Encephalitozoon Cuniculi in a Dog

While more common in rabbits, encephalitozoon cuniculi can also infect dogs.
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In a dog’s world, sniffing and licking are a way of exploring his surroundings. Unfortunately, those actions often cause him to pick up unwanted parasites. One of these parasites, Encephalitozoon cuniculi, causes a parasitic infection known as encephalitozoonosis or microsporidiosis in dogs. At the same time, these parasites are zoonotic and able to spread to humans and other animals, making isolation and precautions essential when dealing with a sick dog.

How These Parasites Infect Your Dog

Encephalitozoon cuniculi infections are common in rabbits but, while rare, can affect dogs and other mammals, including humans. The parasite enters the body when a dog sniffs or licks urine from an infected animal. The parasitic spores spread throughout the body where they can lead to infection.

Symptoms Depend on Age Acquired

Once spores enter the body of an adult dog, lesions begin to grow on the brain, heart, kidneys and lungs. Symptoms can include brain abnormalities, aggressive behavior, seizures, blindness and kidney failure. Adult female dogs can pass the infection to unborn puppies. Symptoms seen in infected puppies include stunted growth, neurological complications, poor hair coat and failure to thrive. Severe infections typically occur in newborn puppies or adult dogs with weakened immune systems.

Treatment Focuses on Supportive Care

In most cases, healthy dogs that become infected with encephalitozoon cuniculi recover without the need for medical treatment. No treatment currently exists that will effectively kill encephalitozoon cuniculi. Any treatment is supportive in nature and can include intravenous fluids and fungicidal drugs. In cases of severe infection, where there is severe brain disease or kidney failure, euthanasia is often the only humane option.

Reducing the Risk of Spreading

Because encephalitozoon cuniculi can cause infection in other animals, including humans, it is essential to disinfect areas where infected animals have urinated. Clean any areas exposed to urine with a 70 percent ethanol solution in order to kill any spores. Keep your dog isolated from any other pets. If you or other family members are immune-compromised, avoid all contact with an infected dog. Use gloves when handling your dog as well as when cleaning soiled areas. Encephalitozoon cuniculi spores can survive in the environment for months, so thorough cleaning is essential to prevent reinfection.