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  Discussion on Research Summary: Precaution about Bute Use
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Moderator:
DrO

Posted on Friday, Nov 21, 2008 - 9:03 am:

Here is another precautionary study about bute use. I think it overemphasizes the risk of clinical use as they use a dosage regimen of 4 gm per thousand pounds given at one time every 24 hours. It would be safer if this dosage was split into 2 gm bute twice daily and what is more common in clinical use..
DrO

J Am Vet Med Assoc. 2008 Nov 15;233(10):1604.
Pathophysiologic effects of phenylbutazone on the right dorsal colon in horses.

McConnico RS, Morgan TW, Williams CC, Hubert JD, Moore RM.

Objective-To determine pathophysiologic effects of phenylbutazone on the equine right dorsal colon (RDC). Animals-12 healthy adult horses. Procedures-A controlled crossover observational study was conducted. Clinical and serum variables, colonic inflammation (histologic grading), and measurement of myeloperoxidase (MPO) activity, malondialdehyde (MDA) and prostaglandin E(2) (PGE(2)) concentrations, ingesta volatile fatty acid (VFA) content, and arterial blood flow in the RDC were evaluated for a 21-day period in horses administered phenylbutazone (8.8 mg/kg, PO, q 24 h) or a control substance. Results-Data from 8 horses were analyzed. Plasma albumin concentrations decreased significantly from days 10 to 21 during phenylbutazone treatment, compared with results during the same days for the control treatment. Phenylbutazone treatment caused neutropenia (< 3.0 x 10(3) cells/muL). No other clinical or hematologic abnormalities were detected for phenylbutazone or control treatments. Two horses developed colitis while receiving phenylbutazone. No significant differences were detected in the RDC between phenylbutazone and control treatments for MPO activity, MDA and PGE(2) concentrations, and histologic evidence of inflammation. Arterial blood flow in the RDC was significantly increased during phenylbutazone treatment, compared with values for the control treatment. Differences were identified in VFA production during phenylbutazone treatment, compared with the control treatment, with a decrease in acetic acid concentrations over time. Conclusions and Clinical Relevance-Prolonged phenylbutazone administration caused hypoalbuminemia, neutropenia, changes in RDC arterial blood flow, and changes in VFA production. Veterinarians should monitor serum albumin concentrations and neutrophil counts and be cautious when making dosing recommendations for phenylbutazone treatment of horses. (Am J Vet Res 2008;69:1496-1505).
Member:
frances

Posted on Sunday, Nov 23, 2008 - 8:01 am:

Hi DrO,

Have you seen this recent article on the adverse effects of bute in The Horse magazine recently?

https://www.thehorse.com/ViewArticle.aspx?ID=13073
Moderator:
DrO

Posted on Sunday, Nov 23, 2008 - 5:30 pm:

I did not see the article but it seems to be about the AJVR paper we report on above. Is there something in the article that particularly interests you?
DrO
Member:
frances

Posted on Monday, Nov 24, 2008 - 7:29 am:

I was unsure whether it was based on the AJVR paper or on separate research (they mention LSU).

Up till now, I have felt that bute was a good standby for an arthritic horse at times of flare-ups, or perhaps as a single dose after a more taxing workout than planned. Do you believe that due to new research results we should make every effort to obtain relief in such circumstances with topical treatments (Surpass, clay poultices etc) before turning to bute - in other words, should we treat bute with more caution than previously?
Moderator:
DrO

Posted on Monday, Nov 24, 2008 - 6:51 pm:

In my opinion Surpass has not worked that well though there is a mild effect. I believe the dosages and regimen they used were a bit extreme using 4 grams at a single time and that is a very high dose for 14 days continuous use. 25 years of bute use and I have not had a toxic reaction and I have pushed the envelope. I consider the use of flunixin or even firocoxib when I need more pain relief than I can get with a dose of 2 grams twice daily for a few days then 1 gram twice daily in a 1000 lb horse.
DrO
Member:
frances

Posted on Tuesday, Nov 25, 2008 - 6:35 am:

Thank you DrO.
Member:
ekaufman

Posted on Tuesday, Nov 25, 2008 - 11:26 pm:

Hi DrO,

Do you think we can extrapolate anything from this study that suggests caution with long-term, low dose use of bute? We all knew horses in the past that lived for years on the stuff; guess they hadn't read the studies that would have made them sick from it?

(Context: I have an aged small pony mare who is sounder and brighter on 1/4gram bute daily; I am wondering now if I should do periodic bloodwork just in case, or try to reduce or find an alternative to the bute).
Moderator:
DrO

Posted on Wednesday, Nov 26, 2008 - 6:56 am:

Elizabeth, I don't think there is anything in this report that says you should stop your current treatment but we need to exercise some degree of caution with all medication administration. I see nothing wrong with occasionally checking the horse and discussing the alternatives available with your veterinarian so as to make better decisions. As is so often the case your goals and resources should govern your actions.
DrO
Member:
dres

Posted on Wednesday, Nov 26, 2008 - 9:44 am:

Elizabeth, i too, give a low dose , 1/2 gram of bute to a gelding of mine daily..
If i were to have blood tests done on him Dr. O what tests would i ask for??

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

Posted on Wednesday, Nov 26, 2008 - 1:30 pm:

Hi Ann,

My question too, but going by the study, it looks like a blood panel would be sufficient: "Veterinarians should monitor serum albumin concentrations and neutrophil counts" looks like the main caution, as well as potential problems with EGUS (not mentioned in this study). So a normal blood panel would catch both the values mentioned, unless I've misunderstood.
Moderator:
DrO

Posted on Friday, Nov 28, 2008 - 9:18 am:

Ann the article above suggests: "Veterinarians should monitor serum albumin concentrations and neutrophil counts".
DrO
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