How to Identify Different Worms in Dogs (with Pictures)

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How to Identify Different Worms in Dogs (with Pictures)
How to Identify Different Worms in Dogs (with Pictures)

Many species of worms can infect dogs. The most worrisome are roundworms, solitaires, heartworms, hookworms and whipworms. Each type of worm has a slightly diverse life cycle, with symptoms that hardly vary between species. Thus, it is not possible to determine which type of worm your dog has by looking at the symptoms alone. Exams may be required. However, knowing what are the symptoms, risks and characteristics of each type of worm can help you to treat and care for your canine friend.


Part 1 of 3: Identifying a Worm Infection

Identify Different Dog Worms Step 1

Step 1. Be aware of the risk factors for specific types of worms

Since different worms can be very similar, one of the best ways to identify the type of parasite your dog has is to understand the environmental or situational factors that preceded the infection.

  • Roundworms are usually passed to pups by an infected mother, as the eggs and larvae enter the placenta and affect the young in the womb. Eggs can also be transmitted through the mother's milk. Puppies must be routinely dewormed.
  • Roundworms enter the dog's body when he eats something that contains the worm. Fleas carrying roundworm eggs can also transmit the parasite. Thus, hunting dogs or animals infected with fleas can become contaminated.
  • Hookworms and whipworms grow in moist soil. Dogs most at risk of contracting such worms are those raised on grass, especially in warm, humid environments. These parasites are more common in dogs that live in kennels with access to grass.
  • Heartworms are transmitted by insects such as mosquitoes and are endemic in areas where such insects are common. The highest risk areas are spread along the Atlantic coast, such as the southeastern United States and the coast of Brazil.
  • Lung worms are spreading more through fox droppings, slugs and snails. Contact with any of these animals is considered a risk factor.
Identify Different Dog Worms Step 2

Step 2. Observe the symptoms

Many of the symptoms caused by worms are common and not very specific. Thus, it is not possible to diagnose what type of worm your dog has just by looking at its physical and behavioral changes. However, the presence of these signs in a dog that has not been dewormed recently is a cause for concern and the owner is advised to further investigate the animal's health.

Identify Different Dog Worms Step 3

Step 3. Look for worms in the stool

Sometimes, even in a dog that doesn't have symptoms, you may notice physical evidence of worms in the stool he passes out. If you don't trust your ability to recognize the type of worm present in the stool, put it in a container and take it to a veterinarian.

Taking a stool sample to the vet is much more effective than trying to describe what the worms look like to him, since to the naked eye most worms are the same

Identify Different Dog Worms Step 4

Step 4. Identify gastrointestinal signs

Although life cycles vary, all worms at some point travel through the intestines. The dog will not show symptoms if there are few worms in the gut. On the other hand, severe intestinal parasites can irritate the bowel tissue, causing dizziness, diarrhea (sometimes with mucus and/or blood), loss of appetite and weight.

Identify Different Dog Worms Step 5

Step 5. Take a stool sample

Worms live in or pass through the intestine. Therefore, at certain times, evidence of infection may appear in the animal's feces. You will be able to see worms in the droppings if the animal has severe worms, whereas in less acute worms only eggs or larvae, which are harder to see with the naked eye, are present in the stool.

  • Take a stool sample with a popsicle stick or disposable spoon and place it in a container that has a screw top (your veterinarian can give you a specific jar for this purpose if you don't have anything suitable).
  • Store the sample in an environment with a temperature of less than 30 degrees Celsius and provide it to the veterinarian when you can. The sample does not have to be fresh to show evidence of worms.
  • If your veterinarian orders a set of samples, you will collect stool for three days in a row and place them in the same container. This may be necessary to reverse a “false negative” exam. The sample set reduces the risk of unreliable results.
  • The veterinarian can analyze the droppings himself, with a microscope, to identify eggs or larvae, or send the sample to a laboratory.
Identify Different Dog Worms Step 6

Step 6. Ask your veterinarian for a blood test

Some worms that cause serious problems, such as lung and heart worms, can be identified with a blood test. The veterinarian takes a small blood sample (between 1 and 2 mL) for testing.

  • Several tests can be done, but the ELISA is the most common. The test identifies the presence of antibodies that fight the heart worm through substances that change color if the test is positive.
  • Most veterinarians working in high-risk areas recommend that the dog be examined once a year before prescribing monthly preventive treatment.
Identify Different Dog Worms Step 7

Step 7. Avoid coming into contact with dog feces and worms

Some worms, such as roundworms, can be transmitted from dogs to humans. Children infected with roundworms can suffer from eye damage.

  • Infected worms and feces should be removed from places where children play.
  • Excrement from infected animals should only be handled with gloves.
  • Always wash your hands thoroughly with soap and water after handling the feces of animals with worms.

Part 2 of 3: Distinguishing Types of Worms

Identify Different Dog Worms Step 8

Step 1. Document any symptoms or risk factors that apply to your dog

Sometimes the best way to diagnose worm types is to document the risk factors for your dog. Make notes about the environment the dog lives in, the climate and the animal's habits. Document the severity and duration of any symptoms of illness and provide the information to the veterinarian if you suspect a worm.

Identify Different Dog Worms Step 9

Step 2. Look for distinguishing characteristics of each type of worm

If the worms (or parts of them) can be seen in the animal's feces or vomit, you can identify them. While many worms look the same, each of them has unique characteristics that can help you identify each species.

  • Roundworms look like strands of cooked noodles. They are 8 to 10 cm long, but can reach 18 cm. They have smooth, rounded bodies.
  • Solitaries have distinctly flat bodies separated by small sections. The extension varies according to the species, but it can be between 50 cm and 250 cm. Most of the time, the animal eliminates only parts of these worms in vomit and feces rather than expelling them in its entirety.
  • Hookworms and whipworms are much smaller than loners and roundworms. They are usually between 0.5 cm and 2 cm in length and are as thin as a strand of hair. Due to their size, these worms can appear transparent and are difficult to identify with the naked eye.
Identify Different Dog Worms Step 10

Step 3. Watch for signs of heart or respiratory problems

Lung and heart worms infest your pet's blood vessels, which can bring out symptoms such as coughing, heavy or fast breathing, lack of energy and even fainting and death.

  • Lung and heart worms can impair blood clotting. Some dogs do not stop bleeding even if slightly injured, which is alarming.
  • If you experience any of these signs, see your veterinarian immediately. Although a little expensive, proper medical treatments tend to have positive effects.
Identify Different Dog Worms Step 11

Step 4. Look for egg sets

A sure sign of solitary infection is the set of eggs attached to the fur near the animal's anus. This happens when solitary adults release eggs into the intestinal lumen. The set is attached to the animal's anus and causes itching in the region.

  • These sets look like sesame seeds or rice grains attached to the hairs near the dog's buttocks.
  • If you look closely, you will see small cream-colored objects dangling near the animal's anus.
Identify Different Dog Worms Step 12

Step 5. Check the dog's physical condition

The worms absorb nutrients from the dog's food, which becomes malnourished. Infected dogs may not have much fat covering their bones, but their bellies are swollen from the profusion of worms. The animal will have the ribs well highlighted, belly and opaque hair.

Identify Different Dog Worms Step 13

Step 6. Take a sample of the worm or roe to the vet

Asking your veterinarian to examine the worm is the best way to diagnose the species that is parasitizing your pet. The veterinarian will be able to examine the worms under a microscope and will be experienced enough to identify the small differences that distinguish one species from another.

The difference between the eggs of one type of worm and another can be subtle. An oval egg is different from a round one. Perhaps the egg can only have one tip

Part 3 of 3: Preventing or treating worm contamination

Identify Different Dog Worms Step 14

Step 1. Identify and treat worms quickly

Worms tend to get worse if they go untreated for a long time. An infection with a large number of adult worms can negatively affect your dog's health, so it is best to treat the infection before it develops into a serious condition.

  • Some canine worms can cause gastrointestinal problems such as diarrhea.
  • Some worms can kill the dog. Lung and heart worms are the most lethal.
Identify Different Dog Worms Step 15

Step 2. Administer preventive treatment monthly

If you live in a high-risk area or one populated by a lot of mosquitoes, your dog should get some preventive treatment every month to keep heartworms from affecting him. Medicines to fight heartworms require a prescription.

  • Most veterinarians will require an examination to verify that the animal is not infected with heartworms before prescribing preventive treatment.
  • Many preventative treatments are chewy and have a meaty flavor. This makes it easy to manage them.
Identify Different Dog Worms Step 16

Step 3. Keep your dog free from fleas

Since some worms are transmitted by them, submitting your pet to flea treatments is a way to keep his health up to date.

  • Some companies distribute a chewable pill that fights both fleas and heartworms.
  • It is possible to administer a monthly topical flea treatment. The medicine is usually squeezed into the back of the animal's head.
Identify Different Dog Worms Step 17

Step 4. Restrict your pet's access to harmful environments

Ensuring the dog stays away from potentially worm-filled environments can help eliminate the need for deworming.

  • Keep your dog away from hot, grassy areas frequented by dogs that have not been dewormed.
  • Do not allow your dog to come into contact with wild or game animals.
  • Avoid humid, warm environments that have high concentrations of insects such as fleas and mosquitoes.
  • Do not allow your dog to eat or rub in the feces of other dogs and animals.
Identify Different Dog Worms Step 18

Step 5. Administer a dewormer if necessary

The type of treatment and its duration depend on the risk factors involved. Discuss with your veterinarian.

  • Dewormers are usually powders that can be mixed with the pet's food or with another food such as yogurt (consult your veterinarian before giving the dog food made for humans).
  • Most dewormers only need to be administered once. However, if your veterinarian prescribes fenbendazole, you will have to give it repeatedly for a few days. Fembendazole is a fairly mild dewormer often used in puppies.
  • Read the medicine package insert and consult the veterinarian before submitting the animal to any type of treatment.
Identify Different Dog Worms Step 19

Step 6. Visit the veterinarian regularly

A dog constantly examined by a veterinarian will be in good health. The veterinarian will have the opportunity to identify problems before they become extreme and cause lasting harm to your canine companion.


  • Collect the dog's feces when you walk him.
  • Flea control is essential at all times of the year.
  • Do not allow the dog to smell or eat feces, dirt or dirt. Puppies have a habit of eating whatever they see, which increases the likelihood of worm contamination.


  • Roundworms and whipworms can be transmitted to humans. Be careful and know how to handle the animal's feces properly. Talk to a doctor if you are concerned about your health or that of any family member.
  • Heartworms will cause your dog to have a heart attack if they are not discovered and treated in time.
  • Worms can kill if not treated quickly.
  • See a veterinarian immediately if your dog exhibits any signs of fatigue or has vomiting and diarrhea.

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