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  Discussion on Small area on top of neckline has indentation plus heavy scurf
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Member:
sondra

Posted on Saturday, Mar 8, 2008 - 11:08 pm:

Dr O: I have no idea where to post this and my vet has never seen this before. My 5 year old gelding jumper has a 4-inch area under his mane at about the middle of his neck that has a heavy amount of scurf. I first noticed it 2 weeks ago and treated it topically as if it were fungal. The scurf went away (temporarily), then a few days after, it came back AND I noticed his neck topline had developed a depression (like a shallow U-shaped depression), as if the flesh there had deteriorated.

Tomorrow it's being ultrasounded; my vet suspects a larval or parasitic issue - migration, kill-off, or a foreign body (from an old tick? is this possible?) that is causing this flesh-wasting in that area. It can't be trauma induced because if it were, there wouldn't be this scurf coming out (it looks like large white-ish flakes of dry skin being shed under the mane).

Note: I did administer a Panacur Powerpak prior to this issue. The horse has ALWAYS been on a regular de-worming program, however.

While I want to get to the bottom of this, I'm also worried about whether my gelding's neckline will ever return to normal; will the missing fleshy area fill in again? If it doesn't return naturally over time, would a stem cell treatment work?

Do you have any ideas about this at all?
Moderator:
DrO

Posted on Monday, Mar 10, 2008 - 6:57 am:

Hello Sondra,
I am uncertain what is going on here and it is not clear to me that the superficial scurf is related to the apparent tissue wasting. I would love to see images that demonstrated the scurf and the depression. What did you treat with prior to the depression forming?
DrO
Member:
sondra

Posted on Monday, Mar 10, 2008 - 10:59 am:

Thanks DrO. I suspect the depression in tissue had already started at the time when I saw the scurf but that I just hadn't noticed it yet. It seems too coincidental that there is scurf in the EXACT area and length of the dip in tissue. In any case, what I used was: first I washed that area of his mane with a dandruff shampoo (I think I used Selsun Blue). Then I sprinkled some ionic silver talc on it.
Member:
ekaufman

Posted on Monday, Mar 10, 2008 - 5:22 pm:

Hi Sondra,

Can you take a picture?

For what it's worth, I have horses that rub their manes, or squish them under fence rails and feeders, and it produces quite a noticeable dent along their neckline that's really just mashed/displaced hair. Those areas tend to be more scurfy looking as well, just because of the disturbance. I'm not saying that's what's up with your gelding, but it might be worth checking to see whether it's truly tissue damage (which sounds weird and awful) or just a real ugly squish mark.

Regards,

- Elizabeth
Member:
sondra

Posted on Monday, Mar 10, 2008 - 8:01 pm:

Thanks Elizabeth. I will take a picture tomorrow. I don't think it is from rubbing. I wish that were the case though :-(

How do I post a picture here?
Member:
sondra

Posted on Saturday, Mar 15, 2008 - 8:31 pm:

update: The ultrasound showed some scar tissue in the form of tiny lines that the vet said was caused by some kind of larval migration, as previously thought. He said it is very rare for this to happen in this area of the neck - it is more common for it to occur near the withers. He said the flaking indicates the body is trying to get rid of the dead organism(s) and that eventually a sore will probably develop when they do leave the body (they're dead of course) and that heals after a few weeks. He told me to give my gelding another Ivermectin in 3 or 4 weeks too. As for the change in neck shape, he was unsure whether or not it will re-form but said it is possible.

I found this so odd since this horse has been on a regular deworming schedule since I bought him 3 years ago.
Moderator:
DrO

Posted on Saturday, Mar 15, 2008 - 10:22 pm:

I must say I have never heard of such a thing Sondra. What parasite does the vet think is migrating through the tissues?

When I first started practicing I came in about the time when ivermectin was first introduced to the equine world. So here were all these horses with severe infections of the neck thread worm, onchocerca, who were being dewormed for the first time with something that would kill the microfilariae (larvae). Well we had remarkable heat, swelling, pain, fever that sometimes lasted a week or two, but never had such a necrotic event as you describe.
DrO
Member:
sondra

Posted on Saturday, Mar 15, 2008 - 11:18 pm:

Thanks DrO. A specific parasite was not identified. The whole thing does seem weird. The Zimectrin site, https://www.zimecterin.com/parasite/identification/neck_threadworms.html , contains this statement regarding symptoms: "Symptoms: Signs of neck threadworm infestation can appear in fly season and in winter. Clinical signs include skin lesions, hair loss, itching and other indications common with dermatitis."

The vet had not seen a resulting tissue depression such as this either. He however did feel that the reduction of flesh was probably in the fatty area as opposed to the ligament area. Two separate vets agree that the signs point to a parasitic issue however I don't have a definitive explanation yet as to why or how they came to this conclusion other than the scurf (they'd seen this before) and the ultrasound. I am not so sure myself now what this could possibly be. The horse does not rub himself there; I don't know of any trauma experienced there (and the ultrasound did not indicate any; it did indicate that on the right side of his neck in the very area under the scurf in his mane and the depression, there was some scarring evident in the ligament), and there is no pain when palpated there.
Moderator:
DrO

Posted on Monday, Mar 17, 2008 - 7:13 am:

Do you have your horse on a diet, or are there signs of weight loss elsewhere on the body?
DrO
Member:
scooter

Posted on Monday, Mar 17, 2008 - 8:00 am:

Interesting Dr.O. when you asked that question the appearance of my 2 geldings necks flashed. Hank and Sam have lost weight and they have a "dent" in their necks. They always have scruff in the winter especially in their manes.

Sondra does it look like this
Member:
sondra

Posted on Monday, Mar 17, 2008 - 10:11 am:

He hasn't lost weight but he did have an area at the top of his hind area on one side that looked like a missing area of tissue. I attributed that, however, to a fall he took when he was being lunged the previous day. I never thought one might be related to the other.

The depression in his neck is not on the side of his neck. It is on his topline - right under the mane.
Member:
scooter

Posted on Monday, Mar 17, 2008 - 6:20 pm:

Weird. In the pic above I was refering to the spot in his mane right where the tan board runs down. So it is under his mane and not right at the top as pictured above?
Member:
sondra

Posted on Tuesday, Mar 18, 2008 - 1:46 am:

Diane - ok yes, it DOES look like that. But it is higher on his neck, about halfway between his ears and his withers. Did you ever investigate why that happened with your horses? Re the scruff - my horse had the scruff ONLY in the area where the dip in his neck is.
Also what comes to mind since you say your horses lost weight at the time, did they lose weight because of something specific? I'm thinking maybe they needed to be wormed? Remember, this happened to my horse very soon after he was dewormed with a 5-day Panacur Powerpak.
Also, did your horses neck shape ever improve?
Member:
scooter

Posted on Tuesday, Mar 18, 2008 - 6:21 am:

Sondra the horse above WAS fat and had a cresty neck. He has been on a diet for a year. I never noticed when it happened it probably was a sloe process and it just became apparent to me. My arab...also on a diet didn't have as much of a cresty neck as the horse above. His "dip" is much more apparent and a little higher. Mine tend to get the "scruff" where they itch their manes. Their necks have not gone back to normal.

This may be totally unrelated to your horse, but wanted to show you a pic of mine...it has been caused by weight loss as Dr.O. refered to above.
Moderator:
DrO

Posted on Tuesday, Mar 18, 2008 - 7:00 am:

I think DianeE photo represents a differential loss in fatty tissue stored along the neck and yours may too Sondra.

I find onchocerciasis a unlikely diagnosis as the location is not right. Though it is the "neck" threadworm where the adults are in the nuchal ligament the cause of the dermatitis is the microfilarae which collect on the ventral midline. I also presume you use ivermectin regularly. For more on this see Diseases of Horses » Skin Diseases, Wounds, and Swellings » Hair and Coat Problems / Itching / Irritated Skin » Ventral Midline (Belly) Dermatitis and Onchocerciasis.
DrO
Member:
sondra

Posted on Tuesday, Mar 18, 2008 - 10:43 am:

Thanks Dr. O and Diane. Dr O: the vet did not specify onchocerciasis in his diagnosis, in fact he said it was probably not the neck thread worm. I just wanted to clarify that (I had asked him about this specifically after seeing it mentioned here by name).

Can you explain a bit more what you mean by a differential loss in fatty tissue stored along the neck, and any further suggestions along these lines? Also, would you venture to say he has a chance at restoring his neck shape eventually? His future is supposed to be as a show horse and I'm worried about this as aesthetics plays a big role in both the hunter and equitation ring. -Sondra
Moderator:
DrO

Posted on Wednesday, Mar 19, 2008 - 6:54 am:

Sondra, you bring up onchocerciasis in your post on zimectrin.

The stored fat around the nuchal ligament of horses does have a tendency to become a bit thick and irregular particularly if a horse has been through a extended period of fatness. Then when weight is loss there is some irregularity to the top line. The irregularity is fairly persistent. Not being able to examine your horses Sondra, I am uncertain if this is what is going on in your horse so cannot diagnose nor prognose your horses condition.
DrO
Member:
sondra

Posted on Monday, Mar 31, 2008 - 3:45 pm:

Hi Dr. O: my vet contacted a specialist, Dr. Robert Mackay at Univ. of Florida regarding my horse's condition. He was pretty certain that what has affected my horse is warbel larvae (i.e. hypodermis bovis). He has even encountered such muscle wasting before in horses (in addition to the scaling/scurf in the mane) - even though this is more common in cattle. Our ultrasound scans are being emailed to him today and I'm sending photos of his neck area too.

He said the larvae are most likely dead and that the body wants to expel the matter. Anti-inflammatory treatment or Pred may be prescribed. I hope to gain more insight and solutions (if any) to this when I speak with him tomorrow. This is all surprising, as my horse has been wormed regularly and does not live with cows (at least not since I got him, at age 2).

A search for "horses hypodermis bovis" revealed the following information in the Merck Vet Manual:

https://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/71402.htm

Do you have any further comment or ideas? My immediate concern is expulsion of the dead larvae and any chance at my horse's neck shape returning to normal. Thank you.
Moderator:
DrO

Posted on Tuesday, Apr 1, 2008 - 9:26 am:

It is an interesting thought Sondra but not what I typically consider lesions of Hypodermiasis in horses. I no longer see this condition in horses but back in the eighties, we would see a case every year or so. The location near the withers is right but the lesion we most often saw consisted of bumps or even nobules, and I even saw one that developed a breathing hole. The regular use of ivermectin or moxidectin should prevent the warble from getting to this stage.

If the ultrasound has picked up a late stage larva removal might be best.
DrO
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