Equine Matters - Spring 2018

21 Equine Matters Spring 2018 What treatment options are available? Figure 2: Nose nets can improve symptoms in 75% of cases (Photo courtesy of Dr Veronica Roberts) Figure 3: Horse receiving EquiPENS therapy Grading: 0 no headshaking 1 mild and does not affect ridden exercise 2 headshaking at exercise enough to make ridden work impossible or dangerous 3 headshaking at rest The majority of headshakers are managed rather than cured as most current treatments have little effect on correcting the trigeminal hypersensitivity. The most common options for management and treatment are: Home treatment and management: l minimise known trigger factors such as avoiding bright sunlight or use a UV blocking face mask l use of a nose net (Figure 2) has been shown to improve symptoms in 75% of cases. Nose nets are thought to work by dampening down the nerve response by the contact of the material with skin (similar to when you bang your elbow and you rub it to make it feel better) l fly control l acupuncture Medical treatment: There are a large number of medical treatment options available; however, there is a very variable response to treatment and possible side effects to each drug. The most common drugs trialled in headshaking cases are: l antihistamines such as chlorphenamine maleate or cyproheptadine l magnesium supplements l melatonin l tegretol, carbamazepine, penobarbitone or gabapentin l pulsed steroid therapy Surgical treatment: Surgical treatments including cutting the infraorbital nerve and implantation of a platinum coil have been trialled. However these are now not recommended as recurrence of headshaking, severe pain and self-trauma were reported. EquiPENS TM therapy: Percutaneous Electrical Stimulation (PENS) therapy was pioneered by Dr Veronica Roberts MRCVS from the University of Bristol. The procedure involves the electrical stimulation of the trigeminal nerve and aims to re-set the threshold level for nerve firing to normal and hence normalise the facial sensations experienced. The safe procedure involves placing a probe directly over the nerve and stimulating it for a set period of time (Figure 3). It is performed in the standing sedated horse usually three times during a 15-day period and repeated if and when necessary. Current research suggests that 30% of those treated go into remission after three procedures with some still in remission over three years later. Of those that relapse, 80% go back into remission after another procedure. Euthanasia: Severe cases of headshaking may have a considerable welfare impact on the horse, preventing them from performing even simple activities such as eating. Cases may cause significant self trauma or become too dangerous to handle. In these cases the horse may need to be euthanised. Key Points: l involuntary, vertical flick of the head and nasal irritation l often worse during exercise and in the spring/summer l associated with pain within the trigeminal nerve l diagnosis often requires multiple diagnostic tests which may require referral to a specialist l there is currently no reliable cure but most cases can be managed with nose nets, medical treatment or electrical stimulation