Normal Greyhound Thyroid Levels?

[Guest Fasave]

My boy Tucker is 5 and he's been with me for 1.5 years. In April he was diagnosed with Leproid Granulomas and as part of the diagnostic testing they did a full Thyroid Panel. His T4 came back at less than .5 and noted as low but also a note about the greyhound range. His free T4 came back in the normal range but also said insignificant quantity to verify. Neither my vet or the lab seemed concerned. Tucker has become increasingly aggressive in the last few weeks and we've had two rather scary incidents in the last 24 hours. He is scheduled for an annual this month and thinking I should probably re-run the thyroid panel but can't seem to find my notes on what is considered a "normal" low for greyhounds. I'm thinking it is more likely behavioral as he continues to settle into retirement. He is a very confident greyhound and has always been a little bit of a punk but want to rule out medical first. Any information would be appreciated.

 

Thanks!

[MaryJane]

Lucy also came up with similar results with the Total T4 <0.5 and everything else relatively normal. In her case, her seizures were escalating and since low thyroid could be the cause, we started thyroid meds. We started on a higher dose of thyroid meds then I would have liked but, she is going to get checked in about a week or so and we'll reconfirm the dose. Also, we had thyroid tests from before on her and she was in the normal range back then, so this set of blood work was different.

 

You mentioned aggression and two scary incidents - can you explain a bit more. As some people have noted on the forum, low thyroid can cause aggressive tendencies - I haven't seen anything different in Lucy but, she's always been a .... diva ... and does not hesitate to put me or the boys in place so she does have her triggers ....

[Batmom]

Actually, low thyroid isn't thought to be a cause of or to correlate with aggression. Dogs with low thyroid are LESS likely to be aggressive. Been studied a couple of times. Don't know why the myth persists.

 

A T4, TT4, even fT4 can be zero and the dog can be normal. For purposes of "should I do a full panel?" you'd want to see some symptoms indicative of thyroid problem (lethargy, cold intolerance, weight gain on very little food, exercise intolerance) and you'd want to see a T4/TT4/fT4 well below normal range. Many people feel that @ 1/2 the low end of all-breed normal is probably normal for a greyhound. If the greyhounds T4/TT4/fT4 is in normal range for all breeds (or for greyhounds if your lab has the specific range), that would indicate that the dog's thyroid gland is currently doing its job and there wouldn't be any point in doing the full panel.

 

 

 

 

ETA: You can't really look at a specific number because all labs are different -- different equipment, different normal ranges, etc. You can only look at what your number is in comparison to your lab's normal range.

Edited August 12, 2013 by Batmom

[seeh2o]

Link to Dr. Stack's information on thyroid.

[Guest Fasave]

Thank you for the information. He's not symptomatic. Good energy, good coat, good appetite. Interesting that Dr Stacks info says thyroid could be low if fighting a disease which he was at the time. I'll discuss with my vet. Just wanted to double check medically that his behavior isn't be driven by the fact that he might not be feeling well. Thyroid just showed up when I reviewed his last lab work. Thanks everyone.

[kudzu]

Maybe run a check for TBDs, especially Lyme. There are incidents of seizures manifesting as aggression. And then, just to make matters more confusing, there could be a link between Lyme & seizures.

 

If the fT4 is showing ok for a Grey, neither your vet or lab is worried, then looking for other causing might be a better use of your time, energy & money.

[macoduck]

Fasave, I couldn't PM you. Can you contact me at macoduck @ ec.rr. com

[Batmom]

If you feel further study is warranted, if you believe he could have or has other illness, you'd need a fT4ed (free T4 by equilibrium dialysis) and TSH to properly assess his thyroid function. There are some alternative testing methods that one or two commercial labs are trying to popularize; they can be misleading, particularly when the dog is ill with something else or on certain medications (phenobarbital is one).