28. Diseases of the hypophysis in dogs and cats.

Question 1

Hypophysiotropic hormones

hypothalamus hormones?

Answer 1

GHRH - growth hormone
LHRH - luteinising hormone
TRH - thyrotropin
CR - corticotropin

Question 2

another name for the hypophysis

Answer 2

pituitary gland

Question 3

Pituitary hormones

Answer 3

ACTH
GH
PRL
TSH
LH
FSH
aMSH
ADH
Oxytocin

Question 4

Congenital hyposomatotropism

Answer 4

pituitary dwarfism
autosomal recessive inheritance

Question 5

Pathogenesis of congenital hyposomatotropism

Answer 5

cyst formation of the anterior pituitary lobe causing decreased GH -> decreased TSH –> decreased T4

Question 6

What does decreased T4 result in

Answer 6

secondary hypothyroidism

Question 7

Predisposed to congenital hyposomatotropism

Answer 7

g. shepherd
karelian bear dogs

Question 8

Clinical signs of congenital hyposomatotropism

Answer 8

Poor growth in puppies
retention of lanugo
alopecia
thin skin
hyperpigmentation
brachygnathia inferior

after 2-3 years —— decreased activity, appetite

Question 9

Diagnosis of congenital hyposomatotropism

Answer 9

Skin biopsy - decreased elastic fibres
Insulin like growth
Xylazine - stimulation test
Clonidine - stimulation test
GHRH - stimulation tests

Question 10

Treatment of congenital hyposomatotropism

Answer 10

Bovine - GH
Porcine - GH
Human - GH
(not permanent solution) (autoantibody development)
T4 therapy

Question 11

Prognosis of congenital hyposomatotropism

Answer 11

max 5yrs
euthansia due to anorexia and renal failure

Question 12

Alopecia X

Answer 12

arrest of hair cycle
umbrella term for
- GH-responsive dermatosis
- Castration-responsive dermatosis
- Oestrogen-responsive dermatosis
- Biopsy-responsive dermatosis
- Adrenal hyperplasia-like syndrome

Question 13

Pathogenesis of Alopecia X

Answer 13

not completely understood

Question 14

Predisposition of Alopecia X

Answer 14

Nordic breeds
Poodle - fluffy breeds
Pomeranian
Chow- chow
Samoyed

Question 15

Possible causes of Alopecia X

Answer 15

increased androgen production
mild cushing’s

Question 16

Clinical signs of Alopecia X

Answer 16

Cosmetic
symmetrical non inflammatory alopecia
hyperpigmentation on neck, trunk & caudal surface of thighs

Question 17

Treatment of Alopecia X

Answer 17

Castration - testosterone therapy
Trilostane
Melatonin

Question 18

Pathogenesis of Acromegaly

Answer 18

Middle aged bitches - exogenous progestogens, mammary tumour, metoetrus, ovarian cyst
Middle/ old aged male cats - pituitary tumour

Question 19

Clinical signs of Acromegaly

Answer 19

large head
large paws
increased interdental space
distended abdomen
loose skin
snoring
dyspnoea
pupd
protruding skin

Question 20

Lab d of Acromegaly

Answer 20

Glucosuria

Question 21

Treatment of Acromegaly

Answer 21

Insulin therapy
Progestogen & agleprisone
Ovariectomy
Hypophysectomy, cobalt irradiation (cats)

Question 22

Cause of Diabetes Insipidu

Answer 22

Decreased ADH

Question 23

Cause of decreased ADH

Answer 23

Decreased Production
Decreased sensitivity

Question 24

Role of ADH

Answer 24

renal water resoprtion control
urine production & concentration

Question 25

Predisposed to Diabetes Insipidus

Answer 25

middle aged/ old bitches

Question 26

Types of Diabetes Insipidus

Answer 26

Central Nephrogenic

Question 27

Central Diabetes Insipidus

Answer 27

Most severe Partial (low ADH) or complete (no ADH) Due to; tumour of - pituitary, hypothalamic, hypophysectomy, inflammation, trauma

Question 28

Nephrogenic Diabetes Insipidus

Answer 28

Most common Impaired action of ADH on kidneys decreased sensitivity Potentially reversible Due to; kidney/ liver failure, hypercalcaemia, addison's, cushing's, pyometra

Question 29

Clinical signs of Diabetes Insipidus

Answer 29

PU/PD Dehydration death

Question 30

Diagnosis of Diabetes Insipidus

Answer 30

Blood sample abdo US cortisol measurement Urinalysis

Question 31

How to distinguish nephrogenic from central Diabetes Insipidus

Answer 31

Modified water deprivation test Desmopressin Test

Question 32

Modified water deprivation test

Answer 32

Be careful as dehydration is risky in Diabetes Insipidus patients CDI - USG >1.030 NDI - no change

Question 33

Desmopressin test

Answer 33

Give desmopressin for 7 days CDI - decreased pu/pd by day 7. increased USG NDI - minimal improvement

Question 34

Treatment of Central Diabetes Insipidus

Answer 34

Desmopressin

Question 35

Treatment of nephrogenic Diabetes Insipidus

Answer 35

decreased Na diet provide continuous source of water thiazide diuretics