I do not like giving medication to my dogs; I believe it’s always scary and potentially harmful, not just for me, but for them as well. Whenever possible, I look for a holistic/homeopathic remedy, but there are times when the condition mandates a hard-core treatment. Heartworms are one of those conditions.
If you are a pet owner, you are surely familiar with heartworm preventative medications, but in case you’re unfamiliar with the disease itself, here’s a quick overview:
- Heartworms are large parasitic worms that are injected into your pet’s bloodstream by mosquitos via larvae*
- Once the larvae mature, untreated worms can live in your pet’s system up to 7 years*
- Over time, heartworms attack an animal’s veins, liver, lungs, heart, and other vital organs*
- Your pet may not show any symptoms until the disease has already progressed*
Almost as bad as the worms themselves is the treatment to destroy them. The current treatment for heartworm disease is a series of 3 intra-muscular injections of a medication called Immiticide®, which is, essentially an organic form of arsenic which “blasts” the heartworms into pieces. The goal is for the heartworm fragments to be dispersed into the animal’s bloodstream and then eliminated. Due to risk of pulmonary embolism, the animal is placed on a 4-week regimen of predisone (predisolone), a strong corticosteroid, following the injections to control inflammation.
Short term use of Prednisone is associated with a wide range of side effects (for humans and pets): from fluid retention, insomnia, lethargy, increased thirst, inappropriate urination, and constipation or diarrhea. Those side effects are considered “normal” and generally your vet will give you a heads up to expect one or some of those.
…but nobody mentions the potential for psychological side effects from prednisone:
steroid-induced psychosis, or “roid rage.”
Our newest family member is Chloe, a 1 1/2 year old Golden Retriever mix that was adopted from a local SPCA but needed to be re-homed because she was lonely. She is a very sociable and playful girl who loves other dogs and was better suited for a multi-dog household. Chloe came to our house for a “meet and greet” and after just five minutes with our 6-month old Eskie puppy, they were BFF’s. Our Brittany Spaniel also liked her and our, somewhat ornery 14-year old Pomeranian approved as well. We were thrilled! Chloe was heartworm positive when we adopted her and already scheduled for her treatments. Since she was an otherwise healthy dog, we didn’t expect any surprises from her treatment.
Chloe was visibly different when we took her home from the vet but that didn’t seem unusual considering the nature of the injection. As expected, the prednisone made her extra hungry and thirsty and she peed in the house. But after about a week, there were obvious personality changes in Chloe.
Without warning or provocation, Chloe attacked our little Pomeranian, Kimba.
Thankfully, Kimba was ok, but I was beside myself! What the hell had happened?! Even Chloe didn’t seem to understand. Her body was tense but in her eyes I saw fear and confusion.
I called the manufacturers of both Immiticide and Prednisone. I was told by both companies that the behavior I described was not a known side effect, nor had anything like that been reported previously; however, my reports would be filed with the FDA as is standard (and required) protocol.
As we weaned Chloe off the Prednisone, her behavior (and overall state of mind) was improving. She seemed much happier and there were no more accidents in the house. A friend’s 12-week old puppy came over for a play date and she was thrilled to play with the little cutie.
Thirty days after the first injection, Chloe went back for her second and third injections, followed by more Prednisone. Two days after Round 2 (a Sunday), another friend brought over her puppy for a play date and within seconds, Chloe lunged at the puppy in attack mode. I grabbed her before she reached the pup and, just like last time, I saw that look of fear in her eyes. I truly do not think Chloe was in control and she seemed to know it. I discontinued her Prednisone the next day (Monday). However, that night, she attacked Kimba again.
As an aside, let me just write that I blame myself for allowing her near Kimba and I am incredibly grateful that he is ok – at least physically. Kimba came to us from a long history of neglect and abuse. He has come so far in his ability to trust and, until these incidents, I had never seen him happier. He has now retreated back to his shell, which is devastating. I am hopeful that with a little time I can fully regain his trust. It is truly one of the worst things to lose in any relationship.
I have scoured the internet looking for other pet owners who may have experienced similar types of behavioral changes in their dog after taking Prednisone and have found dozens of posts with similar stories, including:
- A 2012 blog post on petmd.com
- An article on dogtime.com that lists medication as a common factor in dog aggression
- Numerous posts on a boxer forum from owners who experienced similar reactions
- Forum posts on dogster.com
Additionally, a small, 2011 study on the effects of using Prednisone with dogs concluded a possible correlation between the drug and canine aggression, when 35% of participating dogs experienced negative behavioral changes. So, I followed up with the in-house veterinarian at Lloyd, Inc., the pharmaceutical company that makes PrednisTab® and I asked why such significant potential side effects are not common information among prescribers. The answer was simple:
The incidents are not being reported to them.
Any type of negative interaction with any medication by your pet should be reported to either the in-house veterinary team at the pharmaceutical company or directly to the FDA.
The news is full of reports about the risks of drug interactions for us, humans. Less than a month ago, results of a 5-Year Study reported that more than 15% of senior citizens may be at risk of a drug interaction. That kind of information will surely initiate changes to help minimize those risks. But change doesn’t happen on its own.
Just blogging, posting, complaining to your vet or your friends about the side effects does nothing to help our animals!
For the sake of all animals, please report significant or unusual negative pharmaceutical side effects! I will continue to monitor Chloe carefully. Hopefully everything will go back to normal and she’ll feel like her happy, carefree self again (only without the heartworms.)
- If you notice any unusual side effects with your animals from pharmaceutical drugs or devices, call the manufacturer or complete and mail this prepaid form to the FDA.
- Animal Vaccines – contact the USDA APHIS Center for Veterinary Biologics at (800) 752-6255
- Flea and Tick Products (not approved by FDA) or Other Pesticides – contact the National Pesticide Information Center at 800-858-7378