Fluid and electrolyte therapy in endocrine disorders: diabetes mellitus and hypoadrenocorticism.

Diabetic ketoacidosis, hyperglycemic hyperosmolar syndrome, and acute adrenal crisis are life-threatening endocrine emergencies that have marked effects on fluid, electrolyte, and acid-base homeostasis. Rapid identification of these disorders and aggressive therapy to correct fluid, electrolyte, and acid-base imbalances are crucial to a successful outcome for the patient. An understanding of the pathophysiology behind the development of these endocrine disorders helps to guide therapy and improves the clinical outcome.     

Hypercalcemia due to latrogenic secondary hypoadrenocorticism and diabetes mellitus in a cat.

A 9-year-old, spayed female domestic shorthair cat presented for polyphagia, polydipsia, and polyuria following chronic methylprednisolone acetate therapy for pruritus. Initial diagnostics were consistent with uncomplicated diabetes mellitus. Serum calcium was within reference range. Within 12 hours the cat developed depression, anorexia, vomiting, and severe dehydration. Laboratory analysis indicated marked hypercalcemia as measured by both ionized and total calcium concentration. No underlying neoplastic or inflammatory process was identified. An adrenocorticotropic hormone stimulation test was indicative of adrenocortical insufficiency. The hypercalcemia resolved with glucocorticoid supplementation and correction of the dehydration. The diabetes mellitus and adrenal insufficiency both resolved within 9 weeks.     

Atrial fibrillation in the dog: a review of eight cases

Eight cases of canine atrial fibrillation encountered in small animal practice are reported. Details are included of age, sex and breed, history and clinical signs, thoracic radiography, electrocardiography, clinical pathology, treatment and survival periods.     

Concurrent disorders in dogs with diabetes mellitus: 221 cases (1993-1998)

OBJECTIVE: To characterize concurrent disorders in dogs with diabetes mellitus (DM). DESIGN: Retrospective study. ANIMALS: 221 dogs with DM. PROCEDURE: Medical records were reviewed, and clinical signs, physical examination findings, and results of clinicopathologic testing, urinalysis, aerobic bacterial culture of urine samples, coagulation testing, endocrine testing, histologic evaluation, diagnostic imaging, and necropsy were recorded. RESULTS: For most dogs, CBC results were normal. Common serum biochemical abnormalities included hypochloremia (127 dogs, 60%) and high alanine aminotransferase (163, 78%), aspartate aminotransferase (78, 71%), and alkaline phosphatase (188, 90%) activities. Venous pH and serum ionized calcium concentration were measured in 121 and 87 dogs, respectively, and were low in 56 (46%) and 41 (47%) dogs. Lipemia was observed in 92 (42%) dogs. Urine samples from 159 (72%) dogs were submitted for aerobic bacterial culture, and 34 (21%) yielded bacterial growth. Escherichia coli was the most commonly isolated organism. Thirty-six (16%) dogs had dermatitis or otitis. Hyperadrenocorticism was diagnosed in 51 (23%) dogs on the basis of clinical signs and results of a low-dose dexamethasone suppression test (41 dogs), an adrenocorticotropic hormone stimulation test (5), both tests (4), or histologic evaluation of necropsy specimens (1). Acute pancreatitis was diagnosed in 28 (13%) dogs. Eleven (5%) dogs had tumors for which a histologic diagnosis was obtained. Eight (4%) dogs were hypothyroid. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dogs with diabetes mellitus may have many concurrent disorders. The most commonly identified concurrent disorders included hyperadrenocorticism, urinary tract infection, dermatitis, otitis, acute pancreatitis, neoplasia, and hypothyroidism.     

Megaoesophagus and glucocorticoid-deficient hypoadrenocorticism in a dog

A seven-year-old German shepherd dog was referred for acute onset regurgitation. Muscle weakness and severe dermatological disease were present. Thoracic radiographs revealed generalised megaoesophagus. Diagnostic testing revealed glucocorticoid deficiency, and rapid resolution of the megaoesophagus followed appropriate supplementation. The dog made a full recovery. Unique features of this case include a transiently positive antinuclear antibody titre and clinical features of myasthenia gravis.     

Lateral fabellar fractures in the dog: A review of eight cases

Fractures of the lateral fabella were recorded in seven medium or large breed dogs. Six dogs had unilateral fractures and one had bilateral fractures. The fractures appeared to occur spontaneously, without external trauma. Four fractures were managed conservatively and four were treated by surgical removal of the fracture fragments. Both treatments were successful in resolving the lameness.     

Diagnosis and management of diabetes mellitus in five cats with somatotrophic abnormalities

The clinical findings and management of five cats with abnormalities consistent with acromegaly were examined retrospectively. Growth hormone (GH) concentrations were elevated in four cats. In one, a minimal elevation of GH was accompanied by a marked elevation in insulin-like growth factor-1 (IGF-1). Insulin-like growth factor-1 concentrations supported the diagnosis in three of four cats measured, but was not elevated initially in one cat, despite a markedly elevated GH concentration. These findings suggest that elevated IGF-1 concentrations are a reliable indicator of acromegaly, but that values within the reference range do not exclude such a diagnosis. Clinical signs of acromegaly were similar to those previously reported, although upper respiratory stridor occurred in one cat, and insulin-resistant diabetes mellitus was not a consistent feature. Despite the lack of a widely available definitive treatment for acromegaly, good control of the clinical signs of diabetes mellitus can be achieved for long periods despite high doses of insulin often being required.     

Atherosclerosis in a dog with diabetes mellitus

A seven-year-old male Pomeranian with unstable insulin-dependent diabetes mellitus developed atherosclerosis. Hyperlipidaemia, consisting of hypertriglyceridaemia and hypercholesterolaemia, was diagnosed concurrently with the onset of lipid-laden aqueous humour. Serum lipoprotein analysis was characterised by the presence of chylomicrons, an increase in the very low density lipoprotein fraction, with a broad very low density lipoprotein-low density lipoprotein band, and a reduced high density lipoprotein fraction. The dog developed ketoacidosis one year later and died. At postmortem examination, atherosclerotic plaques were observed in the terminal aorta and in medium-sized arteries, including the coronary arteries, renal and arcuate arteries, and arteries of the brain. Mineralised plaques or complicated plaques were not observed. The absence of clinical signs of organ ischaemia was thought to be associated with the absence of thrombosis and/or complete occlusion of all vessels examined. Signs of chronic organ hypoxia, although considered likely owing to the severe vessel lumen reduction, were restricted to only a low voltage QRS complex on the electrocardiogram.     

Diagnosis and management of the overweight dog

Canine obesity remains one of the most commonly encountered problems in small animal practice; yet the average owner rarely presents the dog because it has been recognized as being overweight. More frequently, the dog is presented because it is suffering from one of the numerous health problems that being overweight can cause. The present paper discusses the causes, development and clinical signs of obesity, the differential diagnosis of the condition and finally the management of cases.     

Monitoring techniques for diabetes mellitus in the dog and the cat

One of the keys to achieving glycemic control in animals with diabetes mellitus is the appropriate selection and interpretation of analytic monitoring tests. Diabetic animals are subject to many of the same problems described in human diabetics. Diabetics are more susceptible to infection, and wound healing is often impaired. Decreased insulin promotes lipolysis and moderate hyperlipidemia, which can lead to falsely lowered fructosamine levels, impaired renal circulation, and atherosclerosis. Hyperglycemic, hypoinsulinemic animals continue to lose weight despite an increased appetite and an increased intake because they are not able to use glucose. Many unregulated diabetic animals will present with vomiting and diarrhea that can exacerbate electrolyte abnormalities seen with the osmotic diuresis present in an uncontrolled state. Canine diabetics are prone to cataract formation secondary to sorbitol accumulation in the lens. Cats, on the other hand, can present with diabetic distal neuropathy, which may be reversible with appropriate treatment. With all of these potential complications, it is important to monitor these animals regularly; this is the only way that glycemic control can be properly maintained over time. This article reviews the monitoring parameters available to the modern practitioner and outlines the benefits of each test, as well as caveats, in their interpretation.     

Concurrent central diabetes insipidus and panhypopituitarism in a German shepherd dog

This report describes a German shepherd dog that was presented with proportionate dwarfism and coat changes typical of hypopituitarism but that was also profoundly polydipsic and polyuric. Investigations established a diagnosis of concurrent central diabetes insipidus. Treatment with desmopressin was successful in managing the polyuria and polydipsia.     

Keratoconjunctivitis sicca and diabetes mellitus in a dog.

Diabetes mellitus and keratoconjunctivitis sicca were diagnosed in a female Poodle. The dog was treated for diabetes and keratoconjunctivitis sicca until blood glucose concentrations were within normal limits. Treatment for keratoconjunctivitis sicca was suspended then, and signs of this disorder did not appear again. Most of the factors known to predispose to keratoconjunctivitis sicca were not applicable to this dog. On the basis of observations made in this dog, we suggest that diabetes mellitus and keratoconjunctivitis sicca may be linked. Clinical signs of the disorders developed simultaneously and resolved when diabetes mellitus was controlled with insulin.