Roundworm-A Serious Zoonosis

 Donald H DeForge, VMD

SilverSandsVeterinary.com

DonDeForge100@gmail.com

General Companion Animal Care

Walk-In Emergency and Urgent Care

Roundworm-The Hidden Zoonosis

Roundworm a Serious Zoonosis

Toxocariasis

Toxocara

Roundworm

A Serious Zoonosis

Roundworm infection, or Toxocariasis, is a zoonotic disease — a disease that can be transmitted from animals to humans. Dogs and cats are the definitive hosts for the roundworm species that commonly cause human disease. 

Zoonotic Potential - Roundworm Infection

Roundworm is common in our pet population in the United States.  It can be found in all ages of dogs and cats but is most commonly seen in kittens and puppies.  Because of this, it is critical to bring your pet to a veterinarian as soon as it is adopted; purchased; or rescued.  

Your pDVM will set into place a very important deworming program to prevent your pet from being affected by roundworm and to prevent it from being spread to family; friends, or others in contact with your new your puppy, kitten, or a recent adult adoptee.

Roundworms can cause disease in humans. People can become infected by ingesting eggs; handling fecal material without gloves during disposal; toddlers and adults being licked in the face by the puppy, kitten, or adult infected pet; and children playing with fecal material and then eating without washing.  

These see far fetched but infections occur each year, especially, in young children from poor hygiene and lack of parental supervision of pet with child.  The pediatrician has a responsibility to discuss this zoonosis with parents.

Toxocara can also be spread by other animals called paratenic hosts. Eggs consumed by another animal, such as a rodent, can hatch and produce larvae that continue their development into adult worms when consumed by the primary host—a cat or a dog

 Because roundworm infection of humans is not a reportable disease, the exact number of persons affected each year is difficult to determine

Children are infected more commonly than adults. Because humans are dead-end hosts, the larvae do not become infective and do not encyst but continue to migrate through the body tissues. Somatic migration of roundworm larvae in humans can cause visceral larval migrans (migration through internal organs) or ocular larval migrans (migration to the eye), which usually renders that eye blind. The round worm can also affect the Central Nervous System. 

As with dogs and cats, preventing exposure is key to preventing infection. Preventing roundworm infection depends on routine handwashing after playing with puppies/kittens or being exposed to dog/cat feces, regularly removing dog/cat feces from the yard and public areas, and routinely treating companion dogs/cats to prevent egg shedding in the environment.

For Your Information:

• Roundworms are among the most common parasites that infect dogs and cats.

• Roundworms steal nutrients from growing animals.
• Female dogs/cats can become re-infected during pregnancy, which can lead to infection of puppies before birth or during nursing. Thus, females should receive treatment before breeding, and dam and puppies/kittens should receive treatment after delivery.
• Treatment medications are very effective but only when given consistently and on schedule.  Do not use over the counter dewormers but consult with your pDVM concerning prescription products that are safe and effective.
• People can become infected by handling infected puppies/kittens and adult dogs/cats or their feces or directly from the environment. Risk is highest for families with young children or immunocompromised adults.
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• There must be a triad composed of your family pediatrician; your veterinarian, pDVM; and yourself to protect your family from roundworm exposure and infection. 
• Remember, even though this zoonosis is most common in children because of poor hygiene practices, it can occur in adults.

The Companion Animal Parasite Council-Update

General Guidelines for Cats and Dogs 

Parasite Control

One of the most misunderstood areas of concern by the public is simple parasite control in companion animals.  

There are zoonoses-diseases that can spread from pets to people that are simple to understand to protect the pet owner and their families from developing parasites.  These guidelines also protect and prevent the pet from harboring parasites.

Toxocariasis-Roundworm-is a very serious parasite that can be spread from pets to people.

GENERAL GUIDELINES FOR DOGS AND CATS FOR DOG LAST UPDATED: SEP 16, 2022

Parasite Testing and Protection Guided by Veterinarians

• Conduct preventive physical examinations at least every 6 to 12 months.
• Conduct annual heartworm testing in dogs; test cats prior to placing on heartworm preventive and thereafter as indicated.
• Test annually for tick-transmitted pathogens, especially in regions where pathogens are endemic or emerging.
• Conduct microscopic fecal examinations by centrifugation at least four times during the first year of life, and at least two times per year in adults, depending on patient health and lifestyle factors.
• Based on sample size, clinical signs, suspected parasites and skill and experience of the clinic or laboratory, alternative diagnostics and screening with advanced technologies, such as fecal antigen, PCR (Polymerase Chain Reaction) and AI (Artificial Intelligence), may be preferred.
• Prescribe control programs to local parasite prevalence and individual pet lifestyle factors.
• Adapt prevention recommendations to address emerging parasite threats.
• In areas where Lyme disease is considered endemic or emerging, vaccinate dogs against Borrelia burgdorferi.
• Confirm pets have been both recently tested for parasite infection and are current on broad-spectrum internal and external parasite control prior to boarding or visiting shared space animal facilities

Every Pet, All Year Long

• Administer year-round broad-spectrum parasite control with efficacy against heartworm, intestinal parasites, fleas, and ticks. Control of parasites with zoonotic potential is essential.
• Administer anthelmintic treatment to puppies and kittens starting at 2 weeks of age and repeating every 2 weeks until regular broad-spectrum parasite control begins.
• Maintain pregnant and nursing dams on broad-spectrum control products.

Healthy Lifestyle, Healthy Pets, Healthy People

• Feed pets commercial or cooked food (not raw diets) and provide fresh water.
• Cover sandboxes when not in use, and protect garden areas from fecal contamination.
• Pick up feces immediately when walking a dog in a public area and from the yard on a daily basis.
• To prevent roaming and limit predation, keep dogs on a leash or behind a fence and keep cats indoors.
• Permanently identify dogs and cats through microchip implantation.
• Do not handle animal feces or urine with bare hands, and wash hands immediately after incidental contact. This recommendation is particularly important for children and individuals at increased risk.
• Properly dispose of animal waste according to local municipal regulations.
• Spay or neuter all pets not intended for breeding.

If Year-Round Broad-Spectrum Parasite Control Cannot Be Maintained

• For puppies and kittens, administer anthelmintics starting at 2 weeks of age, repeating every 2 weeks until 2 months of age, monthly until 6 months of age, and quarterly thereafter.
• Treat all adult pets four times a year with a broad-spectrum anthelmintic with efficacy against intestinal parasites.
• Appropriate fecal diagnostics performed at least 2-4 times a year.
• Encourage annual testing for heartworm and other vector-borne infections in dogs and routine, year-round use of heartworm preventive, monthly intestinal parasite control, and flea and tick control in all pets.