Current recommended treatments to reduce or eliminate headshaking syndrome symptoms:
Important note: Headshaking syndrome is caused by the hypersensitization of the cranial facial nerves (trigeminal nerves). Therefore it is best to reduce anything that causes the nerves to fire more frequently. Exposure to sunlight is number one! The next trigger with the biggest reaction appears to be riding or working the horse. It is very important not to continue work once the headshaking is seen. It will only make the headshaking worse. It is ok to try to work the horse daily but the minute the symptoms start it is best to stop the work. These horses are in extreme pain!
I feel it is best to start with the safest treatment first. I suggest the following order:
Most important first treatment for ALL headshakers: No daylight! Not even a few hours! This may drastically reduce the symptoms!
A 90% UV blocking mask on 24/7 (see section on optic trigeminal summation)
Lighter mask, possibly the ones online with the visor, for riding and grooming
Screened or otherwise dark stall during the day, turn out at night, if possible
Nose net for riding
Bug repellents, garlic, fly spray and sheets (they are very sensitive to bugs!)
Magnesium supplementation (MagRestore or Quiessence) at high doses (gradual introduction and increase until symptoms are reduced ( maybe 3-4 times recommended dose, refer to your vet) then decrease to effective amount)
Cyproheptadine (if colicky reduce dose and gradually work up again)
Dexamethasone pulse therapy
Combination dexamethasone and cyproheptadine (currently being studied, see new research section)
Antihistamines and/or allergy desensitization shots
Some owners have reported positive results with cranial sacral treatments by a qualified chiropractor.
1. Dexamethasone Pulse Therapy (injectable liquid): I have been recommending this protocol for many years due to the mostly positive feedback from owners. It seems as though it works well for some and not at all for others. Many owners have stated that it saved their horse’s life. With that said, I was disappointed to see that the study we did with New Bolton did not show significant improvement overall with the dex pulsing. We did have some problems with the data collecting. I still think it is a good treatment for those horses that respond to it.
All doses are given ORALLY by syringe. It is best to avoid giving it in the feed if possible.
You can use less liquid if you use the 4mgs/ml concentration.
Give 60mgs liquid dexamethasone, ORALLY, daily, for four consecutive days.
Repeat in 21 days.
Important! This dose is for a 500kg horse. Adjust dosage to weight. Be careful in your calculations and conversions from mgs to mls or ccs. Get help from your vet with this.
Example dosing: 1100 lb horse
Dexamethasone 2mg/ml concentration you would dose 30cc to get 60mg.
Dexamethasone 4mg/ml concentration you would dose 15cc to get 60mg.
Remember, this is ORALLY!
Even though you are using the injectable liquid you will be giving it ORALLY.
Continue protocol for at least 4-6 months. After that you may extend out the time between pulses gradually to every 28 days, 32 days and so on. Resume the above protocol if symptoms start to appear. Most horses eventually only need to be pulsed seasonally as they start to have symptoms and can go off the treatment in the off season.
Although the pulsing greatly reduces the chance of side effects, this protocol is not for use in horses with cushings, founder, laminitis or any infections. I have never had any serious side effects reported to date and I have treated hundreds of horses with this protocol, but there always is a chance that a side effect may occur.
If your horse has a sensitive tummy you can give some aloe vera or other soother.
Low doses of steroids with long term tapering do not appear to be effective! The desired effect is dose and time dependant.
2. Cyproheptadine: an antihistamine and serotonin antagonist. Sedation and colic are the main reported side effects. Dosage: 0.3mg/kg twice daily orally or as directed by your vet. Again liquid administration by syringe is best to make sure he gets all the medication. See new research on the dex pulsing combined with the cyproheptadine.
3. Use of a nose net for counter-stimulation: Used when riding. This takes a few times for the horse to become accustom to it. It is best to only put it on for a few minutes at first and walk or lunge the horse so he can gradually get use to it. Some horses do ok with a weighted half net or beads. Some do not tolerate these at all
Guardian Mask or other 90% UV blocking face mask: helps with sunlight sensitivity and should be used at all times, 24/7 for full effect.
5. Stall screens, dark stalls
6. Diet:I have not found changing the diet makes too much difference. No alfalfa, rye grass or clover, as these are allergenic. A mineral block or balancer may be helpful. Adding 1-2 T sea salt is recommended. It is healthier for the horse to have a low protein and low carbohydrate grain in the smallest amount needed.
7. Magnesium supplementation: Magnesium helps by calming and reducing the nerve firing. It will reduce the symptoms but not eliminate them completely. Magnesium can be found online and under links on this website. Give between 20-30 grams daily. Introduce gradually.
8. Trigger Avoidance:
Triggers include anything that initiates tics such as:
Sunlight: use mask, UV screens and blankets, dark stalls, night turnout
Wind: avoid fans directly on face or fan sounds
Riding: may be possible with mask or nose net. Otherwise do not ride
when symptoms are present.
Bathing and/or grooming: soft brush, avoid soaps near face.
Stress: slow quiet work, long and low
Bugs: fly repellant, fly sheet and mask, avoid riding in tall grass
9. Allergy desensitization: Often the first inclination with headshaking is to assume it is caused by allergies due to the symptoms. Unfortunately the treatments with antihistamines do not appear to be very effective. Not many horses stop headshaking with allergy desensitization alone. I have had a few that stopped with the combination of dex pulsing and the allergy shots but I think it was mostly because of the dex.
It is preferable to do a dermal test (gold standard) at a vet school or clinic where they do many allergy tests. Blood testing may also be done. I like Bio-Medical labs the best. I feel like the reason many horses are not helped by this treatment may be because of the quality of the lab.
This may be useful data for investigators and your own veterinarian.
If you choose to also do the dex pulsing, do the allergy testing before starting the dex treatment. It does take at least 6 months to see results. Often tests need to be redone if the horse is moved or continues to have symptoms. Sometimes the shots can elicit headshaking symptoms but these are temporary.
I strongly recommend keeping a daily journal and would appreciate getting any data that you observe.
More information on dexamthasone:
“ Dexamethasone … is used in high doses … for anaphylactic reactions, spinal cord trauma, or shock”. This implies that it is useful for allergic reactions, nerve compression, or toxemia. “Systemic side effects to corticosteroids are generally dependant on dose and duration of the treatment. Short-term administration of even large doses is unlikely to cause serious harmful side effects due to adrenal suppression”. (Dexamethasone For Veterinary Use, Forney, Barbara, DVM, www.wedgewoodpharmacy.com/monographs/dexamethasone2.asp).