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Posted on Sunday, Jun 20, 1999 - 7:42 pm:

Hello, I have a 3 yr old filly that has been running a constant fever for nearly two months. At the onset, she had edemma in the hind legs. She has been anorexic this entire time and lost 125 lbs. CBC/SMAC showed slight elevations in muscle enzymes and elevated white count with slight anemia. Her gums are slightly jaundiced. Initially she received 30cc PenG 2x day for five days and the fever broke. Within ten days the fever returned and was high as 106. At this time we started back the PenG (same dose)for seven days with no success. Then added 30cc Gentocin 2x daily with the PenG. Still no effect. Then she started Tribrissen 960mg 9 tablets 2x daily and fever rose to 104 so discontinued. We will pull more blood Monday. Vet wants to do another Coggins although test in Dec. was negative. Should this worry me for EIA? How long can this go on without knowing what is causing this? How common is this and do you know of any cases that escalated to more severe symptoms ie colic laminitis or death? I appreciate any info and advice. Marilyn Tuffcowboy@aol.com

Posted on Sunday, Jun 20, 1999 - 8:04 pm:

dear tuff in response have u cosidered bringing your filly to a hospital for further observation and testing your horse should be scoped and cultures taken to identify all known viruses i believe your vet is crap shooting i had a problem simular to yours and i was killing one germ with an antibiiotic and i had 4 germs so i was making more room for the more severe strains hence my filly got sicker when i finally scooped her i was able to identfy all four and the lab was able to recommend antibiotic that worked on all 4 i think u should consider this option your horse deserves better diagnostics sincerely fastfoe

Posted on Monday, Jun 21, 1999 - 8:03 am:

Hello Marilyn and Janet
Lets see, Janet, remember you cannot treat viruses with antibiotics.

Persistent fever of unknown origin can be a diagnostic dilemma but when combined with a CBC indicative of infection usually comes from one of these sources:
liver disease,
cancer,
viruses: particularly EIA and the encephalitis viruses,
large populations of encysted strongyles (worm larvae) in the intestines,
internal abscess or other chronic infection.
However autoimmune diseases, poisons, and even most of the antibiotics available to the equine vet can cause fever.

Yes, I think the EIA is a valid concern, when horses initially become ill they are always negative and it takes time to build a detectable titer, 30 days I believe, so this is a possibility, how likely depends on how endemic the problem is in your area.

I am assuming that repeated careful physical exams has not helped localize or better define this disease. Am I correct? The number of possibilities is so large that without defining a organ system involved or a disease process the rule out list is too ungainly. In your case inflammation seems to be part of the process, but remember it can be secondary. Some of the tests that may help you further define the disease is:

Required:
Rectal exam
Abdominal tap
Urinalysis
Blood exam for parasites and culture
Fecal exam and culture
Serology, minimum is for EIA and encephalitis viruses but other diseases should be considered.

If initial exam and lab implicate or process remains undiagnosed:
Scoping of the upper respiratory tract
Transtracheal washes
Electrophoresis of serum proteins
Liver Ultrasound and Biopsy
Kidney Ultrasound and Biopsy
Rectal Biopsy
Ultrasonography of the heart and chest

Search for possible plants and poisons:
Chronic ionophore (cattle growth promoters) exposure in feed
Blister beetles
Selenium
Arsenic
Mercury
Pyrrolizidine alkaloid containing plants including algae
Algae
Castor bean
Water hemlock
Jimson weed
Mycotoxins

If after all this the problem remains undiagnosed, suspect CNS disease and consider tap for CSF. I know the list seems daunting, it is amazing how often repeated thorough exams turn up the cause as small changes become detected with gained familiarity with the horse.

Sometimes antibiotics that are not curing the disease but causing it to smolder, hinder the diagnosis. This is particularly true when cultures are being run. Talk to your vet about treating for tapes and encysted strongyles and whether in your case it makes sense. Usually diarrhea or colic will be present with this problem but fever and weight loss could be consistant. Good Luck and keep us informed.
DrO

Posted on Monday, Jun 21, 1999 - 9:16 pm:

Today we pulled more blood for CBC/SMAC/EIA. Rectal palpation was normal. Very very slight rattle in right lung. Fever went to 105 today, so I broke down and gave 3cc banamine IV. Filly was not eating or drinking prior to injection, so I was really worrying. Vet had wanted her to go without any meds since Saturday, but I just couldnt let her suffer as her respirations were high too. So next step depending on bloodwork is the transtracheal wash. Question, does Calf Manna have the ionophores? She started this supplement one month prior to onset. Also, at that time we started using the CDS Pouron insecticide (concentrate permectrin), but only as directed no more that 15cc per horse per week and no one else showed any signs they were having a problem even a weanling. I am just trying to figure out what has happened to her. Maybe its something I have exposed her to. Anyway, I am not using the permectrin anymore on her and if you think I should delete the manna from her diet, please just say so. By the way, we are located in Sarasota, Florida where we have lots of pests, but we religiously vaccinate every six months for encephalitis. Thanks for your input.
Marilyn

Posted on Tuesday, Jun 22, 1999 - 7:38 am:

Marilyn,
No the calf manna will not have the ionophore and I would not worry about permectrin used according to the label.

Gadzooks!..is it possible that your horse is a nonsweater (anhiDrOsis) and cannot regulate body temperature? With you being in southern FL and it being summer...your statement about fast respirations got me thinking.

Fever and hyperthermia are very different although in both cases the body temperature is above normal. Hyperthermia is the result of a horse producing more calories of heat than it can dissipate with all it's cooling mechanisims running full, we would call it overheating. In fever the body is trying to raise its core temperature and in the other the body is trying to lower it. You stated that your horse had rapid respirations and this is one of the ways the body lowers it's temp. What do you think? Do you notice the problem is worse during the hottest part of the day? Could a fan, a water mister, and a cool barn solve your problems?
DrO

Posted on Tuesday, Jun 22, 1999 - 1:22 pm:

Dr. O I wish that was her problem. But I dont think so, she has always sweated more than adequately. Unless it came up very recently. Of course, we havent used her for two months now. This past weekend, when I was instructed not to give any bute or banamine, she poured sweat with her temp at 103 so I installed a box fan directly in front of her, even though we have ceiling fans in all the stalls, within an hour the temp was down to 102.3, So this did help her some and also I have her on electrolytes also. I will have all bloodtest results except EIA tomorrow and will repost then. Thanks so much for your time and input, it has helped me to remain patient and relieved some stress. Marilyn

Posted on Wednesday, Jun 23, 1999 - 7:39 am:

You know Marilyn your message continues to make me unsure, animals with fevers do not pour sweat but animals trying to get their temperature down do. If the humidity is approaching 100% even a light sweat may look like a downpour because it cannot evaporate.

Think about it: when you develop a fever you go dry and get chills and goose bumps, it is not till the fever breaks that you sweat heavily as the bodies thermostat tries to lower your temperature.

AnhiDrOsis is a developmental problem probably brought on by the an inability to deal with the stress from hot, humid environments. No horse is born with this condition, it develops in environments like yours. Early in the course of the disease the sweat glands are not nonfunctional but become quickly exhausted. Over time with contined stress they irreversible atrophy.

You continue to give me clues the body wants to get its temperature down, elevated respiratory rate (with no other evidence of respiratatory disease) and sweating, but is just unable to. Just more to think about.

I know it may be a bit of a long shot but I see nothing in your posts that rules it out. Is the fever low in the early morning hours and goes up as the day progresses. Does the fever seem to be porportional to that days temperature and humidity readings? You have to take three factors into account: temperature, humidity, and wind speed. See if you see a pattern.
DrO

Posted on Wednesday, Jun 23, 1999 - 12:03 pm:

Hello, Dr. O - Her fever is usually at peak first thing in morning. The past ten days, we have had some tropical weather, many clouds and lower temps due to heavy rain. But I am going to discusss this thoroughly today with my vet, especially if all blood is pretty normal again. Temp was 104 this am and I gave 3cc banamine because she hasnt eaten any grain in two days, only a couple pounds of hay and grazing. I will repost after my vet calls. Thanks again. Marilyn

Posted on Wednesday, Jun 23, 1999 - 6:58 pm:

Okay the blood work is in and still slight anemia, high white count and now globulins elevated, so they are running further tests on the globulins and possibly start steroids this weekend. They said this is telling him she has an autoimmune deficiency. Can you better define this for me? Fecal was negative and coggins has been sent in, but wont know til next week, please say a prayer for us it is still negative. This is my 9 year old sons horse and she is so special and extra gentle. We raised her and she is really irreplaceable. Re the nonsweater, she only sweat that one day and I believe it was when her fever was on its way down when I added that extra box fan. Also, today I added some oats to her diet and she ate pretty good. So, I think she and I both feel a little better.

Posted on Thursday, Jun 24, 1999 - 6:55 am:

Hello Marilyn,
I suspect he said a autoimmune disease. This is where the immune system is attcking the body thinking it is a foreign invader. Symptoms of infection and disease of whatever system is being attacked results. What is the:
Hematocrit (maybe called PCV),
Hemoglobin,
White blood cell count and differential,
Total protein,
Globulin,
values of the blood work.
DrO

Posted on Thursday, Jun 24, 1999 - 7:47 am:

Hello,

These are the results of the blood drawn 5/24/99:

WBC 22.3
RBC 6.76
HCT 27.9 Hemotocrit?
Protein 9.4
Globulin 6.2

Also not in range:

Alk Phos 341
CK 286
AST 182
HGB 9.9
Lymphocytes 20

I wasnt able to get my hands on the test results drawn Monday, but will do so today and will repost. Many thanks again. Marilyn

Posted on Friday, Jun 25, 1999 - 1:57 pm:

Dr. O I was wondering if my fillies diet could be causing this problem. She is really eating the oats I added, so I got to thinking. About a month before all this began, I changed my horses diet to alfalfa pellets 15% protein and calf manna 25% (1/2 lb daily) with T/A and alfalfa hay. Also, our pastures were fertilized in April. Could this large amount of protein be too much for her and she just cant process it and thus cause the heat? That may sound far out, but she sure is happy to have these oats back, so I got to wondering. Marilyn

Posted on Sunday, Jun 27, 1999 - 11:22 pm:

Hello Marilyn,
We have been out of town. Though this is not likely to be diet related, it is interesting to note there is increased heat production with protein being used as energy sources. You certainly have the protein way too high. The oats ought to help get things back in shape and the calf manna discontinued (consult your vet on this). Considering the diagnostic dilemma I think it would be prudent to return any recent changes in care to the same management being used prior to the onset of the problem.

The changes in the blood work could indicate: stress or chronic inflammation from infection, allergy, autoimmune disease, or neoplasia. It is pretty nonspecific. However the electrophoresis may help diagnose some conditions. Does the 16 lymphocytes indicate a absolute number or percentage of total WBC. Is there no degeneration or left shift in the neutrophils? Still no localizing clinical signs?

Posted on Tuesday, Jun 29, 1999 - 8:25 am:

That is amazing Marilyn,
I feel the majority of horses would have been able to deal with the excessive protein without the hyperthermia and like everything in life, may be the result of a combination of factors. I have never seen a report of a situation like yours but have read several reports of large studies of horses fed excessive amounts of protein without the kind of complications you have had. Certainly your environment contributes to it but I still think that those two factors alone are not enough. So lets throw in a possible early anhyDrOsis, your horse can still sweat just not enough, and we may be getting closer to the whole picture. Of course we may be celebrating early..

It looks like they were percentages and if the population of neutrophils was mature with no toxic changes may be simply the result of stress.
DrO

Posted on Friday, Jul 2, 1999 - 7:03 am:

I don't suppose you had several cool (decrease in temperature, humidity, or increase wind speed) days and now it has turned hot again. Remember from a cooling stand point that humidity and wind speed are as important as air temperature.
DrO

Posted on Friday, Jul 2, 1999 - 3:11 pm:

Just an idea, but it helped me to isolate patters
when we were trying to figure out an elusive
problem with one of our horses... I made a logg
for the last three years of my horse, you would
probably only need a few months, of feeding,
behavior, riding, vaccinations, worming (including
products), symptoms, and any other outside
influences or other things you can think of. You
might even want to talk to people on neighboring
fence lines as they might have a tid bit to offer.
Put it all in writting and see if you can find a
pattern and let your vet look it over. That was
one of the main things that helped the Universtiy
find the problem with my mare. They were able to
match things I didn't think were significant with
a disease pattern. Just an idea, hope this all
comes into view soon for you, I know it is
frustrating when you can't find the source of the
problem.


---

Posted on Saturday, Jul 3, 1999 - 8:51 am:

Emily's idea is a good one and of course I would put on that chart: daily air temp range, humidity, wind speed, amount of sweating, respiratory rate, and daily body temperature, taken at the same time each day, preferably in the morning.

The questions about prevenitive medicine would best be answered by your vet, I would think no vaccination and yes to deworming, using ivermectin would be close to right, but let the vet decide.

The electrophoresis results should not be interpreted so strictly, as elevation in the beta range could also represent chronic infection, viral infection, and intestinal parasitism (pg 13 of Diagnositic Techniques in Horses, Taylor and Hiilyar 1997). I place no reliability in the current crop of allergic tests, blood or skin. Evaluations of them have indicated both false positives and false negatives are common place. If the correlation between several days of normal temps and a much less stressful environment this might be significant.
DrO

Posted on Sunday, Jul 4, 1999 - 11:26 am:

Hell Marilyn,
Remember the hazards of drawing quick conclusions: it tends to close your eyes to new observations and thoughts. Keep those records and update us when youy have time.
DrO
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