Primary idiopathic hypoparathyroidism in St. Bernard dogs

Primary hypoparathyroidism was diagnosed in three St. Bernard bitches. Anorexia, behavioural changes, muscle tremors, seizures, panting respiration, and cataracts were the clinical signs observed. The serum concentration of calcium was low, the phosphorus concentration elevated, and the immunoreactive parathyroid hormone level low in all dogs. The aetiology of the hypoparathyroidism was not determined in any of the dogs. Treatment with synthetic vitamin D (1,25-dihydroxycholecalciferol) and an oral calcium supplement was successful in restoring and then maintaining a normal concentration of serum calcium in two of the dogs.     

The persistence of antibodies against Brucella ovis and Brucella abortus in rams following vaccination: A field study

Primary hypoparathyroidism was diagnosed in three St. Bernard bitches. Anorexia, behavioural changes, muscle tremors, seizures, panting respiration, and cataracts were the clinical signs observed. The serum concentration of calcium was low, the phosphorus concentration elevated, and the immunoreactive parathyroid hormone level low in all dogs.

The aetiology of the hypoparathyroidism was not determined in any of the dogs. Treatment with synthetic vitamin D (1,25-dihydroxycholecalciferol) and an oral calcium supplement was successful in restoring and then maintaining a normal concentration of serum calcium in two of the dogs.     

Fanconi's Syndrome in a Dog With Primary Hypoparathyroidism

An 11 -year-old castrated male mixed breed dog was referred for evaluation of muscle twitching, polyuria, polydipsia, anorexia, and periocular alopecia. Primary hypoparathyroidism was diagnosed by documenting decreased serum concentrations of parathyroid hormone and ionized calcium. Neurological, gastrointestinal, and dermatological signs resolved after calcium repletion. Initially, 1,25-dihydroxycholecalcif erol PO was required to correct the hypocalcemia. Dihydrotachysterol, in combination with oral calcium supplementation, was used for long-term maintenance of normal serum calcium concentration. Aminoaciduria, glucosuria, and hyperchloremic metabolic acidosis were consistent with a diagnosis of Fanconi's syndrome. This diagnosis was further supported by the presence of hypokalemia and increased urinary fractional excretion of sodium, potassium, calcium, phosphorus, and magnesium. Renal tubular dysfunction resolved after oral supplementation with calcium and vitamin D₃. Fanconi's syndrome in this dog may have been caused by decreased serum concentration of 1,25-dihydroxycholecalciferol, which was secondary to decreased parathyroid hormone production.     

Canine distemper virus-associated hypocalcemia.

A retrospective study was done to correlate serum calcium concentrations and parathyroid gland ultrastructure to clinical, immunologic, and pathologic changes experimentally induced in gnotobiotic dogs by canine distemper virus (CDV). Dogs infected with CDV had significantly reduced serum calcium concentrations associated with ultrastructural evidence of parathyroid gland inactivity, degeneration, and viral inclusions. Although CDV-infected dogs exhibited neurologic signs, minimal lesions were present in the central nervous system. It is suggested that viral-induced parathyroid dysfunction may contribute to neutrologic disturbance of CDV infection.     

Treatment of primary hyperparathyroidism in a Miniature Horse using chemical ablation of abnormal parathyroid tissue localized by 3‐phase computed tomography

A 15‐year‐old Miniature Horse mare with persistently increased plasma calcium (total and ionized) and serum parathyroid hormone concentrations was presented for suspected primary hyperparathyroidism. Ultrasonography of the thyroid region identified an enlarged heterogeneous mass axial to the right thyroid lobe suggestive of an enlarged parathyroid gland, which was further confirmed using sestamibi nuclear scintigraphy and 3‐phase computed tomography. Percutaneous ultrasound‐guided ethanol ablation of the mass, a method not previously described in the horse, was performed under general anesthesia resulting in rapid normalization of plasma ionized calcium and serum parathyroid hormone concentrations. Ablation of abnormal parathyroid gland tissue may be a suitable alternative to surgical resection in certain cases of primary hyperparathyroidism in the horse.     

Primary hypoparathyroidism in dogs: a retrospective study of 17 cases

OBJECTIVE: To evaluate the clinico-pathological findings, response to treatment and prevalence of complications in dogs with primary hypoparathyroidism. DESIGN: Retrospective study of 17 dogs presenting to the University of Melbourne Veterinary Clinical Centre and Murdoch University Veterinary Hospital over a 15 year period (1990 to 2004). Case records were evaluated for signalment, body weight, diet type, historical and clinical findings, serum total calcium, phosphate, albumin and parathyroid hormone concentrations, urinary fractional excretion ratios of calcium and phosphate, electrocardiogram (ECG) results, treatments administered, outcome and period of follow-up. RESULTS: The most common breeds identified were St Bernard (three dogs), Chihuahua (two dogs), German Shepherd (two dogs) and Jack Russell Terrier (two dogs). Three dogs were cross bred. Seizures, muscle tremors and fasciculations, stiff gait, tetany, muscle cramping, behavioural change and hyperventilation were the most common clinical signs. Vomiting, inappetence, diarrhoea, abdominal pain, hyperthermia, facial pruritus, ataxia, weakness, cataracts, and circling also occurred with less frequency. The mean duration of observed clinical signs preceding diagnosis was 33 days (median 13 days, range 1 to 173 days). All dogs had marked hypocalcaemia with normal or mildly increased serum albumin concentrations. Mean phosphate concentrations were significantly higher in inappetent dogs (P = 0.049). Mean serum calcium concentrations were significantly lower in dogs with cataracts compared to those without (P = 0.046). There were no other significant relationships between serum calcium or phosphate concentrations and the clinical presentation or outcome. No significant correlations were identified between the presence of a particular clinical sign and the duration of clinical signs. ECGs were obtained in four dogs and all exhibited QT interval prolongation due to a ST-segment prolongation. Sixteen of 17 dogs were treated successfully for hypocalcaemia and discharged from hospital. Acute management included parenteral calcium gluconate (10 dogs) and intravenous anticonvulsants (five dogs). Chronic therapy included oral vitamin D analogues and calcium supplementation. Treatment complications occurred in two dogs and included acute renal failure (one dog) and iatrogenic tissue necrosis following subcutaneous calcium administration (one dog). The mean follow-up period was 14.5 months (median 13 months, range 0 to 39 months). Twelve dogs were alive at the last follow up and two dogs were euthanased for unrelated reasons. The type of vitamin D analogue used was not associated with outcome. CONCLUSION: Primary hypoparathyroidism was an uncommon diagnosis in dogs. Saint Bernards, cross bred dogs, German Shepherd dogs and Terrier breeds were most commonly affected. Neurological signs were the most common presenting clinical signs, although alimentary signs may have been more common than previously reported. Dogs with primary hypoparathyroidism appeared to have a good prognosis following initiation of calcium supplementation and vitamin D therapy. Complications of treatment were uncommon and could be minimised with regular monitoring.     

Primary hyperparathyroidism in cats: seven cases (1984-1989).

The medical records of 7 hypercalcemic cats with primary hyperparathyroidism were evaluated. Mean age was 12.9 years, with ages ranging from 8 to 15 years; 5 were female; 5 were Siamese, and 2 were of mixed breed. The most common clinical signs detected by owners were anorexia and lethargy. A cervical mass was palpable in 4 cats. Serum calcium concentrations were 11.1 to 22.8 mg/dl, with a mean of 15.8 mg/dl calculated from each cat's highest preoperative value. The serum phosphorus concentration was low in 2 cats, within reference limits in 4, and slightly high in 1 cat. The BUN concentration was greater than 60 mg/dl in 2 cats, 31 to 35 mg/dl in 2 cats, and less than 30 mg/dl in 3 cats. Abnormalities were detected in serum alanine transaminase, aspartate transaminase, and alkaline phosphatase activities from 2 or 3 cats. Parathormone (PTH) concentrations were measured in 2 cats before and after surgery. The preoperative PTH concentration was within reference limits in 1 cat and was high in 1 cat. The PTH concentrations were lower after surgery in both cats tested. A solitary parathyroid adenoma was surgically removed from 5 cats, bilateral parathyroid cystadenomas were surgically resected in 1 cat, and a parathyroid carcinoma was diagnosed at necropsy in 1 cat. None of the cats had clinical problems with hypocalcemia after surgery, although 2 cats developed hypocalcemia without tetany, one of which was controlled with oral administration of dihydrotachysterol and the other with oral administration of 1,25 dihydroxyvitamin D. All 5 of the cta that underwent removal of an adenoma were alive at least 240 days after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hyperkalaemic periodic paralysis in Australian Quarter Horses

SUMMARY Three Quarter Horse stallions and 5 of their 11 tested progeny were diagnosed as affected with the inherited autosomal dominant defect hyperkalaemic periodic paralysis in Victoria in 1992. The diagnoses were based on the appearance of clinical signs and associated increased plasma potassium concentrations in response to oral potassium loading. All affected horses were descendants of the American Quarter Horse Impressive. Indirect evidence indicates that at least 3 other affected Quarter Horse stallions have stood or are standing at stud in Australia. The clinical details of the affected horses are described and the size of the affected population in Australia is discussed.     

Hypercalcaemia associated with granulomatous lymphadenitis and elevated 1,25 dihydroxyvitamin D concentration in a dog

A seven-year-old Labrador was presented with weight loss and mild generalised lymphadenopathy. Histopathology of an excised lymph node by the referring veterinarian demonstrated granulomatous lymphadenitis. At the time of referral, fine-needle aspirates of the lymph nodes confirmed the presence of ongoing granulomatous inflammation. Further investigations revealed marked hypercalcaemia, a low parathyroid hormone concentration, a parathyroid hormone related protein concentration within the reference range, and an elevated serum concentration of 1,25 dihydroxyvitamin D. An underlying cause of the granulomatous lymphadenitis could not be identified. The clinical signs, hypercalcaemia and elevated serum concentrations of 1,25 dihydroxyvitamin D resolved following prednisolone treatment. In contrast to dogs, hypercalcaemia occurred secondarily to granulomatous disease and elevated 1,25 dihydroxyvitamin D concentrations is a well-recognised condition in human beings. To the authors' knowledge, this is the first case report to describe elevated serum calcium and 1,25 dihydroxyvitamin D concentrations in a dog with histologically confirmed granulomatous disease.     

Acute and chronic oxalate toxicity in Miniature Horses associated with soursob (Oxalis pes‐caprae) ingestion

Over the period of 11 years (2004–2015) 14 miniature horses in six separate outbreaks presented with clinical signs consistent with acute or chronic oxalate toxicity. All animals had access to Oxalis pes‐caprae or soursob. Miniature horses with acute oxalate toxicity and hypocalcaemia had muscle fasciculations, tremors and synchronous diaphragmatic flutter; these horses responded to treatment with intravenous and oral calcium. Chronic oxalate toxicity was associated with ill‐thrift, stiffness, enlarged heads, kyphosis and neurological signs. These animals had normal serum calcium concentrations, but increased serum alkaline phosphatase activity. Radiographs indicated that affected animals had bones that were osteopenic, often with pathological fractures. Bones that were examined histologically showed increased osteoclastic and osteoblastic activity, consistent with nutritional secondary hyperparathyroidism and fibrous osteodystrophy. These animals were treated, with mixed success, with oral calcium supplementation. A palatability trial showed that horses will readily eat soursobs, and measured total oxalate concentrations in soursobs collected from five different properties ranged from 13.5 to 18.5%. The presentation of affected animals with either acute hypocalcaemia or nutritional secondary hyperparathyroidism, together with a history of grazing soursobs, suggest that acute and chronic oxalate toxicity are the cause of the clinical signs seen in affected miniature horses.     

A probable case of hypoparathyroidism in a cat

Idiopathic hypoparathyroidism was suspected in a young female cat. The relevant historical and clinical findings were: anorexia, intermittent muscle tremors, hindlimb ataxia, behavioural changes and cataracts. Salient laboratory findings were: hypocalcaemia, hyperphosphataemia and normal renal function (normal serum urea and creatinine concentrations with hypersthenuria). No evidence of intestinal malabsorption, pancreatitis or nutritional secondary hyperparathyroidism was found. Treatment with oral synthetic vitamin D (1,25 dihydroxycholecalciferol) and intravenous and oral calcium supplements was successful in correcting the hypocalcaemia and abolishing the clinical signs.     

An unusual case of generalized soft-tissue mineralization in a suckling foal

An atypical case of severe soft-tissue mineralization in a 3-week-old foal from a herd of Andalusian horses is described. The herd clinical history and the laboratory findings were compatible with a diagnosis of secondary hyperparathyroidism due to a mineral imbalance in the diet (low calcium and high phosphorus intake). Mares showed a marked increase in serum parathyroid hormone (PTH) approximately 10 times normal levels. Serum PTH was marginally elevated in foals. Clinical signs (unthriftiness, painful joints, lameness in one or more limbs, and stiff gait) were more pronounced in foals than in mares. Two foals died and necropsy of one of them revealed extensive soft-tissue mineralization of arterial walls and pulmonary parenchyma. Clinical signs in mares and foals resolved by 4 weeks after diet adjustment.     

Hypercalcemia in two cats with squamous cell carcinomas

Hypercalcemia was identified in 2 cats with squamous cell carcinomas. One cat was referred because of multiple cutaneous tumors; the second cat had metastatic disease from an oral squamous cell carcinoma. In both cats, serum immunoreactive midmolecule parathyroid hormone concentration was within the range determined for clinically normal cats. The high serum calcium concentration in these cats may have resulted from the neoplastic disease, as evidenced by the reduction in serum calcium concentration after decrease in tumor size in response to treatment, and by failure to identify other known causes of hypercalcemia.     

Canine calcium oxalate urolithiasis. Case-based applications of therapeutic principles.

The case study presented here illustrates the diagnosis and management of calcium oxalate urolithiasis in a Bichon Frise, a breed at increased risk for this type of stone. If the Bichon Frise had persistent hypercalcemia, we would have evaluated serum concentrations of ionized calcium, parathyroid hormone, and vitamin D to identify an underlying cause. Because his urine was alkaline, additional potassium citrate was not provided. Likewise, as a fortified diet was fed to him, vitamin B6 therapy was not considered. This case study illustrates the benefits of radiographic evaluation immediately following surgery and during follow-up examinations. If we had postponed radiographs until the patient developed clinical signs, additional surgical procedures may have been required.     

Pretreatment clinical and laboratory findings in dogs with primary hyperparathyroidism: 210 cases (1987-2004)

OBJECTIVE: To evaluate pretreatment clinical and laboratory findings in dogs with naturally occurring primary hyperparathyroidism. DESIGN: Retrospective study. ANIMALS: 210 dogs with primary hyperparathyroidism and 200 randomly selected, age-matched control dogs that did not have primary hyperparathyroidism. PROCEDURE: Medical records for dogs with primary hyperparathyroidism were reviewed for signalment; clinical features; and results of clinicopathologic testing, serum parathyroid hormone assays, and diagnostic imaging. RESULTS: Mean age of the dogs with primary hyperparathyroidism was 11.2 years (range, 6 to 17 years). The most common clinical signs were attributable to urolithiasis or urinary tract infection (ie, straining to urinate, increased frequency of urination, and hematuria). Most dogs (149 [71%]) did not have any observable abnormalities on physical examination. All dogs had hypercalcemia, and most (136 [65%]) had hypophosphatemia. Overall, 200 of the 210 (95%) dogs had BUN and serum creatinine concentrations within or less than the reference range, and serum parathyroid hormone concentration was within reference limits in 135 of 185 (73%) dogs in which it was measured. Urolithiasis was identified in 65 (31 %) dogs, and urinary tract infection was diagnosed in 61 (29%). Mean serum total calcium concentration for the control dogs-was significantly lower than mean concentration for the dogs with primary hyperparathyroidism, but mean BUN and serum creatinine concentrations for the control dogs were both significantly higher than concentrations for the dogs with primary hyperparathyroidism. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that urolithiasis and urinary tract infection may be associated with hypercalcemia in dogs-with primary hyperparathyroidism, but that development of renal insufficiency is uncommon.     

Clinical,histological and immunophenotypic findings in a mare with a mammary lymphoma associated with anaemia and pruritus

An 18‐year‐old Quarter Horse mare presented with an 18 week history of dermatological lesions characterised by recurrent urticaria and recent signs of enlarged mammary glands, pyrexia, alopecia and intense pruritus. Haematological and serum biochemical analyses revealed anaemia, leucocytosis, thrombocytopenia and hyperfibrinogenaemia. Mammary discharge was evaluated and revealed neutrophilia. Cytological examinations of fine needle aspirates from the parotid lymph nodes were normal. Common causes of anaemia were ruled out by specific tests. The initial diagnosis was mastitis and 2 weeks later the animal returned to the hospital with worsening of clinical signs, intermittent fever, intense pruritus and generalised alopecia. Blood samples were collected for haematological and serum biochemical analyses, and the mammary gland and parotid lymph nodes were biopsied. Rectal palpation revealed a large irregular mass near the left kidney with adhesions of surrounding structures. The animal died before the laboratory results were ready. This report details the clinical, histological and immunophenotypic findings of a case of large lymphoma in a mare.     

Idiopathic Hypoparathyroidism in Five Cats

Idiopathic hypoparathyroidism was diagnosed in five young to middle-aged cats of mixed breeding. Three of the cats were male and two were female. Historic signs included lethargy (n = 5), anorexia (n = 5), muscle tremors (n = 4), weakness (n = 4), generalized seizures (n = 3), ataxia (n = 3), mental dullness or disorientation (n = 3), panting (n = 2), pruritus (n = 1), ptyalism (n = 1) and dysphagia (n = 1). Weakness (n = 4), dehydration (n = 2), cataracts (n = 2), hypothermia (n = 1), and bradycardia (n = 1) were found on physical examination. Results of electrocardiography revealed a prolonged Q-T interval in two cats. Results of initial laboratory tests revealed profound hypocalcemia and severe hyperphosphatemia with normal renal function. The diagnosis of hypoparathyroidism was made on the basis of the history, clinical signs, and results serum biochemical testing (i.e., severe hypocalcemia and hyperphosphatemia); in two cats, the diagnosis was also confirmed by histologic examination of parathyroid glands. Initial treatment included intravenous administration of 10% calcium gluconate and oral administration of large loading doses of calcium and vitamin D (dihydrotachysterol). Successful long-term management with dihydrotachysterol and calcium was achieved in all cats. The final dosage of dihydrotachysterol required to maintain normocalcemia in the five cats ranged from 0.004 to 0.04 mg/kg/day (mean = 0.015 mg/kg/day). Long-term calcium supplementation was given to three of the cats in dosages ranging from 29 to 53 mg/kg/day (mean = 42 mg/kg/day) of elemental calcium. One cat died after 28 months of therapy from widely metastatic hemangiosarcoma; the other three cats are still alive and well after 5 to 37 months of treatment.     

Functional analysis of ectopic parathyroid activity in cats

The ability of ectopic parathyroid tissue to support calcium homeostasis was evaluated by measuring serum concentrations of calcium, phosphorus, albumin, magnesium, and parathyroid hormone before and for 12 weeks after bilateral thyroparathyroidectomy in 14 cats. During the immediate postoperative period, significant decrease was observed in serum calcium, magnesium, and parathyroid hormone (PTH) concentrations. Serum PTH concentration remained subnormal and did not significantly increase during the 12-week observation period. Despite persistent hypoparathyroidism, serum calcium and magnesium concentrations gradually increased. Ectopic parathyroid tissue is not capable of maintaining normal serum calcium concentration immediately after thyroparathyroidectomy. Serum calcium concentration gradually normalizes after thyroparathyroidectomy, apparently by means of a PTH-independent mechanism.     

Hypercalcemia following renal transplantation in a cat

An 11-year-old 3.0-kg (6.6-lb) neutered male Persian was referred for renal transplantation. Serum total calcium concentration was slightly high prior to surgery, but the week after surgery, total and ionized calcium concentrations were extremely high, and a small mass was palpable on the right side of the trachea at the level of the thyroid and parathyroid glands. Exploratory surgery of the ventral aspect of the neck was performed, and a right external parathyroid mass was removed. One hour after surgery, the serum ionized calcium concentration was within reference limits, and the serum calcium concentration remained normal for the next 14 months without any specific treatment. The gross and histologic appearance of the mass, combined with the rapid decrease in serum calcium concentration following its removal, confirmed that the mass was a functional parathyroid adenoma. Although a common postoperative complication in people, hypercalcemia following renal transplantation appears to be a rare complication in cats. Surgery should be considered if the condition is a result of a parathyroid adenoma.     

Historical and current perspectives on the treatment, control and pathogenesis of milk fever in dairy cattle

Milk fever has been recognised in cattle for about 215 years and its clinical signs have not changed since they were described by Victorian veterinary surgeons in the mid-nineteenth century. It was only 80 years ago that abnormal parathyroid gland function was associated with the pathogenesis of the hypocalcaemia characteristic of the disease, and the current basis for its treatment with intravenous calcium salts was established. Although this treatment is effective, most recent research has focused on preventing the disease through an understanding of the endocrine control of extracellular calcium homeostasis. In the 1970s the synthetic vitamin D analogue 1alpha-hydroxycholecalciferol was developed for intramuscular injection before a cow calved, but variable results encouraged other preventive strategies to be considered, including restricting the dietary intake of calcium, and manipulating the dietary cation-anion balance of cows before they calved. Currently, the role of extracellular calcium receptors in the parathyroid gland is under investigation as a preliminary step to devising more effective treatments and/or preventive methods for milk fever.