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  Discussion on Atrial Fibrillation following injection with radioactive isotope
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Member:
judyhens

Posted on Tuesday, Mar 3, 2009 - 11:34 pm:

Our stallion with the continued shoulder lameness went back to A & M for a routine follow-up scan of his shoulder (it still shows a hot spot). The vet called us shortly after noon today with pretty horrifying news. We had left him yesterday and he was fine. This morning he was scheduled for the scan mid-morning. They injected the radioactive isotope. Within 35 minutes he was covered with hives, started trembling, and developed an irregular heartrate. They immediately transferred him to ICU where his EKG is constantly monitored. He still had atrial fibrillation at 5:00 PM. They feel it was a severe allergic reaction to the isotope. However, they had never seen this reaction in any other horse. It is my understanding that they called a specialist in Ca. who only knew of one other allergic reaction to this substance. The vet said that if you just looked at Magico, that he looked pretty normal. Eating hay and apparently no longer trembling or covered with hives. She said they were treating the symptoms and supporting him and he was being watched 24/7. Apparently they could not do the blood work they need to do to assess possible heart damage because he is still radioactive. Unless he is totally back to normal tomorrow they are planning to have a cardiologist assess him. I believe a team of vets is working with him. I was given several names and the attending's cell so that we can stay in touch. They are also communicating with our private vet.

Have you ever heard of such an immediate and serious reaction to a radioactive isotope? Prognosis? We love this horse with all our heart and soul and are praying hard for his full recovery. It's terrible to take a healthy, happy horse for a routine test and suddenly be fighting for his life.

Any light that could be shed on this would be helpful. Your thoughts and prayers are greatly needed and appreciated.

Judy
Member:
hollyw

Posted on Wednesday, Mar 4, 2009 - 12:25 am:

So sorry to hear of Magico's reaction and AF, Judy. Glad he is looking better and that he has so many experts monitoring him. Maybe his reaction will actually help the vets help other horses who have to undergo similar tests.

Take heart. He's in God's Hands.
Member:
mrose

Posted on Wednesday, Mar 4, 2009 - 12:58 am:

Hi Judy,
I'm so sorry to hear of Magico's problems. Our stallion had reaction to something, still not sure what, that caused hives all over, and swelling in his legs and testicles. That was scarey enough. I can't imagine what you're going through with this. Texas A&M is a great place with excellent doctors and state of the art equipment. I'm sure he will get the very best care possible.

I'll be thinking of you and praying for Magico. He is obviously a wonderful, exceptional stallion. I've looked at his pictures on your site; no wonder you love him so much! I certainly wish you the best. It's encouraging at least that he seems to be improving. Poor boy. Keep us posted please.
Moderator:
DrO

Posted on Wednesday, Mar 4, 2009 - 5:55 am:

Hello Judy,
I am sorry to hear about your horse. I agree it sounds like a immediate hypersensitivity immune reaction known as anaphylaxis.

Don't let the fact that it is radioactive throw off your understanding of what is happening. It is not the radioactivity that causes the reaction it is the chemistry, more importantly the shape of the molecules that stimulates the immune system.

Giving a prognosis for your horse requires an examination but in general once stabilized the prognosis of for such reactions is good.
DrO
Member:
canter

Posted on Wednesday, Mar 4, 2009 - 7:18 am:

Judy, what a shocker for you! I'll be thinking of Magico and will keep my fingers crossed that he makes a 100% recovery.
Member:
judyhens

Posted on Wednesday, Mar 4, 2009 - 9:13 am:

Thanks for everyone's input, thoughts, and prayers. Your support means a lot to us! Magico has had this test once before, without problems. Perhaps it sensitized him???

They haven't called yet this morning. The primary vet said they would make rounds and look at the lab work and then call. But she did say that they would call immediately if he took a turn for the worse....So I have to assume that no news is reasonably good news!

My husband had surgery in Austin yesterday for a torn rotator cuff. Hopefully they will release him today. It is really tough for both of us. Not only are we dealing with post-op pain and rehab for my two legged honey, but we both want to drive to see our boy and can't.

Will keep you posted. Again, you are so appreciated!

Judy
Member:
dres

Posted on Wednesday, Mar 4, 2009 - 10:23 am:

I am sure your horse is in good hands...

On the first day God created horses, on the second day he painted them with spots..
Member:
judyhens

Posted on Wednesday, Mar 4, 2009 - 7:50 pm:

Update: I received a call from the vet at A & M this afternoon. Magico is continuing to improve re: arrythmia. They did have a cardiology consult with echo. The heart itself is perfectly normal. The cardiologist feels that there is no underlying pathology. The enzyme test results are not back which will show if the reaction caused any heart muscle damage. Hopefully it didn't. Praise the Lord. He recommended stopping all the cardiac drugs they put him on when this happened. If the arrythmia gets worse, they will restart them, then wean him off gradually. The vet said he was still lethargic which she thinks results from him still being worn out and not feeling back to normal, or from some of the drugs they used to stabilize him - which also included Valium. She feels that he should recover once all the meds are out of him.

She also said that we were very, very fortunate that this happened at A & M rather than an outlying clinic. And that he should never receive a radioactive isotope for a bone scan again. Now I am worried about what might happen if he got injured when we were out of the country or something and someone, not knowing the history ordered a bone scan. Is there a "Medic Alert" system for horses?

Thanks again for your thoughts and prayers.
Judy
Member:
lilo

Posted on Wednesday, Mar 4, 2009 - 8:12 pm:

Good news. I hope Magico continues to improve. There should be something like a "Medic Alert" for horses.
Lilo
Member:
mrose

Posted on Wednesday, Mar 4, 2009 - 8:24 pm:

I'm so glad he's continuing to improve! I know an experience like he had would take a lot out of him (anyone, animal or human.) I'd expect it to take him awhile to get back to normal.

Medic Alert would be a great idea. You know those "Medic Alert" braclets and "dog tags" for people? They come blank so you can have inscribed information on it. Get one of those and have it inscribed with the allergy info and attach it onto his halter. A cheaper thing would be to get the metal dog tags they sell at the vets and the feed stores and get one inscribed. Excellent idea!
Member:
canter

Posted on Thursday, Mar 5, 2009 - 7:26 am:

Judy, do you keep charts/records on each horse at their stalls? If so, for Magico, write the medical alert in big bold letters at the top of his chart...always. I would also recommend you ask your regular vet(s) to add the allergic reaction to his records and obviously, any caretaker needs to be alerted when you are going away.

One of my cats, several years back, had a horrible reaction to one particular antibiotic, resulting in a midnight emergency run to the vet. It was flagged in his medical records, and any time he's had to receive an antibiotic since then, I always double check to ensure that it's not the one that nearly shortened his life.

I'm very glad Magico continues to improve!
Member:
frances

Posted on Thursday, Mar 5, 2009 - 8:54 am:

That's such good news, Judy. Here's hoping for a negative on heart muscle damage, and that he perks up once his system is clear.

What a lovely looking horse.
Member:
judyhens

Posted on Thursday, Mar 5, 2009 - 1:47 pm:

Praise the Lord!!! The vet just called and Magico's heartrate normalized completely, off all cardiac drugs, during the night last night. She said the only residual now is some continued itching from the hives. I think they are gone, but he is still a little itchy. He can come home tomorrow. They still saw a hot spot on the shoulder and x-rays show some reactive bone development (I think that is what she said....) They will assess him this afternoon re: lameness and possible treatments.

Fran, the vet seconded your suggestions. The vet said that it was critically important that Magico never receive this radioactive isotope again. It could potentially kill him. She recommends putting a sign on his pasture gate and even going so far as to put one of the mare breeding neckbands on him alerting everyone that he has a potentially lethal allergy if we are gone and he is in the care of someone who isn't thoroughly familiar with this situation. She also said to contact all the area vets that treat our horses and make them aware of the situation.

Does anyone know in what situations, besides bone scans, radioactive isotopes might be used?

Thanks again for your support and ideas. Each of you is soooo appreciated!
Judy
Moderator:
DrO

Posted on Thursday, Mar 5, 2009 - 6:50 pm:

Judy, I am sorry to complicate this concern of yours but to be accurate in may not be the radioisotope but could be any of the other chemicals within the particular injection given your horse like stabilizers or preservatives in the injection. If it is the radioisotope it will likely be only the one used in this injection and not other types of radioisotopes.

To answer your question directly, radioisotopes are only used for imaging in the horse though it may be to image soft tissue structures also.
DrO
Member:
judyhens

Posted on Saturday, Mar 7, 2009 - 2:55 pm:

RE: shoulder lameness: Magico came home yesterday and seems to be walking much more comfortably after the rt. elbow was injected with hyaluronic acid, amikacin, and vetalog. He was also given Bute just prior to discharge. We have not routinely given him any medication. The current game plan is to continue with A & M's recommendations and get a second opinion. As I think 3 of your suggested, we did contact Dr. Wayne McIlwraith in Ft. Collins, Co. He has agreed to review the CD with all Magico's previous and current ultrasounds, bone scans, and x-rays. A & M recommends the Magico take Bute for 10 days (5 days – 2 gms./day; 5 days 1 gm/day) and be given Adequan IM 1 X week for the next month, then every other week. He is to rest for 2 weeks prior to riding. He has not been ridden for 12 months, so we clearly need instruction on conditioning. I will look up your conditioning info. Their impression: “Enthesophyte of the Medial Collateral Ligament of the right elbow joint, Cardiac Arrhythmia (presumed anaphylactic reaction to the radioisotope used for bone scan which was technicium)”. On a positive note, they stated that the bone scan showed that the uptake was notably less on current images than those made on March 26, ’08, but were still abnormally intense and that the enthesiophyte seen on the medial aspect of the radius does not appear to be progressive. However, there is now evidence of mild osteoarthritis of the right elbow joint. For a 12 year old stallion who has been competitive in dressage, hunt seat, western pleasure, and halter work, do you often see this? Any other suggestions????

Re: Anaphylactic Shock - In reading the info, he really did come close to death I think. They say that: "On presentation, Magico was bright alert and responsive... Cardiothoracic auscultation yielded a normal, synchronous rate with no detectable abnormalities...Technetium (phosphate bound isotope) was injected in preparation for the bone scan. About 20 minutes after injection, Magico was noted to be severely depressed and unstable. Severe muscle fasiculations, urticaria, and tachycardia with an irregular rhythm was noted. EKG revealed a ventricular tachycardia with VPC and occasional R on T waves. The stallion was taken to the ICU...Treatment with Magnesium Sulfate was initiated and the ventricular tachy converted to an Atrial Fibrillation....Magico again converted into a ventricular tachycardia later in the afternoon. Treatment with magnesium in addition to lidocaine was initiated. Shortly after initiating the lidocaine, Magico showed signs of seizure like activity. The lidocaine was discontinued and procainamide...administered as a continuous rate infusion. The heart rhythm stabilized and a normal sinus rhythm was noted....An echocardiogram was performed by cardiology service. No abnormalities were noted. The medications were discontinued and a normal sinus rhythm was maintained. Magico was bight and alert, with a good appetite and otherwise normal vital signs....Based on recent events, MAGICO SHOULD NOT BE BONE SCANNED AGAIN."

Now, Dr. O., you have not really complicated my concern. Just want to know all the possible things that we need to watch for in this horse re: future testing. We will clearly have to devise some medic alert system any time we are not home.

On a very positive note, Magico is happy, wanting to be scratched, enjoying carrots, and playful...i.e, he is back to normal!!!!!!

Thanks for everyone's thoughts, prayers, and suggestions! You are appreciated!
Judy
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Moderator:
DrO

Posted on Saturday, Mar 7, 2009 - 7:15 pm:

I think the treatments you have instituted about cover the gamut for possible DJD of the shoulder Judy, for more on this see the Overview Article on Arthritis. Let us know what Dr McIlwraith says and thanks for keeping us appraised.
DrO
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