Dogs with worms do not always look unwell. Mild infections can cause no obvious symptoms, while heavier worm burdens may lead to digestive problems, poor growth, weight loss, anaemia or visible worms in your dog’s faeces.
The signs also depend on the type of worm involved. Roundworms are more likely to cause a pot-bellied appearance and poor growth in puppies, hookworms can contribute to blood loss and pale gums, whipworms may cause recurring diarrhoea, and tapeworm segments often look like small grains of rice around a dog’s bottom.
However, these symptoms are not exclusive to worms. Vomiting, diarrhoea, weight loss and scooting can have many other causes, so it is important not to diagnose your dog based on one sign alone.
This guide explains the most common signs of worms in dogs, what different worms may look like, when to contact your veterinarian and how worm infections are properly diagnosed.
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Contents
- The quick answer
- Can dogs have worms without showing symptoms?
- Common signs of worms in dogs
- What do worms in dog poo look like?
- Signs of roundworms in dogs
- Signs of hookworms in dogs
- Signs of whipworms in dogs
- Signs of tapeworms in dogs
- Signs of worms in puppies
- Does scooting mean a dog has worms?
- How are worms diagnosed?
- When should you contact a veterinarian?
- What should you do if you think your dog has worms?
- Reducing your dog’s risk of worms
- Frequently asked questions
The Quick Answer
Possible signs of worms in dogs include:
- Worms or worm segments in faeces
- Rice-like pieces around the anus or bedding
- Diarrhoea
- Blood or mucus in the stool
- Vomiting
- A swollen or pot-bellied abdomen
- Unexplained weight loss
- Poor growth in puppies
- A dull or unhealthy-looking coat
- Reduced energy
- Pale gums
- Weakness
- Scooting or licking around the bottom
- Changes in appetite
Not every dog with worms develops these signs. Some infections remain unnoticed until worms are seen, a faecal test is performed or the worm burden becomes more significant.
Equally, seeing one of these symptoms does not prove that your dog has worms. Many digestive, dietary and medical conditions can cause similar changes.
Can Dogs Have Worms Without Showing Symptoms?
Yes. A dog can carry intestinal worms without appearing noticeably ill.
This is particularly common when the number of worms is low. An adult dog may continue eating, exercising and behaving normally while still passing microscopic worm eggs into the environment.
The absence of visible worms is also not proof that a dog is worm-free. Adult worms generally live inside the digestive tract, and their eggs are usually too small to see without a microscope.
Some worms release eggs intermittently, while tapeworm segments may only appear occasionally. This means a dog’s faeces can look completely normal even when an infection is present.
Symptoms are more likely when:
- The worm burden is heavy
- The dog is very young
- The dog is elderly or unwell
- The infection has continued untreated
- The worms are causing blood loss or intestinal inflammation
- The dog has another health condition affecting its resilience
This is why routine parasite management should not rely entirely on waiting for symptoms to appear.
Common Signs of Worms in Dogs
1. Worms or worm segments in the faeces
The clearest possible sign is seeing a worm or worm segment in your dog’s stool.
Roundworms may look like pale strands of spaghetti. Tapeworm segments are much smaller and often resemble grains of rice, cucumber seeds or small flat pieces.
However, many infected dogs never pass clearly visible adult worms. Most worm eggs are microscopic, so a normal-looking stool does not rule out infection.
2. Rice-like pieces around the bottom
Small white or cream-coloured pieces around your dog’s anus, on the fur beneath the tail or in bedding may be tapeworm segments.
Fresh segments can sometimes move. Once dry, they may become yellowish and resemble sesame seeds or dried grains of rice.
If you find a suspicious piece, placing it in a sealed container or taking a clear photograph may help your veterinarian identify it.
3. Diarrhoea
Several intestinal worms can irritate the digestive tract and cause loose or recurring stools.
Diarrhoea associated with worms may be:
- Intermittent rather than constant
- Soft or watery
- Coated in mucus
- Streaked with fresh blood
- Dark or tar-like if bleeding occurs higher in the digestive tract
Diarrhoea has many possible causes, including dietary changes, infections, stress, food intolerance and other intestinal disease. Worms are only one possibility.
4. Blood or mucus in the stool
Hookworms and whipworms can damage or inflame the intestinal lining. In heavier infections, this may lead to visible blood or mucus in the faeces.
Bright red blood usually comes from the lower digestive tract, while very dark, sticky or tar-like faeces can indicate digested blood.
Blood in your dog’s stool should not automatically be assumed to be worms. Contact a veterinarian, particularly if the bleeding is substantial, recurrent or accompanied by weakness, vomiting or reduced appetite.
5. Vomiting
Dogs with roundworms may occasionally vomit adult worms, particularly when the worm burden is high.
A vomited roundworm may look like a long, pale, smooth strand. It is often described as resembling spaghetti.
Vomiting without visible worms can still occur during an intestinal infection, but it is not specific to parasites. Repeated vomiting requires veterinary assessment because dehydration and more serious illness can develop quickly.
6. A swollen or pot-bellied abdomen
A rounded, distended abdomen is most commonly associated with a significant roundworm burden in puppies.
The puppy may have a large-looking belly while the rest of the body remains thin or poorly developed.
A swollen abdomen can also be caused by overeating, gas, fluid accumulation, organ enlargement or a serious digestive emergency. A suddenly enlarged or painful abdomen needs urgent veterinary attention.
7. Weight loss despite eating normally
Intestinal worms may interfere with digestion, nutrient absorption or the health of the intestinal lining.
Some infected dogs lose weight even though their appetite appears unchanged or has increased. Others become less interested in food and lose weight because they are eating less.
Unexplained weight loss should always be investigated. Worms are one possible explanation, but dental disease, chronic digestive conditions, diabetes, kidney disease, cancer and other health problems can produce similar changes.
8. Poor growth in puppies
Puppies are particularly vulnerable to roundworms and hookworms. Infection can contribute to:
- Slow weight gain
- Failure to grow as expected
- A thin body with a rounded abdomen
- Poor muscle development
- Reduced playfulness
- A dull coat
Because some puppies acquire roundworm larvae from their mother before birth or through nursing, worms can be present even in puppies that have never been outdoors.
9. Pale gums
Healthy gums are normally pink, although natural pigmentation can make gum colour harder to assess in some dogs.
Pale, white or grey-looking gums may indicate anaemia or poor circulation. A heavy hookworm infection can cause blood loss because hookworms attach to the intestinal lining and feed on blood.
Pale gums are not a symptom to monitor casually at home. They can also indicate internal bleeding, immune-mediated disease, shock or other serious conditions and should prompt urgent veterinary advice.
10. Weakness or reduced energy
A heavily infected dog may become tired, reluctant to exercise or less interested in normal activities.
This may result from:
- Anaemia
- Dehydration
- Blood loss
- Poor nutrient absorption
- Abdominal discomfort
- General illness
Lethargy alone does not identify worms, but it becomes more concerning when combined with diarrhoea, pale gums, weight loss or visible parasites.
11. A dull or rough coat
Dogs with significant or longstanding intestinal disease may develop a dry, coarse or generally unhealthy-looking coat.
This can occur when illness affects nutrition or overall condition. It is a nonspecific symptom and can also be associated with poor diet, skin disease, hormonal disorders and other medical problems.
12. Changes in appetite
Worm infections can affect appetite in different ways.
Some dogs may appear hungrier than usual while losing weight. Others may become nauseous, uncomfortable or less willing to eat.
A persistent change in appetite deserves attention, particularly when it occurs alongside vomiting, diarrhoea or weight loss.
13. Irritation around the bottom
Tapeworm segments passing from the anus can cause irritation, leading some dogs to lick, bite or drag their bottom along the ground.
However, anal gland problems are a much more common reason for scooting. Skin irritation, allergies, matted fur and diarrhoea can also cause discomfort around the anus.
What Do Worms in Dog Poo Look Like?
Different worms have different appearances, but owners often do not see the worms themselves.
| Worm type | Possible appearance | Where it may be noticed |
|---|---|---|
| Roundworm | Long, pale and smooth, often compared with spaghetti | Faeces or vomit |
| Tapeworm | Flat segments resembling grains of rice, cucumber seeds or sesame seeds | Around the anus, on fur, in bedding or on faeces |
| Hookworm | Usually too small to identify easily without laboratory examination | Normally detected through faecal testing rather than by sight |
| Whipworm | Thin at one end and thicker at the other, but rarely seen by owners | Usually diagnosed using faecal testing |
Undigested food, grass, mucus and plant material can sometimes be mistaken for worms. A photograph or sample can help your veterinarian distinguish between them.
Do not handle suspected worms with bare hands. Wash your hands thoroughly after cleaning up faeces and keep children away from contaminated areas.
Signs of Roundworms in Dogs
Roundworms are large intestinal worms. Puppies are particularly at risk because the most important canine roundworm, Toxocara canis, can pass from a mother to her puppies before birth and through her milk.
Dogs can also become infected by swallowing microscopic eggs from contaminated soil or by eating infected prey animals.
Possible signs include:
- A pot-bellied appearance
- Poor growth
- Failure to gain weight
- Diarrhoea
- Vomiting
- A dull coat
- Visible spaghetti-like worms in faeces or vomit
- Reduced body condition
Many adult dogs with a lighter infection show few or no visible signs.
Very heavy roundworm burdens are most concerning in young puppies because they can interfere with growth and, in rare severe cases, contribute to intestinal obstruction.
Signs of Hookworms in Dogs
Hookworms are small worms that attach to the lining of the small intestine. Some species feed on blood, which means a significant infection can lead to anaemia.
Possible signs include:
- Pale gums
- Weakness
- Reduced energy
- Poor growth in puppies
- Weight loss
- Diarrhoea
- Dark or tar-like faeces
- Blood in the stool
- Dehydration
Young puppies can become seriously unwell from hookworm-related blood loss more quickly than healthy adult dogs.
Hookworms are generally not identified by simply looking at the stool. Diagnosis usually involves detecting eggs or parasite material through veterinary faecal testing.
Signs of Whipworms in Dogs
Whipworms live primarily in the lower intestinal tract, including the caecum and colon. Light infections may produce no symptoms.
When the worm burden is heavier, possible signs include:
- Recurring or persistent diarrhoea
- Mucus in the stool
- Fresh blood in the stool
- Straining to pass faeces
- Weight loss
- Reduced body condition
- Dehydration
- Anaemia in severe cases
Whipworm symptoms can resemble other forms of large-bowel disease. The diarrhoea may improve temporarily and then return, which can make the underlying cause difficult to identify without testing.
Whipworm eggs are not necessarily present in every stool sample. Your veterinarian may recommend repeat faecal testing or other diagnostic tests when whipworm remains a possibility.
Signs of Tapeworms in Dogs
Tapeworms are flat, segmented intestinal worms. Many infected dogs show little or no illness, particularly when the number of worms is low.
The most noticeable sign is often the appearance of tapeworm segments.
Possible signs include:
- Rice-like segments around the anus
- Segments on fresh faeces
- Dried segments in bedding
- Licking or biting around the bottom
- Scooting
- Occasional digestive upset
- Weight loss in heavier infections
The common flea tapeworm, Dipylidium caninum, is acquired when a dog swallows an infected flea while grooming.
Dogs can also acquire other tapeworms by eating infected prey, raw offal or animal carcasses. This means hunting and scavenging behaviour can be relevant even when a dog receives regular external-parasite control.
Controlling the source of infection is important. Treating an intestinal tapeworm without addressing the way the dog acquired it can lead to reinfection.
Signs of Worms in Puppies
Worm infections can affect puppies more severely than healthy adult dogs.
A puppy with worms may show:
- A rounded or pot-bellied abdomen
- Slow weight gain
- Poor growth compared with littermates
- Diarrhoea
- Vomiting
- Visible roundworms
- A dull coat
- Reduced appetite
- Weakness
- Pale gums
- Low energy
Puppies do not need to eat contaminated soil before they can become infected. Roundworm larvae can pass from the mother before birth, and both roundworms and some hookworms may be transmitted through nursing.
This is why puppies require an age-appropriate worming programme rather than waiting for signs to develop.
Contact a veterinarian promptly if a puppy develops repeated vomiting, bloody diarrhoea, pale gums, marked weakness, poor feeding or failure to gain weight.
Does Scooting Mean a Dog Has Worms?
Scooting can occur with tapeworms, but it does not automatically mean a dog has worms.
Dogs drag their bottoms along the ground when the area around the anus feels itchy, painful or irritated.
Possible causes include:
- Full or inflamed anal glands
- Tapeworm segments
- Diarrhoea or residue around the anus
- Skin allergies
- Matted fur
- A local skin infection
- A wound or growth near the anus
Anal gland problems are a particularly common cause. Repeated scooting, licking or a strong fishy smell should be assessed rather than automatically treated with a wormer.
How Are Worms in Dogs Diagnosed?
Seeing a worm can provide a useful clue, but veterinary testing is often needed to determine whether worms are present and which type is involved.
Faecal examination
A veterinarian may examine a stool sample under a microscope to look for worm eggs.
Because eggs may not be shed continuously, one negative sample does not always rule out infection. Repeat testing may be recommended when symptoms continue or exposure risk remains high.
Faecal antigen testing
Some veterinary tests detect material produced by the parasite rather than relying only on finding eggs. Availability and suitability depend on the worm being investigated and the clinic’s testing methods.
Identification of worms or segments
A visible worm, tapeworm segment or clear photograph can assist with identification.
Place a fresh sample in a clean, sealed container and follow your clinic’s instructions for storage and delivery.
Blood tests
Blood testing does not usually identify common intestinal worms directly, but it can reveal effects such as anaemia, inflammation, dehydration or protein loss.
Additional investigation
Because worm symptoms overlap with many other conditions, your veterinarian may recommend further testing when the signs cannot be explained by a straightforward intestinal-parasite infection.
This may include:
- Blood tests
- Additional stool testing
- Imaging
- Dietary investigation
- Testing for bacterial or protozoal infections
- Assessment for inflammatory intestinal disease
When Should You Contact a Veterinarian?
Arrange veterinary advice if you see worms or suspect that your dog may have an infection.
More urgent assessment is appropriate when your dog has:
- Pale, white or grey gums
- Severe weakness or collapse
- Repeated vomiting
- A painful or rapidly swollen abdomen
- Large amounts of blood in the stool
- Black, tar-like faeces
- Severe or persistent diarrhoea
- Signs of dehydration
- Difficulty breathing
- Rapid weight loss
- An inability to keep water down
Puppies, elderly dogs and dogs with existing health conditions should be assessed sooner because they may deteriorate more quickly.
Do not repeatedly administer different worming products in an attempt to treat serious symptoms at home. The dog may have a condition that requires a different treatment entirely.
What Should You Do if You Think Your Dog Has Worms?
1. Inspect the stool carefully
Look for visible worms, rice-like segments, blood, mucus and changes in colour or consistency.
A clear photograph can be helpful, but avoid unnecessary handling.
2. Collect a fresh sample
Your veterinary clinic may ask you to provide a recent faecal sample.
Use a clean, leak-proof container or sample bag and label it if necessary. Follow your clinic’s advice regarding refrigeration and how quickly it should be delivered.
3. Check your dog’s recent parasite treatments
Record:
- The exact product name
- The date it was last given
- The dose or weight range used
- Your dog’s current weight
- Whether the dose was swallowed or applied correctly
Not every parasite product covers every worm. The exact product matters more than the general brand name.
4. Consider your dog’s exposure
Tell your veterinarian if your dog:
- Scavenges or eats animal carcasses
- Consumes raw meat or offal
- Hunts rodents or rabbits
- Visits kennels, daycare or dog parks
- Lives with other pets
- Has recently had diarrhoea
- Has missed scheduled worm treatments
5. Use a treatment that covers the identified worm
Worming treatments for dogs differ in their coverage. A product that treats roundworm and hookworm may not treat tapeworm, while another may cover tapeworm but not whipworm.
Use the correct product for your dog’s age and current body weight, and follow the New Zealand label directions.
6. Clean up faeces promptly
Removing faeces reduces environmental contamination and lowers the opportunity for worm eggs to accumulate where dogs and people spend time.
Wash your hands after handling waste, gardening or cleaning areas used by pets.
Reducing Your Dog’s Risk of Worms
No single measure can prevent every worm infection, but several practical steps can reduce risk.
- Follow an appropriate worming programme for your dog’s age and lifestyle.
- Pick up faeces promptly at home and in public places.
- Wash hands after handling dog waste or soil.
- Discourage scavenging and hunting where possible.
- Avoid feeding untreated raw offal.
- Control access to animal carcasses.
- Maintain appropriate control of parasites that can act as intermediate hosts.
- Treat all relevant pets in the household as advised.
- Ask your veterinarian whether periodic faecal testing is appropriate.
- Weigh growing puppies regularly to ensure the correct dose is used.
The ideal programme is not identical for every dog. Age, diet, location, hunting behaviour, household pets and exposure to shared environments can all affect risk.
Can People Catch Worms From Dogs?
Some canine intestinal worms can also affect people.
Humans do not usually become infected simply by touching a healthy dog. The main risk comes from accidentally swallowing microscopic worm eggs from contaminated soil, faeces, hands or surfaces.
Young children may face greater exposure because they play close to the ground and are more likely to put their hands in their mouths.
Practical precautions include:
- Picking up dog faeces promptly
- Washing hands after gardening or handling waste
- Supervising children around animal toileting areas
- Keeping sandpits covered when not in use
- Maintaining an appropriate parasite-control programme
- Preventing dogs from licking children’s faces immediately after eating or scavenging
Speak with a medical professional about concerns relating to human exposure. A veterinarian can advise on reducing parasite risks from pets.
Final Thoughts
The signs of worms in dogs vary considerably. Some dogs pass visible worms or tapeworm segments, while others develop only vague symptoms such as diarrhoea, weight loss, a dull coat or reduced energy.
Many infected dogs show no outward signs at all.
The most important symptoms to watch for include:
- Visible worms or rice-like segments
- Persistent diarrhoea
- Blood in the stool
- A swollen abdomen in a puppy
- Poor growth
- Unexplained weight loss
- Pale gums
- Weakness
- Repeated vomiting
These signs do not confirm worms by themselves. Veterinary examination and faecal testing may be needed to identify the cause and select a treatment with the correct worm coverage.
If your dog is seriously unwell, has pale gums, passes black or bloody faeces, repeatedly vomits or becomes weak, seek veterinary advice promptly rather than waiting to see whether routine worming resolves the problem.
Frequently Asked Questions
What is the most obvious sign of worms in a dog?
The most obvious sign is seeing a worm or worm segment in the dog’s faeces, vomit, bedding or fur around the anus. Roundworms may resemble spaghetti, while tapeworm segments often look like small grains of rice. Many dogs with worms never pass anything visible.
Can a dog have worms and still act normally?
Yes. Dogs with light infections may eat, exercise and behave normally. Symptoms are more likely when the worm burden becomes heavier or when the dog is very young, elderly or otherwise unwell.
What does dog poo look like when a dog has worms?
The stool may look normal, or it may be soft, watery, coated in mucus or streaked with blood. Some dogs pass visible worms or tapeworm segments, but worm eggs are usually microscopic and cannot be seen by looking at the faeces.
What do roundworms look like in dogs?
Adult roundworms are long, smooth and pale. They are commonly compared with pieces of spaghetti and may occasionally appear in faeces or vomit.
What do tapeworms look like in dogs?
Owners usually see individual tapeworm segments rather than the entire worm. The segments may resemble white grains of rice when fresh and sesame seeds when dry. They can appear around the anus, in bedding or on faeces.
Can worms cause blood in a dog’s stool?
Yes. Hookworms and whipworms can damage or inflame the intestinal lining, potentially causing fresh blood or dark, tar-like faeces. Blood in the stool can also have many other causes and should be discussed with a veterinarian.
Can worms make a dog’s gums pale?
A heavy hookworm infection can cause blood loss and anaemia, which may make the gums appear pale. Pale, white or grey gums can also signal other serious conditions and require prompt veterinary assessment.
Does a pot belly mean a puppy has worms?
A rounded abdomen is a recognised sign of a heavy roundworm burden in puppies, especially when accompanied by poor growth or a thin body. However, abdominal swelling has other possible causes, so the puppy should be properly assessed.
Does scooting mean my dog has tapeworm?
Tapeworm segments can irritate the area around the anus and contribute to scooting. However, full or inflamed anal glands are a more common cause. Allergies, diarrhoea and local skin irritation can also lead to scooting.
Can worms make a dog vomit?
Yes. Dogs with roundworms may vomit, and adult roundworms can occasionally be seen in the vomit. Repeated vomiting can quickly lead to dehydration and should not be assumed to be caused by worms without veterinary advice.
Can worms cause weight loss even if my dog is eating?
Yes. Intestinal parasites can interfere with digestion, nutrient absorption and intestinal health. A dog may lose condition despite eating normally. Persistent weight loss should be investigated because many other diseases can cause the same sign.
Can I tell which worm my dog has from the symptoms?
Symptoms can provide clues but usually cannot confirm the exact worm. Roundworms, hookworms and whipworms can all cause digestive signs, while some infections cause no symptoms. A faecal test or identification of a visible worm may be required.
Will a routine worming treatment remove every type of worm?
Not necessarily. Worming products differ in their active ingredients and parasite coverage. Some treat roundworm and hookworm but not tapeworm or whipworm. Check the current New Zealand label for the exact worms covered.
Should I worm my dog if I see worms in the stool?
Your dog will likely require treatment, but the correct product depends on the worm involved. Contact your veterinarian if you are unsure, particularly when your dog is a puppy, is unwell or has blood in the stool, pale gums, vomiting or weakness.
How does a veterinarian test a dog for worms?
A veterinarian will commonly examine a faecal sample for worm eggs or parasite material. Repeat testing may be needed because eggs are not always passed in every stool. Visible worms or segments can also be identified.
Can indoor dogs get worms?
Yes. Dogs can encounter microscopic eggs in soil, shared outdoor spaces or material carried into the home. They may also acquire worms through prey animals, raw offal, other pets or intermediate hosts. An indoor lifestyle may reduce some exposures but does not make infection impossible.
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This article provides general information for New Zealand dog owners and is not a substitute for veterinary advice. Symptoms associated with worms can also occur with other medical conditions. Always follow the current New Zealand product label and contact your veterinarian if your dog is unwell.