Indomethacin Toxicity in Dogs

Indomethacin is a type of NSAID in human medicine.  It is not recommended for dogs as it causes severe issues, especially within the gastrointestinal tract.  Symptoms of toxicity can range from drowsiness, abdominal pain and depression to weakness, gastritis and hematemesis (vomiting of blood).  Treatment is symptomatic in accordance with the severity of your dog’s symptoms.  His prognosis of recovery will depend on the extent of damage within his gastrointestinal tract.

Indomethacin toxicity can severely affect your dog.  If you believe or know he ingested this medication, take him to his veterinarian immediately.

Symptoms of indomethacin toxicity may include:

• Depression
• Anorexia
• Melena 
• Hematemesis 
• Abdominal pain
• Gastritis 
• Vomiting 
• Weight loss 
• Pale mucous membranes
• Weakness
• Lethargy
• Drowsiness 

Types

Indomethacin is a type of nonsteroidal anti-inflammatory drug (NSAID) that works by reducing hormones that cause inflammation in the body.  It is a prescription medication for humans, not for dogs; if your dog ingests this medication, it is potentially toxic.  Indomethacin is a derivative of acetic acid and you can expect your dog to manifest adverse effects from ingestion of the medication.

In dogs, indomethacin is absorbed rapidly.  It is metabolized in the liver and excreted in the urine.  A very small amount of medication can cause your dog to experience an adverse reaction.  Your veterinarian will not prescribe your dog this medication; if he somehow ingests it, it is may be due to him possibly finding it himself and accidentally eating it without knowing any better.

Your veterinarian will begin by performing a full physical exam on your dog.  While doing this, she will also want to collect a verbal history from you.  She will want to know any and all details in regards to his condition.  She will want to know when his symptoms started, if they have progressed and if so how quickly, if you witnessed him ingesting anything or if suspect he did, if he is taking medications or if you administered any to him, or anything else helpful in regards to his situation.    

If you suspect your dog got into some type of medication he should not have, be sure to bring in the medication with you.  This will allow your veterinarian to have in front of her exactly what he ingested, the dosage and possibly how many pills.  Having an idea of what medication your dog may have ingested will help the veterinarian with her treatment plan. 

If your veterinarian is unsure of what is causing your dog’s symptoms, she will begin her diagnosis with blood work and additional lab work.  In regards to blood work, a complete blood count (CBC) and chemistry panel will provide your veterinarian with general information on how his organs are functioning and his blood chemistry levels and its productivity.  This blood work will show if your dog is experiencing any type of organ system failure.  Many dogs that ingest indomethacin develop renal failure.  Additionally, a urine sample may be collected for a urinalysis; this will give information on the health of your dog’s kidneys and bladder.  

In order to diagnose and properly view the degree of gastric irritation, your veterinarian may employ diagnostic imaging.  If practiced with an ultrasound she may utilize it to view the gastrointestinal tract for any abnormalities and how it is flowing.  Other imaging will include radiographs with barium contrast.  This will show where the abnormalities are and how deep the ulcerations go within the tract. Endoscopy is also a good imaging option to view how extensive the damage to the digestive tract is.  

If your veterinarian needs further diagnostics, she will perform them based on your dog’s symptoms.

If your dog is, in fact, experiencing toxicity from ingesting indomethacin, the sooner he receives treatment the better.  Decontamination is ideal in cases of toxicity, especially in cases where the medication can cause severe gastrointestinal ulceration.  If it has not been too long, the veterinarian may attempt to induce vomiting to expel the drugs from your dog’s stomach before they are absorbed further.  If this is unsuccessful, she may choose to administer activated charcoal or some other form of absorbent to make the drug bind for removal from his system.  She may also administer a medication such as sucralfate which works by binding to and coating ulcers within the GI tract.  This will prevent further damage to the intestinal tract.

Your dog will likely need to be hospitalized as he will need supportive care until the drugs leave his system completely.  He will be kept for treatments and monitoring by the veterinarian and her staff.  An intravenous catheter will be placed in one of his front legs as soon as possible in order to begin administration of intravenous fluids.  The fluids will correct any degree of dehydration your dog is experiencing as well as correct any electrolyte imbalances.  The fluids will also support renal function and flush the toxin from his system quicker.  

Medications will be administered depending on what symptoms your dog is experiencing.  Additional therapies will be included as needed by your dog.  If he is vomiting, an anti-nausea medication will be administered; if he is having diarrhea, a medication will be give in an attempt to help soothe his digestive tract.  Whatever his needs, your veterinarian will be able to provide for them in the best way possible.

The time of duration between ingestion and therapy will affect your dog’s prognosis of recovery.  If not treated promptly and properly, your dog has a poor prognosis at a good recovery.  Once the GI tract is damaged, it can make eating painful, certain exercise painful and other actions of everyday life more agonizing.  The best thing you can do for your dog is prevent him from ingesting this medication in the first place.