Sudden-Onset Cribbing and Headshaking
By Sue McDonnell, PhD, Certified AAB • Feb 20, 2014 • Article #14564
Q. My pony started tossing his head and cribbing at about the same time. The head tossing has increased to the point of not being able to ride him. He has had his teeth floated and has been checked by a vet for common problems. He has never had any problems before, and has always been a great pony hunter. I have changed bits and even used a hackamore, longed him with tack and he still has the same problems. He does not toss his head when turned out. This only happens when he is being ridden or under tack. It started in April and has gotten worse (now late September). Can you suggest anything?
Michele, via e-mail
A. In the case of a sudden onset of head tossing in a horse that has been a good performer for many years, it's always good to look long and hard for something physically irritating as the root cause. And in the case of your pony that started cribbing at the same time, it's probably even more important to keep looking for something physical that is bothering him. After what you have done already, it might be best to ask your veterinarian to refer you to a large veterinary referral hospital, for example a veterinary teaching hospital, where a team of clinicians with in-hospital imaging equipment can systematically evaluate the many possibilities. Repetitive head movements—headshaking, tossing, rubbing, etc.—can be provoked by almost anything abnormal in the head area—including ears, eyes, mouth, or guttural pouches. Infections, allergies, parasites, neurologic abnormalities—any number of conditions should be systematically ruled out. There is a condition known as photic trigeminal hyperstimulation, or photic headshaking syndrome, in which bright light induces rubbing, sneezing, and sometimes frantic headshaking.
It can be frustrating sorting out the relationship of headshaking with riding and tack. When the horse only does the headshaking when ridden or under tack, it might be the tack itself that is presently irritating the horse, or just that the tack and riding exacerbate an existing irritation. Theoretically, the behavior could become learned—it could continue after the irritation goes away. In my experience, this has rarely been the case. In other words, if you can identify and eliminate the physical irritation, the behavior immediately goes away.
These are some physical conditions that can cause headshaking and should be ruled out by a veterinarian:
- Teeth and mouth discomfort—dental problems, bit-induced injury/pain, soft tissue pathology in the mouth.
- Ear discomfort—parasites, abscess, inner ear infection.
- Respiratory discomfort—inflammation or irritation of airways in the head (for example, with allergies, vasomotor rhinitis, or congestion of nasal mucosa), foreign bodies in the nasal passages.
- Abnormalities in vision—serious "floaters" (one or more spots that appear to drift in front of the eyes), partial blindness.
- Eye pain or irritation—conjunctivitis (pink eye), corneal ulcer.
- Other head discomfort—guttural pouch infection, fractures, bone pathology, temporomandibular joint pain.
- Other disorders of the skull—temporohyoid osteoarthropathy (a.k.a, hyoid disease), neuropathology (for example, trigeminal neuralgia), equine protozoal myeloencephalopathy.