Multiple pituitary hormone deficiencies in a kitten: Hyposomatotropism, hypothyroidism, central diabetes insipidus and hypogonadism.

In humans, post-traumatic hypopituitarism (PTHP) is a common complication of traumatic brain injury, with the most frequently reported hormonal deficiencies resulting in hyposomatotropism and hypogonadism, followed by hypothyroidism, hypocortisolism, and central diabetes insipidus. To date, PTHP has rarely been reported in cats, and the reported cases often describe a single hormone deficiency. This report details an approximately 7-month-old cat with a history of suspected traumatic brain injury at 5 wk of age, that presented with growth retardation (1.53 kg) and polyuria-polydipsia. Thyroid panel, thyrotropin-releasing hormone stimulation test, thyroid scan with Technetium-99, repeat measurement of serum IGF-1, resting cortisol, endogenous ACTH concentration, and ACTH stimulation testing were performed. The cat was diagnosed with presumptive PTHP leading to hyposomatotropism, hypothyroidism, central diabetes insipidus, and hypogonadism. In this case, treatment of the hypothyroidism and central diabetes insipidus were successful. Hyposomatotropism and hypogonadism were not treated. Although reported feline PTHP cases have described a single hormone deficiency, this report details a cat with presumptive PTHP leading to hyposomatotropism, hypothyroidism, central diabetes insipidus, and hypogonadism. Attention should be paid to the potential for the development of PTHP in cats secondary to traumatic brain injury. Key clinical message: Post-traumatic hypopituitarism in cats can lead to multiple hormone deficiencies, leading to hyposomatotropism, hypothyroidism, central diabetes insipidus, and hypogonadism.

Insuffisances hormonales hypophysaires multiples chez un chaton : hyposomatotropisme, hypothyroïdie, diabète insipide central et hypogonadisme. En médecine humaine, l'hypopituitarisme post-traumatisme crânien (HPPT) est une complication fréquente après un trauma crânien. Les insuffisances hormonales les plus fréquemment rapportées sont l'hyposomatotropisme et l'hypogonadisme, suivis de l'hypothyroïdie, de l'hypocortisolisme et du diabète insipide central. À ce jour, l'HPPT a rarement été décrit chez le chat, et les cas publiés décrivent bien souvent une déficience hormonale unique. Dans le cas présent, un chat âgé d'environ 7 mois, avec un antécédent de trauma crânien suspecté à l'âge de 5 semaines, a été présenté avec un retard de croissance (1,53 kg) et un syndrome polyurie-polydipsique. Les examens d'endocrinologie complémentaires incluaient le dosage des hormones thyroïdiennes, la stimulation de l'hypophyse par la thyrolibérine, une scintigraphie thyroïdienne (Technetium-99), le dosage de l'IGF-1, du cortisol basal, de la concentration d'ACTH endogène, et un test de stimulation à l'ACTH. Le chat a été diagnostiqué de manière présomptive avec un HPPT causant de multiples insuffisances hormonales hypophysaires : hyposomatotropisme, hypothyroïdie, diabète insipide central et hypogonadisme. Chez ce chat, le traitement de l'hypothyroïdie et du diabète insipide central a été réussi. L'hyposomatotropisme et l'hypogonadisme n'ont pas été traités. Alors que les rapports de cas publiés sur l'HPPT félin décrivent souvent une seule déficience hormonale, ce chat a été diagnostiqué avec de multiples insuffisances hormonales hypophysaires. Les cliniciens doivent rester attentifs au développement potentiel d'un hypopituitarisme après un trauma crânien.Message clinique clé :L'hypopituitarisme post-traumatique chez le chat peut entraîner de multiples déficiences hormonales, entraînant un hyposomatotropisme, une hypothyroïdie, un diabète insipide central et un hypogonadisme.(Traduit par les auteurs).

Hypophysitis, Panhypopituitarism, and Hypothalamitis in a Scottish Terrier Dog.

A 6-year old male neutered Scottish Terrier was referred with a 1 week history of progressive lethargy and anorexia. Neurological examination localized a lesion to the forebrain and hormonal testing showed panhypopituitarism. Magnetic resonance imaging (MRI) of the brain revealed a rounded, well-defined, suprasellar central mass. The mass was slightly hyperintense to the cortical grey matter on T2-weighted (T2W), hypointense on T1-weighted (T1W) images and without T2* signal void. There was a central fusiform enhancement of the mass after contrast administration which raised the suspicion of a pituitary neoplasm. Rapid deterioration of the dog prevented further clinical investigations. Histopathologic examination revealed a lymphocytic panhypophysitis of unknown origin suspected autoimmune involving the hypothalamus (hypothalamitis). This is a unique case report of a dog presenting with inflammatory hypophysitis and hypothalamitis of suspected autoimmune origin with detailed clinical, MRI, histology and immunohistochemistry findings.

Hypothalamic-anterior pituitary hormone deficiencies following traumatic brain injury in dogs.

Traumatic brain injury is an important cause of hypopituitarism in human beings, but limited information exists in the veterinary literature regarding this condition. The primary study objective was to investigate whether hypothalamic-anterior pituitary axis dysfunction exists following traumatic brain injury in 17 client owned dogs. In this retrospective, observational, open, cohort study, information about dogs presented to four separate referral centres between April 2008 and October 2013 was reviewed. Cases were included if they had suffered from non-fatal traumatic brain injury, resulting in neurological dysfunction, and follow-up evaluation included measurement of the serum concentration of insulin-like growth factor 1 (IGF-1), endogenous adrenocorticotrophic hormone (ACTH), basal cortisol, thyroid-stimulating hormone, total thyroxine (TT4) and, if appropriate, free thyroxine. Decreased IGF-1 concentration was the most common abnormality detected (7/17, 41 per cent; median 132 ng/ml, range <15-536), followed by a decreased TT4 concentration (4/17, 23 per cent; median 19, range 4-49). Basal cortisol concentration was less than 20 nmol/l in two cases (2/17, 12 per cent; median 65, range <20-1735), with concurrently undetectable ACTH (<5 pg/ml). This study demonstrates that dogs with a history of traumatic brain injury can develop endocrine abnormalities indicative of hypothalamic-anterior pituitary dysfunction.

Lymphocytic hypophysitis in a dog with diabetes insipidus.

An 8-year-old male German longhaired pointer was referred for diabetes insipidus responsive to treatment with desmopressin. The dog had polyuria and polydipsia, exercise intolerance and a dull hair coat. Plasma concentrations of thyroid-stimulating hormone, thyroxine, growth hormone (GH) and insulin-like growth factor-1 were decreased; plasma adrenocorticotropic hormone (ACTH) was slightly elevated and plasma α-melanocyte-stimulating hormone (MSH) was within the reference range. Computed tomography revealed a heterogeneously contrast-enhancing pituitary mass compressing the hypothalamus. Transsphenoidal hypophysectomy was performed and microscopical examination of the surgical biopsy samples revealed hypophysitis without evidence of pituitary adenoma. The hypophysitis was characterized by marked lymphocytic infiltration of the adenohypophysis that contained a mixed population of neuroendocrine cells expressing GH, ACTH or α-MSH. The lymphocytes were identified as T cells, resulting in a final diagnosis of lymphocytic hypophysitis strongly resembling human primary lymphocytic hypophysitis.

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.

[Hypopituitarism as the possible cause of prolonged gestation in cattle]. / Hypopituitarismus als mögliche Ursache für eine verlängerte Gestation beim Rind.

Multiple malformations were shown in a bovine fetus delivered at slaughter after a gestation period of 469 days. Hypoplasia of the adenohypophysis and a bilateral agenesis of the adrenal cortex suggest that the failure of initiation of parturition resulted from a fetal deficiency of ACTH and glucocorticoid hormones. ACTH, GH (growth hormone) and prolactin could not be demonstrated immunohistochemically within the adenohypophysis. However, TSH immunoreactive pituitary cells were demonstrable. Nevertheless, considering the extremely reduced size of the adenohypophysis a fetal deficiency of TSH is suspected. This view is supported by a bilateral hypoplasia of the thyroid gland. Additionally, the complex fetal endocrine dysfunction had led to a growth retardation of the fetus.

Delayed growth in two German shepherd dog littermates with normal serum concentrations of growth hormone, thyroxine, and cortisol.

Four German Shepherd Dogs from a litter of 10 were evaluated because of postnatal onset of proportionate growth stunting that clinically resembled well-documented hypopituitary dwarfism in that breed. Although 2 pups had histologic evidence of hypopituitarism, the remaining 2 pups had normal serum growth hormone concentration and adrenocorticotropin secretory capability, and normal adrenal function test and thyroid function study results. Furthermore, the initially stunted German Shepherd Dogs grew at a steady rate until at 1 year, body weight and shoulder height approximated normal measurements. Seemingly, delayed growth in these pups may represent one end of a clinical spectrum associated with hypopituitarism in German Shepherd Dogs.

Hypodipsic hypernatremia and associated myopathy in a hydrocephalic cat with transient hypopituitarism.

Hypodipsic hypernatremia developed in association with hypopituitarism and hydrocephalus in a 7-month-old cat. Initial clinical signs (generalized weakness, cervical ventroflexion) were related to a hypernatremia-induced polymyopathy. Forced water intake and dietary sodium restriction corrected the hypernatremia and signs of muscle dysfunction. After restoration of eunatremia, secretion of pituitary hormones normalized. It was speculated that hypothalamic dysfunction, possibly related to hydrocephalus, induced both hypodipsia and transient hypopituitarism.

Radioimmunoassay of canine growth hormone.

A sensitive radioimmunoassay (RIA) for canine growth hormone (GH) was developed. Antibodies were elicited in rhesus monkeys. One antiserum exhibited a working titer at a dilution of 1: 500 000. Radioiodination was performed enzymatically employing lactoperoxidase. Logit-log transformation and least squares fitting resulted in straight line fitting of the standard curve between 0.39 and 50 ng/ml. Formation of large-molecular [125I]GH during storage caused diminished assay sensitivity. Therefore [125I]GH was re-purified by gel chromatography. Using this procedure, high and reproducible assay sensitivity was obtained. Tracer preparations were used for as long as 3 months after iodination. Diluted plasma from normal and acromegalic dogs resulted in a dose-response curve parallel to the standard curve. Canine prolactin exhibited a cross-reactivity of 2%. The within-assay coefficient of variation (CV) was 3.8 and the between-assay CV was 7.2%. Mean plasma GH concentration in normal dogs was 1.92 +/- 0.14 ng/ml (mean +/- SEM). GH levels in acromegalic dogs were appreciably higher. Insulin-induced hypoglycaemia, arginine and ornithine administration resulted in inconsistent and sluggish GH increment. A better response was obtained by injecting a low dose of clonidine. Clonidine administration to hypopituitary dogs resulted in absent or poor GH increment.