Chap 295 : Canine GH Disorders

Question 1

Stimulation of GH by non GHRH secretagogue

Answer 1

Ghrelin, prod by stomach. Stim food intake, stim gastric emptying
More potent than ghrh in young dogs

Progestin, progesterone

Question 2

Cause of HGH in dogs

Answer 2

Endogenous progesterone (luteal phase), exogenous progestins

Hypothyroidism

Rarely : gh producing mammary tumor, pituitary somatotroph adenoma

Question 3

Predisposed breed

Answer 3

German sheperd dog

Question 4

Limit of IGF1 ?

Answer 4

Strong size correlation : breed specific range required

Question 5

Treatment of acromegaly

Answer 5

Progesterone induced : OV. May prevent/revert DM.

Progestin induced : discontinue ttt, aglepristone.

hT4 : levothyroxine normalize GH and IGF-1

GH-adenoma : hypophysectomy, radiation, somatostatin analogue

Question 6

Predisposed breed to pituitary dwarfism

Answer 6

BSD, saarloos, CZK dog

LHX3 autosomal recessive inherited

Question 7

Hormonal profile in P dwarfism

Answer 7

Low : GH, TSH, PRL, LH/FSH

Normal ACTH

Question 8

Associated malformation with PD

Answer 8

Rathke putch Kyst
Atlanto axial joint anomaly

Question 9

Azotemia in PD?

Answer 9

Abnormal glomerular dvpt due to gh / tsh deficiency

Question 10

Diagnosis of pituitary dwarfism

Answer 10

Basal GH may be low in healthy animal.
Low IGF-1 is not a definitive diagnosis

Definitive diagnosis : stimulation test with ghrh or alpha adrenergique (clonidine, xylazine)
At 30min, x2-4 gh concentration in healthy dog

LHX3 mutation test

Question 11

Treatment of PD

Answer 11

GH porcine analogue : AA sequence identical to dog

Progestin (gh production in canine mammary gland) : proligestone, MXP

T4 supplementation

Question 12

Progestine adverse effect

Answer 12

Pyoderma, skeletal maldeveloppement, pyometra, DM, HGK, mammary tumors, acromegaly
Bitches should be OV