When does immune mediated destruction of the adrenals normally occur?
1-5 year old dogs.
What is the main problem with hyperadrenocorticism?
The loss of aldosterone. it acts on the salt balance so that the urine salt balance causes loss of fluid and dehydration. There is therefore an increase of angiotensin II in the blood with Addison's because the body is trying to correct the dehydration, but its not working on the adrenals cos they are destroyed.
Hypoadrenocoticism is mostly?
An immune mediated destruction
Hypoadrenocoticism immune mediated destruction occurs in what age and breed?
1) young to middle aged 1-5 year old, often females 2) Standard Poodles, Bearded Collies, Rottweiler's, West Highland White Terriers, German Shorthaired Pointers.
Haematology with hypoadrenocoticism might show what?
Anaemia: GI losses, Bone marrow suppression, IMHA, dehydration masks severity of this. 70% of cases are anaemic.
What does a reversed stress leucogram refer to?
Dogs that is ill will normally have a stressed leucogram= high neutrophils, eosinophils and lymphocytes low. But in Addison's it's the opposite- low neutrophils., and higher eosinophils and lymphocytes (most dogs are normal).
What kind of biochem results can you expect in Addison's?
What are some causes of high potassium and low sodium?
1) Hyperkalaemia: RBC lysis, failure to excrete 2) Hyponatraemia (metabolic condition) over hydration and massive loss
What is the sodium: potassium ratio in a dog with Addison's?
Less than 20
Is sodium : potassium ratio a diagnostic on its own?
What does hypoadrenocorticism and renal failure have in common?
1) acute episode after periodic illness 2) thin, dehydrated, may have collapsed 3) renal azotaemia (increased urea/creatinine) USG: 1.007-1.030. 4) high potassium 5) low sodium
What are the differences between renal failure and hypoadrenocoticism?
1) hAC: NA very decreased, K 90%, ca increased. USG: >1,008. no stress wbc, anaemia 2) CRF: USG: 1.008-1.002, Stress wbc, anaemia, no na or K 3) ARF: na decreased, k increased, USG: >1.030, stress wbc, no anaemia
What test can you use to diagnose Addison's?
1) ACTH stimulation test before starting therapy - no response its Addison's. 2) Could also use cortisol but cannot distinguish primary hAC from iatogenic HAC or recent steroid admin 3) aldosterone: same as cortisol
If the ACTH stimulation test come back increased its?
Stress, HAC- Cushings
How do you tx Addison's?
1) initially aggressive fluid therapy 2) if acute: hypovolaemia, sodium deficit and hyperkalaemia. 3) if chronic: minaralocoricoid replacement, glucocorticoid replacement and dietary changes
Calculate this: total fluid replacement for a dog with 10% dehydration?
2kg = 2 litres + 20 kg x 50 ml /24h = 1000 ml = 3 litter in 24 hours + any additional losses
What is maintenance fluid per day?
What fluids do you use to treat hyperkalaemia?
Saline. IV if possible. 20-60ml/kg/h for 2 hours then 4ml/kg/h.
If you don't have saline what can you give to treat hyperkalaemia?
What is a short term treatment for Addison's?
Hydrocortisone sodium succinate. Mineralocorticoid + glucocorticoid (if don't have use methylprednisolone/dexamethasone)
What do you have to monitor during acute phase Addison's?