Heartworm awareness for working dog owners

Key facts

Transmission

Through infected mosquitoes [source]

Important distinction

Prevention and treatment of established disease are different processes [source]

Understand transmission

Cornell describes heartworm disease as involving worms transmitted through mosquitoes, with effects centred on the circulation associated with the heart and lungs. It is not the same as routine intestinal worming. Do not assume a product described informally as a wormer covers heartworm; identify the exact product and its intended use.

Map history and exposure

Tell the veterinary team where the dog lives and travels, which preventives were used and any gaps or uncertainty. Keep dates rather than relying on memory. A newly acquired dog’s history should remain unknown where records are absent; a healthy-looking appearance does not establish freedom from infection.

Understand testing and illness

Ask what testing is appropriate and how timing and history affect interpretation. Cough, reduced tolerance for activity or other illness can have many causes, so describe signs rather than self-diagnosing heartworm. Sudden breathing difficulty, collapse or marked deterioration needs urgent veterinary contact regardless of the suspected cause.

Keep the plan safe

Use the veterinarian’s current prevention or treatment instructions for this dog and clarify missed or duplicated treatments. Do not give medication intended for livestock or another animal, or start a treatment protocol from an online summary. Treatment of established disease and routine prevention are not interchangeable. Keep the record accessible when the dog changes handlers or travels so responsibility for the next step remains clear.

Common questions

Sources & further reading

References for this guide. Rules and services can change; check the responsible organisation for current details.

• Cornell: Heartworm disease (opens in a new tab)

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