It happens. Despite millions of dollars in research, and detailed testing beforehand, sometimes it happens. Sometimes a side effect occurs when we use a drug in a patient.

I’m worried this is happening for Lemmy.

For the past six weeks, he has used a daily anti-inflammatory medication, and it has given him a new lease on life. He has run and jumped in ways that weren’t seen for years. His owners had no idea how big a difference his arthritis must have been making.

But now, for the last week, he has taken a downturn. Lethargy, inappetence and explosive liquid diarrhea have been noted. The diarrhea is sometimes bloody.

I’m worried the drug is causing impairment of either his liver or kidney functions. It’s not very common, but it’s possible.

Lemmy limps in, having been off his medication for the past week. He gives me a cursory handshake and lies down. This is not the dog I know.

His physical exam is unremarkable. Laboratory testing shows me my worry was misplaced.

Lemmy’s problem isn’t because of impaired organ function secondary to his arthritis medication. Instead, he has a nasty intestinal parasite: whipworms.

This particular worm isn’t as common as hookworms or roundworms, which are the two most common worms for puppies.

However, it can be more immediately threatening to an adult dog. Diarrhea can become so severe dehydration and death can occur.

Lemmy’s owners have a valid question. The heartworm prevention he takes says it is “guaranteed” to protect against whipworms. Unfortunately, this is more labeling and marketing than actual science. The product doesn’t always prevent whipworms, but the company pays for treatment if the worm crops its ugly little head. Slimy? Maybe. But cheaper than reformulation for government approval. It irks me.

I treat his worms and he recovers. But from now on, he will use a heartworm preventive that actual does what it’s guaranteed to do.

After all, whipworm eggs live a long time.

Matthew Sisk is a practicing veterinarian from Habersham County. Have questions about your pet? He can be reached at mattsisk2003@yahoo.com.