Fencing your dog can protect him from parasites. Fencing your dog can prevent many dangers including car accidents and eating toxic substances in garbage. Though a fence can help keep a dog safe, fencing will not protect the dog from all parasites.

A dog that is not fenced may be at greater risk for hookworms if the dog goes to an area where a dog with hookworms has defecated. The hookworms could be present in the feces or ground around the feces. Hookworms can burrow through the skin of a dog to infect the dog.

Threadworms can be acquired through the skin by being near feces from infected animals as well. Threadworms cannot only be passed through feces of infected dogs, but also other carnivores. Fencing can protect the dog from being in contact with feces from infected dogs, cats, or wildlife.

A potentially dangerous parasite that can infect a dog that eats an infected animal is gnathostoma. After being ingested, the gnathostoma burrows through the dog's stomach and travels around the dog's body causing damage before returning to the stomach. This is another parasitic infection that's risk is reduced by fencing since a dog fence keeps the dog isolated from most other animals.

Like the gnathostoma, the spirocerca lupi is acquired by eating an infected animal. Spiocerca lupi lives in the dog's stomach after being ingested. Spirocerca lupi can cause damage to blood vessels and cancer of the esophagus.

A dog is at risk for certain parasites while the dog is outdoors whether the dog is fenced or not. Mosquitoes cannot be stopped by fences and are usually responsible for heartworms in dogs.

The risk of fleas and ticks can be greatly reduced by a fence which keeps the wildlife and other dogs out that may carry ticks and fleas, but fleas and ticks could still be present in a fenced area. Spraying outdoor areas for ticks and fleas can further reduce the risk of ticks and fleas.

Another parasite that could live within the dog's fenced area is the cuterebra. The eggs of cuterebra can be found in soil or on rocks and may be ingested. The eggs may develop into larvae that penetrate the skin of the dog or other host.