Heartworm disease is a threat to pets across the United States, but the southern states and coastal areas, including Texas, have a particularly high incidence. Preventive medications can protect pets from this devastating disease, but many pet owners do not understand the importance of year-round protection. Our Neighborhood Veterinary Centers teams’ goal is to empower you to protect your pet proactively from this disease. Learn six essential facts about heartworm disease and prevention.

#1: Mosquitoes transmit heartworms to pets

When a mosquito bites an infected animal, they can ingest heartworms. If the infected mosquito bites your pet, they transmit the worms to your four-legged friend. The heartworms work their way into your pet’s body, eventually reaching your furry pal’s heart and surrounding blood vessels, where they set up shop and reproduce, becoming a new infection reservoir. Because mosquitoes are prevalent in our area and can easily get inside your home, all pets have a heartworm risk—including indoor cats.

#2: Heartworm disease affects dogs and cats

Many people think only dogs can contract heartworms, but cats are also at risk. Dogs are heartworms’ preferred host, meaning these parasites easily thrive and reproduce after infecting a dog. Cats, on the other hand, are not natural heartworm hosts, so most worms do not survive to adulthood or reproduce inside a cat. The one or two of these parasites that survive in a cat’s body usually causes them a life-threatening condition. 

#3: Heartworms can cause pets serious organ damage or death

Canine heartworm infection is initially silent, but over time, the worms—potentially hundreds,  which can each grow to a foot long—reproduce, eventually damaging the infected dog’s heart, lungs, and blood vessels. Once damage occurs, the infected dog’s heart may begin to malfunction or fail, potentially causing the animal’s death. Once heartworm damage begins, a dog may show the following signs:

  • Coughing
  • Exercise intolerance
  • Weight loss
  • Abnormal fluid buildup in the chest or abdomen
  • Rapid breathing

A cat infected with heartworms may show no signs, or may demonstrate chronic disease signs that your veterinarian may find difficult to diagnose. An infected cat’s heartworm signs may include:

  • Coughing, wheezing, or difficulty breathing
  • Weight loss
  • Vomiting
  • Seizures
  • Sudden death

#4: Year-round heartworm prevention protects pets from infection

A heartworm preventive is an oral or topical product that your veterinarian will strongly recommend you administer to your pet monthly. These products contain medications that kill immature heartworms before they can migrate and mature into adults. Once the worms reach a certain stage, they can no longer be easily killed, which is why you must ensure your pet receives their preventive every month. Year-round protection is vital, as skipping months provides heartworm larvae the opportunity to mature, leading to infection. Heartworm preventives also help control many intestinal parasites, which are also a year-round threat to pets in any climate. 

#5: Annual heartworm testing ensures infections are identified early in pets

The heartworm life cycle is such that your veterinarian cannot detect whether your pet is infected until the worms mature to adulthood, six to seven months after a causative mosquito bite.  An infected dog’s first test may be negative, but the next test positive. Our Neighborhood Veterinary Centers teams strongly recommend that your dog receive annual heartworm blood testing to ensure infection does not go undetected, especially newly adopted dogs with unknown preventive administration histories. 

Feline heartworm testing is not recommended on a regular basis, because detecting these parasites in cats is more complicated. Your veterinarian will perform a heartworm blood test only if they strongly suspect your feline friend has contracted this deadly disease, or before starting them on a preventive regimen.

#6: Pets’ heartworm treatment is costly, painful, and not guaranteed

If a dog becomes infected with heartworms, your veterinarian can treat them with a specific, months-long medication regimen. Heartworm treatment involves several oral medications, deep muscle injections, day hospitalizations, strict cage rest, and substantial costs. This regimen is not safe for cats—they can only be provided supportive care and monitoring until the worms die on their own.

Warm, humid regions are mosquito and heartworm hot spots, and all pets who live in our area are at high risk. Keep in mind that the more pets tested, treated, and placed on preventive medication in our area, the safer all area pets become. Schedule your pet’s next wellness visit, heartworm test, and heartworm prevention consultation at a Neighborhood Veterinary Centers location near you.