Puzzling Pieces

In my last post, I reported making the discovery that Larry has multiple symptoms of headshaking syndrome (HSS).  Ever since, I have been trying to assemble the pieces of his symptoms and his triggers so that I can figure out how to deal with this condition.  So far it has felt like someone mixed several 1,000 piece puzzles together into one bin and told me to solve them without any guidance or even the picture on the box.

I have been looking at scientific journal articles trying to see what causes and treatments have been investigated (though a lot are pay sites, which is unfortunate).  I have looked at public websites and forums about the condition (taken with a grain of salt - some are useful, some seem to be complete bunk like the one endorsing a costly homeopathic remedy that blames the condition on vaccinations but doesn't go into the modality of HOW vaccines would cause the condition or how their homeopathic remedy cures it).  I did find this excellent website about headshaking put together by a British university.  It addresses multiple facets of the condition and has a basis in scientific study.  http://www.lincoln.ac.uk/dbs/research/headshaking/ 

So here are the puzzle pieces I've been trying to fit together.

BACKGROUND INFO:
Larry is an 8 year old Standardbred gelding.  He was on the racetrack until he was 5 or 6, but only ran a few qualifiers and made one start.  He was kicked in the jaw when younger, but unfortunately I don't have any details.  He does have a small bony bump under his jaw that feels like a retained cap but doesn't seem to cause him any problems.  He was apparently difficult to train at the track and may have had some training anxiety issues where he would get very tense about being harnessed.  He was shown extensively by his prior owner (his track groom) in halter and showmanship classes, but was seldom ridden as his prior owner doesn't ride.  He had some walk-trot riding work in jumping and western pleasure with a couple different riders during that time period, but it was sporadic.  He never progressed to canter work, though he did jump (from a trot).

I got him in October of his 7 year old year.  He is generally quite laid back, kind of lazy, and seldom spooky to work with.  He is relaxed on cross-ties and totally unfazed by being tacked up.  He handles new environments well.  I honestly can't tell how much of a willing learner he is, since it is hard to assess any progress when the horse is constantly distracted by flipping his head.  He spent a fair amount of time stabled when he lived in NJ, but is now pastured in central KY (the allergy capitol of the world).


SYMPTOMS:
Rotary Headshaking - Larry violently flings his head in circles when standing with his head over the stall door.  I originally attributed it to dental pain or a learned behavior he'd developed at the track from boredom or anticipation of feeding.  He has done this year round.  He continues to do it even after the dentist examined him and gave him a clean bill of health.

Horizontal Headshaking - Larry has a tendency to jerk or twitch his head upwards and to the side on the lunge line and while ridden (it is especially noticeable while ridden, particularly at the trot).  It is very much like a nervous tic and he will often get very tense with his head and neck and will move very short and stiltedly at the trot.  On worse days, he will fling his head up, especially when asked to go from walk to trot, moreso than the typical "Standardbred Shuffle" they often do in anticipation of moving the weight of the cart and driver forwards when first starting out.  He does this both on the lunge line and under saddle.  Now that I am more aware of it, I have started noticing his tic in hand, too, both at home and at shows.  It is more manageable then because we aren't moving fast or doing a lot in hand. 

Striking at Nose With Forelegs - In an earlier post, I described Larry's semi-rear.  He'll be walking or trotting (usually trotting) along on the lunge line or under saddle and suddenly toss his head and flip his forelegs out individually, often accompanied by a grunt.  At the time, I thought he was being unruly and that he was basically flipping me the bird.  After reading more about headshaking, I now realize this was his attempt to rub his nose with his forelegs while moving.  Because I thought he was acting out, I had been punishing him for this behavior.  While lunging, I would make him change directions and work harder when he did it.  I found it hard to reward him on the lunge line since I couldn't get more than 5 or 6 strides without some sort of fit, though the feet flipping did reduce quite a bit the more I lunged him and punished him for it.  I was working him pretty consistently at the time, trying to "work him out" of what I attributed to "his bad attitude."  Under saddle, I resorted to striking him with a crop on the shoulder and spinning him the other direction.  The behavior was quite erratic under saddle, so I never could tell if that had any effect on the behavior, though for a while between the lunging and riding punishment, it felt like he was trying to suppress the behaviors somewhat.

Excessive Rubbing of the Nose - I have noticed this also on the lunge line and under saddle.  There was one day several months ago that I was lunging him and he trotted over a lap with his nose dragging the ground and his front feet brushing his chin.  I checked him for back pain, thinking he was stretching, but found nothing.  He has done it at other times, but that was the most blatant episode.  Lately I have noticed that he will rub his nose on his forelegs (or sometimes objects) a lot after a brief period of riding.

Snorting/Blowing the Nose - I have been noticing this one ever since I discovered the link between his behaviors and headshaking syndrome.  He seems to do it more when wearing the nose nets I made for him (more on that later).

Flipping the Nose or Upper Lip - He has always been a mouthy/nosy horse - the type that gets into stuff, chews on the leadrope or sometimes the fence plank, and generally wants to get his nose into things and/or mooch for treats (which I have been trying to curb by feeding a lot less treats).  On cross-ties, sometimes he will chew/gnash his teeth or wiggle his lips.  I have seen many horses that have mouthy and lippy behaviors without displaying any other symptoms of HSS, though, so I wouldn't take this as a definitive sign by itself.  He also chews the bit a lot, and I spent a lot of time trying out different bits (and a sidepull and a bosal) to see what he went best in, as I thought he might have a low palate.  Naturally, I had the dentist out first, who gave him a thorough exam and floating and gave him a clean bill of health.  I have a prior blog post about that if you want to see more detail.

Rolling - This isn't listed as a symptom that I have seen, but it may or may not be related.  Larry rolls more than any other horse I've known.  He rolls multiple times a day in the field, possibly because he is itchy, though he doesn't respond to currying as dramatically as my other mare who has very distinct itchy spots.  Other than this, he doesn't seem to show any other symptoms in the pasture. 

OTHER SYMPTOMS:
 Protecting the head, eye discharge, clamping the nostrils, hair loss/facial swelling (from rubbing), general hypersensitivity of the head.  Larry doesn't really show any of these symptoms.  He does like to hang out in the run-in shed on hot sunny days, but that could easily be good sense rather than avoiding sunlight.

PATTERNS:
This has been the most difficult component to determine.  There seems to be a stress component to his fits, as he gets worse when I am trying to teach him something new or we are in a new and stressful environment.  Though he is generally calm to handle at shows, under saddle classes do seem to exacerbate his head shaking.  Training wise, I can never tell if he has figured out a new concept (such as turns on the forehand and haunches) because of his fits, but inexplicably, weeks later, he was suddenly able to pivot on command whereas he wouldn't before.

Along with stress, work seems to trigger it.  The headshaking usually appears most prominently during trot work, either lunging or riding.  The harder he is worked, the worse it gets.  Last week when trying to get a canter under saddle (which involves a lot of effort on his part as he figures out what to do with himself), he went from a decent riding day HSS wise to pretty bad.  With his apparent training anxiety at the racetrack, it seems likely that he's been an undiagnosed lifetime headshaker.  Certainly the discomfort from his attacks could make him fear and resent harnessing and the many subsequent training miles he was expected to go at the track.

A common trigger for many headshakers is light.  This is termed photic headshaking and strong sunlight can set them off.  I haven't been able to pinpoint if this plays into Larry's behavior.  I mostly ride in the evenings to avoid the summer heat, so the sun is setting, though there are some long shadows and areas of sun vs. shade where we ride.  In June, he had episodes in the outdoor warmup area at Henry Co., but was quite a bit better in the semi-dim covered arena.  At a mid-July evening show, he had some awful episodes in the dim warmup area as well as the unevenly lit outdoor arena (rearing/bucking for the first time under saddle).  Less a week later, with his new nose net, he was ok at the outdoor Oldham Co. show (early evening), nearly perfect at the Franklin Co. evening show the following night, and great but tired at the sunny Grant Co. daytime show two days later.  (Mind you, he is only going in 2 or 3 classes per show, nothing more strenuous than walk-trot, and this was an aberration as I don't ordinarily show him more than every other week, so I'm not working him to death here.)  But last week, back at the Henry Co. covered arena (with nose net on), he was ok in the hunter walk-trot (with snaffle) and awful in the western walk-trot (with bosal).  One evening in late July/early August, we tried to get some video of him being ridden with and without his nose net.  Without the nose net, he responded by rearing in the same two corners of the arena every time, which could be related to the play of shadows and sunlight in the evening, but it's hard to tell.  With the net, he still flipped his head, but no longer reared.  I lunged him with his fly mask to see if shielding the light would help, but it didn't appear to make a difference.  I plan to try again to give it a fair shake. 


I presume there's a seasonal component to his behavior, but since this is the first year I've had him and it started so insidiously, I really can't say when it started.  I don't ride much over the winter due to weather and footing, so that makes it harder to determine the onset.  Here in KY in July and August, his behaviors do seem to be getting worse.  I don't know yet if/when it will abate in the fall.  Seasonality could be related to sunlight triggered hormone levels (eg the pineal gland's response to lengthening sunlight, shedding the coat and ramping up estrous hormones in mares) and also to allergens.  KY is often called the allergy capitol of the world.  My older STB mare has had mild allergies for years since living here, but they are confined to a seasonal runny nose and itchy skin and I treat her with oral antihistamines when her symptoms get too bad.  Larry hasn't shown any of these types of signs (with the possible exception of his rolling in the dirt, mentioned above), but he has been snorting/sneezing more frequently lately.

RULING THINGS OUT:
I initially thought he had bitting problems, so I had him examined and floated by a very good equine dentist.  I tried a wide variety of bits on him, finally settling on a three piece loose ring snaffle of moderate thickness for hunt seat use.  For western, I used either a thinner curved sweet iron loose ring, a side pull, or a bosal.  His issues were no different in the bitless options as with a bit.  I was told by the girl who rode him western before that he didn't like curb straps or the chain under his jaw with his western halter.  I have been riding in a snaffle, but did test this twice; he didn't seem thrilled by the strap, but wasn't horrible.

I thought back pain or lameness could have been causing his discomfort, but palpation and examination haven't shown either one of these to be problems, and trying Bute didn't change anything.   I also put him on a course of ranitidine, thinking it was stress or ulcers but there was no difference.

Some people blame such behaviors solely on poor riding.  I consider myself a pretty accomplished amateur rider with numerous national titles in a variety of disciplines with my older STB mare.  In addition, Larry shows the behaviors on the lunge line (with no rider) just as much as under saddle.

I initially thought it was stubbornness.  As described above, I put him in a regular work regimen in which he was rewarded with praise and less work for good behavior and had to work harder and longer when he behaved badly.  I saw some improvement in the worst of the feet flipping with the lunging work, but the other behaviors continued both under saddle and on the lunge line.  I found it hard to find opportunities to reward the good behavior, as he could barely string together half of a 20 m circle without flipping his head.  It got to the point where I would say "good boy" and he would plow to a stop after just 5 fit-free trot strides because that was the most he could manage. 

TREATMENT:
It is normal for horses to occasionally bob their heads in response to flies or other stimuli.  However, Larry does this and far more with and without fly spray and in the presence and absence of flies.

I tried lunging him with his fly mask once to see if shading the light would help, but it didn't seem to.  I will try working him with it again to give it a fair shake.

Another non-invasive option was the nose net.  It looks like this: http://www.smartpakequine.com/equilibrium-net-relief-muzzle-net-6680p.aspx except that I made my own out of black organdy (a sheer but semi-stiff fabric used for prom dresses, etc.) tailored to his nose in styles to work with both my English and western bridles.  At first, I thought this was going to solve all of our problems.  The first three times he wore it, he was improved at Oldham Co., and the best he'd ever gone in his life at Franklin Co. and Grant Co.  For the first time ever, he was able to trot multiple laps of the arena without flipping his head.  Less than a month later, though, it is only bringing about some improvement.  We videotaped him with and without it one evening.  He reared and cramped himself up without it, and with it, the rearing was gone, but he still had head flipping and snorting episodes.  This past weekend, he was somewhat ok with it in his hunt seat classes, but truly awful with it and his bosal in the western class.  He has started to flip it askew on his nose, so last night I put a flash noseband over it to hold it in place (anticipating adding an elastic cord to secure it under the jaw if that worked), but there was no improvement.  I also tried hair nets and panty hose over his nose, but he tried to pull those into his mouth and eat them so I gave up on that idea.

I haven't tried him on allergy medicine yet, as I wanted to try the non-chemical routes first, but that is next on the list.  I have a jar of Hist-All that I will probably start him on today.

The other move at the top of my list is to see what other veterinary options are available.  I wanted to gather as much information on my own as I could to make the most of the vet's visit.  (That and my sick cat took over any available veterinary funds for the month).  I really hope that there is an effective surgical option available.  I would really rather physically stop the problem than have to constantly medicate him or have a would-be show horse that can't be ridden from April through October.

I honestly don't know what I'm going to do.  I got him to use as a riding and show horse.  He is a gorgeous horse and has the raw materials to be a good show horse, but we can't make any training progress if he's too bothered by his head to learn, and it seems foolish to keep hauling him to shows if I know he's going to have issues more often than not.  (Before I realized he had HSS, I was hoping that I could work him out of his anxieties/issues by taking him lots of places and doing a lot with him, but now I realize that it's a neurologic problem rather than behavioral in origin.)  He's pretty limited as a show horse if we can't trot in a straight line with our head pointed in (mostly) one direction.  I certainly hope there's a solution to this puzzle, but right now I just have a whole lot of pieces and no clear picture.