When Grass Goes to Seed – Beware of Grass Awns

Henry is a handsome 9 year old Standard Schnauzer with lots of coarse, silver fur. He is our Pet of the Month for September. In August, he was seen at Hawthorne Hills Veterinary Hospital after he started licking persistently his left front paw. He had licked the fur away and made the area quite red and swollen even though his owner had just noticed the lesion the day before. During our examination, we found a second area of swelling and bruising on the backside of his rear leg.

 

Both areas were quite tender to the touch so we sedated Henry and gave him pain medication to allow us to open the wounds and explore the area. We discovered a grass awn embedded in the wound on the right front paw, see photo below. The wound on the hind leg was a large abscess presumably also from a grass awn although we were not able to find one under the skin. Grass awns are a common source of foreign bodies and can be quite painful. With Henry’s thick fur, we advised the owner to keep her scheduled appointment with the groomer and have Henry shaved short. The groomer did find a number of additional grass awns caught in the fur. Fortunately for Henry, he has made a complete recovery.

During the dry part of the year, especially late summer, wild grasses [examples: Cheat grass, Foxtail, Feathergrass] produce seed pods that can pose a significant health risk to you and your pets. The grass seeds, referred to as ‘grass awns’ or ‘foxtails’ have a sharp fan of bristles with tiny little barbs that allow the grass seed to attach to a variety of surfaces and be transported to a new location. This works well for the plant to disperse seeds, however when those seeds attach to your pet’s fur, the consequences can be problematic. The pointed end of the grass seed can puncture through the skin and allow the seed to migrate through the body, sometimes quite a distance from the initial entrance point. Patients have been found with grass seeds in the chest, in the nasal passages, in the ears, in the eyes, and in body organs.

Symptoms that might indicate a grass awn foreign body:

• Persistent licking at an area of the body, especially if there is a visible lesion
• Limping or painful paws
• Evidence of swelling or a draining wound
• Violent sneezing
• Shaking the head, rubbing the ears persistently
• Rubbing the eyes, squinting the lids closed, increased discharge or redness

Treatment is focused at finding and removing the seed. However, it can be challenging to search for and find the seed once it has penetrated the body. The inflammation combined with the fact that the seeds can migrate under the skin, make it difficult to locate the seeds. Sedation or anesthesia is often required. Depending on the location on the body, and how many seeds are involved, it may take repeated attempts to locate and remove grass awns. Persistent licking, limping, swelling or draining tracts, are all indications to look further. Once removed, in most cases, the symptoms resolve within a few days.

Prevention is the best plan. If your pet goes hiking with you, romps through fields of tall grass, plays in a yard with ornamental grass that has gone to seed or loves to sniff and walk through weeds along the city trails, they are at risk. Trimming long haired breeds shorter helps, but even short coated dogs are vulnerable too. Check your pet’s fur daily for any seeds or other debris caught in the fur; pay particular attention to the paws, armpits, ears, tail and groin. Comb the fur to remove all mats and tangles. People can get grass awns caught in their clothing, especially socks. If you notice seed pods on yourself, inspect your pet carefully. If you think your pet has encountered grass awns make an appointment with your veterinarian as they can check your pet’s ears and eyes in addition to any area of swelling or discomfort.

 Images of grass awns

Robin E. Riedinger, DVM Hawthorne Hills Veterinary Hospital, Seattle WA | Foreign Body, Infections, Lumps and Skin Masses