Fecal confirmed gapeworm resistance to fenbendazole

[klbaker75]

Hi, I have had gapeworm in the past confirmed by both the vet and myself (I now do my own fecals) and in the past I’ve used three days at 1cc per hen per day (4-5 lbs) and it’s worked.

One of my hens has been stressed with a moult (she moults in the summer instead of fall) and I always check a fecal once a week since I had such issues with gapeworm in the past. It’s been two to three months since I’ve had any issues. When she started making noises and acting off on Saturday I tested and found one egg. So I treated them Sunday through Tuesday and retested the fecal on Wednesday morning (yesterday) to see if longer treatment was needed.

There were even more eggs and the symptoms were still present. So I increased the dose to 1.25 cc yesterday and once again this morning (day 5) even more eggs and symptoms. So I treated them with 1.5 cc today (day 5). That is the very high end dose.

Is it normal to see eggs still being shed in the stool on day five? I know they can still have symptoms for a while like gurgling etc as the worms are being killed off. But I’m pretty sure I shouldn’t still be seeing eggs, let alone more eggs. Or maybe the egg load is random since sometimes I test and see none.

I am at the feed store now getting valbazen just in case. Though the vet said give them a drug holiday for a few days.

Is it possible the worms have developed resistance or do I give this more time? I don’t have a ton of time with gapeworm since it’s so dangerous.

 

[pibb]

I thought for fenbendazole and gapeworm the medicine was to be given for 5 days in a row and then repeated in 10-14 days since the medicine doesn't kill the eggs. You said nothing about repeating another 5 day round of medicine so the eggs may have hatched into worms that shed more eggs. Just a thought since I don't know if this is what happened or not.

 

[pibb]

The OP says gapeworms, not tapeworms. Hehe.

 

[casportpony]

The OP says gapeworms, not tapeworms. Hehe.

So sorry, my bad. I will go crawl under a rock now, lol. Post deleted (oh the shame, lol).

 

[pibb]

No shame. It happens when you read alot of posts and help several people. Things go criss-cross.

 

[klbaker75]

I thought for fenbendazole and gapeworm the medicine was to be given for 5 days in a row and then repeated in 10-14 days since the medicine doesn't kill the eggs. You said nothing about repeating another 5 day round of medicine so the eggs may have hatched into worms that shed more eggs. Just a thought since I don't know if this is what happened or not.

I did treat for five days. Yesterday was my 5th day. This was round one. I will be retreating in 10 days to kill off the hatching eggs. I’m thinking I shouldn’t be seeing eggs in their stools on day 5.

 

[casportpony]

Maybe @Sue Gremlin or @KsKingBee will know?

 

[klbaker75]

Maybe @Sue Gremlin or @KsKingBee will know?

Last night and this morning all fecals were clear. I went ahead and did a 6th day since the first three days were on the lower end of dosing. I believe what may have happened is I didn’t dose enough the first three days to kill the worms, hence seeing the continued eggs in their stools. So I’m leaning towards that now instead of an actual resistance. I also gave them cayenne pepper every hour on the hour in small amounts. I don’t know if that helped as well. But for now they seem to be gone.

 

[Sue Gremlin]

I can't comment about resistance, but if you see ova a day after treatments, there are probably still worms. FBZ is short-acting, so they should clear right out if they're going to. That class of drugs is indicated for gapeworms, but it is a tough one because of where the adult worms live. It's hard for the drug to get into the airway where the adult worms are since it doesn't get into the blood and stays in the gut.

In any case, it seems like you have it figured out. Keeping the coop really clean is key to prevention of reinfection.

 

[Sue Gremlin]

Ivermectin gets in the blood and would probably be what I'd use for that reason, by the way, even though you'd have to refrain from eating the eggs for a long time.