Maxillomandibular deformity in a canine with fibrous osteodystrophy secondary to chronic kidney disease

Background: Cases of renal fibrous osteodystrophy are usually associated with nutritional causes, which of renal causesare considered uncommon in dogs. This disorder is characterized by the intense proliferation of fibrous connective tissue inbones, impairing bone stiffness. The aim of this study was to report a case of fibrous osteodystrophy secondary to chronickidney disease in a canine with a “rubber jaw” facial deformity.Case: A 4-year-old male unneutered mongrel dog weighing 5.2 kg had a history of apathy, progressive weight loss andvomiting for one month, and polyuria and polydipsia for more than three months. In addition, the owner complained aboutthe deformed appearance in the muzzle region of the animal, which was evidenced flexibility of the same, with a displacement of the mandible and maxilla on physical examination, similar to the “rubber jaw”. Blood tests revealed macrocyticanemia, elevated total plasma proteins, and lymphopenia-associated neutrophilia, as well as hyperphosphatemia (24 mg/dL), uremia (283.6 mg/dL) and increased creatinine (8.6 mg/dL), ALT (143.2 UI/L) and alkaline phosphatase (3222.2UI/L), while calcium (8.8 mg/dL) and albumin (1.9 g/dL) were decreased. A serological test for visceral leishmaniasis wasalso performed, which was negative. Abdominal ultrasound imaging revealed kidneys with alterations in tissue architecture, increased thickness and complete loss of cortico-medullary relationship, while the parathyroid gland was enlargedand spindle-shaped. Cranial radiography showed marked radiopacity of the bilateral maxillary bones, with destructionof the nasal, turbinate and frontal bones, as well as loosening of the teeth and destruction of the mandibular bone matrix,characterizing an aspect of “rubber jaw”. Based on the history, history and evidence of azotemia, hyperphosphatemia andloss of facial bone density, the diagnosis of fibrous osteodystrophy secondary to chronic kidney...(AU)

Maxillomandibular deformity in a canine with fibrous osteodystrophy secondary to chronic kidney disease

Background: Cases of renal fibrous osteodystrophy are usually associated with nutritional causes, which of renal causesare considered uncommon in dogs. This disorder is characterized by the intense proliferation of fibrous connective tissue inbones, impairing bone stiffness. The aim of this study was to report a case of fibrous osteodystrophy secondary to chronickidney disease in a canine with a “rubber jaw” facial deformity.Case: A 4-year-old male unneutered mongrel dog weighing 5.2 kg had a history of apathy, progressive weight loss andvomiting for one month, and polyuria and polydipsia for more than three months. In addition, the owner complained aboutthe deformed appearance in the muzzle region of the animal, which was evidenced flexibility of the same, with a displacement of the mandible and maxilla on physical examination, similar to the “rubber jaw”. Blood tests revealed macrocyticanemia, elevated total plasma proteins, and lymphopenia-associated neutrophilia, as well as hyperphosphatemia (24 mg/dL), uremia (283.6 mg/dL) and increased creatinine (8.6 mg/dL), ALT (143.2 UI/L) and alkaline phosphatase (3222.2UI/L), while calcium (8.8 mg/dL) and albumin (1.9 g/dL) were decreased. A serological test for visceral leishmaniasis wasalso performed, which was negative. Abdominal ultrasound imaging revealed kidneys with alterations in tissue architecture, increased thickness and complete loss of cortico-medullary relationship, while the parathyroid gland was enlargedand spindle-shaped. Cranial radiography showed marked radiopacity of the bilateral maxillary bones, with destructionof the nasal, turbinate and frontal bones, as well as loosening of the teeth and destruction of the mandibular bone matrix,characterizing an aspect of “rubber jaw”. Based on the history, history and evidence of azotemia, hyperphosphatemia andloss of facial bone density, the diagnosis of fibrous osteodystrophy secondary to chronic kidney...

Maxillofacial Fibrous Osteodystrophy in Equine: Case Report

A 14 year-old pregnant mare developed poor body condition (2/5) and diarrhea while grazing in kikuyu grass (Pennisetum clandestinum). Clinical findings included bulging of nasal and maxillary bones and mouth lacerations associated to spicules on the surface of molars and premolars. Teeth were easily fragmented and fell off. Necropsy findings included severe softening of the maxillary and mandibular bones. The mandible was easily breakable near to the masseter´s fossa. The parathyroid gland was increased in size. Histological findings were characterized by multiple irregular and very thin bone spicules in the bone tissue, most of them with microfractures, severe osteoclasts-mediated bone resorption and fibrous connective tissue proliferation. Hyperplasia and hypertrophy of parathyroid chief cells with cytoplasmic vacuolization were also observed. In conclusion, maxillofacial fibrous osteodystrophy caused by nutritional secondary hyperparathyroidism developed in a pregnant mare while grazing kikuyu grass for long periods of time without appropriate supplements. Kikuyu grass is characterized by high levels of oxalic acid that forms insoluble oxalates responsible for low calcium absorption in the small intestine and the progress of hyperparathyroidism.(AU)

Maxillofacial Fibrous Osteodystrophy in Equine: Case Report

A 14 year-old pregnant mare developed poor body condition (2/5) and diarrhea while grazing in kikuyu grass (Pennisetum clandestinum). Clinical findings included bulging of nasal and maxillary bones and mouth lacerations associated to spicules on the surface of molars and premolars. Teeth were easily fragmented and fell off. Necropsy findings included severe softening of the maxillary and mandibular bones. The mandible was easily breakable near to the masseter´s fossa. The parathyroid gland was increased in size. Histological findings were characterized by multiple irregular and very thin bone spicules in the bone tissue, most of them with microfractures, severe osteoclasts-mediated bone resorption and fibrous connective tissue proliferation. Hyperplasia and hypertrophy of parathyroid chief cells with cytoplasmic vacuolization were also observed. In conclusion, maxillofacial fibrous osteodystrophy caused by nutritional secondary hyperparathyroidism developed in a pregnant mare while grazing kikuyu grass for long periods of time without appropriate supplements. Kikuyu grass is characterized by high levels of oxalic acid that forms insoluble oxalates responsible for low calcium absorption in the small intestine and the progress of hyperparathyroidism.

Osteodistrofia fibrosa nutricional em caprinos / Nutritional fibrous osteodystrophy in goats

Seven out of 25 goats from a southern Brazilian flock developed nutritional fibrous osteodystrophy. Affected animals were younger than 1 year of age and were confined in stalls and fed a concentrate ration containing 1:6 calcium:phosphorus ratio. The remaining flock (35 goats) was managed at pasture and showed no disease. Clinical signs were characterized by mandibular and maxillary enlargements, varying degrees of mouth opening and protruding tongue, dyspnea, apart of abnormalities of prehension and mastication. Affected animals had increased seric levels of phosphorus and parathormone, as well as higher alkaline phosphatase activity. Postmortem examination on three succumbed goats revealed bilateral enlargement of the maxilla and mandibula, and loose teeth, apart of multiple incomplete rib fractures in one of them. Severe diffuse proliferation of loose connective tissue surrounded the osteoid trabeculae, many of which were partially or completely non-mineralized. Mineralized osteoid trabeculae showed osteoclasts in the Howship's lacunae.(AU)

Sete de um total de 25 caprinos jovens (menos de um ano de idade) de um rebanho no sul do Brasil desenvolveram osteodistrofia fibrosa nutricional. Os animais afetados eram confinados em baias e alimentados com concentrado, cuja relação Ca:P era 1:6. O restante do rebanho (35 cabras) era mantido na pastagem e não desenvolveu a doença. Os sinais clínicos se caracterizaram por aumento de volume da mandibula e maxila, vários graus de abertura de boca com protrusão da língua, em associação com dispneia e anormalidades de apreensão de alimento e mastigação. Os animais afetados apresentaram os níveis séricos de fósforo e paratormônio aumentados, bem como maior atividade de fosfatase alcalina. Três caprinos foram necropsiados e os achados de necropsia incluíram aumento bilateral da maxi-la e mandíbula, dentes frouxos, além de múltiplas fraturas incompletas de costelas em um caprino. Microscopicamente, havia intensa proliferação de tecido conjuntivo frouxo ao redor de trabéculas ósseas, muitas das quais estavam parcial ou completamente não mineralizadas. Trabéculas ósseas mineralizadas apresentaram osteoclastos em lacunas de Howship.(AU)

Osteodistrofia fibrosa nutricional em caprinos / Nutritional fibrous osteodystrophy in goats

Seven out of 25 goats from a southern Brazilian flock developed nutritional fibrous osteodystrophy. Affected animals were younger than 1 year of age and were confined in stalls and fed a concentrate ration containing 1:6 calcium:phosphorus ratio. The remaining flock (35 goats) was managed at pasture and showed no disease. Clinical signs were characterized by mandibular and maxillary enlargements, varying degrees of mouth opening and protruding tongue, dyspnea, apart of abnormalities of prehension and mastication. Affected animals had increased seric levels of phosphorus and parathormone, as well as higher alkaline phosphatase activity. Postmortem examination on three succumbed goats revealed bilateral enlargement of the maxilla and mandibula, and loose teeth, apart of multiple incomplete rib fractures in one of them. Severe diffuse proliferation of loose connective tissue surrounded the osteoid trabeculae, many of which were partially or completely non-mineralized. Mineralized osteoid trabeculae showed osteoclasts in the Howship's lacunae.

Sete de um total de 25 caprinos jovens (menos de um ano de idade) de um rebanho no sul do Brasil desenvolveram osteodistrofia fibrosa nutricional. Os animais afetados eram confinados em baias e alimentados com concentrado, cuja relação Ca:P era 1:6. O restante do rebanho (35 cabras) era mantido na pastagem e não desenvolveu a doença. Os sinais clínicos se caracterizaram por aumento de volume da mandibula e maxila, vários graus de abertura de boca com protrusão da língua, em associação com dispneia e anormalidades de apreensão de alimento e mastigação. Os animais afetados apresentaram os níveis séricos de fósforo e paratormônio aumentados, bem como maior atividade de fosfatase alcalina. Três caprinos foram necropsiados e os achados de necropsia incluíram aumento bilateral da maxi-la e mandíbula, dentes frouxos, além de múltiplas fraturas incompletas de costelas em um caprino. Microscopicamente, havia intensa proliferação de tecido conjuntivo frouxo ao redor de trabéculas ósseas, muitas das quais estavam parcial ou completamente não mineralizadas. Trabéculas ósseas mineralizadas apresentaram osteoclastos em lacunas de Howship.

Fibrous Osteodystrophy in a Captive Common Eland Antelope (Taurotragus oryx)

Fibrous osteodystrophy (FO) is a common condition described mainly in domestic species, with only few cases described in wild ones kept in captivity. Herein we report a case of FO in a 2 yr-old female common eland antelope (Taurotragus oryx) maintained in captivity and fed with a horse pelleted ration plus hays. The animal showed a firm bilateral symmetrical enlargement of upper maxillary bones which was submitted to histological evaluation. Microscopic findings were those related to extensive bone resorption and fibroplasia.(AU)

Hiperparatireoidismo em gatos com hipertireoidismo experimental / Hyperparathyroidism in cats with experimental hyperthyroidism

Os efeitos do hipertireoidismo experimental, 150µg/kg/dia/42 dias de levotiroxina sódica, na homeostase do cálcio foram estudados em 14 gatos sem raça definida, com idades entre um e três anos. A cada 14 dias foram colhidas amostras de soro para a determinação da concentração da tiroxina total (T4), tiroxina livre (FT4), paratormônio intacto (PTH), cálcio total e ionizado, fósforo e, além disso, realizaram-se radiografias para a determinação da densidade mineral óssea (DMO). Observou-se aumento das concentrações séricas do PTH a partir do momento inicial (M0), com diferença significativa deste em relação às concentrações obtidas aos 14 (M1), 28 (M2) e 42 (M3) dias. Não houve diferença significativa nas concentrações séricas de cálcio total e fósforo entre todos os momentos. O cálcio ionizado diminui de M0 para M1 e de M1 para M3, com diferença significativa. Os hormônios tireoidianos apresentaram correlação positiva com o PTH e negativa com o cálcio ionizado. A correlação entre DMO e PTH a partir de M2 foi negativa e entre DMO e fósforo foi negativa somente em M2. Não se observou correlação entre DMO e as demais variáveis. Em M1, M2 e M3 foi observada correlação negativa entre o PTH e o cálcio ionizado. Conclui-se que o hipertireoidismo em gatos adultos jovens está associado ao hiperparatireoidismo secundário devido ao aumento do PTH e diminuição do cálcio ionizado. Os efeitos combinados dos hormônios tireoidianos e do PTH contribuíram para a diminuição da DMO.

The effect of experimental hyperthyroidism, 150µg/kg/day/42 days, on calcium homeostasis was studied in 14 mongrel cats aging from one to three-year-old. Total thyroxine (T4), free thyroxine (FT4), parathyroid hormone (PTH), total and ionized calcium, phosphorus, bone mineral density were measured. Serum concentrations of PTH of increased from the initial moment (MO), with significant differences to when measured after 14(M1), 28(M2), and 42(M3) days. However, significant differences on serum concentrations were not observed among the values of M1, M2, and M3. The ionized calcium significantly decreased from M0 to M1 and from M1 to M3. Thyroid hormones showed positive correlation with PTH and negative with ionized calcium. Bone mineral density showed negative correlation with PTH from M2 to M3 and with phosphorus on M2, with no correlation with the other variables. Negative correlation of PTH with ionized calcium was observed on M1, M2, and M3. In conclusion, hyperthyroidism in young adult cats is associated to secondary hyperparathyroidism due to increase of PTH and decrease of ionized calcium. The combined effects of thyroid hormones and PTH contributed to the reduction of bone mineral density.

Hiperparatireoidismo em gatos com hipertireoidismo experimental / Hyperparathyroidism in cats with experimental hyperthyroidism

Os efeitos do hipertireoidismo experimental, 150µg/kg/dia/42 dias de levotiroxina sódica, na homeostase do cálcio foram estudados em 14 gatos sem raça definida, com idades entre um e três anos. A cada 14 dias foram colhidas amostras de soro para a determinação da concentração da tiroxina total (T4), tiroxina livre (FT4), paratormônio intacto (PTH), cálcio total e ionizado, fósforo e, além disso, realizaram-se radiografias para a determinação da densidade mineral óssea (DMO). Observou-se aumento das concentrações séricas do PTH a partir do momento inicial (M0), com diferença significativa deste em relação às concentrações obtidas aos 14 (M1), 28 (M2) e 42 (M3) dias. Não houve diferença significativa nas concentrações séricas de cálcio total e fósforo entre todos os momentos. O cálcio ionizado diminui de M0 para M1 e de M1 para M3, com diferença significativa. Os hormônios tireoidianos apresentaram correlação positiva com o PTH e negativa com o cálcio ionizado. A correlação entre DMO e PTH a partir de M2 foi negativa e entre DMO e fósforo foi negativa somente em M2. Não se observou correlação entre DMO e as demais variáveis. Em M1, M2 e M3 foi observada correlação negativa entre o PTH e o cálcio ionizado. Conclui-se que o hipertireoidismo em gatos adultos jovens está associado ao hiperparatireoidismo secundário devido ao aumento do PTH e diminuição do cálcio ionizado. Os efeitos combinados dos hormônios tireoidianos e do PTH contribuíram para a diminuição da DMO.(AU)

The effect of experimental hyperthyroidism, 150µg/kg/day/42 days, on calcium homeostasis was studied in 14 mongrel cats aging from one to three-year-old. Total thyroxine (T4), free thyroxine (FT4), parathyroid hormone (PTH), total and ionized calcium, phosphorus, bone mineral density were measured. Serum concentrations of PTH of increased from the initial moment (MO), with significant differences to when measured after 14(M1), 28(M2), and 42(M3) days. However, significant differences on serum concentrations were not observed among the values of M1, M2, and M3. The ionized calcium significantly decreased from M0 to M1 and from M1 to M3. Thyroid hormones showed positive correlation with PTH and negative with ionized calcium. Bone mineral density showed negative correlation with PTH from M2 to M3 and with phosphorus on M2, with no correlation with the other variables. Negative correlation of PTH with ionized calcium was observed on M1, M2, and M3. In conclusion, hyperthyroidism in young adult cats is associated to secondary hyperparathyroidism due to increase of PTH and decrease of ionized calcium. The combined effects of thyroid hormones and PTH contributed to the reduction of bone mineral density.(AU)