The Dangers of Cheatgrass and Dogs

Tiny grass seeds can cause enormous health problems for hunting dogs without better prevention or awareness of the risks

Dr. Lindsay Vega was a second-year veterinary student pursuing her doctorate from the Virginia-Maryland College of Veterinary Medicine when she observed a board-certified surgeon remove a foreign body from a coonhound’s ear canal. Although that was eight years ago, she remembers that day well.

The hound under the knife that day was her then-foster, Jillian, a pure-bred Treeing Walker Coonhound born near Blacksburg, Virginia, to hunt raccoons, deer, bear, or large cats, but before she was given a real chance at developing, her prior owners decided they wanted her euthanized for “health issues.” Those health concerns arose from a persistent ear infection as well as an abscess above her eye, but the shelter refused to euthanize her based on her otherwise good health. At that point, officially a surrendered pet, Jillian was taken in by a local rescue affiliated with the VT-UMD vet school. Over the following six months, Jillian bounced around foster homes and the rescue. Plus, her ear infection wasn’t getting better, no matter what topicals, antibiotics, or ear flushes veterinarians gave her.

“She had a lot of calcified extra tissue from chronic inflammation so, instead of continuing to be on antibiotics long-term, the decision was made to remove her ear canal surgically with a total ear canal ablation. When they went in, we didn’t know what could have been causing it. It could have been a cancerous process or foreign material, and when they performed the surgery I got to watch. When we got down into the middle ear canal there was an actual piece of plant foreign material with barbs—it was a grass awn.”

“It was something the surgeon there had never seen and was pretty excited about. The infection would have never cleared up with it being in her ear. So after we took her ear canal out, the infection completely went away and she hasn’t had an issue since.”

Jillian, now 10 years old, has lived a long happy life with Vega since the days of her stinky ear infection, albeit no longer hunting. With that, Jillian’s story brings to light the risk grass awns pose to animals—especially hunting dogs.

What is a grass awn and why do they matter to matter to hunting dogs?

Grass awns are sharp, barbed seeds that are dropped by annual grasses like cheatgrass, Canada wild rye, and foxtail that work their way into animals’ skin and continue to move inward. They can also be inhaled. If not caught soon enough, a seed can dig through the skin into the subcutaneous layers and will eventually work its way into the chest cavity or other parts of an animal’s body and do serious damage—sometimes killing the animal.

“Their sharp edges can lodge into tissues and they can cause local wounds that have obvious plant-foreign material in it, to actual deep infections under the skin to things such as infections along the spine and the muscles; to even infections within the chest where pus will set up and eventually cause enough inflammation to create fluid, and that fluid will eventually restrict their ability to breathe,” Vega explained. “Your dog isn’t going to look at you and tell you it can’t breathe. If there’s fluid preventing the lungs from expanding and getting enough oxygen, your dog’s respiratory rate and effort may be increased more than usual, it may be panting more frequently, and may become lethargic, restless, or less tolerant of exercise.”

Vega further explained that grass awns are a “zebra” or a rarity among differentials at her practice in West Virginia. This, however, can vary depending on the region the doctor is practicing in. An example is Dr. Joe Spoo, a veterinarian based in South Dakota, who sees the damage grass awns do frequently.

“We see it multiple times a year,” Spoo said. “We’ll have them in the chest where the dog’s chest is full of pus and dying, to migrating in the muscles of the back and the sides. It’s one of my pet peeve conditions. My own setter, I think 15 years ago, I ended up in her chest because she had a migrating awn that was on the outside that we ended up poking in the chest. So I’ve dealt with it personally. If these seeds get into the musculature, it can truly be like a needle in a haystack and it can kill these dogs and be quite expensive with quite aggressive care.”

“Here in South Dakota, the primary two awns we see are foxtails and Canada rye. My dog had Canada rye, and part of that is it’s in a lot of the initial plantings. So when we reclaim land and put it back into CRP or whatever, the USDA initial seed mixes and even Pheasants Forever seed mixes contain Canada rye because it’s quick, good ground cover but this is the downside of it.”

Spoo noted that some groups are lobbying against these seeds being included in the mixtures, but the push back is that these are habitat projects for birds and wildlife, not protection for dogs.

Outside of reclamation work, grass awns are also common in areas where cheatgrass has a death grip on native species. The best example is the Great Basin. According to a 2004 study by Columbia University, cheatgrass was introduced to the western United States in the late 1800s, first in Washington in 1893 and in Utah a year later. Then, as folks took part in gold and silver rushes, cattle were transported to mines, and “previously ecologically isolated areas” became ranches, which then led to overgrazing.

“Overgrazing was identified as a serious threat to ecosystem health in the late 1800s, but by this stage, the damage had become so widespread that it was effectively irreversible,” the study states. “Because of a lack of intensive grazing pressure throughout evolutionary history in these areas, grasslands never developed the resilient and competitive native sod-forming grasses that might thrive under conditions of overgrazing, and instead are characterized by a delicate layer of cryptogams covering the soil between shrubs, which are susceptible to damage from cattle. Thus, the alteration of natural ecosystem processes essentially created a new and open niche, prime for occupation. It seems possible that B. tectorum may actually have been introduced into rangelands on purpose to stabilize damaged shrublands.”

Then in the 1940s, Aldo Leopold began to see the long-term effects of cheatgrass’s spread. His warnings went unheard, however, and now, eighty years later, we’ve reached a point where areas that once thrived and provided food and cover for many different species, such as sagebrush habitat, are now losing ground to the invasive annual.

Climate change and the spread of cheatgrass

As our climate changes, wildfires fuel the expansion of cheatgrass, as it is able to spring up every year much more easily than native plants like sagebrush. It also helps fuel the very fire cycles it has changed. According to the same Columbia University study, “Cheatgrass has a life cycle such that it is regarded as a winter annual. It seeds in late summer and germinates in fall. Its seedlings over-winter and those that survive have the advantage in spring of having hearty root and photosynthetic systems while other species are establishing. Early in the season, cheatgrass produces above-ground biomass sooner and in greater bulk than its competitors, so that it dries after seeding in summer before the autumn rains. This creates large quantities of fuel during the dry season. Moreover, it is distributed more continuously than native vegetation, guaranteeing the faster spread of fire in addition to increased frequency. Thus, cheatgrass can reduce the time between fire events to as little as 10 years, effectively decimating its native competitor’s chances of success.

“In addition, and perhaps more subtly than the effect on changing fire season, cheatgrass and native shrubby vegetation have different mycorrhizal requirements. Native shrubs are obligate symbionts with vesicular-arbuscular mycorrhizae (VAM), while cheatgrass is merely a facultative symbiont. Thus, it out competes native vegetation in circumstances in which disturbance and thus the disruption of soil infection with mycorrhizae is more frequent. Thus, here again, cheatgrass has a competitive edge when grazing and frequent fires are introduced into native ecosystems.”

What are ways to mitigate cheatgrass and its damage to hunting dogs?

Wildlife agencies have begun combating the spread of cheatgrass. According to Moser, many western states are turning to an herbicide, Imazapic, that’s proven to be successful in Oregon, Nevada, and Idaho for certain applications.

“You can fly it on with an airplane right after the fire, and what it does is suppress germination of those annual grass seeds in the soil,” Moser said. “It appears to not affect the perennial grasses—it can knock them back a little bit, but we’ve seen some good results with it. It doesn’t prevent cheatgrass from coming back forever, but after that fire, it prevents it from coming in and outcompeting the natives. So if we can reseed on top of that, especially with sagebrush, we’re giving it a good advantage since it’s not competing with cheatgrass. Nothing’s perfect, but we are getting better at restoration.”

Further, while work needs to be done to reverse the climate change trend we’re currently on—or at the very least mitigate damage from it—there are avenues that hunters can take to protect their dogs as much as possible without waiting for government agencies to take action.

Spoo’s answer? Know what grasses can cause damage to your dog, and then avoid those areas altogether.

“There’s not a preventative sort of thing,” he said, “other than being able to identify when you’re hunting in areas that have these types of grasses. Depending on where you hunt, the plants in your area that can do this to dogs because it’s a devastating thing. I grew up in northwest Iowa and there’s tons of ground that they brought back for public hunting and I don’t hunt them because of the degree of Canada rye. There are places out here in South Dakota where there are tons of foxtails that I choose not to hunt my dogs in those areas.

“A bit of the preventive part is to become a bit of a botanist as a hunter and understand these areas that contain these and what it looks like. The dogs you get more concerned about are the ones that likely inhale these and they pop out of the lungs and start migrating into the body, or come in along the chest wall. And there’s not anything you’re going to do to prevent that other than trying to avoid that heavy inoculation of those seeds. Identification is huge.”

He also believes some dogs are more predisposed than others: Springers, Setters, and Shorthairs, mostly. He pointed out that Springer owners have created a site dedicated to understanding potentially deadly grasses called meanseeds.org. Also, both doctors agree that if you can’t avoid these areas, grooming is of the utmost importance.

“We see it in other breeds, but not representative to the degree we see of those dogs out in the field,” Spoo said. “Here in South Dakota, tons of Labs, tons of Wirehairs, and having those types of dogs, if you hunt through an area that has these types of seeds, combing the dog out when you get back to the truck and making sure we don’t leave some of these seeds to penetrate the body is important. But as far as a preventative, out-in-the-field thing, I think it’s almost impossible. Some of these products like the net over the dog’s head, I don’t know how effective a dog will hunt and scent with that type of apparatus over its head.”

Finally, Spoo noted that more veterinarians and owners need to be educated about grass awns and the horrendous potential they have once they’ve dug into a dog’s body.

“A lot of these start as a little swelling that people think is just a swollen abscess or a little tumor,” he said. “I treat these like aggressive cancer because they can cause so much unseen damage that when you get in there for surgery it’s a disaster. If you hunt but live in an area where your vet doesn’t see a lot of hunting dogs, being able to explain to them that this is a potential possibility and asking, ‘Have you dealt with it?’ is huge. Truly, avoidance and early recognition when the problem happens is the key to successful treatment.”

Overall, this is an under-recognized problem in both the veterinary world and the hunting community. Whether annual grasses are spread by man-induced climate change or man-made seed mixtures, many dogs have suffered or perished from these small seeds. Moving forward, more focus needs to be turned on how to properly mitigate these issues, for the sake of the sport and the animals we hold so dear.