Todayโs path rounds are on ๐๐๐๐๐ ๐ญ๐จ๐ฑ๐ข๐๐ข๐ญ๐ฒ!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐๐๐๐๐ฌ (non-steroidal anti-inflammatory drugs) are a common class of drug used as anti-inflammatories and pain control. Human examples you might know include aspirin, ibuprofen and naproxen. We commonly use other NSAIDs in our veterinary species as well!
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
Any species can develop this toxicity!
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
NSAID toxicity can develop in a few ways. The most obvious is exposure to a lot of NSAIDs all at once, for example a dog getting into the medicine cabinet. However, NSAID toxicity can also occur in cases where animals are given a prescribed NSAID for a long period of time. This ๐๐ก๐ซ๐จ๐ง๐ข๐ (long-term) exposure is probably the most common cause of NSAID toxicity, particularly in species like horses.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
The way that NSAIDs work is that they block the production of ๐ฉ๐ซ๐จ๐ฌ๐ญ๐๐ ๐ฅ๐๐ง๐๐ข๐ง, a critical hormone in the inflammatory pathway. This occurs by inhibiting the enzyme ๐๐๐, which produces prostaglandin. There are actually two forms of COX: COX-1 is expressed by pretty much every tissue in the body to produce prostaglandin needed for normal bodily functions, and COX-2 is associated with inflammation.
Most NSAIDs inhibit ๐๐จ๐ญ๐ก COX-1 and COX-2, meaning that they can also disrupt normal bodily functions. The most common use of COX-1 is protecting the digestive tract from damage, so these ๐ง๐จ๐ง๐ฌ๐๐ฅ๐๐๐ญ๐ข๐ฏ๐ NSAIDs can lead to ๐ฎ๐ฅ๐๐๐ซ๐๐ญ๐ข๐จ๐ง (damage to the mucosa) within the stomach and intestines. COX-2 also helps regulate the amount of blood flow to the kidney, so chronic NSAID exposure can decrease this blood flow. This leads to ๐ฉ๐๐ฉ๐ข๐ฅ๐ฅ๐๐ซ๐ฒ ๐ง๐๐๐ซ๐จ๐ฌ๐ข๐ฌ, or cell death in the most central tissues of the kidney.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Diagnosis is usually based on a history of NSAID use, combined with clinical signs like abdominal pain, diarrhea, vomiting or signs of kidney failure. In some cases, ulcers within the esophagus and stomach can be seen on ๐๐ง๐๐จ๐ฌ๐๐จ๐ฉ๐ฒ, where a long camera is used to examine the digestive tract.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐?
First and foremost, the animal must be taken off any NSAIDs. Treatment then involves fluid therapy, to increase blood flow to the kidneys, and use of medications that help replace the normal protective coating of the digestive tract to prevent further damage. An example of this type of medication is ๐ฌ๐ฎ๐๐ซ๐๐ฅ๐๐๐ญ๐, which basically coats any ulcers and forms a protective barrier.
๐๐ก๐จ๐ญ๐จ๐ฌ
1) Ulcers on the tongue from NSAID toxicity.
2) Stomach ulcers in a horse.
3-4) Ulcers in the large intestine from NSAIDs.
5-7) Examples of papillary necrosis! One of the images has a large ๐ง๐๐ฉ๐ก๐ซ๐จ๐ฅ๐ข๐ญ๐ก (kidney stone) which can also occur due to reduced blood flow.
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Khan SA. Analgesics (Toxicity). Merck Veterinary Manual 2016.
Photos 1, 3-4, 6-7 ยฉ Noahโs Arkive contributors Acland, Rosell, Panciera licensed under CC BY-SA 4.0.
Photos 2 and 5 ยฉ University of Calgary Diagnostic Services Unit.