Gastrointestinal parasitism in the spotted-tailed quoll (roundworms)

What is it?

Gastrointestinal parasitism caused by roundworms (nematodes) is a common condition in the spotted-tailed quoll, a carnivorous marsupial native to Australia. These parasites live in the animal's intestines and sometimes the stomach, feeding on its reserves or blood. Light infestations often go unnoticed, but a heavy parasite burden can seriously weaken the animal, particularly young or already vulnerable individuals. This condition affects both wild quolls and those in captivity, including those in conservation programmes and zoological parks.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Causes and risk factors

Infestation is caused by intestinal nematodes, roundworms of several species that can colonise the digestive tract of carnivorous marsupials. Some species are fairly specific to dasyurids (the quoll family), while others can be shared with other carnivores. These worms lay eggs that are shed in the faeces, contaminating the environment and potentially being ingested by the same animal or other individuals, thus completing the parasitic cycle.

Young animals, nursing females, and stressed or immunocompromised individuals are more vulnerable to heavy infestation.

Crowded living conditions in captivity, poorly maintained enclosures, high animal density, or inadequate hygiene promote the accumulation of infective eggs and larvae in the environment.

Imbalanced diet or concurrent illness can weaken the animal's natural defenses against parasites.

Transmission

Transmission occurs via the faecal-oral route: the animal ingests worm eggs or larvae present in the contaminated environment (soil, food, water) following the shedding of eggs in the faeces of an infested animal.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

Treatment

Treatment relies on broad-spectrum antiparasitic drugs chosen and tailored by the veterinarian based on the parasite species identified and the animal's condition. Nutritional support and rehydration may be necessary if the animal is significantly weakened. Thorough environmental cleaning accompanies treatment to prevent immediate reinfection.

Prevention

Possible complications

Untreated heavy infestation can cause severe anemia, dehydration, growth retardation in young animals, and general weakness that predisposes to other infections. In severe cases, particularly in already fragile animals, the outcome may be fatal.

When to see a veterinarian

Prognosis

The prognosis is generally good when infestation is detected early and treated promptly, with marked improvement following deworming and environmental management. The prognosis becomes more guarded in cases of very heavy parasite burden, in young animals, or when complications such as severe anaemia or significant dehydration are present.

Frequently asked questions

References

WOAH — Organisation mondiale de la santé animale (ex-OIE)

ESCCAP — European Scientific Counsel Companion Animal Parasites

Content reviewed by the TunisieVet editorial team · Updated 02 September 2026