of body fat were key factors in achieving a longer lifespan. The results suggest that a combination of a high quality plane of nutrition with appropriate husbandry and healthcare are important in obtaining a greater than expected proportion of Labrador retrievers living well beyond that of the expected breed lifespan: 89.7 % (95 % CI 74.8-96.7 %) dogs were alive at 12 years of age and 28.2 % (95 % CI 15.6-45.1 %) reaching an exceptional lifespan of ≥15.6 years.

The dog aging project: translational geroscience in companion animals

Studies of the basic biology of aging have identified several genetic and pharmacological interventions that appear to modulate the rate of aging in laboratory model organisms, but a barrier to further progress has been the challenge of moving beyond these laboratory discoveries to impact health and quality of life for people. The domestic dog, Canis familiaris, offers a unique opportunity for surmounting this barrier in the near future. In particular, companion dogs share our environment and play an important role in improving the quality of life for millions of people. Here, we present a rationale for increasing the role of companion dogs as an animal model for both basic and clinical geroscience and describe complementary approaches and ongoing projects aimed at achieving this goal.

Animal models of aging research: implications for human aging and age-related diseases

Aging is characterized by an increasing morbidity and functional decline that eventually results in the death of an organism. Aging is the largest risk factor for numerous human diseases, and understanding the aging process may thereby facilitate the development of new treatments for age-associated diseases. The use of humans in aging research is complicated by many factors, including ethical issues; environmental and social factors; and perhaps most importantly, their long natural life span. Although cellular models of human disease provide valuable mechanistic information, they are limited in that they may not replicate the in vivo biology. Almost all organisms age, and thus animal models can be useful for studying aging. Herein, we review some of the major models currently used in aging research and discuss their benefits and pitfalls, including interventions known to extend life span and health span. Finally, we conclude by discussing the future of animal models in aging research.

Pilot study of a myostatin antagonist in dogs with cardiac cachexia

OBJECTIVES

Cardiac cachexia, a loss of lean body mass caused by heart disease, often accompanies congestive heart failure (CHF). Blocking myostatin, which is a protein that inhibits muscle growth, appears to greatly enhance muscle size and strength in rodent models and human clinical trials. The objective of this study was to evaluate a dog-specific myostatin antagonist (CAP-031) in a pilot study to test its safety and efficacy in dogs with CHF and cardiac cachexia.

ANIMALS

Dogs with CHF and cardiac cachexia.

METHODS

Eligible dogs received four weekly subcutaneous injections of CAP-031. Endpoints were body weight, body condition score (BCS, on a 1-9 scale), muscle condition score (MCS, on a five-point scale, where 0 = no muscle loss and 4 = severe muscle loss), appetite, and a quality of life (QOL) score.

RESULTS

Seven dogs with CHF and moderate-to-severe cachexia were enrolled in the study. For the six dogs that completed the study, the median age was 8.8 years (range 6.4-10.6). At baseline, the median body weight was 27.0 kg (range 17.3-62.0), the median BCS was 4 (2-5), and median MCS was 3 (3-4). There were no significant changes in body weight, BCS, appetite, or QOL score. The change in MCS (from a median of 3 at baseline to a median of 2.5 at week 4) was not statistically significant (p = 0.06).

CONCLUSIONS

The myostatin antagonist appeared to be well tolerated in most dogs. Earlier identification of cachexia is important, and randomized, controlled trials of myostatin antagonists or other drugs to treat cardiac cachexia are needed.

Cardiovascular-renal axis disorders in the domestic dog and cat: a veterinary consensus statement

OBJECTIVES

There is a growing understanding of the complexity of interplay between renal and cardiovascular systems in both health and disease. The medical profession has adopted the term "cardiorenal syndrome" (CRS) to describe the pathophysiological relationship between the kidney and heart in disease. CRS has yet to be formally defined and described by the veterinary profession and its existence and importance in dogs and cats warrant investigation. The CRS Consensus Group, comprising nine veterinary cardiologists and seven nephrologists from Europe and North America, sought to achieve consensus around the definition, pathophysiology, diagnosis and management of dogs and cats with "cardiovascular-renal disorders" (CvRD). To this end, the Delphi formal methodology for defining/building consensus and defining guidelines was utilised.

METHODS

Following a literature review, 13 candidate statements regarding CvRD in dogs and cats were tested for consensus, using a modified Delphi method. As a new area of interest, well-designed studies, specific to CRS/CvRD, are lacking, particularly in dogs and cats. Hence, while scientific justification of all the recommendations was sought and used when available, recommendations were largely reliant on theory, expert opinion, small clinical studies and extrapolation from data derived from other species.

RESULTS

Of the 13 statements, 11 achieved consensus and 2 did not. The modified Delphi approach worked well to achieve consensus in an objective manner and to develop initial guidelines for CvRD.

DISCUSSION

The resultant manuscript describes consensus statements for the definition, classification, diagnosis and management strategies for veterinary patients with CvRD, with an emphasis on the pathological interplay between the two organ systems. By formulating consensus statements regarding CvRD in veterinary medicine, the authors hope to stimulate interest in and advancement of the understanding and management of CvRD in dogs and cats. The use of a formalised method for consensus and guideline development should be considered for other topics in veterinary medicine.

Nutrition for working and service dogs

Conformation, genetics, and behavioral drive are the major determinants of success in canine athletes, although controllable variables, such as training and nutrition, play an important role. The scope and breadth of canine athletic events has expanded dramatically in the past 30 years, but with limited research on performance nutrition. There are considerable data examining nutritional physiology in endurance dogs and in sprinting dogs; however, nutritional studies for agility, field trial, and detection are rare. This article highlights basic nutritional physiology and interventions for exercise, and reviews newer investigations regarding aging working and service dogs, and canine detection activities.

Macronutrients in feline health

Dietary macronutrients include protein, fat, and carbohydrates. Current nutritional recommendations establish minimums but not maximums for protein and fat but not for carbohydrates; thus, commercial feline maintenance diets have a wide range of macronutrient distribution depending on manufacturer, ingredients, and processing. There is growing interest and discussion, however, in defining the ideal macronutrient composition of feline diets to maximize longevity and health. Current recommendations should be tailored to each patient based on age, body condition, presence of muscle mass atrophy, and the presence of disease.

Myogenic potential of canine craniofacial satellite cells

The skeletal fibers have different embryological origin; the extraocular and jaw-closer muscles develop from prechordal mesoderm while the limb and trunk muscles from somites. These different origins characterize also the adult muscle stem cells, known as satellite cells (SCs) and responsible for the fiber growth and regeneration. The physiological properties of presomitic SCs and their epigenetics are poorly studied despite their peculiar characteristics to preserve muscle integrity during chronic muscle degeneration. Here, we isolated SCs from canine somitic [somite-derived muscle (SDM): vastus lateralis, rectus abdominis, gluteus superficialis, biceps femoris, psoas] and presomitic [pre-somite-derived muscle (PSDM): lateral rectus, temporalis, and retractor bulbi] muscles as myogenic progenitor cells from young and old animals. In addition, SDM and PSDM-SCs were obtained also from golden retrievers affected by muscular dystrophy (GRMD). We characterized the lifespan, the myogenic potential and functions, and oxidative stress of both somitic and presomitic SCs with the aim to reveal differences with aging and between healthy and dystrophic animals. The different proliferation rate was consistent with higher telomerase activity in PSDM-SCs compared to SDM-SCs, although restricted at early passages. SDM-SCs express early (Pax7, MyoD) and late (myosin heavy chain, myogenin) myogenic markers differently from PSDM-SCs resulting in a more efficient and faster cell differentiation. Taken together, our results showed that PSDM-SCs elicit a stronger stem cell phenotype compared to SDM ones. Finally, myomiR expression profile reveals a unique epigenetic signature in GRMD SCs and miR-206, highly expressed in dystrophic SCs, seems to play a critical role in muscle degeneration. Thus, miR-206 could represent a potential target for novel therapeutic approaches.

Muscular senescence in cetaceans: adaptation towards a slow muscle fibre phenotype

Sarcopenia, or senile muscle atrophy, is the slow and progressive loss of muscle mass with advancing age that constitutes the most prevalent form of muscle atrophy. The effects of ageing on skeletal muscle have been extensively studied in humans and laboratory animals (mice), while the few reports on wild animals are based on short-lived mammals. The present study describes the age-related changes in cetacean muscles regarding the three factors that determine muscle mass: fibre size, fibre number, and fibre type. We show that the skeletal muscle fibres in cetaceans change with advancing age, evolving towards a slower muscle phenotype. We suggest that this physiological evolution constitutes an adaptation that allows these marine mammals to perform prolonged, deep dives.

Feline CKD: Diagnosis, staging and screening - what is recommended?

PRACTICAL RELEVANCE

Feline chronic kidney disease (CKD) is frequently encountered by veterinarians. Timely diagnosis and staging may facilitate the initiation of adequate therapy and improve the prognosis for patients.

CLINICAL CHALLENGES

Feline CKD is diagnosed based on the presence of compatible clinical signs and renal azotaemia, which implies that urinalysis (particularly urine specific gravity) is mandatory to confirm the diagnosis. Although the diagnosis of advanced feline CKD and associated complications is usually straightforward, based on complete blood and urine examination, all routine blood and urine tests have their limitations in detecting early CKD. Therefore, diagnosing early or non-azotaemic CKD is much more challenging. Although determination of glomerular filtration rate (GFR) would be ideal to identify early kidney dysfunction, practical limitations hamper its routine use in clinical practice.

PATIENT GROUP

CKD is typically a disease of aged cats, but may affect cats of all ages. Conclusive breed and sex predispositions for feline CKD are not reported.

AUDIENCE

This review is directed at practising veterinarians and provides an overview of the required diagnostic tests, the classification system established by the International Renal Interest Society, and the importance of and possible techniques for early detection of CKD.

EVIDENCE BASE

Staging of cats with CKD is essential as it directs management and provides a prognostic guide. Given that diagnosis at early disease stages is associated with more prolonged survival times, simple, inexpensive and accurate methods for early CKD diagnosis are needed. Techniques currently under investigation include limited sampling strategies to estimate GFR, clearance marker cut-off concentrations to identify cats with low GFR, new indirect GFR markers and urinary biomarkers.

Anesthesia of the geriatric equine

Advancements in veterinary medicine have resulted in an increased number of geriatric horses being presented for medical or surgical procedures that require general anesthesia. Due to the physiological changes associated with aging and the likelihood of concurrent disease conditions, the geriatric equine is at an increased risk during anesthesia. The main physiological changes associated with aging, and their impact on anesthesia, are discussed in this review.