Get the latest COVID-19 Updates
  • Mosquito Borne Diseases
  • Asian Tiger Mosquitoes
  • Beekeeping Guidelines
  • Ticks
  • Chikungunya
  • Zika Virus
  • Dog Heartworm
    • What is Dog Heartworm?

      Dog Heartworm is a disease common in canines throughout most of the United States. It is caused by a parasitic roundworm (nematode) that lives its adult life primarily in the heart and large vessels of the lungs.

      The worms seriously impair the operation of the heart by prohibiting proper valve closure. In heavier infestations, the blood vessels become clogged by the worms. It is transmitted by the bite of an infected mosquito.

      The Role of the Mosquito

      A female mosquito takes a blood meal from a dog infected with the microscopic larval stage of heartworm called microfilariae. The microfilariae migrate to the mosquito’s digestive tract and transform. Next, they break into the mosquitoes body cavity and migrate to the mouthparts.

      As the mosquito takes her blood meal, the larvae are deposited onto the skin of the host animal. The worms burrow into the skin and lodge in the tissue for several months. Once the worms have increased in size they enter the bloodstream and eventually lodge in the chambers of the heart where they mature.

      Signs and Symptoms

      • increased fatigue
      • shortness of breath
      • frequent coughing
      • exhaustion

      In very severe cases dogs will experience jaundice, heart failure and death. See your veterinarian immediately if you suspect dog heartworm.


      Heartworm is sometimes treatable with very harsh chemicals that are designed to kill and slowly disintegrate the worms. If all the worms were killed at the same time the animal would suffocate from the tissues. Microfilariae still in the bloodstream are eliminated with another treatment. Treatment lasts between 4 to 6 months, includes isolation of the animal and is very expensive.

      Remember: an infected dog can be a constant source of infection for heartworm free dogs.

      Dog Heartworm Prevention

      • Remove any containers that can hold water from the yard.
      • Change animal’s drinking water daily.
      • Recycle any abandoned tires.
      • Fill in ruts and low areas on property.
      • Stock ornamental ponds with fish.
      • Change water in birdbath every 2—3 days.
      • Limit your dog’s outside activity when mosquitoes are present.
      • Eliminate mosquito habitat by eliminating standing water.
      • A monthly heartworm prevention medicine is available through your veterinarian. Always follow your veterinarian’s advice.
      • A topical pesticide that is absorbed into the dog’s skin can be used to deter mosquitoes, as well as fleas and ticks.

      Heartworm tri-fold brochure to print and distribute.

  • West Nile Virus
    • What is West Nile Virus?

      West Nile virus (WNV) is a disease spread to humans, birds, horses and other animals, by infected mosquitoes.  Mosquitoes get the disease from infected birds and pass it on to other animals while taking a blood meal.

      In a very small number of cases West Nile has been spread through blood transfusions, organ donation or mother to baby.

      Who is at risk for infection with West Nile virus?

      Anyone living in an area where West Nile virus is present in mosquitoes can get infected. West Nile virus has been detected in all lower 48 states (not in Hawaii or Alaska). The first outbreaks in the United States occurred in New York City 1999, outbreaks have been occurring ever since.
      The risk of infection is highest for people who work outside or participate in outdoor activities because of greater exposure to mosquitoes.

      What are the symptoms of West Nile virus disease? (

      • No symptoms in most people. Most people (70-80%) who become infected with West Nile virus do not develop any symptoms.
      • Febrile illness in some people. About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.
      • Severe symptoms in a few people. Less than 1% of people who are infected will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues). The symptoms of neurologic illness can include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or paralysis.
        Recovery from severe disease may take several weeks or months. Some of the neurologic effects may be permanent. About 10 percent of people who develop neurologic infection due to West Nile virus will die.
      • Most cases occur between June – October.

      How do I protect myself and family?

      • Use a personal insect repellant, DEET, picaridin, IR3535, and some oil of lemon eucalyptus products are all recommended by the CDC.
      • Remove standing water from your property. Children’s toys, flower pots, tarps, etc.  should be emptied out frequently.  Bird baths should be cleaned out once a week.
      • Consult with your local mosquito control agency.  Call or visit their website for a list of their services. The Division of Mosquito Control offers free mosquito control services to all of its residents.
      • Protect yourself at home and away, this is a serious illness that has been documented in 48 states and several other countries.

      Morris County Division of Mosquito Control Action Plan

      Morris County monitors mosquito population levels and for presence of the disease in mosquitoes and birds.  Mosquito samples are sent to the New Jersey Department of Health for disease testing.
      Control efforts will be intensified if disease shows up, targeting the aquatic stage of the mosquito first, then the adult mosquitoes.