Feline Orofacial Pain (FOP)

***Before taking the steps to participate in any of our research projects, please read the article here.

Lead contact: Lyons Lab –felinegenome@missouri.edu


Oral discomfort and tongue mutilation are the characteristic clinical and behavioral signs of feline orofacial pain syndrome (FOPS) in cats. The disease was first reported in the early 1990s (1). A follow-up study undertaken to better understand the condition reviewed findings in 113 cases, 100 of which were Burmese cats (2). Affected cats are most commonly presented with exaggerated licking and chewing movements, and pawing at the mouth. More severe cases develop self-mutilation of tongue, lips and buccal mucosa confined to one side of the oral cavity and lips (3).

FOPS is suspected of representing a neuropathic pain disorder and the preponderance of Burmese cats suggests an underlying inherited disorder, possibly involving central and/or ganglionic processing of sensory information arising from structures subserved by the trigeminal nerve. It seems likely that cats have parasthesias or allodynia as a response of subtle or even unapparent lesions in the teeth and/or gums. The disease is characterized by an episodic, typically unilateral, discomfort with variable pain-free intervals. In many patients discomfort is triggered by movements of the mouth such as eating, drinking or grooming. The syndrome is often recurrent and with time may become unremitting, with up to 10% of the cases being euthanized as a consequence of the condition despite treatment.

Population Study

The disease is also reported in other breeds, such as Burmilla, Siamese, British Shorthair, Somali and also within the domestic shorthair population. Retrospective analysis of cases reveals a peak incidence in immature Burmese cats (6 months or younger), with 75% of the affected cats having recurrent or ongoing problems (2).

Genetic Study

We are performing association and whole genome sequencing studies to identify the causal DNA variant for dwarfism in the Burmese breed. Cases of FOP in different breeds are welcome

How can you help?

  • We need diagnosis of FOP cats:
  1. If you are near MU – we will perform the diagnosis at no cost (if your cat has the common FOP clinical signs)
  2. Diagnosis can be accepted from other veterinarians – please contact the Lyons laboratory to obtain details on the types of information needed.
  • For the genome-wide association study (GWAS) approach (DNA arrays):
  1. We need buccal swab samples from FOP cats, their normal parents and siblings. Buccal swab instructions and the submission form can be found Once we have found the gene and the DNA variant, DNA from the buccal swabs will be used to type additional cats to verify the accuracy of our discovery and to develop a genetic test.
  • For potential whole genome sequencing (WGS):
  1. We need 6 ml of EDTA whole blood from trios of cats – two parents and an offspring – where one or two individuals are normal. Instructions for collection and shipping are found here.
  2. Gonads can be submitted for DNA isolation as well. If you have a cat that is to be altered / desexed/ neutered or spayed – we can use these tissues for the projects as well (WGS or GWAS). See instructions here.
  3. Tissues from a cat that you have recently had to be euthanized or has passed can also be submitted. We are sorry for your loss – but maybe this kitty can contribute to science for other cats. Instructions for tissue submissions are here.
  • Breeding information:
  1. We are always interested in your experience with breeding to demonstrate the inheritance of FOP. Since FOP cats have been found worldwide, we need to consider more than one causal DNA variant. Please share your knowledge and expertise.


  1. Roche GM (1994) Irritation from erupting teeth. Vet Rec 134:360.
  2. Rusbridge C, Heath S, Gunn-Moore DA, Knowler SP, Johnston N and McFadyen AK (2010) Feline orofacial pain syndrome (FOPS): a retrospective study of 113 cases. J Feline Med Surg 12:498-508. doi: 10.1016/j.jfms.2010.03.005.
  3. Rusbridge C, Heath SE, Johnson NW and Gunn-Moore DA (2002) Feline Orofacial pain syndrome. Proceedings of the 15th annual symposium of the European society of veterinary neurology, Philadelphia J Vet Intern Med.


This project was funded in part previously by the National Center for Research Resources R24 RR016094 and is currently supported by the Office of Research Infrastructure Programs OD R24OD010928, the Winn Feline Foundation and the Cat Health Network.