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Posted on Sunday, Feb 24, 2002 - 9:13 pm:

I have a 25 year old TB gelding who has had a chronic infection (possible internal abscess) for the past seven months. In mid-July he had a vaccination for Potomac Horse Fever and within 36 hours was running a fever of 104. We gave Banamine to keep the fever down and he was started on Tribrissin. It was the middle of a heat wave and three days into the fever he began blowing but not sweating. I was able to keep him semi-comfortable with constant hosing of the legs and misting of the body, as well as using a stall fan. The blood test results showed a high white count (18,000) and anemia. After a week on the Tribrissin the white count went up and we changed to Naxcel. The whites went up again and after another week, we changed to Baytril. The fever stopped after the third week, but the whites went up and then down to about 17,000 and he was started on Doxycycline hyclate. In August I took him to a clinic in New Jersey where they did ultrasounds, more blood work, checked for Lyme's disease, belly taps, rectal exams, tracheal wash, etc. They only found strep in one of the cultures and a heart murmur which they ruled out as the source of the infection. He was sent home to continue on the Doxycycline (30 am and 30pm) and return in a year for another ultrasound of the heart. My vet then tried Isoniazid with the Doxycycline. My horse had a reaction to 25 am and 25 pm (totally listless, lethargic, facial twitch) and I cut him down to 5 and 5. I was supposed to take him up to 15 and 15, but we reached 10 and 10 and he got lethargic again. The whites had gone down to 14,000 but my vet said take him off everything for a week and re-check the blood work. After a week of no medicine (this was 2 weeks ago) the whites were back up to 17,000. He has now changed the antibiotic to Metroniazid and we have been on this for the past two weeks, 13 a.m. and 13 p.m. He wants to check the blood work again in another 2 weeks. He thought we might try Rifampin with Erythromycin next. I'm getting frantic! Any ideas would be greatly appreciated. Thanks.

Posted on Monday, Feb 25, 2002 - 6:31 am:

Hello Bonny,
I have one suggestion if I understand your post correctly: Quit Treating The WBC Count! Particularly mild changes like this. There are many reasons why WBC counts can change upward, including the stress of giving these medications. Also older horses with Cushings (very common at 25) may have elevated WBC counts do to their hormonal status.

You should treat fever but unless CLEARLY indicated as a bacterial infection, you use oral NSAID's not antibiotics. In your post, and as you specifically note in one situation, the medications you are using could be responsible for much of your symptomology and keep it up and you might have a antibiotic induced colitis.

Of course I cannot really prescribe treatment from my computer and if there is more to your case than what you have written I would be glad to entertain a different view, but I do not see much evidence of "chronic abscesses" from your post.
DrO

Posted on Monday, Feb 25, 2002 - 10:43 pm:

Thank you for your prompt reply! He hasn't had a fever since eary August, except for one day, a few months later and I gave him Banamine for that. Are there any special blood tests or other tests that I could ask my vet to run? I think I mentioned before that the only thing that came back on the early cultures was Strep. I've had him on One-AC for the anhyDrOsis and have been giving him B12 for the anemia. He doesn't have any of the usual clinical signs for Cushings so that was not entertained as a possible diagnosis. The highest his WBC went was at the clinic in August, where they tested it at around 24,000. Any ideas on how to get his RBC up? Thanks for your help. If there's anything else you need to know, I'd be happy to try to get the information to you. Thanks again. Bonny

Posted on Tuesday, Feb 26, 2002 - 7:41 am:

For information on anemia in horses see, Equine Diseases: Cardiovascular, Blood, and Immune System: The Diagnosis of Anemia.

Laboratory tests are funny things Bonny, they tend to find what you are looking for whether it exists or not. Tests are at their very weakest and most inaccurate when they are run to "see what is wrong". Tests are best run to confirm suspicions based on exam findings. It really is the integration of the results of a good history, good exam, and lab findings that result in a good diagnosis. If clinically your horse is normal what would you want to test for?
DrO

Posted on Sunday, Mar 3, 2002 - 7:43 am:

Dr. O. We finish the Metronidazole on Monday (tomorrow) and I guess my vet will be out to do another blood test. I will share your comments and ideas with him, and see where we go from there. I forgot to mention that in the belly taps he had (three in all) they found some blood, which they thought was unusual, but when they checked further they said there were no abnormal cells, and just let that go. (??) Another thought, is it safe to go ahead and get the usual battery of spring shots (including rabies, EWT, rhino, and this year I was going to do the West Nile for the first time)? I've never had a problem with shots before (other than a lump at the injection site with the Rhino), until I had that PHF shot and this whole thing started. Thanks in advance for your reply. Bonny & Nisquy

Posted on Monday, Mar 4, 2002 - 3:36 am:

When you stick a needle into something and you get some blood the first thing you have to think of is the needle caused the bleeding. I would wait on the shots until this thing is clearer but this is a decision between you and your vet.
DrO

Posted on Tuesday, Mar 26, 2002 - 7:06 am:

Dr. O. After finishing the Metronidazole, the vet said his whites had gone up another thousand to, I think 18,000, so he wanted to try something different. He said he would order it and get back to me. We were on no medication for two weeks and he seemed fine, except for going off his feed a little. On 3/21/02 the vet came out and brought Erythromycin (400 mg.) and Rifampin (300 mg.) and told me to start giving him the Erythromycin at 15 tablets three times a day, and Rifampin 7 tablets two times a day. Since it was late Thursday, we opted to start the medication on Friday. (I'm at work on Fridays so the barn manager gave him the medication at the prescribed dosage and on schedule.) By Saturday A.M. when I came out, he was refusing to eat all grain. He was drinking and eating hay, but I was concerned. His temperature was normal. I gave him the morning dose of meds and watched him. He developed diarrhea and I didn't give him his next round of meds, and called the vet, who was angry that I stopped the medication. He said to give him a day or so to get used to the new medication. He asked me to let his eating get back to normal, and then feed first and give meds after. It's Tuesday, and as of yesterday he had started eating a little grain, but not what you would call normal. I'm going out today and will see how he is. What I don't understand is, why didn't he take a blood test prior to giving the new medication? What is the normal dosage for these drugs? Isn't there something the horse will tolerate that can be used long-term for a chronic infection? Why does he change the medications all the time? We were doing fine on the Doxycycline, blood work almost normal at 14,000, at a dose of 30 caps a.m. and 30 p.m. Maybe there is a lower dose that would be maintenance level. I should note that we also got new hay a week ago, which is pretty green, and could be the cause of the stomach upset, but there's no way for me to know and the non-eating and diarrhea started 24 hours after starting the new meds, so I'm guessing there's a connection there. Thanks for your thoughts. I just want my normal horse back!

Posted on Tuesday, Mar 26, 2002 - 11:28 pm:

As to why your vet does the things that he does you are going to have to ask him/her. Personally I would not be chasing the WBC count with antibiotics but I have already said this.

As for the correct dosages for these two drugs see the article on Foal Pneumonia or just run a search on Rhodococcus and it should come up with the link to the article. It does not give the side effects and GI upset is one. Currently I am out of town and when I return will put together more on these two.
DrO

Posted on Saturday, Mar 30, 2002 - 9:18 pm:

Hi, Dr. O. I still haven't put him back on the antibiotics. His manure is still a bit soft, and he is eating better, but still not his usual amount. My vet said maybe we have to put him on ulcer medication. (?) In the meantime, he got a bump on his leg and I sweatted it for two days and it went down, then a week later (this past Thursday), I went to the barn and the whole area (front left, inside between tendon and bone in front) was puffy and hot. It goes down when I cold hose it, but then returns. He's not lame, but I'm concerned the scratch I found (which is by the way healed and doesn't look like much), might be the cause. If it's infected, I'm not sure what to do, since I'm adverse to putting him back on A/B's. (Normally I would do a cold hose, hand walk, sweat routine, in addition to Gentamicin for 5 days.)

Also, when his stomach got upset, I took him off all his supplements: One AC, Accel Lifetime, Probios and Cosequin. Can I put him back on these supplements without upsetting his digestive tract any further? I would think the Probios is important, although I've been giving it all along and it seemed to be working until he went off his feed and then the diarrhea showed up. Anyway, I'll close for now. If you have any further thoughts, please share then with me. Thanks much! Bonny

Posted on Sunday, Mar 31, 2002 - 10:38 am:

Usually infection will not go down with cold hosing and is almost invariably painful enough to cause lameness. But that does not mean it might not turn that way. I do not know what is in the first two supplements but I don't think the Probios and Cosequin will upset his stomach.
DrO

Posted on Wednesday, May 1, 2002 - 9:51 pm:

Hi, Dr. O. After the incident with the Rifampin and Erythromycin I took my horse off all A/B's. He has been getting a probiotic for the manure and it's back to normal as well as his eating. Of course, his white count is still up at around 17,000! Other than that, his blood test results were normal (including the rbc).

I was just reading an article on parasites and it was mentioned that a horse with encysted strongyles can go off feed, lose weight, be lethargic and perhaps have a high white count (among other symptoms that may or may not be present). They recommend a larvacidal dose of either Safeguard or Panacur (double dose for 5 days). Could it be as simple as this?

Also, the vet is coming out tomorrow to administer spring shots to the horses at our barn. I signed up for Rabies, Eastern/Western/Tetanus, and the Coggins test. I was wondering if it might be advisable to just do one shot at a time? Maybe also follow up with bute to ward off any reactions? Of course, I won't be giving him the PHF shot that started this whole mess last summer! Thanks for your help! Bonny

Posted on Friday, May 3, 2002 - 5:12 am:

Hello Bonny,
I don't remember you reporting weight loss before and the diarrhea is easily accounted for by the antibiotic regimen. For horses with chronic weight loss see, Equine Diseases: Colic and GI Diseases: Weight Loss in Horses. Encysted strongyles can be a problem if there is a history of poor parasite management (lack of treatment or unusually high exposure).

I think those two injections are pretty safe so if you have not had a reaction to them before I see no reason for extra caution until they prove themselves harmful.
DrO

Posted on Saturday, May 4, 2002 - 9:29 pm:

Hi, Dr. O.
Nisquy had just rabies and E/W/T. Got a small lump almost immediately at the site of the EWT injection and was a little "mushy" the day of the shots. (Thursday). I didn't see him Friday (was at work) but today (Saturday) he is fine. No lump. Ate everything. Seemed perfectly normal. What a relief! Next week we will do the Flu/Rhino and hopefully that will also be uneventful.

As far as the weight loss, initially last July/August when he ran the fever for 3 weeks, we took him off all grain and he only got hay and soaked beet pulp. He lost a ton of weight. Then after going back on grain, he put a lot of it back on. He's shedding out and I can see that he is still underweight. I added corn oil to his beet pulp and am trying to get him out to eat grass, but it's hard in a city barn to find any.

I asked my vet about the encysted strongyles and he said it wasn't likely since on his blood tests his EOS were always low. (I'm sure the article said that the encysted ones don't show up on normal blood work!) What's your input on this? I have him on a daily wormer (Strongid C), but the article I read (www.StarwoodFarm.com) said even missing one day of the daily wormer can open the door for an infestation!

Anyway, I'm leaning toward trying the worming, just in case.

Have a good weekend. Many thanks for your great advice! This site is truly invaluable!

Bonny and Nisquy, NYC

Posted on Saturday, May 11, 2002 - 7:19 pm:

Just wondering what happened...I never got a response to my last post on 5/4/02. I haven't done the worming for encysted strongyles yet. I wonder if I should go the safe route and do Zimecterin first, then wait a month, then do the larvacidal dose of Panacur? Would three days be long enough, or do you have to do five days?

We made it through the vaccinations without a problem other than a small lump from the Flu/Rhino shot as well as the prior small lump from the E/W/T shot.

I'm considering a move to pasture for the summer and have started grazing him for 15-20 minutes to get him used to eating grass. (We've been in a city barn for years.) I'm also hoping it will round out his posterior a bit! Hope to hear from you. Thanks. Bonny & Nisquy in New York City

Posted on Sunday, May 12, 2002 - 8:05 am:

I missed your question in the last post. Elevated eos are an inconsistant sign of parasitism in my experience but it is something we are all taught. I would follow the package instructions as they are designed for the dosage in the tube. And unless the horse has a history of poor deworming pretreatment should not be essential.
DrO
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