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Question Posted August 27, 2005
I am looking for a paper or article to help dissuade a couple of my fellow doctors from recommending aspirin-based products so frequently compared to other NSAID's. (Feel free to comment if you believe aspirin IS safe and effective in dogs). I have attended several lectures concerning aspirin's ability to quickly irritate the stomach lining as well as being limited in providing any measurable relief in some dogs.
I also have been looking for a recent overview article, possibly in JAVMA, that detailed several disadvantages to doing vaccinations at the same time as an anesthetic procedure. If anyone can point me in the right direction I would appreciate it.
Bill B. Moore
Response 1
This might not be very helpful, but i know there was an article done within the last few years that showed endoscopically ulcer formation after aspirin administration...i will try and find article for you...
Corrie Bates
Response 2
There have been many interesting studies on aspirin (ASA) in dogs. of note, a dutch study that showed significant differences between buffered aspirin, enteric coated aspirin, and regular aspirin. for the most accurate and preditable dosing, using either the powdered form mixed with food or the regular or buffered tablets seems to be best; the enteric coated tablets can stay in the dog's stomach for a couple days. the powdered form may also be less likely to cause ulceration, because there is not prolonged contact of any particular part of the stomach mucosa with a tablet. the dogs in this study received 25 mg/kg po tid.
Nap RC. et al. [Analgesics; the use of aspirin in dogs; effects of tablet type and food intake on plasma salicylate level]. Tijdschrift voor Diergeneeskunde. 118(13):439-42, 1993
Administration of acetylsalicylic acid (aspirin) in the dog may cause gastric mucosal damage. Enteric-coated tablets protect the canine stomach during oral aspirin medication. A therapeutic plasma salicylate concentration can be attained using enteric-coated aspirin tablets at a dosage of 25 mg/kg TID. In a series 4 of experiments using adult beagle and large mixed breed dogs and two types enteric-coated tablets, the influence of food intake on the plasma salicylate concentration was studied. Tablets were administered with 8h
intervals and food intake was either once daily or three time daily with 8h intervals. Plasma salicylate concentrations were also studied during fasting. It is concluded that, when using enteric-coated tablets, the plasma salicylate concentration in the dog after oral medication is strongly influenced by the aspirin dosage, the tablet type and the feeding pattern. Large enteric-coated tablets may accumulate in the stomach over several days and are not suitable for use in the dog. The gastric accumulation is caused by the enteric-coating of the large tablets and not by the aspirin medication.
What is also interesting about this article and others is the fact that with chronic dosing of ASA will result in an accumulation of salicylate in the blood, which may contribute to prolongations of the pt by inhibition of vit k dependent clotting factors.
We are also presenting an abstract at this year's IVECCS where we demonstrate possible hypercoagulability after aspirin treatment in 8 dogs. It is also important to remember that aspirin irreversably inhibits platelet cyclooxygenase, as opposed to other nsaids, who only show transient platelet inhibition, so there may be an increased bleeding tendency in animals treated with ASA.
This may be the article that you are looking for:
Reimer, M. E. et al. The gastroduodenal effects of buffered aspirin, carprofen, and etodolac in healthy dogs. Journal of Veterinary Internal Medicine. 1999. 13: 5, 472-477
24 healthy mixed-breed dogs were divided into 4 groups. Group 1 received a placebo PO q12h, group 2 received an average of 16.5 (15.1-17.8) mg/kg buffered aspirin PO q12h, group 3 received an average of 2.2 (2.0-2.4) mg/kg carprofen PO q12h, and group 4 received an average of 12.8 (11.7-13.8) mg/kg etodolac PO q24h (with a placebo in the p.m.). All treatments continued for 28 consecutive days. Gastroduodenal endoscopy was performed on days -9, 0, 5, 14, and 28. Multiple gastric biopsies were obtained endoscopically on day -9 to determine each dog's Helicobacter infection status. Four regions in the stomach and one region in the proximal duodenum were evaluated endoscopically, and each was assigned a score from 1 to 11. Scores for each region then were added up to give a total score for each endoscopic evaluation. Erosions and submucosal haemorrhages were seen in all dogs receiving aspirin. Only minor gastric lesions were observed in the carprofen, etodolac and control groups. No adverse clinical signs were noted in any dog given any treatment. Median total score on days 0, 5, 14 and 28, respectively, were as follows: group 1: 5.0, 5.0, 5.0, 5.0; group 2: 5.0, 27.0, 26.0, 27.5; group 3: 5.0, 5.0, 6.0, 5.0; group 4: 5.0, 7.0, 5.0, 5.0. There was no significant difference among dogs receiving carprofen, etodolac or placebo. The administration of carprofen, etodolac or placebo to healthy dogs resulted in significantly less gastroduodenal lesion development than in dogs receiving buffered aspirin.
There is also,
Forsyth, S. F. Guilford, W. G. Lawoko, C. R. O. Endoscopic evaluation of the gastroduodenal mucosa following non-steroidal anti-inflammatory drug administration in the dog. [Journal article] New Zealand Veterinary Journal. 1996. 44: 5, 179-181
The gastroduodenal mucosa of 30 healthy dogs was examined by endoscope after 7 days of oral non-steroidal anti-inflammatory drug administration. The dogs were divided into 5 groups. One group received ketoprofen (1 mg/kg every 24 h), one group copper-indomethacin (0.2 mg/kg every 12 h), one group 1 mg of prednisolone and 200 mg of cinchophen (1 tablet/20 kg every 12 h), one group aspirin (15 mg/kg every 12 h) and one group gelatin (1 capsule every 12 h). Occult blood was not detected in the faeces either before or after non-steroidal anti-inflammatory drug administration. Packed cell volume, total plasma protein and buccal mucosal bleeding times did not significantly change after non-steroidal anti-inflammatory drug administration. Gastroduodenal lesions were observed in 22 dogs. There was no significant difference in lesions between the ketoprofen, copper-indomethacin and prednisolone-cinchophen groups, but the gelatin group had significantly fewer severe lesions and the aspirin group had significantly more severe gastric lesions. The gastroduodenal lesions were mild and none of the dogs showed any clinically adverse effect.
Ben Brainard