Intestinal worms are the quietest problem in a dog’s body. A mild burden of roundworms or hookworms often produces no obvious signs at all, which is exactly why parasite control is built on schedules rather than symptoms. The good news is that the schedule is well established, and it is cheaper than treating a heavy infestation later.
The Worms Worth Knowing
| Worm | How dogs pick it up | What owners tend to notice |
|---|---|---|
| Roundworm | Across the placenta or through the mother’s milk, or from contaminated soil | Pot-bellied puppies, poor growth, spaghetti-like worms in stool or vomit |
| Hookworm | Swallowing larvae or burrowing through the skin, including paw pads | Anaemia, pale gums, weakness, dark tarry stool in heavy infections |
| Whipworm | Contaminated soil; eggs survive for years and resist most weather | Chronic intermittent diarrhoea and weight loss; famously hard to detect on a single test |
| Tapeworm | Swallowing an infected flea, or eating rodents and raw carcasses | Rice-like segments near the anus, scooting, an itchy rear end |
| Heartworm | Mosquito bites — not intestinal, but part of the same prevention conversation | Often silent for months, then coughing, exercise intolerance |
Puppies: Start Early, Repeat Often
- First deworming at 2 weeks of age, targeting roundworms acquired before birth
- Repeat at 4 and 6 weeks — each dose catches larvae that have matured since the last one
- At 8 weeks, broaden coverage to whipworms and tapeworms, and run a first faecal test
- Continue at 10 and 12 weeks, then move to a monthly broad-spectrum product until around 6 months
- Faecal testing at least four times during the first year
Puppies are the highest-risk group because their immune systems are still developing and some infections arrive before they are even born. Litter-mates should be treated on the same calendar.
Adult Dogs: Match the Schedule to the Lifestyle
- Baseline: broad-spectrum treatment at least four times a year is the common veterinary floor for adult dogs
- Monthly year-round preventives that cover heartworm plus intestinal worms are the default for most pets, and they usually remove the need for separate deworming doses
- Higher exposure — dog parks, kennels, daycare, hunting, raw feeding, flea problems — points to monthly coverage and faecal testing every 3 to 6 months
- Low exposure indoor-only dogs may sometimes be scaled back to every 6 months, but your vet should make that call
- Drug choice follows the worm: pyrantel pamoate for roundworms and hookworms, fenbendazole over 3 to 5 days for whipworms and Giardia, praziquantel for tapeworms
- Senior dogs do not need less prevention. Ageing immune systems control parasites less effectively, not more, so keep the routine going
Signs That Are Easy to Miss
- Soft stools or intermittent diarrhoea that comes and goes
- A pot-bellied look in a puppy who is otherwise eating well
- Weight loss or slow growth despite a normal or increased appetite
- A dull, rough coat, or a dog who scoots across the floor
- Pale gums and unusual tiredness, which suggest blood-feeding worms
Treat the Environment, Not Just the Dog
- Pick up stool immediately. Roundworm eggs become infective in 2 to 4 weeks and then persist for years; whipworm eggs can survive up to five years in soil
- Wash pet bedding weekly in hot water — around 60°C — during an active problem
- Vacuum daily for two to three weeks, and empty the canister outside
- Keep flea control airtight if tapeworms are the issue, because the common tapeworm arrives inside a swallowed flea
- Dose by an accurate current weight, and flag herding breeds with your vet — a MDR1 mutation makes some dogs sensitive to high-dose ivermectin
Deworming is one of the few areas where prevention is genuinely simple: accurate weight, the right product, a calendar you actually follow, and a faecal test once or twice a year. Do that, and worms stay a background detail instead of a household crisis.