Primary hyperparathyroidism in a dog.

A 6-year-old male Standard Poodle had hypercalcemia, hypophosphatemia, and a urinary concentrating defect. A parathyroid adenoma involving the left caudal parathyroid gland was surgically removed. Transient hypocalcemia followed, which resolved without treatment. A renal biopsy did not demonstrate renal parenchymal mineral deposition. Urinary concentrating ability returned after surgery.     

Primary hyperparathyroidism in a dog.

Anorexia, severe skeletal demineralization, and muscular weaknesss developed in a 9 year-old Collie. Hypercalcemia, hypophosphatemia, and nephrocalcinosis were found on clinical evaluation. The surgical removal of a parathyroid adenoma was followed by profound hypocalcemia that was unresponsive to calcium therapy, and the dog died. The persistent hypocalcemia was attributed to increased deposition of calcium in mineral-deficient bone.     

Primary hyperparathyroidism in a dog: biochemical, bone histomorphometric, and pathologic findings

An adult Keeshond had clinical signs associated with hypercalcemia, including inappetence, polyuria, polydipsia, and vomiting. Blood biochemical findings and urinary clearance studies were consistent with a diagnosis of primary hyperparathyroidism. Histomorphometric analysis of trabecular bone in an iliac crest biopsy indicated increased bone remodeling activity. Surgical exploration of the neck revealed an oval mass, which was removed by blunt dissection. Histologic diagnosis was parathyroid gland adenoma. The dog died because of renal failure on the eighth postoperative day. This report defines primary hyperparathyroidism in the dog, thus facilitating diagnosis for the veterinary clinician.     

Seizures as a manifestation of primary hyperparathyroidism in a dog

Hypercalcemia caused by primary hyperparathyroidism was believed to be responsible for seizures in a dog. A diagnostic evaluation showed no primary causes of seizures. After surgical excision of the adenomatous parathyroid gland, phenobarbital treatment was discontinued, without recurrence of seizures.     

Primary polycythaemia in a dog

A 7-year-old, crossbred, desexed bitch had a fluctuating illness of more than 6 months duration, with signs of inappetence, reduced exercise tolerance, restlessness, panting, black diarrhoea, and red eyes and ears. Haematological examination disclosed persistent polycythaemia, reticulocytosis, normoblastaemia , and normal total plasma protein concentration when not dehydrated. Splenomegaly was present, but there was no evidence of significant pulmonary, cardiac or renal disease on physical, radiographic or electrocardiographic examination. Further investigations revealed normal arterial Po2 and oxygen saturation, and increased total erythrocyte volume. Primary polycythaemia was diagnosed. The dog was rendered anaemic by bleeding, then treated with a single injection of radioactive phosphorus. The patient has had no recurrence of signs and remains well 50 months later.     

Suspected primary hyperparathyroidism in the dog

Abstract

Extract

Primary hyperparathyroidism is the term given to a group of primary pathological conditions of the parathyroid gland which result in the excessive production of parathyroid hormone. It was first described as a disease entity in man by Barr et al. (1929 Barr, D. P., Bulger, H. A. and Dixon, H. H. 1929. Hyperparathyroidism. J. Amer. med. Ass., 92: 951–952.  [Google Scholar]) who grouped under this heading a series of conditions that had hitherto been described as osteomalacia, multiple cystic tumours of the bone, or parathyroid tumours.     

Primary hyperparathyroidism and concurrent hyperthyroidism in a cat

A cat was presented for anorexia and vomiting. Hyperthyroidism and primary hyperparathyroidism were diagnosed. A thyroid adenoma and parathyroid adenoma, respectively, were responsible for these conditions. Unilateral thyroidectomy and parathyroidectomy successfully resolved both disorders.     

Primary peri-aortic hemangiosarcoma in a dog

A 10-year-old intact male Norwich terrier dog was evaluated for progressive, intermittent increased respiratory effort. Thoracic radiographs, ultrasonography, and computed tomography were used to identify a caudodorsal thoracic extrapulmonary mass and the presence of pulmonary metastasis. Blood transfusion and stabilization measures were not successful and the patient died. Necropsy confirmed the origin of the mass to be the adventitial layer of the aorta and determined it to be hemangiosarcoma. This is a rare site for the primary lesion.     

Primary ocular osteosarcoma in a dog

An adult male Rottweiler presented to the veterinary medical teaching hospital at Purdue University with a 1-month history of hyphema. On physical examination conjunctivitis, episcleral hyperemia, corneal edema, hyphema, mild glaucoma and loss of vision were observed in the left eye. No other abnormalities were found. The left globe was surgically removed because of the high likelihood of neoplasia and it was fixed in 10% buffered formalin and submitted for pathology. A histologic diagnosis of primary osteosarcoma of the eye was made. Radiographic evaluation did not reveal any evidence of other tumors or pulmonary metastasis. This is the fourth canine case of primary intraocular osteosarcoma to be documented.     

Primary pulmonary osteosarcoma in a dog

An 11-year-old mixed breed dog was referred because of coughing and painful swelling of the distal extremities which had not resolved with antibiotic treatment. A consolidated left cranial lung lobe and hypertrophic osteopathy were identified by radiographs. A unique feature of this report is the marked, rapid reduction in pain and lameness associated with hypertrophic osteopathy after treatment with corticosteroids. Histological examination of an 8 cm diameter, spherical mass found in the excised cranial lung lobe revealed osteosarcoma. No evidence of local or distant metastases was present. The dog survived one year after diagnosis.     

Primary vertebral hemangiosarcoma in a dog

A 7-year-old spayed Cocker Spaniel was evaluated for recurrent hind limb paraplegia. Radiography and myelography revealed a compression fracture of T-9 secondary to a lytic process. Findings at necropsy and histologic and immunohistochemical examinations revealed 3 sites of hemangiosarcoma in each of the bodies of T-9 to T-11. Primary vertebral hemangiosarcoma is rare, and in this dog may have represented a multicentric occurrence or a primary neoplasm with adjacent metastatic foci.     

Primary cardiac fibrosarcoma in a dog

A primary cardiac fibrosarcoma in the right atrium of a 6-year-old Chihuahua dog is described. At necropsy, there was a firm, whitish and spherical mass in the right atrium. Histopathologically, the mass had moderate cellularity composed of spindle-shaped cells with scattered multinucleated giant cells. The tumor cells were arranged in interwoven bundles and sheets in the collagenous stroma. No metastases were observed. Ultrastructurally, the tumor cells mainly consisted of fibroblasts. Multinucleated giant cells did not have any certain organelles that would indicate a higher order of differentiation. Primary cardiac sarcomas in dogs are extremely rare.