All pets are susceptible to parasites, which can cause your four-legged friend significant health complications. Our Neighborhood Veterinary Centers team describes common parasitic diseases, and how to minimize your pet’s health risk. 

Heartworm disease in pets

According to the Companion Animal Parasite Council, heartworm infection rates are increasing, the disease’s geographic distribution is spreading, and Texas has become a high-prevalence area. Mosquitoes transmit heartworms by first ingesting an infected domestic or wild canine’s blood contaminated with baby heartworms (i.e., microfilariae). The parasites develop to an infective stage within the mosquito, who transmits them to a susceptible pet when the mosquito feeds again. Important heartworm facts include:

  • Dogs’ heartworm signs — Dogs are natural heartworm hosts, in whom parasites can grow to adulthood, mate, and produce offspring.  In the initial disease stages, dogs typically do not exhibit signs. As the worms invade the dog’s lung vasculature, signs include a chronic mild cough, lethargy, and weight loss. As the dog’s condition progresses, the heart starts to fail, and the dog’s abdomen may appear swollen from excess fluid accumulation.  
  • Cats’ heartworm signs — Cats are atypical heartworm hosts in whom parasites rarely grow to adulthood, but they can still cause your cat significant health problems.  When the heartworms reach a cat’s lung tissue, their immune system reacts strongly, causing severe inflammation—heartworm-associated respiratory disease (HARD)—and signs include coughing, panting, increased respiratory rate, vomiting, and weight loss. 
  • Diagnosis — A blood test can detect heartworm antigens in dogs, and annual testing is recommended. Diagnosing a cat’s heartworm disease is more difficult because the parasites rarely reach adulthood. A blood test to detect a cat’s antibodies against heartworm larvae can be performed. In both species, additional blood work, X-rays, and ultrasound may be used to evaluate the infection’s severity.
  • Treatment — Heartworm treatment in dogs initially involves stabilizing their condition, and restricting their exercise. Medications to kill heartworms must be administered carefully, because when a large number of worms suddenly die, the host dog can experience severe health problems. Canine heartworm treatment typically takes at least 60 days. Unfortunately, no approved treatment is available for cats.
  • Prevention — Preventing heartworm disease is easy. All pets, including indoor-only pets, should receive year-round heartworm prevention medication to protect them from these dangerous parasites.

Ehrlichiosis in pets

Ehrlichiosis—a bacterial infection the brown dog tick most commonly transmits—is prevalent in the U.S. Southwest, south central, and coastal Atlantic states. An infected tick must remain attached to the host animal for at least 24 hours to spread infection. Several Ehrlichia species can infect pets, but Ehrlichia canis is the most common species causing ehrlichiosis in dogs. Cats are rarely infected. Important ehrlichiosis facts include:

  • Signs — Ehrlichiosis has three illness phases:
    • Acute — About one to three weeks after infection, lethargy, decreased appetite, fever, and enlarged lymph nodes can develop.
    • Subclinical — The organism sequesters in the spleen, and the pet appears normal during this phase.
    • Chronic — Not all pets progress to the chronic phase, but if they do, their prognosis worsens. Signs include bleeding abnormalities, severe eye inflammation, and neurological problems.
  • Diagnosis — Your veterinarian will perform a blood test to detect antibodies against Ehrlichia or Ehrlichia DNA to diagnose the disease. This test is part of your dog’s annual parasite screening, along with heartworm, Lyme disease and anaplasmosis, recommended by our veterinarians.
  • Treatment — Ehrlichiosis is usually susceptible to a certain antibiotic class, and treatment typically takes at least a month. Pets in the chronic stage may need supportive care and blood transfusions.
  • Human ehrlichiosis risk — Your pet cannot transmit ehrlichiosis to you, but if your pet has the disease, you may also have been exposed to an infected tick.
  • Prevention — Check your pet for ticks after every outing. Common hiding places include under the tail, in the groin area, under the collar, in the ears, and between the toes. In addition, all pets should receive year-round flea and tick prevention medication to ensure ticks cannot transmit ehrlichiosis and other debilitating tick-borne illnesses. 

Intestinal parasites in pets

Pets commonly contract intestinal parasites, such as tapeworms, roundworms, hookworms, and whipworms. Transmission can occur through several routes, including by ingesting worm eggs or larvae in the environment, infected birds or small mammals, or an infected mother’s milk, or in utero. Important intestinal parasite facts include:

  • Signs — Healthy pets may not exhibit disease signs when they have an intestinal parasite infection, but puppies, kittens, and immunocompromised adult pets can develop significant health problems. Potential signs include lethargy, weight loss, failure to thrive, vomiting, diarrhea, and anemia. 
  • Diagnosis — By performing a fecal examination, your veterinarian can determine whether an intestinal parasite has infected your pet. Annual fecal screening is recommended since intestinal parasite infections are so common. 
  • Treatment — If a parasite problem is diagnosed, your veterinarian will prescribe an appropriate deworming medication. 
  • Risk to humans — Roundworms, hookworms, and whipworms can cause humans to experience health problems, with children and pregnant women having an increased health complication risk. 
  • Prevention — Prevent your pet from coming in contact with other pets’ feces, and eating birds and small mammals. In addition, ensure your pet receives year-round parasite prevention medication.

Parasitic diseases are problematic for pets, but you can protect your four-legged friend by ensuring they receive year-round parasite prevention medication. If your pet is due for their annual heartworm test or fecal check, contact Neighborhood Veterinary Centers to ensure they are parasite-free.