FEC results

[HeyMich]

Hello lovely HHOers. I hope you are all well and surviving the apocalypse? Just a quick question, if you don't mind me picking your brains....

I have a 22 yr old retired companion mare (Welsh cross, 15.2hh) who has repeated high FEC results. When I say high, they range from 500 ish to 1500 epg, but are usually closer to 1500. They go down after treatment usually, but never to <200, then at the next FEC, usually 2-3 months later, it's back up again. She had LV on all 4 legs over the winter, which is fine at the moment, is happy and healthy in all other ways. She's out 24/7 on hilly, poor grazing. She's a bit stiff occasionally, if she's been in the stable for longer than a few hours for any reason, but she moves freely again after the first few steps, and I put that down to her age and general aches and pains. The rest of the herd (2 native ponies and an IDx mare) have consistently low results, <100 each time. The herd all co-graze at times, and her long-term companion, the IDx, has a consistent FEC of zero.

The vet has us treating her with Pramox and Strongid-P, on an alternating basis. The vet has suggested that there maybe an underlying immunity problem, but we've not found anything. The last time she was Cushings tested (6 months ago) it was negative, and there are no other symptoms.

Is this common? Is there anything else, treatment wise, you would suggest? Any other reason for the repeated high FEC results? Is this just something I'm going to have to deal with with her in the long-term? I don't mind, I just feel bad that the worm burden could be causing her discomfort, and the repeated chemical treatments can't be pleasant!

Thanks x

 

[planete]

Which test did your vet do for Cushings?

 

[soloequestrian]

It read to me like Cushings until the bit about the test! Perhaps worth trying Prascend anyway? I'm not sure I would be too worried about the 'high' burden - there is evidence out there to suggest that what we currently think of as high is actually very low. If she has no other health problems and doesn't seem to be acting as a source of eggs for your others perhaps leave her for a bit and see if she stabilises at a particular level? Radical I know but perhaps nicer and certainly less likely to promote resistance problems than continually dosing with anthelmintics.

 

[HeyMich]

Which test did your vet do for Cushings?

It was just the ACTH test. Do you think it's worth re-testing or doing the TRH stim test?

 

[shortstuff99]

Is there a possibility of testing the eggs/worms to see if they are resistant to wormers? It could be you just have resistant worm population.

 

[HeyMich]

It read to me like Cushings until the bit about the test! Perhaps worth trying Prascend anyway? I'm not sure I would be too worried about the 'high' burden - there is evidence out there to suggest that what we currently think of as high is actually very low. If she has no other health problems and doesn't seem to be acting as a source of eggs for your others perhaps leave her for a bit and see if she stabilises at a particular level? Radical I know but perhaps nicer and certainly less likely to promote resistance problems than continually dosing with anthelmintics.

That's really interesting. I'll mention it to my vet and see what they say - might be a bit too radical!

 

[HeyMich]

Is there a possibility of testing the eggs/worms to see if they are resistant to wormers? It could be you just have resistant worm population.

Wouldn't the others in the herd also have high counts if this was the case?

Plus, I think the mare in question had repeated high counts at the livery yard she was at before she came to mine (my other mare was there too, so I've known her and her owners/sharers for years).

Worth thinking about though, thanks.

 

[Goldenstar]

It’s probably an immunity issue .

 

[Shay]

We have a horse on yard who is just like this - he also gets threadworm regularly. The vets say it is an immune problem probably dating back to when he was a youngster and he will just be one of those that needs constant worming.

 

[HeyMich]

We have a horse on yard who is just like this - he also gets threadworm regularly. The vets say it is an immune problem probably dating back to when he was a youngster and he will just be one of those that needs constant worming.

Ok, thanks for that. It's reassuring (in the nicest possible way) to hear that there are other horses around with regular high worm counts. Do you do anything different with his management? Are there any other problems that go hand in hand with it?

 

[planete]

It was just the ACTH test. Do you think it's worth re-testing or doing the TRH stim test?

Because of seasonal variations I think you would need to wait until November to do a TRH test now. I only thought of Cushings re. high FEC because I read it could be caused by an immune system weakened by Cushings. I bought a young Forest bred pony who had constantly elevated FECs while the horse with him had very low ones. Shay's explanation makes sense. Not sure I would risk the worm burden getting worse if unchecked by wormers, any experiences of cases where this has worked @soloequestrian?

 

[ihatework]

I’d probably do some resistance testing. But it’s most likely immunity.
The saying is 20% of horses carry 80% of worms!

 

[soloequestrian]

[QUOTE="planete, post: 14364967, member: 72373"Not sure I would risk the worm burden getting worse if unchecked by wormers, any experiences of cases where this has worked @soloequestrian?[/QUOTE]
Not off the top of my head - I'd have to go and dig and don't have time at the moment. I know there is one study out there that suggested that healthy horses can cope fine with burdens of at least up to 10,000 epg and a student study showed that horses in ideal body condition can have very high worm burdens. The key seems to be 'healthy' - a high burden seems fine when the horse is in good health but if anything else goes wrong then the worms can cause problems. If OP's horse is generally healthy then personally I would probably look to stabilise it at 1000-1500epg rather than try to keep it below the (arbitrary) 200epg.

 

[ester]

what IHW says is correct, it is normal to have a horse in the herd that carries most of the burden, usually young or old!
If you have resistance to both pyrantel and moxidectin that's a big problem but much less likely.

If the horse is otherwise ok, and counts do drop after worming I wouldn't be overly worried.

 

[HeyMich]

what IHW says is correct, it is normal to have a horse in the herd that carries most of the burden, usually young or old!
If you have resistance to both pyrantel and moxidectin that's a big problem but much less likely.

If the horse is otherwise ok, and counts do drop after worming I wouldn't be overly worried.

Thanks Ester. See, I just needed someone to tell me to stop stressing!