Restraining Your Dog: It’s the Leash You Can Do
Protecting the land under its care is a fundamental mission of the Sudbury Conservation Commission. When conservation lands also feature trail systems or are otherwise accessible to the public, protecting them can pose a particular challenge. Here in the densely populated metro-Boston region of eastern Massachusetts, conservation and recreation values are frequently at odds with each other. The goal of the Commission is to strike a meaningful balance that bolsters both.
To that end, in 2009 the Commission adopted its Land Use Policy & Regulations for Use of Sudbury Conservation Lands. The very first paragraph reiterates their mission: “to preserve and protect the Town’s valuable water, land, animal, and plant resources for the benefit of present and future generations … to educate the community on the benefits of resource protection and to encourage community participation in all town resource issues; to promote enjoyment and stewardship of our open spaces and natural resources.” In support of this, the policy regulates many common outdoor activities, such as camping, boating, bicycling, swimming, and so forth.
It should come as no surprise that another popular activity on conservation land is dog walking. There are a lot of dogs in the United States. According to the American Veterinary Medical Association, almost 60 million households kept dogs as pets in 2024. Nearly half of all homes in this country, or about 46%, have at least one pooch. This figure is mirrored in Sudbury, which contains about 6,300 households with approximately 3,000 licensed dogs. As of January of 2024, the Conservation Commission’s policy regarding dogs aligns exactly with Chapter 117—Article II of the Town’s General Bylaws; dogs must be restrained with a leash whenever outside of their owner’s premises, including conservation land.
What exactly is the cause for concern? To paraphrase the old saying, many folks consider their dogs to be their best friends, or even family. The bond that a dog makes is powerful and uncomplicated. Be they chihuahua, Great Dane, or another of the myriad breeds and mixes, they make us a part of their wolf pack. And as domesticated wolves, the call of the wild is never far away. For those dog owners who enjoy nature as much as they love their pets, the temptation to let them slip the leash and heed the Call can be great.
While our feelings may be uncomplicated, the interaction between a free-roaming dog and the natural world is not. By keeping our dogs on a leash, we can effectively avoid potentially tragic outcomes. There are numerous risks, including injury, disease, wildlife disturbance, and habitat degradation.
As coyotes, coy-dogs, and coy-wolves increase their numbers in eastern Massachusetts, encounters are becoming more frequent. Generally, these newcomers keep to themselves. However, there have been cases of dog attacks. According to Dave Wattles, a wildlife biologist with Mass Wildlife, attacks on dogs that have been leashed are uncommon, as coyotes are typically shy in the presence of humans. However, an off-leash dog exploring far from its owner, may not have the benefit of their protection. Pack mates protect each other. Leashing your dog is one thing we can do to co-exist with coyotes who, in controlling populations of prey animals, fill an important ecological role.
The spread of avian flu is another concern. If your dog eats an infected bird, they are at risk for developing the disease. Death has been known to occur in some instances. As recently as 2023, a dog near Toronto, Canada, developed respiratory symptoms and succumbed after eating a dead goose. With cases of avian flu on the rise around the globe, the likelihood of encountering an infected animal may also be increasing. Again, by leashing your dog, you are lowering the odds that this will happen.
Conversely, birds are at risk from off-leash dogs. This is true not just in the case that a dog actually catches a living wild bird. The more pernicious impact is the disturbance caused by the mere presence of dogs. Sensing danger, birds can abandon their nests, leaving the eggs vulnerable to predators and the elements. Additionally, birds and other wildlife tend to avoid areas that have been scent-marked by a canine.
That is just one of the possible impacts to the natural world. Dogs can also disrupt vernal pools, a threatened habitat. Amphibians, some threatened or endangered, can be particularly affected. Wood frogs, spring peepers, and various salamander species deposit their egg masses in vernal pools every spring. Wading dogs can dislodge the eggs, thereby further jeopardizing species already in decline.
Dog waste is another issue. Most dog walkers will bag their dog’s waste and carry it off-site for proper disposal, be it out of respect for their fellow trail users, out of love for nature, a wish to abide by the rules, or some combination of the three. Dog waste can hypercharge the soil with nitrogen, altering it to favor the growth of invasive and potentially harmful species. Dog waste can also act as a conduit for parasites like roundworm. As presumably everyone will agree, it is also downright unpleasant for those who have had the singular misfortune of having to scrape it off their hiking boots. When a dog is off-leash, the owner is less likely to be aware of when their dog has made a “deposit”.
Lastly, consider this: as adorable and friendly as a dog may be, other trail users may not wish to engage with him or her. A friendly pooch barreling down the trail towards another hiker may be a pleasure for those who can interpret canine behavior and welcome the interaction, but it can be anxiety-provoking for others. It is the wish of the Conservation Commission that everyone who visits Sudbury’s conservation land is able to enjoy it.
To put this in a familiar real-world context, consider our Hop Brook Marsh Conservation Land. Just off of Dutton Road, nestled amongst nearby Sudbury Valley Trustees and Federal conservation lands*, it is among the most popular open space destinations in Town. It also hosts numerous endangered or threatened animal species under the protection of the Natural Heritage and Endangered Species Program, including various species of salamanders and turtles, as well as ground nesting birds. Unleashed canine visitors in this sensitive habitat can wreak havoc. Another problem is the erosion of banks at points along the Hop Brook itself. This is caused by off-leash dogs repeatedly entering the water for a swim. Erosion affects water quality and consequentially aquatic wildlife. (*Please be aware that the SVT and the United States Fish and Wildlife lands have their own policies.)
As always, the Sudbury Conservation Commission welcomes and encourages you to visit the Town’s Conservation Land. And if you have a companion of the canine variety, this warm invitation includes them as well. We acknowledge that, just like their humans, dogs can benefit from immersion in natural and open spaces. However, keeping dogs on a maximum 6-foot leash is the law and is enforced with monetary penalties. In advance, we extend our sincere appreciation to all visitors for being mindful and considerate of their responsibility to each other, and to the wildlife in whose home we are guests.
Please click here for our brochure regarding the benefits of the Leash Law.