How Roundworms Affect Dogs
Roundworms can affect dogs of all ages, but they are particularly hazardous to young puppies. Newborns are at the greatest risk of developing severe disease or even dying from these parasites. Puppies between 2 and 6 months of age may have mild signs from roundworms, including abdominal pain (belly-aches), diarrhea and general ill-thrift. Adults and adolescents over 6 months of age rarely develop detectable symptoms when they are infected with roundworms.
Symptoms of Roundworms
Newborn puppies get roundworms either through the placenta before they are born (in utero), or through their mother’s milk. In very young dogs, the typical symptoms of roundworm infection include one or more of the following:
- Vomiting (mild to severe; with or without visible worms in the vomitus that look like moving strands of spaghetti)
- Diarrhea (mild to severe; with or without visible worms in the feces that look like moving strands of spaghetti)
- Gagging (intermittent)
- Coughing (intermittent)
- Dull hair coat
- Poor skin condition
- Distended abdomen (“pot-bellied” appearance)
- Abdominal pain (crying; whimpering; biting at belly)
- Stunted growth
- Loss of appetite (inappetence; anorexia)
- Weight loss
- Ill thrift (chronic and often dramatic)
In severe cases, roundworms cause anemia, which is an abnormally low level of red blood cells in circulation. Anemia often causes:
- Pale gums
- Extreme weakness
- Respiratory distress (difficulty breathing; dyspnea)
Puppies with an especially large burden of roundworm larvae can develop severe parasitic pneumonia. Their lungs and liver are commonly damaged by the maturing parasites. Unfortunately, when this happens, the puppies often die, especially during the first week or two of life. Adult roundworms can become tangled in the digestive tract of older puppies and cause death due to intestinal obstruction or rupture, although this is uncommon.
Dogs at Increased Risk
Very young puppies – especially those whose mother was not vaccinated before and during pregnancy – have a highly increased chance of becoming infected with roundworms. Older dogs with compromised immune systems also are at increased risk of developing roundworm infections. These parasites do not discriminate between genders or breeds; dogs of either sex and of any breed or mix of breeds are equally susceptible to infection.