The Influence of Chronic Kidney Disease on the Structural and Mechanical Properties of Canine Bone

Effects of Paricalcitol on Renal Secondary Hyperparathyroidism and Proteinuria in Dogs With Chronic Kidney Disease

BACKGROUND

Renal secondary hyperparathyroidism (RHPT) is an inevitable consequence of chronic kidney disease (CKD). Paricalcitol might safely attenuate RHPT and proteinuria.

HYPOTHESIS/OBJECTIVE

Paricalcitol decreases parathyroid hormone (PTH) and proteinuria in dogs with CKD.

ANIMALS

Thirteen dogs with naturally acquired CKD.

METHODS

Placebo-controlled clinical trial. Dogs were randomly allocated to receive a placebo or paricalcitol (14 ng/kg/day) in a crossover design of 2, 12-week arms. Dogs were evaluated every 3 weeks. Associations between treatment, visit, and the outcome variables were assessed using generalized estimating equations.

RESULTS

PTH decreased by 22% (95% CI, 7%-35%, p = 0.006) in the paricalcitol-treated dogs and increased by 18% (95% CI, 2%-37%, p = 0.022) in the placebo-treated dogs with each visit. FGF-23 at 12 weeks increased compared with baseline in the paricalcitol-treated (mean 6941 pg/mL, 95% CI, 1781-20 057 vs. 489 pg/mL, 95% CI, 188-1272, p < 0.001, respectively), but not in the placebo-treated dogs (696 pg/mL, 95% CI, 316-1531 vs. 955 pg/mL, 95% CI, 308-2963, p = 0.529). Urine protein-to-creatinine ratio at 12 weeks increased compared with baseline in the placebo-treated (0.8, 95% CI, 0.3-1.3 vs. 0.5, 95% CI, 0.2-0.9, p = 0.04, respectively), but not in the paricalcitol-treated dogs (0.6, 95% CI, 0.3-0.9 vs. 1.0, 95% CI, 0.1-1.8, p = 0.35). Ionized calcium was unchanged between baseline and 12 weeks in the paricalcitol- and placebo-treated groups (1.3 mmol/L, 95% CI, 1.29-1.35 and 1.34, 95% CI, 1.27-1.40 vs. 1.30, 95% CI, 1.25-1.35, p = 0.12 and 1.28, 95% CI, 1.24-1.32, p = 0.034, respectively). However, 7/13 dogs developed mild hypercalcemia. Adverse effects were not reported by the owners.

CONCLUSION AND CLINICAL IMPORTANCE

Paricalcitol attenuated RHPT and stabilized renal proteinuria in dogs with CKD.

An update on oral manifestations of systemic disorders in dogs and cats

Oral lesions are common in dogs and cats, and determining the underlying etiology of these lesions can be challenging. A wide range of systemic ailments may lead to lesions in the oral cavity, including immune-mediated diseases, adverse drug reactions, viral and bacterial infections, and metabolic and autoimmune diseases. A complete history and thorough physical examination (including a fundic examination) should be obtained in affected patients. It is critical to perform a detailed oral examination, which in some patients may need to be performed under sedation or general anesthesia. Tailored diagnostic plans and a multidisciplinary approach are necessary to fully characterize co-morbid disorders in affected patients. This narrative review aims to aid veterinarians in recognizing oral manifestations of systemic disorders based on the most recent reports and available research.

Evaluation of cortical bone strength using a quantitative ultrasound measurement device in dogs

This study was performed to evaluate cortical bone strength in dogs using a quantitative ultrasound measurement device. In this study, 16 clinically healthy dogs with no lameness underwent measurement of the ultrasound propagation velocity of cortical bone (namely, speed of sound [SOS]) at the radius and tibia. Additionally, computed tomography examination with a calibration phantom was performed in 10 dogs. We calculated the bone mineral density (BMD) and Young's modulus from the computed tomography data using bone strength evaluation software. SOS, BMD, and Young's modulus were statistically compared between the radius and tibia. In addition, we examined the correlation between SOS and BMD and between SOS and Young's modulus. We also examined the correlation between SOS and age in the 13 dogs whose age was known. BMD and Young's modulus were not significantly different between the radius and tibia, but SOS was significantly different (P<0.05). Moreover, SOS and BMD showed a positive correlation in both radius and tibia. Similarly, SOS and Young's modulus showed a positive correlation. In addition, SOS and age showed a strong positive correlation (radius: r=0.77, P<0.05, tibia: r=0.83, P<0.05). Our finding that SOS of the radius and tibia cortical bone was correlated with BMD and Young's modulus indicates that quantitative ultrasound can be useful for evaluating cortical bone strength in dogs.

Gastric pH and serum gastrin concentration in age-matched healthy dogs and dogs with chronic kidney disease

BACKGROUND

Gastric hyperacidity and hypergastrinemia are purported to cause gastric ulceration in dogs with chronic kidney disease (CKD); however, no published studies have evaluated gastric pH with serum gastrin concentrations in dogs with CKD.

HYPOTHESIS

To compare mean intragastric pH, mean percent pH distribution, and serum gastrin concentrations in dogs with CKD to age-matched, healthy dogs. We hypothesized there would be no difference in mean gastric pH or serum gastrin between groups.

ANIMALS

Thirteen dogs with CKD; 10 aged-matched healthy dogs.

METHODS

Prospective, case-control study. Serum chemistry, complete blood count, urinalysis, and serum gastrin concentrations were evaluated in all dogs before radiographic-assisted gastric placement of a pH capsule. Forty-eight-hour continuous gastric pH monitoring was performed in all dogs. Serum gastrin concentration, mean pH, and mean percentage time that gastric pH was strongly acidic (pH <1 and pH <2) were compared between groups using a repeated measures mixed-model ANOVA.

RESULTS

No significant differences were observed between groups for any pH measurements, including mean ± SD gastric pH (CKD, 2.37 ± 0.87; healthy, 2.39 ± 0.99; P > .05). Serum gastrin concentrations were not significantly different between groups (median [range]: CKD, 10.5 ng/dL [<10-17.1]; healthy, 10.9 ng/dL [<10-15]; P > .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Our client-owned dogs with CKD did not have lower gastric pH or higher serum gastrin concentrations compared to healthy dogs. Our results suggest that prophylactic gastric acid suppression in dogs with CKD is not warranted unless other clinical indications for use are present.

Computed Tomography Osteodensitometry for Assessment of Bone Mineral Density of the Canine Head-Preliminary Results

Simple Summary

Metabolic bone disease can have disastrous consequences on canine health. Unlike in human medicine where awareness of osteoporosis and bone mineral density (BMD) disorders have led to the holistic application of osteodensitometry, application of osteodensitometry in dogs is limited. We aimed to assess the utility of quantitative computed tomography (qCT) bone mineral density (BMD) measurement of the canine calvarium using semiautomated osteodensitometry software and define host factors associated with canine BMD in a skeletally healthy population. Calvarium qCT can be used to rapidly obtain BMD measurement of dogs. Canine BMD was negatively associated with weight, whereas there was no relationship between BMD and age or sex. Many chronic canine diseases can significantly affect bone health via a variety of pathophysiological mechanisms. This efficient qCT method could facilitate rapid BMD screening in dogs undergoing CT evaluation and ultimately encourage further BMD investigation.

Abstract

Despite bone mineral density (BMD) being regularly measured in human patients, BMD studies in clinical cohorts of dogs is lacking. In order to facilitate BMD assessment and in turn better identify dogs suffering from metabolic bone disease, rapid, easy and precise computed tomography (qCT) techniques are required. In this study we aimed to assess the utility of quantitative computed tomography (qCT) bone mineral density (BMD) measurement of the canine calvarium using a semiautomated osteodensitometry software and define host factors associated with canine bone mineral density in a skeletally healthy population. Calvarial qCT at the level of the temporomandibular joints was performed on 323 dogs using a dedicated osteodensitometry calibration phantom during a clinically indicated head computed tomography (CT). Calvarial BMD was analyzed using a dedicated semiautomatic osteodensitometry software for contouring of the calvarial lamellar bone margins and BMD calculation. The mean duration of the calvarial qCT scanning was 64.6 s, and the mean duration of BMD analysis was 34 s, with a mean of two manual adjustments required for the bone margin tracing. The median BMD of all dogs in our study was 659 mg Calcium hydroxyapatite/mL. There was a negative linear correlation between BMD and body weight, but no correlation with age, sex or neutered status. Canine BMD assessment using qCT of the calvarium is a practical and fast technique that can be added to a clinical CT examination with minimal extra time requirements. Canine BMD host-dependent factors exhibit different relationships from that of humans; however, further investigation is warranted.

Nutritional Management for Dogs and Cats with Chronic Kidney Disease

The nutritional management of canine and feline chronic kidney disease and protein-losing nephropathy is discussed. Special attention is paid to assessment of body composition (body weight, body condition score, and muscle condition score) and the dysrexia that often occurs with kidney disease. Various nutrients of concern are discussed and specific dietary options are provided.

Vitamin D Metabolism and Its Role in Mineral and Bone Disorders in Chronic Kidney Disease in Humans, Dogs and Cats

Some differences regarding Vitamin D metabolism are described in dogs and cats in comparison with humans, which may be explained by an evolutionary drive among these species. Similarly, vitamin D is one of the most important regulators of mineral metabolism in dogs and cats, as well as in humans. Mineral metabolism is intrinsically related to bone metabolism, thus disturbances in vitamin D have been implicated in the development of chronic kidney disease mineral and bone disorders (CKD-MBD) in people, in addition to dogs and cats. Vitamin D deficiency may be associated with Renal Secondary Hyperparathyroidism (RSHPT), which is the most common mineral disorder in later stages of CKD in dogs and cats. Herein, we review the peculiarities of vitamin D metabolism in these species in comparison with humans, and the role of vitamin D disturbances in the development of CKD-MBD among dogs, cats, and people. Comparative studies may offer some evidence to help further research about vitamin D metabolism and bone disorders in CKD.