Grass awns, also known as foxtails in the US, are sharp plant parts that have a way of becoming embedded in the flesh of pets during certain times of the year. To make matters worse, their arrow-like barbs mean they have a way of gradually advancing through tissues -- in some cases even into cavities -- so that affected pets can suffer life-threatening clinical signs, signs that may not appear until long after the plant's seasonality is past.
Because they can land anywhere on a dog's body and migrate where they will, the signs of foxtail foreign bodies are varied -- everything from coughing and respiratory distress to head shaking, gagging, eye pain, or lameness. But foxtails are most often described as being found in three separate locations: the oral cavity, thorax, and limbs (paws, especially). This is because they're often ingested, inhaled, or stepped on.
Many species of foxtail-like grass awns exist across the US and Europe. Working dogs with long hair performing non-urban, outdoor tasks are most often affected.
Symptoms and Identification
How foxtails make themselves known depends where they've entered, where they've migrated to, the severity of infection they've occasioned, and the kind of immune response they've recruited along the way.
Oral: Pets who have ingested or inspired foxtails will often get them stuck in their mouths or throats. Common signs include coughing, gagging, oral swelling, and lumps in the neck after these areas become infected.
Thorax: If inhaled, foxtails can lead to severe respiratory reactions, including pneumonia, pyothorax (pus in the thoracic cavity) and pneumothorax (air in the thoracic cavity). Coughing and respiratory distress are the most common signs.
Limbs: Lesions related to the entry and migration of grass awns in paws and limbs of pets can appear like swellings or like nothing at all. Pets may lick at these areas or limp when they walk.
Other: Because they're so wily, grass awns can migrate into eyes, ears, through nostrils, and even into a pet's brain! That's why even neurological signs and blindness can be suspicious for foxtail foreign bodies.
Diagnosis of foxtail foreign bodies is usually made in one or more of the following ways:
Visual inspection and/or exploration of visible lesions or affected area
Ultrasound of visual lesions or affected area
X-rays of lesions or affected area (the head, neck and chest are most amenable to this method)
Definitive diagnosis, however, can only be achieved via identification of the offending grass awn. Surgical exploration is therefore commonly undertaken by way of definitive diagnosis.
There is no breed predisposition. However, hunting and working dog breeds popular in grass awn-rich locales are more likely to be affected than other breeds of dogs.
Treatment of foxtail foreign bodies requires their extraction and the resolution of any resulting infection or inflammatory process. Once they've migrated, surgical excision of the foreign body, drainage of any accumulated infected debris, debridement of any necrotic tissue, and treatment with appropriate systemic antimicrobials is typically undertaken.
The cost of diagnosis can be extensive, especially if it's not exactly obvious that foxtails may be the underlying cause. But even when a foxtail foreign body is suspected, the cost of X-rays, ultrasound, and surgical exploration can be prohibitively expensive to many due to its inherent difficulties.
Pet owners should expect the cost of diagnosis to range from about $50 for extremely obvious isolated incidents, $200-$500 for relatively straightforward cases of grass awn migration to $1,500 or more for those whose conditions require more extensive imaging to ascertain the extent of.
Treatment can be a simple affair, requiring no more than a ready way with some tweezer-like tools to an extensive, high-tech game of hide-and-seek. For this reason, the cost of treatment typically varies anywhere from $20 to $200 for an uncomplicated case to over $5,000 for cases that require surgical exploration of the chest cavity and extensive treatment of this sensitive area.
Preventing foxtails is possible by avoiding areas known to harbor these plants during certain times of the year. Inspecting dogs after they've been outdoors in grass awn-friendly locales is important, too. Brushing dogs to remove any debris in the haircoat (especially with heavy-coated dogs) can be helpful. Clipping long-haired dogs down during the foxtail's season is also recommendable.
Finally, heading to a veterinarian at the first sign of an embedded foxtail is crucial to prevent it from migrating any deeper into the tissues. Never delay!
Brightman AH, McLaughlin SA, Brogdon JD, et al. Intraorbital foreign body in the dog: a case report. Vet Med 1985;80:45-48.
Brennan KE, Ihrke PJ. Grass awn migration in dogs and cats: a retrospective study of 182 cases. J Am Vet Med Assoc 1983;182:1201-1204.