Acromegaly and other Hi-Dose conditions - Here's what we know
Date: April 1, 2009 12:32PM
Acromegaly and other Hi-Dose conditions - Here's what we know
What is Acromegaly:
Acromegaly is long-term excessive secretion of growth hormone (GH) from a tumor in the pituitary gland in the brain. In cats, these tumors grow slowly and may be present for a very long time before you notice any changes in your cat. The medical term for acromegaly is hypersomatotropism. The excess growth hormone causes the liver to make another hormone called Insulin-Like Growth Factor -1 (IGF-1). It's this hormone that causes the problems seen in acromegalic cats, such as diabetes.
How Common is Acromegaly in Cats?
In a recent study, vets were asked to collect blood from diabetic cats to measure how good using IGF-1, Growth Hormone and Fructosamine levels were to diagnose acromegaly. Fructosamine and IGF-1 were determined in 184 cats with variably controlled diabetes, and GH was determined when available. Fifty nine cats (32%) had markedly high IGF-1 concentrations. Of these cats, 18 were subsequently allowed by their owners to be imaged and acromegaly was confirmed in 17 (9.2%) of those cats. This suggests acromegaly is widely underdiagnosed and therefore a lot more common than thought.
How do we spot a potential acromegalic cat? Questions we ask.
*Cats are normally flagged up as potentially not being 'normal diabetics' when they are getting higher than normal doses of insulin and/or it's proven difficult to get control over their BGs.
*Just like a 'normal' diabetic cat we think/ask the same questions of a cat's mom/dad before we think of acromegaly - basics such as appropriate diet, right insulin and doses, and hometesting need to be sorted out first. For example:
1) How long has your cat been on insulin?
2) At what insulin dose did you start?
3) How was the insulin increased and by how much, and over how long a period of time?
4) How did you determine that an increase was needed?
5) Are you home testing now, and if so, have you kept a record?
6) What food are you feeding?
*Once the more common causes of having a cat on high insulin doses have been dealt with, for example dry food, too fast dose rises, infection, etc., - then we start thinking that something else might be going on.
*Acromegalic cats typically have certain patterns or issues going on with them that act as 'red flags' to point us towards thinking 'acromegaly'. It's a collection of these issues that just aren't 'right'. We then start asking more hi-dose specific quesitons such as:
7) Have you noticed changes in the way your cat breathes? Any changes in their eye sight?
8) Have you noticed any behavioral changes in your cat? For example, appearing to be in pain, avoiding bright light.
9) Have you noticed any physical changes in your cat's appearance?
10) Has your cat had a tendency to gain weight despite no increases in amount of food you are feeding?
Link to have blood sent for IGF-1 testing:
For the USA and Canada - costs vary depending where you live:[www.animalhealth.msu.edu]
UK (free test): [www.rvc.ac.uk]
In the US - a result > 100 is considered + for acromegaly; in Great Britain a result > 1000 is positive.
It is IMPORTANT to remember - there is nothing weird or wonderful about how a high dose cat's diabetes is managed. However, we do recommend that one should NOT 'go it alone' without the support of the FDMB and catacromegaly and/or the vet in caring for these cats. Although their care follows basic common sense it also tends to involve more insulin and sometimes more frequent shot times. To get support and guidance on managing your acromegalic cat please register at:
Cat acromegaly website: [catacromegaly.com]
Some falicies about acrocats:
*They never get DKA - NOT TRUE! Several of our acrokitties have been quite ill with DKA - Jennifer's Spunky, Dale Ann's Snuggle's are just a couple of them.
*They ALWAYS have large heads, feet, bodies. - NOT TRUE - oftentimes the physical features aren't seen until much later in the disease process!
*Acromegalic cats won't suffer from hypoglycemia. No, acromegalic cat's BGs can drop to extremely low levels if the IGF-1 levels in their bodys reduce, their own insulin is working and we give them 'extra' insulin.
And if we can't get a diagnosis for a hi-dose cat?
Ultimately if a cat is on the correct diet and insulin regimen, the owner is hometesting, there are no other factors that could be causing raised BGs (infection, pain) and all lab tests have come back negative (IGF-1, Cushings, IAA etc) then it can be a case that the cat is just a hi-dose cat, plain and simple. If that's the case then giving the insulin and doses the cat needs, however large to gain control of the BGs is what needs to be done.
Some of our acrocat's stories:
Beth and Pickles, Stephanie and Pheobe, AND Lara and Paddy: [petdiabetes.wikia.com]
Carolynn and Fletcher: [carolynn.blogster.com]
Patti and Merlin: [petdiabetes.wikia.com]
*Improved Ability to Diagnose Acromegaly in Cats Reveals It May Be More Common Than We Think
*Feline Acromegaly: An Underdiagnosed Endocrinopathy?
Journal of Veterinary Internal Medicine
*"Current thinking and knowledge about FD"
Acrotracker link: [spreadsheets.google.com]
Cats with Insulin Auto Antibodies (IAA)
When insulin is injected into a diabetic cat, the body views it as a foreign substance and the immune system sets out to destroy the "invader" insulin, just as it would destroy cold and flu viruses. When this happens to injected insulin - most of it never reaches the bloodstream thus being unable to control blood glucose. Insulin doses may be increased but the immune system only goes into higher gear and continues to effectively destroy any additional injected insulin. Over time this becomes officially known as insulin resistance.
Sharyn and Fiona states: One article on humans suggests that changing insulin doesn't work. IAA is supposed to be self-limiting, meaning it goes away at some point. (See article link below) "We have a couple of anecdotal reports of kitties who, by continuing to raise the insulin doses, were able to overwhelm the antibodies, eventually lower the insulin doses and gain control of the BG's."
Currently (3/09) Sandy and Black Kitty seem to have done just that. At one point Black Kitty was needing 27 units of Lantus insulin/day. His insulin needs are now being slowly weaned and currently he is needing only 7 units/day.
Link to have blood sent for IAA testing:
A result > 20% is considered positive for IAA.
*Extreme insulin resistance (IAA)
*Beta cell and insulin antibodies in treated and untreated diabetic cats
Cushing's disease is caused by a tumor of either the pituitary or adrenal glands, causing the production of excess cortisol. Cortisol is a naturally-occurring chemical in the body, which helps the body respond to stress such as infection or pain. With Cushing's disease, however, the body continues producing cortisol even when the stressor has been removed. This causes a number of problems one of which is insulin resistant diabetes.
One particular symptom that helps differentiate this disease from acromegaly so quickly is that Cushing's causes very thin fragile skin that may tear easily and/or not heal well. Females are most often the target.
Running count of acrocats and their moms:
2004 - 1
2005 - 5
2006 - 2
2007 - 19
2008 - 16
2009 - 8 (?9)
*Unconfirmed cases (since 2006) 4
These 4 are listed as they were/are all very hi dosed cats that for various reasons could not have the acro test but it was felt that acromegaly was the probable cause of the high insulin needs.
Males = 43 Females = 12
Running count of IAA cats and their moms:
2008 - 2
Sandy and Black Kitty
Sharyn and Fiona
2009 - 1
Christina and Stormy (also + for acro)
Running count of Cushing's cats and their moms:
2008 - 1
Linda and Bear
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
ALL our acrokitties 2004-2009
Dale and Snuggles...Diana and Orion...Teresa and Olivia... Donna and Spike... Tara and Martin... Andreana and Jen...Beth and Pickles...Ralph and Snowball...Carolynn and Fletcher...Patti and Merlin... Lara and Paddy... Tobycats Momma...Stephanie and Pheobe...Kathy and Pepper...Carol and Oscar...Nina and Jaska...Lyn and George...Pilar and Big John...Jennifer and Dylan...Jacqui and Binghi... Jo and Oscar...Ellen and Antony...Anji and Charli...Ulrike and Sasha...Diana and Thomas...Jonathon and Toby...Magnus and Willi...Jennifer and Spunky...Judy and Orphan...Vanassa and China...Shelly and Callie...Phoebe and Norton...Shannon and Little Bit...Linda and Sugar...Caprice and Henrietta...Joan and Madison...Lorna and Girlcat...Jakki and Jake...Wendi and Milo...Laurie and Sammy...Doug and Thomas...Sandy and Cecil...Susan and Wilson...Libby and Sterling...Carolyn and Leo...Sarah and Dusty...Christina and Stormy... Nina and KB...Bonnie and Porscha... CD and Shadow...Dani and Lehmann...KT and Buckwheat awaiting results……
Probables: Ruthe and Smokey...Paul and Celti...Caroline and Sir...Suzie and Spook
This document was written in honor and loving memory of ALL hi dose kitties. For despite all the difficulties they face - they continue to teach their moms/dads daily, purr the loudest, and give us such unconditional love!
The above groups will be updated monthly by Patti and Merlin (always in my heart)