Proliferative parathyroid lesions in captive-bred American bullfrogs (Lithobates catesbeianus) with metabolic bone disease.

Parathyroid gland lesions in anurans are infrequently reported and most often occur secondary to experimental interventions. Husbandry-related parathyroid changes have not been documented in this order of Amphibia. Three American bullfrogs (Lithobates catesbeianus) living in a captive colony were euthanized due to clinical concern for metabolic bone disease secondary to lack of consistent dietary supplementation with vitamin D3. Necropsy revealed cystic dilation and variable proliferation of unidentified structures within the cranial coelom corresponding to the anatomical location of anuran parathyroid glands. Histologically, the structures consisted of sheets and whorls of elongated cells. Immunohistochemistry for pan-cytokeratin revealed strong cytoplasmic staining and Grimelius staining identified neuroendocrine granules in the elongated cells of these structures, supportive of a parathyroid origin.

Juvenile Disease Processes Affecting the Forelimb in Canines.

Several juvenile diseases affect the canine forelimb. The most common are hypertrophic osteodystrophy, panosteitis, and retained cartilaginous core. Panosteitis and hypertrophic osteodystrophy tend to be self-limiting, with a good long-term prognosis, although severe cases can develop. These diseases may recur during growth. Severe cases of hypertrophic osteodystrophy can lead to angular limb deformities and may even be fatal. Retained cartilaginous cores can be benign with no evidence of clinical signs and be found incidentally on radiographs. However, if they disrupt the distal ulnar physis, angular limb deformities may persist requiring surgical intervention with a corrective osteotomy.

CLINICAL AND PATHOLOGIC FINDINGS OF AN OUTBREAK OF VITAMIN D3-RESPONSIVE METABOLIC BONE DISEASE IN HERON AND EGRET (FAMILY ARDEIDAE) CHICKS FED CAPELIN (MALLOTUS VILLOSUS).

An increase in cases of metabolic bone disease (MBD) in chicks of six species of heron and egret (family Ardeidae) was identified at a wildlife rehabilitation center in the spring and summer of 2018. The outbreak affected 34.3% of birds in care for four or more days during the first 3 mo of the study and was the most common reason for euthanasia during that time. Cases were characterized by lameness, increased flexibility of multiple long bones, angular deformities, and bone fractures. Gross postmortem examinations were conducted on 145 nestlings and fledglings that died or were euthanatized either because of MBD or for unrelated conditions. Histology was performed in four cases and three controls. Histologic findings were characterized by multiple lesions in the appendicular long bones, including variable elongation of the physis, retention of cartilage cores in the metaphyseal primary spongiosa, poorly mineralized osteoid seams within the primary spongiosa, thinning or lack of diaphyseal cortical bone compaction, and folding fractures typically propagating through the physis-metaphyseal interface. Folding fractures were often associated with focal metaphyseal fibroplasia. The parathyroid gland diameter of birds diagnosed postmortem with MBD in care was significantly larger than that of unaffected birds. The authors hypothesized that a dietary deficiency of vitamin D3 because of low levels in the bird's captive diet of capelin (Mallotus villosus) was the cause of the MBD. Starting in mid-July every chick's diet was supplemented with 714 IU oral vitamin D3/kg body weight per day, after which the number of birds developing MBD declined to a rate of 4.3%. This study characterizes the clinical, gross, radiographic, and histologic features of vitamin D3-responsive MBD in young herons and egrets and provides evidence to support the recommendation that captive birds on a diet of capelin be supplemented with vitamin D3, especially during growth.

Subchondral focal osteopenia associated with proximal sesamoid bone fracture in Thoroughbred racehorses.

BACKGROUND: Proximal sesamoid bone (PSB) fracture is the most common fatal injury in Thoroughbred (TB) racehorses in the United States. Epidemiological and pathological evidence indicates PSB fracture is likely the acute culmination of a chronic stress-related process. However, the aetiopathogenesis of PSB fracture is poorly understood. OBJECTIVE: To characterise bone abnormalities that precede PSB fracture. STUDY DESIGN: Two retrospective case-control groups of PSBs from TB racehorses with, and without, unilateral biaxial PSB fracture. METHODS: Proximal sesamoid bones were harvested post-mortem from TB racehorses subjected to euthanasia for unilateral biaxial PSB fracture (cases) or causes unrelated to PSB fracture (controls) while racing or training. The fractured medial PSB (FX-PSB) and contralateral intact medial PSB (CLI-PSB) from racehorses that sustained PSB fracture, and an intact medial PSB (CTRL-PSB) from racehorses that did not have a PSB fracture were collected as case and control specimens. Study 1 distributions of morphological features were compared among case and control groups using visual examination, photographs, radiographs and histology of whole PSBs and serial sagittal sections (10 FX-PSB, 10 CLI-PSB and 10 CTRL-PSB). Study 2 local bone volume fraction and mineral densities were compared among case and control PSBs using microcomputed tomography (9 FX-PSB, 9 CLI-PSB and 9 CTRL-PSB). RESULTS: A focal subchondral lesion characterised by colocalised focal discoloration, radiolucency, osteopenia, low tissue mineral density and a surrounding region of dense cancellous bone was identified in most case horses but not in controls. This subchondral lesion was found in a slightly abaxial mid-body location and was bilaterally present in most case horses. MAIN LIMITATIONS: The post-mortem samples may not represent the spectrum of abnormalities that occur throughout the development of the subchondral lesion. Lateral PSBs were not examined, so their contribution to biaxial PSB fracture pathogenesis is unknown. CONCLUSION: Abaxial subchondral lesions are consistent with pre-existing injury and likely associated with PSB fracture.

Bilateral osteoma cutis in a Peach-Faced Lovebird (Agapornis roseicollis).

An osteoma is an infrequent tumor documented in avian species. An adult female Peach-Faced Lovebird (Agapornis roseicollis) with a history of previous trauma was examined due to the presence of bilateral hard and yellowish-white masses in the radio-cubital humerus junction. Histopathological dermal examination revealed a non-neoplastic process of mesenchymal origin, characterized by the formation of well-differentiated trabecular bone, multiple areas of medullary bone and loose connective tissue and coagulation of the necrosis foci. Based on the histological findings and the medical history, the masses were diagnosed as bilateral secondary osteoma cutis. To our knowledge, this is the first report of this pathology with an acute course in this exotic pet bird. The previous trauma could be the initiating cause.

Modelo de indução de osteoporose em coelhas - avaliação radiográfica / Rabbit osteoporosis induction model - radiographic evaluation

In order to establish a bone loss induction model in rabbits to study osteoporosis, 18 rabbits underwent ovariectomy and received methylprednisolone 1mg/kg intramuscularly on alternate days for two weeks. Immediately before ovariectomy up to 42 days after methylprednisolone administration, radiographs of the right olecranon were taken in the mediolateral position to evaluate the radiographic optical density. Before the induction of osteoporosis, rabbits presented mean values of radiographic density of 2.305mm Al and at 42 days of 1.575mm Al. The values obtained were submitted to ANOVA for repeated measures that revealed a significant drop (P< 0.001) in the density over time, proving that the induction was able to trigger bone loss of these animals. With this, it can be affirmed that the adopted protocol was enough to provoke a significant bone loss, characterizing a valid model for the study of new treatments for osteoporosis.(AU)

OSTEODENSITOMETRY AND TOMOGRAPHIC FINDINGS IN FOUR CAPTIVE GIANT SOUTH AMERICAN TURTLES (PODOCNEMIS EXPANSA) WITH METABOLIC BONE DISEASE.

Giant South American turtles (Podocnemis expansa) are at a risk of extinction because of the rapid decline in their population over the last few decades. Metabolic bone disease (MBD) is common in captive testudines, but is often not diagnosed until a later stage. The authors present the cases of four captive giant South American turtles with carapace deformity secondary to MBD that underwent computed tomography (CT) scans of the carapace bones and vertebral column. Findings indicative of changes in geometry were found in both. The cancellous bone pattern was characterized by varying degrees of increased trabecular spacing and cortical thinning of the pleural bones. Bone densitometry analysis of the pleural and neural bones and at the level of the body of the third, fourth, and fifth dorsal vertebrae showed mean density values much lower than those found in two adult specimens of the same species that were considered healthy. In conclusion, CT contributed important information on the degree of demineralization and possible structural changes due to MBD and should be considered a relevant tool for diagnosis of this condition.

Primary Osteoma Cutis in the Interscapular Region of a Dog.

A 9-year-old neutered male Shih Tzu was presented with three contiguous firm nodules in the subcutaneous tissue of the interscapular region. Histopathological examination revealed that the nodules consisted of mature lamellar bone with a Haversian system, with no apparent lesion around the bone. Clinical examination revealed that the dog had no underlying disease and no history of trauma at the lesion site. Based on these findings and on the medical history, a diagnosis of primary osteoma cutis was made. Osteoma cutis is rare in both human and veterinary medicine, and most dogs reported to have secondary osteoma cutis. To our knowledge, this case is only the second report of primary osteoma cutis in a dog.

Paradise lost: Evidence for a devastating metabolic bone disease in an insular Pleistocene deer.

PURPOSE: This communication reports skeletal pathology in a Pleistocene endemic deer from the Mavromouri caves of Crete. MATERIALS: 287 bones and bone fragments from Mavromouri caves are compared to 2986 bones from Liko Cave. METHODS: Bones were evaluated macroscopically, and measurements were made of morphometric characteristics of limb long bones. Representative bone specimens were examined radiographically and histologically. RESULTS: Macroscopic hallmarks were loss of bone mass and increased porosity. The long bones were brittle, some of them having thin cortices, and others reduction of medullary cavities that contain dense Haversian tissue. The flat bones were spongy and fragile. Erosions of the metaphyses and articular surfaces were noted. Histological findings included: sub-periosteal resorption; loss of lamellar bone; enlargement of vascular canals; and remodeling of cortical bone. Two types of fibrous osteodystrophy were recognized in skeletal remains, subostotic and hyperostotic. CONCLUSIONS: The deer of Mavromouri caves were affected by severe metabolic bone disease, likely nutritional secondary hyperparathyroidism. We hypothesize a multifactorial cause, including overgrazing, flora senescence, soil mineral deficiencies, and a prolonged period of climate extremes, degrading the Cretan deer habitat. VALUE: This is the first evidence of a metabolic bone disease causing this level of destructive pathology in an insular fossil deer. LIMITATIONS: The lack of absolute chronometric dates for the site limits potential linking with the prevailing environmental conditions. SUGGESTIONS FOR FURTHER RESEARCH: Investigation of similar skeletal pathologies at other islands or isolated habitats is advised.

Treatment of subchondral lucencies in the medial proximal radius with a bone screw in 8 horses.

OBJECTIVE: To describe the results of screw placement through subchondral lucencies (SCL) of the proximal radius in 8 horses. STUDY DESIGN: Retrospective clinical study. ANIMALS: Horses with cubital SCL causing lameness (n=8). METHODS: Medical record review and clinical follow-up. RESULTS: Eight horses with SCL in the proximal radius causing lameness were treated with a screw placed across the lucency. The horses range in age from 1 to 20 years. In 4 of 8 horses, the lameness had been intermittently severe (apparent at the walk). Lameness was isolated to the cubital joint by intra-articular anesthesia in 5 horses and diagnosed radiographically in all 8. All horses had a 4.5 mm cortical bone screw placed from medial to lateral (6 lag, 2 neutral) across the SCL using fluoroscopic or radiographic control. Postoperative care included stall confinement with hand walking for 30-60 days, followed by an additional 30-60 days of pasture turnout. Radiographic SCL healing (reduction in SCL size) was demonstrated at 3-4 months after surgery in all horses, and 7/8 horses (87.5%) were used as intended (4 performance, 3 pasture turn-out) within 6 months. Lameness in the remaining horse improved initially (dressage) but returned. CONCLUSIONS: A screw placed through the SCL of the proximal-medial radius was effective in reducing or resolving lameness associated with the elbow joint in 7/8 horses (88%). Screw placement in the proximal radius should be considered for horses with lameness caused by an SCL when a quick return to exercise is desired or conservative therapy is ineffective.

HEPATIC OSTEODYSTROPHY IN A GOLDEN LION TAMARIN (LEONTOPITHECUS ROSALIA).

An 8-yr-old, captive, female golden lion tamarin ( Leontopithecus rosalia ) with a 6-yr history of hyperbilirubinemia was examined for inappetence and weight loss. Physical examination and blood pressure monitoring under anesthesia revealed hypothermia and hypotension, and blood work revealed hypoglycemia, markedly elevated liver enzymes, including serum alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase, and confirmed the hyperbilirubinemia. A complete blood count suggested chronic lymphoid leukemia. The animal's condition deteriorated during recovery, and the animal died despite aggressive treatment. Grossly, there was micronodular cirrhosis of the liver, severe icterus, and diffuse osteopenia of all examined bones. Microscopic examination of the liver confirmed the micronodular cirrhosis and bone lesions were compatible with diffuse osteopenia and osteomalacia. This brief communication presents a case of chronic liver disease and lesions indicative of metabolic bone disease, also known as hepatic osteodystrophy. To the authors' knowledge, this is the first documented case of hepatic osteodystrophy in the veterinary literature.

THE EFFECT OF UVB RADIATION ON SERUM VITAMIN D AND IONIZED CALCIUM IN THE AFRICAN SPOONBILL (PLATALEA ALBA).

Metabolic bone disease (MBD) was diagnosed in two chicks produced by a captive breeding colony of African spoonbills (Platalea alba). The birds were housed indoor during the winter breeding season and had no access to natural sunlight. When the index cases occurred, the nesting birds and chicks had a mean 25-hydroxyvitamin D (25-OHD) concentration of 9.9 ± 2.7 nmol/L and a mean ionized calcium (iCa) concentration of 0.98 ± 0.12 mmol/L (winter pretreatment). For comparison purposes, serum was collected the following summer; mean 25-OHD was 20.8 ± 3.9 nmol/L and mean iCa was 1.32 ± 0.05 mmol/L (summer). During the following breeding season, ultraviolet B (UVB) lighting was provided to the flock, resulting in a mean 25-OHD of 19.0 ± 5.6 nmol/L and mean iCa of 1.23 ± 0.06 mmol/L (winter treatment 1). Both 25-OHD and iCa were significantly higher compared with winter pretreatment, and 25-OHD was not significantly different from summer, indicating that treatment during the winter months succeeded in increasing 25-OHD levels to summer levels. However, winter treatment 1 and summer iCa were significantly different. During the next breeding season (winter treatment 2), the birds were exposed to a light with higher UVB output. The mean 25-OHD of the flock was 16.5 ± 7.2 nmol/L, and the mean iCa increased to 1.34 ± 0.04 mmol/L. Both were comparable to summer values. Healthy chicks were hatched during both breeding seasons, and no further cases of MBD occurred during the course of the study. Provision of a UVB light source to captive African spoonbills maintained indoors during the winter months can increase 25-OHD and iCa to levels equivalent to those seen in the summer months, when birds have unrestricted access to natural sunlight. UVB lighting is recommended for all breeding spoonbills that do not have access to natural sunlight.

Effect of age and sex on bone markers in Chlorocebus aethiops raised in captivity.

BACKGROUND: The objective was to evaluate the procollagen type I N-propeptide (PINP), osteocalcin (OC), ß-crosslaps (ß-CTX), and parathyroid hormone (PTH) in relation to age and sex of Chlorocebus aethiops in captivity. METHODS: Seventy-three monkeys were divided into four age groups: AG1 (juvenile); AG2 (young adult); AG3 (adult); and AG4 (senile). An electrochemiluminescence immunoassay with an Elecsys 2010 analyzer was used to determine the serum markers of bone. RESULTS AND CONCLUSIONS: Sex did not influence the results of the markers. However, the variables PINP, OC, and ß-CTX were negatively correlated with age (r = -0.643; r = -0.711; r = -0.488; P < 0.001, respectively), and PTH was correlated positively with age (r = 0.418, P < 0.001). The data obtained can be used as biomarkers of bone metabolism reference intervals in healthy C. aethiops in captivity.

Primary isolated osteoma cutis causing eyelid deformation and strabismus in a dog.

Osteoma cutis describes bone formation in skin and is well documented in the medical literature, but veterinary reports are few. We report a single case of a juvenile samoyed that was referred for assessment of a superior eyelid anomaly. Exploratory surgery and histopathology revealed the presence of mature, lamellar bone within the superior eyelid. The histologic appearance was consistent with primary osteoma cutis. The presence of the ossification within the deep dermis of the eyelid was associated with an abnormal conformation causing trichiasis, keratitis and dorsal strabismus. Identification of the osseous lesion during surgery and its removal was curative with no recurrence of disease during the 32 month follow-up period.

Pre-operative fibrous osteodystrophy and severe, refractory, post-operative hypocalcemia following parathyroidectomy in a dog.

A 13-year-old dog exhibited dramatic, radiographic osteopenia consistent with fibrous osteodystrophy secondary to primary hyperparathyroidism. Following parathyroidectomy, the dog developed severe, prolonged hypocalcemia, but was successfully treated and discharged 32 d after surgery. A variety of factors may have contributed to this dog's hypocalcemia including hypoparathyroidism and hungry bone syndrome.

Ostéodystrophie fibreuse préopératoire et hypocalcémie grave, réfractaire postopératoire après une parathyroïdectomie chez un chien. Un chien âgé de 13 ans a manifesté une ostéopénie radiographique dramatique conforme à une ostéodystrophie fibreuse secondaire à un hyperparathyroïdisme primaire. Après une parathyroïdectomie, le chien a développé une hypocalcémie grave et prolongée, mais il a été traité avec succès et a reçu son congé 32 jours après la chirurgie. Divers facteurs peuvent avoir contribué à l'hypocalcémie de ce chien, y compris l'hypoparathyroïdisme et l'hypocalcémie par avidité osseuse.(Traduit par Isabelle Vallières).

Bone Disease in the Common Marmoset: Radiographic and Histological Findings.

The common marmoset (Callithrix jacchus) is a New World primate that is used in biomedical research due to its small size and relative ease of handling compared with larger primates. Although bone disease in common marmosets is well recognized, there are very few detailed descriptions in the literature that cover the range of lesions seen in these animals. For all animals used to model human disease, it is important to be aware of background lesions that may affect the interpretation of study findings. This retrospective study details bone diseases encountered in marmoset breeding colonies at 2 different institutions. Affected marmosets at Johns Hopkins University had lesions compatible with diagnoses of rickets, fibrous osteodystrophy and osteopenia. Affected marmosets at the Wisconsin National Primate Research Center exhibited severe lesions of osteoclastic bone resorption and remodeling that had an unusual distribution and were not easily categorized into a known disease entity. The purpose of this report is to document these naturally occurring skeletal lesions of common marmosets and suggest an approach to evaluating skeletal disease in prospective studies of these animals that will allow the most accurate diagnoses.

Meeting ultraviolet B radiation requirements of amphibians in captivity: a case study with mountain chicken frogs (Leptodactylus fallax) and general recommendations for pre-release health screening.

Conservation breeding programmes are a tool used to prevent amphibian extinctions. The husbandry requirements of amphibians are complex. Ongoing research is needed to ensure optimal management of those captive-bred animals destined, in particular, for reintroduction. The UV-B and vitamin D3 requirements of amphibians are largely unknown. Metabolic bone disease has been reported in a number of species. These include the Critically Endangered mountain chicken frog (Leptodactylus fallax) reared in captivity on diets supplemented with a high-calcium multivitamin and mineral supplement containing vitamin D3 but without UV-B provision. Captive-bred L. fallax being reared for reintroduction to Montserrat were provided with UV-B radiation from metamorphosis and were fed on insects supplemented with vitamins and minerals. Overlapping heat, light and UV-B gradients were provided, mimicking what we believe best represents the natural situation and thereby facilitated self-regulation of UV-B exposure. A subset of 10 frogs was periodically radiographed to assess skeletal health. Radiographic bone density and anatomical integrity appeared unremarkable when compared with a wild caught L. fallax. In addition to other routine health-screening, we recommend that radiography be performed to a structured schedule on a subset of all captive-bred and reared amphibians to assess skeletal health and to gauge the appropriateness of captive husbandry. We demonstrate here that, through the appropriate provision of a combination of both UV-B radiation and dietary supplementation, L. fallax can be bred and reared in captivity with healthy skeletal development.

Nutrition and health in amphibian husbandry.

Amphibian biology is intricate, and there are many inter-related factors that need to be understood before establishing successful Conservation Breeding Programs (CBPs). Nutritional needs of amphibians are highly integrated with disease and their husbandry needs, and the diversity of developmental stages, natural habitats, and feeding strategies result in many different recommendations for proper care and feeding. This review identifies several areas where there is substantial room for improvement in maintaining healthy ex situ amphibian populations specifically in the areas of obtaining and utilizing natural history data for both amphibians and their dietary items, achieving more appropriate environmental parameters, understanding stress and hormone production, and promoting better physical and population health. Using a scientific or research framework to answer questions about disease, nutrition, husbandry, genetics, and endocrinology of ex situ amphibians will improve specialists' understanding of the needs of these species. In general, there is a lack of baseline data and comparative information for most basic aspects of amphibian biology as well as standardized laboratory approaches. Instituting a formalized research approach in multiple scientific disciplines will be beneficial not only to the management of current ex situ populations, but also in moving forward with future conservation and reintroduction projects. This overview of gaps in knowledge concerning ex situ amphibian care should serve as a foundation for much needed future research in these areas.