Capillariasis in Dogs: A 2025 Vet-Approved Guide to Symptoms, Diagnosis & Treatment🐶🧫
By Dr. Duncan Houston BVSc
Capillariasis is a parasitic infection in dogs caused by nematodes of the genus Capillaria, now often referred to as Pearsonema or Eucoleus. These parasites can inhabit various parts of a dog's body, including the urinary bladder and respiratory tract. While infections are often asymptomatic, heavy infestations can lead to significant health issues. Understanding the causes, symptoms, and treatment options is essential for dog owners to ensure their pets' well-being.
🧬 Understanding Capillariasis
Capillariasis in dogs is primarily caused by two species:
- Pearsonema plica (formerly Capillaria plica): Affects the urinary bladder and occasionally the kidneys.
- Eucoleus aerophilus (formerly Capillaria aerophila): Infects the respiratory tract, including the trachea and bronchi.
These parasites have distinct life cycles and modes of transmission, leading to different clinical presentations.
⚠️ Symptoms of Capillariasis
Urinary Capillariasis (Pearsonema plica):
- Frequent urination (pollakiuria)
- Painful urination (dysuria)
- Blood in urine (hematuria)
- Straining to urinate
- Incontinence
Respiratory Capillariasis (Eucoleus aerophilus):
- Coughing
- Wheezing
- Difficulty breathing
- Nasal discharge
- Lethargy
It's important to note that many dogs may not exhibit any symptoms, especially in mild infections. However, heavy infestations can lead to significant discomfort and health issues.
🔬 Diagnosis
Diagnosing capillariasis involves a combination of clinical evaluation and laboratory tests:
- Urinalysis: Detects eggs of Pearsonema plica in the urine sediment.
- Fecal Examination: Identifies eggs of Eucoleus aerophilus in stool samples.
- Imaging: Radiographs or ultrasounds may be used to assess organ involvement.
The eggs of these parasites are characterized by their barrel shape with bipolar plugs, aiding in their identification under a microscope.
💊 Treatment Options
Treatment focuses on eliminating the parasites and alleviating symptoms:
- Anthelmintic Medications: Drugs such as fenbendazole or ivermectin are commonly used to treat capillariasis. The specific dosage and duration depend on the severity of the infection and the dog's overall health.
- Supportive Care: In cases with significant symptoms, additional treatments may be necessary to manage inflammation or secondary infections.
It's crucial to follow your veterinarian's guidance and complete the full course of treatment to ensure the infection is fully resolved.
🛡️ Prevention Strategies
Preventing capillariasis involves minimizing exposure to the parasites:
- Control Intermediate Hosts: Since earthworms can serve as intermediate hosts, preventing dogs from consuming them can reduce the risk of infection.
- Maintain Clean Living Environments: Regularly clean and disinfect areas where your dog spends time, especially if they have access to soil or outdoor spaces.
- Regular Veterinary Check-ups: Routine health screenings can help detect infections early, even before symptoms appear.
Implementing these preventive measures can significantly reduce the likelihood of your dog contracting capillariasis.
📱 Support and Resources
For additional support and information:
- Ask A Vet: Access professional veterinary advice through the Ask A Vet platform.
- Download the Ask A Vet App: For quick access to veterinary support, download the Ask A Vet app.
Early diagnosis and appropriate treatment can significantly improve your dog's quality of life.
🐾 For more expert advice and pet care tips, visit AskAVet.com.
This article is general veterinary education and does not diagnose or treat an individual animal. Always confirm medication names, doses and interactions with the veterinarian who knows your pet.
If your animal is struggling to breathe, collapsed, bleeding heavily, seizing, or has eaten something toxic, contact your vet or the nearest emergency clinic now.
Animal Poisons Helpline (AU) 1300 869 738 · Animal Poisons Helpline (NZ) 0800 869 738 · ASPCA Animal Poison Control (US) (888) 426-4435
More from Ask A Vet
For everyday pet care, one scan or tap of the smart pet ID tag opens your pet's free profile on any phone, no app needed; the GPS pet tracker logs live location and activity trends; and the Ask A Vet app keeps your pet's records and routines together.
QR Code Dog & Cat ID Tag with NFC, HangingView ID TagThe ASK A VET™ Smart ID Tag is a QR scan or NFC tap on any phone, no app needed, with a free profile you can update anytime.
Dog & Cat GPS Tracker for Their CollarView trackerThe ASK A VET™ Tracker logs live location and activity trends, so a change in routine never goes unnoticed.
- Talk to a Vet Online: The Ask A Vet AppExplore the app
Ask questions, speak with vets, and keep your pet's records and routines together with Ask A Vet.

Ask A Vet articles are written by Dr Duncan Houston BVSc, a practising veterinarian, unless another author is named in the byline.




