CASE OF INTEREST

A Case of Burdock Stomatitis in a Cocker Spaniel

By: Richard Fox, Veterinary Pathologist.

A 8.5 year-old, spayed female Cocker Spaniel presented to a local practitioner for difficulty eating soft food. On examination there were multifocal painful swellings of the tongue and lips. Biopsies were taken from the underside of the tongue. and submitted for histopathologic examination.

Histologically in one section a small, refractile piece of plant material surrounded by moderate numbers of eosinophils, macrophages, neutrophils with lesser lymphocytes and plasma cells, was present in the mid to deep submucosa. The histologic diagnosis were moderate, multifocal, nodular, eosinophil-dominated stomatitis with intralesional plant material (suspected burdocks spurs).

Burdock stomatitis is a relatively common, but rarely reported, condition of the mouth of dogs and, less frequently, cats. The burs of the lesser burdock (Arctium minus) become trapped in the haircoat where they cause local irritation and mat formation. Other plants from around the globe can be involved. Grazing animals that eat sharp grass awns, spiny plants such as the prickly pear cactus (Opuntia spp.) or plants with burs such as cocklebur (Xanthium spp.) may injure the oral mucosa. Some common grasses such as foxtail barley, bristle grass and sandbur have seeds with sharp awns that can become embedded in the tongue and gums of animals eating them ³.

The barbs of the burdock prevent easy removal and the burs inwardly migrate. Dogs especially, chew at them to try and remove them. in doing so, induce focal skin lesions but more commonly oral lesions ¹. The anterior aspects of the tongue, lips and nasal philtrum are usually affected. Excessive salivation, characterized by drooling or frothy saliva around the lips, is often seen in initial stages and animals may be anorexic (but some animals are asymptomatic ¹). Lesions often present as pale small papules. Advanced lesions may coalesce and ulcerate. Histopathology can be useful in determining that stomatitis is due to burdock and helps eliminate other aetiologies.

The only effective treatment is the removal of the material. Scraping with a scalpel blade over the affected area under general anesthesia has been used. The patient may be left with varying degrees of scar tissue, especially when the lesions involve the tongue ². Aftercare consists of systemic antibiotic therapy. Semi-liquid food should be offered until the lesions heal. Regular grooming assists in removing the burs and prevents the formation of lesions.

References:
1. Scott DW, Miller WH, Griffin CE. Muller and Kirk’s Small Animal Dermatology 6th ed. W.B. Saunders Company, Philadelphia 2001:1091
2. Thivierge G. Granular stomatitis in dogs due to burdock. Can Vet J 1973; Vol 14 (4):96-97
3. Georgi ME, Harper P, Hyypio PA, Pritchard DK, Scherline ED. Pappus bristles: the cause of burdock stomatitis in dogs.Cornell Vet. 1982 Jan;72(1):43-8.
4. Knight AP & Walter RG, Plants Affecting the Digestive System . Online @ www.ivis.org. 2003