Ascarid Infection in Macaws

Ascarid infection is an intestinal parasite problem caused by roundworms. In pet birds, these worms live in the digestive tract and shed eggs into droppings. A macaw may carry a light parasite load with subtle signs at first, or develop more obvious illness if the number of worms increases.

Roundworms are not among the most common parasites in well-kept indoor parrots, but they can still occur, especially when birds have outdoor exposure, contact with contaminated environments, or a history that includes aviaries, bird stores, rescues, or wild bird exposure. Merck notes that wild birds can transmit nematodes to captive parrots housed outdoors, and VCA notes that intestinal parasites in birds are diagnosed through microscopic fecal analysis.

In mild cases, your macaw may only seem a little quieter, thinner, or less interested in food. In heavier infections, worms can irritate the intestines enough to cause diarrhea, poor nutrient absorption, and weakness. Severe infestations can even obstruct the intestinal tract, which is why ongoing vomiting-like regurgitation, marked lethargy, or a suddenly fluffed, weak bird should be treated as more urgent.

Macaws become infected by swallowing infective parasite eggs from a contaminated environment. That can happen through droppings on cage surfaces, food bowls, perches, aviary flooring, or anything else that has not been cleaned well after exposure to infected feces. In some bird parasite cycles, intermediate hosts may also play a role, depending on the worm species and local environment.

Risk goes up when birds are housed outdoors, live in mixed-species aviaries, come from crowded retail or rescue settings, or have contact with wild birds. PetMD notes that pet birds may pick up roundworms through exposure to wild birds or prior housing conditions, and Merck notes that wild birds may transmit nematodes to captive parrots housed outdoors.

Reinfection is a practical concern. Even when medication works, a macaw can pick up the parasite again if eggs remain in the environment. That is why treatment is usually paired with sanitation, repeat fecal checks, and sometimes evaluation of other birds in the home or aviary.

Diagnosis usually starts with a physical exam and a fecal test. Your vet will look at fresh droppings under the microscope, often using fecal flotation or other concentration methods to search for parasite eggs. VCA notes that intestinal parasites such as roundworms are visible only by microscopic analysis of fecal material, and that a single negative fecal test does not always rule parasites out because eggs may be shed intermittently.

That means your macaw may need repeat fecal testing if signs strongly suggest parasites but the first sample is negative. Your vet may also assess weight trend, hydration, body condition, and whether there are signs of secondary problems such as malnutrition or dehydration.

If your macaw is very sick, additional testing may be recommended. This can include bloodwork, radiographs, or hospitalization to look for intestinal obstruction, severe debilitation, or other causes of similar signs. In advanced cases, diagnosis and treatment often happen at the same time because birds can decline fast once they stop eating well.

Prevention focuses on limiting fecal contamination and reducing exposure to outside parasite sources. Clean droppings from cage surfaces promptly, wash food and water bowls daily, and disinfect perches, grates, and other surfaces on a regular schedule. If your macaw lives outdoors or spends time in an aviary, try to reduce contact with wild birds and wild bird droppings.

Routine wellness care matters too. VCA recommends periodic fecal examinations because parasites may be present even when birds look normal, and a single negative test does not always rule infection out. For many pet birds, one or two fecal checks per year is a practical screening approach, especially if there is outdoor exposure or a history of parasites.

Quarantine new birds before introducing them to your macaw, and bring a fresh fecal sample to your vet during the quarantine period if advised. If one bird in the household is diagnosed with roundworms, ask your vet whether the other birds need testing, treatment, or both. Good sanitation plus targeted veterinary follow-up is the best way to lower the risk of repeat infections.