Case Report: Human Recombinant Growth Hormone Therapy in a DSH Cat Presented With Dwarfism

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.

Dilated cardiomyopathy in a cat with congenital hyposomatotropism

Case summary

A 7-month-old domestic shorthair cat was presented for evaluation of stunted growth, recurrent hypoglycaemia during the first months of its life and altered mentation. Complete blood count and biochemistry were unremarkable, except for mildly elevated serum creatinine concentration (despite low muscle mass) and concurrent isosthenuria. Hyposomatotropism was diagnosed based on persistent low circulating insulin-like growth factor 1 concentrations and a lack of response of circulating growth hormone (GH) concentration after the administration of GH-releasing hormone. Other endocrinopathies such as hypothyroidism and hypoadrenocorticism were excluded. MRI of the brain revealed a fluid-filled empty sella tursica, consistent with a pituitary cyst and atrophy/hypoplasia of the pituitary. Echocardiography was unremarkable at the time of diagnosis of hyposomatotropism. Three months later, ovariohysterectomy revealed immature ovaries, raising the suspicion of luteinising and follicle-stimulating hormone deficiency. At 1 year of age, the cat developed congestive heart failure secondarily to dilated cardiomyopathy (DCM) with severely reduced left ventricular systolic function and died a few days later. Pathology showed atrophy of the adenohypophysis, epithelial delineation of the pituitary cysts, mild cardiomegaly, multifocal fibrosis of the left ventricle and a mild, multifocal, chronic epicarditis.

Relevance and novel information

GH deficiency is a very rare endocrinopathy in cats. This is the first case to describe the development of DCM with concurrent hyposomatotropism, which has previously been reported in human medicine. Other notable abnormalities that could be related to GH deficiency are juvenile self-limiting hypoglycaemia, behavioural changes and possible nephropathy.