Questions About Thyroid Medicine

[GreytMaxsMom]

The vet put my youngest greyhound on .8 mg of Thyroxine twice a day for two weeks and now once a day. I have noticed that his hair is growing back, but I am also noticing some weight loss. Is this common?

 

Ike was a skinny boy to begin with and now his ribs are more pronounced. Should I be concerned or am I overreacting?

 

Thanks for your suggestions!

Mindy

[Batmom]

Did he have a full thyroid panel or just a T4 test? How old is he? What was the reason for putting him on the med?

[GreytMaxsMom]

Did he have a full thyroid panel or just a T4 test? How old is he? What was the reason for putting him on the med?

He just had a blood test. They checked his T3 and T4. One was in normal range and one was .4 with normal being between 1-4. He will be 4 on July 31st. We got his brother back as a return and they found he had thyroid problems. So we got to thinking that maybe with his hair loss maybe he had a thyroid problem also.

 

Thanks,

Mindy

[Batmom]

Quit the thyroid medication, wait 8 weeks, and do a full thyroid panel from MSU if he has symptoms other than hair loss.

 

Greyhounds are poor hair growers to begin with, and this time of year some of them are starting The Great Spring Shed.

 

 

 

ETA: Here is a whole bunch of info about thyroid testing and thyroid hormone concentrations: http://www.animalhealth.msu.edu/FAQ/Endocr...d_Canine.php#10

[RobinM]

That's still pretty in range. What type of symtoms was he having that led you to believe he was hypothyroid.

 

Chloe is hypothyroid- her T4 is 0.2 and I forgot what the others were, but they were off the charts low as well. Lack of hair is not necessarily a symtom of hypothyroidism. Chloe's littermate sister is not hypothyroid in the least. It doesn't have to run in families.

 

My Teddy has a lot more hair loss than Chloe. He is not hypothyroid.

[KF_in_Georgia]

Dogs with hypothyroidism often are a bit overweight. Both my dogs are on thyroxine. When one or the other has an unexplained weight gain, I get their thyroids checked again. (If both gain weight, I'm overfeeding.) It took a while to get Jacey's thyroid output stabilized, and when we did, she dropped the 6+ pounds she had put on.

 

So--to your original question--a weight loss on thyroid meds is not unexpected and is not a sign of a problem.

 

ETA: And please check with your vet before you stop the pills.

Edited February 16, 2009 by KF_in_Georgia

[greysmom]

I disagree in part with KF above. Weight loss can be a sign of HYPERthyroid (too much hormone replacement). Your grey's readings were within normal greyhound limits, and unless there were other symptoms than hairloss, I would seriously discuss using the Rx with my vet.

 

Dude was on thyroid when he came to us (same dosage as yours), and we just automatically continued it for several years until I started reading on GT about greyhounds and thyroid issues. He has always been super skinny, super hyper, unable to concentrate on training, and his body temperature always ran a degree or two higher (though not above normal). His ears never got cold even outside in the dead of winter.

 

So we talked to our vet and ended taking him off his meds. He's gained a normal amount of weight and doesn't look skinny anymore. He is MUCH calmer and can actually stand still of several seconds in a row when we work on obedience. His average body temperature has dropped by a full degree and his ears get cold!

 

Good luck!

greysmom

[KF_in_Georgia]

Isn't ".4" just below normal--even for greyhounds?

[Batmom]

Read thru the info I linked in my previous post. Greyhounds can have a T4 of zero and be normal. T4 isn't a good diagnostic test.

 

And greysmom is right. Putting a skinny dog with some hairloss on thyroid meds without thorough testing is ... odd.

[GeorgeofNE]

My understanding is that thyroid problems are WILDLY over diagnosed in Greyhounds by well meaning vets not that familiar with their idiosyncracies.

 

We have a lot of hounds here in MA (two tracks), so most of them have at least some Greyhound patients, but in other parts of the country, I'm not so sure.

 

I know my mixed breed had a thyroid problem--very obvious and very sudden--and once he got on the proper medication dose you never would have known he had a problem. His coat returned to its normal state--he never did have weight issues because the coat was so obvious I got him in right away.

 

As I recall, there was very frequent testing at the beginning to get the right dose, then every six months thereafter.

[Guest LokisMom]

Read thru the info I linked in my previous post. Greyhounds can have a T4 of zero and be normal. T4 isn't a good diagnostic test.

 

And greysmom is right. Putting a skinny dog with some hairloss on thyroid meds without thorough testing is ... odd.

 

Our Cole came to us already on thyroid meds. He was skinny, shaky, drank excessively, etc, very similar to the post above. He was initially put on thyroid medicine just for hair loss. Given that he was not (or barely) hypothyroid, the amount of meds made him hyperthyroid.

 

I would get a full test and I would not treat without symptoms. I also would not count just hair loss as a symptom.

 

 

[KF_in_Georgia]

My Sam was diagnosed hypothyroid at the age of 3--based on a low T4 and hair loss. Neither the vet nor I were concerned with his seasonal shedding, nor even with his bald-ish butt. However, Sam lost all the hair on his throat in a one-month period. No new collar--and it couldn't be collar wear since the loss extended way up under his chin, where his collar rarely goes. Sam's condition was pretty much what MSU mentions in step #10: the vet considered that his rapid and unusual hair loss was enough of a "clinical presentation" to justify a trial test--even without elevated TSH.

 

My vet put Sam on a starting dose of thyroxine and had us come back in six weeks (exactly what MSU recommends). The levels in the new T4 were in the right range for greyhounds (on thyroxine, Sam consistently registers just slightly below the mid-point for greyhounds), and the missing hair on Sam's throat was growing back. Sam's been on thyroxine ever since (more than 5 years), and he gets a new T4 once or twice a year, depending on what else is going on with him.

 

The original post doesn't mention where Ike's hairloss occurred. It's possible that Ike's vet is not being misled by seasonal hairloss or the greyhound's common occurrence of baldbutt, but is reacting to patterned losses that correspond to hypothyroid symptoms. If so, it sounds like the vet may be following MSU's own recommended protocol: "An objective case review should be conducted after 6-8 weeks of therapy for evidence of clinical improvement. Thyroid supplementation can be discontinued if no improvement has occurred in that time, and the diagnosis reconsidered."

 

Edited to fix wonky grammar.

Edited February 16, 2009 by KF_in_Georgia

[Burpdog]

16. Do some breeds of dogs have thyroid hormone reference ranges that differ from the general dog population?

 

Sighthounds (Greyhounds, Salukis, Afghan hounds, Whippets, Borzois, Irish Wolfhounds, Pharoah hounds, Ibizan hounds, etc.) have lower TT4 and FT4 reference ranges although these are generally not published. In some case studies, the TT4 reference range extends to zero. As such, a dog with hypothyroidism cannot be differentiated from a normal dog using T4 tests alone. Fortunately, general canine population ranges for TSH appear to apply well to these breeds. Thus a sighthound with low TT4 and FT4 concentrations, but with a normal TSH concentration, is unlikely to be hypothyroid and does not require thyroid supplementation.

 

Note it says in some cases and does not mention greyhounds in this statement particularily.

 

If I had a 4 or 5 year old with a low T4, I would do more testing. I also would not test for at least 6 months off the track.

 

Also keep in mind that some dogs are put on thyroid for breeding and enhanced performance, and if left on supplementation long enough, they will have a thyroid insuffiency as the supplements knock out the thyroid.

 

Bald thighs is not reason enough to suspect a low thyroid.

 

Dogs whose thyroids are not working (be it too much or too little) can lose weight.

 

Mindy: how did they diagnose the brother? Was a full panel done?

 

You can literally kill a dog with thyroid meds if they are not needed and the dose is high enough.

[GreytMaxsMom]

We have had Ike since he was 4 months old. He has hair loss on his behind, stomach, chest, and under his chin. He was beginning to lose the hair around his ears. He has always had somewhat of a bald butt, but the additional hair loss was noticed within the last year.

 

I am not sure if a full panel was done with his brother, but he scored in the same range as Ike. We go back in two weeks for a blood check and if the weight loss continue it will be sooner.

 

Burpdog- where did you find this information?

 

Thanks for all the information.

Mindy

 

[Burpdog]

What I quoted is from Batmom's reference link.

 

I had a grey that needed thyroid and gained weight when put on it.

 

My friend's Dobe was almost killed by thyroid supplements because he did not need it. Made him very sick and she got him back just in time.

 

I'd get him off the thyroid then do a full panel.

 

The thyroid is the engine for the body. Mess with it, and you can really mess up the whole dog

[Batmom]

He has hair loss on his behind, stomach, chest, and under his chin. He was beginning to lose the hair around his ears. He has always had somewhat of a bald butt, but the additional hair loss was noticed within the last year.

 

Sounds like my Joseph :lol ... who has a normal T4 (he's actually been within range for normal dogs, not even talking greyhounds).

 

All of those are areas where greyhounds tend to have thin hair and/or baldness, and those things tend to fluctuate around the change of seasons. Sometimes greyhound hair loss may seem to be out of sync with weather changes. Joseph, for example, has started the spring shed. Not coming out in handfulls yet, but it's definitely coming out. Zema hasn't started yet; she will normally have a totally bald butt in early fall, just when you'd think she should be fuzzing up for winter.

 

As Burpdog notes, occasionally a hypothyroid dog turns up who loses weight until medicated, but more commonly a hypothyroid dog will be plump, lethargic, gaining weight on very little food.

 

One of the things that I -- and MSU (the link) and other vets -- don't like about T4 is, it can fluctuate. A lot. From hour to hour and from day to day. I've had the occasion to have comprehensive bloodwork on dogs on consecutive days, and a time or two we've gotten things like .2 T4 one day, 1.8 the next, etc. Just not a useful diagnostic tool.

 

Hugs and best luck with your pupper.

[Guest ibeakila]

The vet put my youngest greyhound on .8 mg of Thyroxine twice a day for two weeks and now once a day. I have noticed that his hair is growing back, but I am also noticing some weight loss. Is this common?

 

Ike was a skinny boy to begin with and now his ribs are more pronounced. Should I be concerned or am I overreacting?

 

Thanks for your suggestions!

Mindy

 

 

Thats funny because my diabetic boy, named Ibe, is also on thyroid,8 mg and his weight fluctuates but the hair has grown back, very thick, he is on it for life morning and night

[KF_in_Georgia]

In case your vet's office didn't mention it: When you take Ike in for a T4, he normally should have his regular thyroid meds--with food--about 4 to 6 hours before the blood will be drawn.

 

At my house, if the dogs are getting blood work at 9 am on my day off, I've been known to get up at 4:30, give everyone pills and breakfast, then go back to bed and sleep till a more reasonable hour.

 

In fact, I now do this for all our routine visits, just in case the vet spots something that warrants blood work, even though it wasn't on the schedule.

[RobinM]

 

 

print out and keep for yourself

 

http://greythealth.com/hypothyroid.htm

 

 

http://www.greyhound-data.com/dir/445/Grey...alth_Packet.pdf

 

 

http://www.greyhound-data.com/dir/446/Maki..._Greyhounds.pdf

 

 

 

 

[cmc333]

We have two greys. Sarge, our boy, tested (full panel) low. He exhibits NO symptoms, so we do not have him on rxs. Gypsy tested low normal, but had all the symptoms of low thyroid: lethargy, gaining weight on a very specific low diet, hair coming out all over (and having skin infection).

 

We put her on .6 thyroid and in time, she changed 180 degrees. She will play with the other girls,has plenty of energy (for a grey), her coat is gorgeous sleek black, she looks good on her feeding amount. So we test her every 6 months and her levels are pretty....well, level. They are right in mid-range. She takes .6 once a day; we had her on .6 twice a day, but found we could go with just one a day.

 

It does get confusing as to when to treat/not to treat. If hair was the only symptom, I wouldn't treat w/o a full thyroid panel.

 

Connie