If you’ve spotted a squirrel acting strangely in your yard or neighborhood, you may be wondering if it’s infected with raccoon roundworm. This parasitic worm is common in raccoons and can be fatal for squirrels. So how long can an infected squirrel survive?
Keep reading to learn everything you need to know about raccoon roundworm and its effects on squirrels.
If you’re short on time, here’s a quick answer to your question: Infected squirrels typically only live for 2-4 weeks after being infected with raccoon roundworm. The parasite attacks the squirrel’s central nervous system and causes significant neurological impairment that eventually leads to death.
What is Raccoon Roundworm?
Definition and background
Raccoon roundworm, also known as Baylisascaris procyonis, is a parasitic nematode (roundworm) that inhabit the small intestines of raccoons. These worms can grow up to 15 centimeters long and produce thousands of eggs per day which are shed in the feces of infected raccoons.
Baylisascaris procyonis was first described in 2002 by the American parasitologist Asa Chandler. Since then, it has become recognized as one of the most common and widely distributed parasitic roundworms infecting raccoons across North America.
Raccoons serve as the definitive hosts for B. procyonis, meaning the worms mature to adults and reproduce within the raccoon’s intestine. The eggs are then passed in the feces, where they can survive and remain infective in the soil for several years.
Life cycle and transmission
B. procyonis has an indirect life cycle, meaning it requires an intermediate host to develop from an egg to the infective larval stage. Over 90 species, including squirrels, mice, and birds can serve as intermediate hosts after ingesting infective eggs from the environment.
Once ingested by the intermediate host, the eggs hatch in the intestinal tract and migrate through the body tissues where they develop into larvae. The life cycle completes when a definitive host like a raccoon predates on the infected intermediate host and ingests the larvae, which then mature into adults in the small intestine.
Humans can also suffer accidental infection through ingestion of infective eggs from contaminated sources. While humans do not support the complete life cycle, migrating B. procyonis larvae can cause significant clinical disease.
Prevalence and distribution
Raccoon roundworm is endemic in raccoon populations across the United States and Canada. Studies have found infection rates from 68% to 82% in certain areas. The worms are most prevalent in regions with high raccoon densities.
B. procyonis has also been reported in parts of Europe and Asia where raccoon populations have been introduced. Increased urbanization and overlap of raccoon habitats with human settlements have contributed to the spread of this parasite.
Clinical cases are uncommon but can be severe when humans accidentally ingest a large number of eggs. Children are particularly vulnerable due to behaviors like putting contaminated material in their mouths.
Effects of Raccoon Roundworm on Squirrels
Neurological impairment
Once infected with raccoon roundworm, squirrels can suffer severe neurological issues over time as the larvae migrate to the brain. Common symptoms include lack of coordination, imbalance, circling movements, apparent blindness, and seizures.
As the infection progresses, squirrels become increasingly debilitated and lethargic.
Studies have shown that over 90% of infected squirrels exhibit central nervous system disorders. Autopsies reveal significant inflammation and damage to brain tissues caused by migrating larvae and their waste products.
These neurological impairments eventually lead to mortality if not directly treated.
Physical symptoms and behavior changes
In the early stages of raccoon roundworm infection, squirrels may show no visible symptoms. After a few weeks, subtle signs like weight loss and matted fur can appear as the larvae travel through the body.
More obvious later stage symptoms include muscle tremors, impaired vision, tufted ears, and awkward movements. Infected squirrels also tend to act abnormally tame or aggressive due to the neurological effects.
According to wildlife rehabilitators, it’s important to observe squirrels over an extended period to determine if emerging symptoms require intervention. Strange behaviors may indicate a potentially fatal roundworm infection.
Ultimate cause of death
If left untreated, most squirrels infected with raccoon roundworm will ultimately die. The migrating larvae progressively damage tissues and organs including the lungs, liver, and central nervous system.
In severe cases, respiratory failure, organ failure, paralysis or uncontrolled seizures can directly end the animal’s life. More often, debilitated squirrels fall prey to predators, accidents or starvation once disabled by the parasite.
The timeframe varies based on individual immunity and infection intensity, but neurological decline leads to mortal outcomes in an estimated 75-90% of cases according to research data. Prompt intervention and anti-parasitic treatment offer the only hope for longer-term survival.
How Long Infected Squirrels Survive
2-4 week survival time
Unfortunately, squirrels infected with raccoon roundworm typically only survive for 2-4 weeks after exposure. The parasite larvae migrate to the brain and cause significant inflammation and damage. Most infected squirrels display obvious neurological signs like circling, head tilting, and stumbling within a couple weeks before dying.
Factors impacting survival time
There are a few key factors that impact how long an infected squirrel can survive:
On average though, most infected squirrels unfortunately perish within 3 weeks post-infection no matter what supportive care given.
Humane euthanasia options
Since raccoon roundworm causes such extreme suffering, humane euthanasia is strongly recommended once infection is confirmed. Options include:
| Chemical injection | Fast acting barbiturate administered by veterinarian that quickly induces coma then respiratory failure. |
| Inhalant agents | Gases like Sevoflurane rapidly render squirrel unconscious then stop breathing. |
| Cervical dislocation | Veterinarian quickly separates cervical vertebrae from head to disrupt spinal cord signaling resulting in rapid death. |
No matter what, the most compassionate path is to minimize the squirrel’s pain once infected with this devastating parasite. For more info check CDC guidance.
Protecting Squirrels from Infection
Avoiding Contact between Species
To protect squirrels from contracting raccoon roundworm, it’s crucial to reduce contact between raccoons and squirrels. This involves taking measures to prevent raccoons from accessing areas frequented by squirrels.
For example, homeowners should ensure trash cans have tight-fitting lids and cannot be tipped over. Raccoons are notorious for raiding garbage for food scraps, so securing trash is key. Bird feeders should also be inaccessible to raccoons with baffles or poles.
Since raccoons may defecate in areas they frequent, limiting access helps break disease transmission routes.
Spaces under porches or sheds should be secured from entry by wildlife with wire mesh screens. Attics should be checked for holes and openings sealed up. Fallen logs or wood piles, which raccoons use as dens, should be removed from yards if squirrels are often present there.
In natural settings like parks, separate feeding stations can be erected for squirrels away from raccoon activity centers. Overall, the goal is decreasing the environmental overlap between the species.
Cleaning Up Raccoon Latrines
Raccoons tend to defecate repeatedly in communal sites, known as latrines. These concentrated piles of feces allow roundworm eggs to accumulate and pose a high risk of infection to squirrels if ingested. As such, prompt identification and sanitation of raccoon latrines can protect squirrels.
Latrines are usually found at the base of trees, on raised horizontal surfaces like fallen logs, and near or in dens used by raccoons. They consist of numerous black, moist droppings in piles. To prevent squirrels from accessing latrines, first wearing PPE, remove all droppings by double-bagging waste then disposing it in the garbage, not the compost pile.
It is crucial to treat soiled areas with boiling water or fire to decontaminate roundworm eggs which persist in soil. Wearing PPE, scrub the area with detergent before rinsing thoroughly. After sanitization dries, the site should be covered with dirt or rocks to further discourage use by raccoons.
Treating Pets for Roundworm
Domestic animals like dogs and cats can acquire raccoon roundworm then shed eggs in their feces which squirrels may ingest while foraging. All pets should undergo regular fecal testing and receive broad spectrum dewormers to eliminate roundworm infection risks.
Ideally, pets should be dewormed at least four times annually and promptly treated if raccoon roundworm eggs or larvae are detected on fecal exams. Common prescription medications used include ivermectin, fenbendazole, milbemycin, moxidectin, and pyrantel pamoate.
Over-the-counter dewormers are often ineffective and should be avoided.
In addition to medical treatment, pet waste must be promptly collected from yards to prevent contamination where squirrels are active. Feces should be bagged and disposed of in the garbage, not composted. Routine fecal testing and deworming helps break parasite life cycles.
Talk to your vet for advice catered to your pet.
Roundworm Risks for Humans and Pets
Hazards of roundworm eggs
Roundworm eggs can survive and remain infectious for long periods of time, especially in moist, shaded areas like raccoon latrines. If accidentally ingested by humans or pets, the eggs will hatch in the intestines and spread quickly, causing an infection called toxocariasis.
This leads to mild symptoms like respiratory problems, skin rashes, and fever, but can result in more serious damage to organs or even blindness if the infection is heavy.
Young pets and children are most at risk of accidentally ingesting roundworm eggs if playing outside where raccoons frequent. The CDC estimates about 70 people in the United States become infected by roundworms this way each day.
Safe cleanup of raccoon latrines
Proper cleanup of latrines, especially if located close to homes, play areas, or gardens, is crucial. First, you must wear gloves, a face mask, and protective clothing to avoid contact with eggs when cleaning.
Any stools should be removed carefully with a sturdy shovel, double bagged securely, and disposed of with other waste to prevent eggs from infecting the soil. Next, the whole area should be treated with boiling water to ensure all remaining eggs are destroyed.
For tough stains on surfaces like wood or cement, steam cleaning followed by bleaching may be necessary.
It is best to leave cleaning and treatment of roundworm hotspots, especially under decks or in attics where raccoons nest, to professionals as the infection risk is too high. If you suspect raccoons have been residing on your property, get a thorough inspection and professional cleaning.
Antiparasitic drugs
Pets like dogs and cats can be regularly treated with antiparasitic drugs as a preventative measure against roundworms and other parasites. The most common are:
- Fenbendazole – prevents larvae from developing into adults
- Ivermectin – paralyzes and eliminates the worms
- Piperazine – paralyzes adult roundworms so they pass in the stool
Always consult with your veterinarian before administering antiparasitics. Most should not be used for puppies, kittens, sick or weak animals. Overuse and incorrect dosage of certain drugs like fenbendazole can lead to toxicity.
Conclusion
Raccoon roundworm is a common parasite that poses a significant threat to squirrels. If infected, squirrels typically only survive for 2-4 weeks before succumbing to the effects of the worm attacking their central nervous system.
By understanding the transmission, symptoms, and risks of raccoon roundworm, you can take steps to protect wildlife in your area. This includes cleaning up raccoon latrines, keeping pet waste contained, and contacting professionals if you see signs of infection in neighborhood squirrels.
With caution and care, we can prevent the spread of deadly parasites to vulnerable squirrel populations.
