Worms in dogs are a common problem. Because canine worms are contracted in several ways, it’s important to be aware of how to protect your pet from infection. Awareness of the different types of worms in dogs is also important so that you may choose the best treatment for your dog.
Different canine worms will require different treatments, as some worms are more dangerous than others. This article discusses the most common canine worms: tapeworm, hookworm, whipworm, roundworm, and heartworm.
How Do Dogs Get Worms?
Being aware of the many ways that your pet can get worms is the first step to protect them from infection. Most dogs are at risk of contracting dog worms in their lifetime. Canine worms are contracted in these ways:
- Eating contaminated feces and soil
- Eating infected prey
- Consuming infected sheep offal
- Mosquito, flea and tick bites
- Flea ingestion
- Drinking contaminated milk
- Direct contact with infected dogs
Puppies are especially at risk. Nearly all puppies are born with roundworms. This is because most others will have dormant roundworm larvae in their bodies. Even if puppies are born without worms, the larvae of other intestinal worms like hookworm are passed on through their mother’s milk. Just one puppy or the dam herself can spread worms to the entire litter.
Because dogs are social animals, it’s not uncommon for a dog to “catch” worms from another dog. The eggs of intestinal worms stick to the anal region of dogs. When a dog greets another dog by sniffing this area, they are likely to make direct contact with the eggs. In addition, mutual grooming causes infection because the eggs are deposited on the coat. Even something as simple as sharing the same bedding adds to the spread.
Types of Worms that can Infest Dogs
Parasitic worms, also called helminths, are large macroparasites that infect dogs. Adults are visible to the naked eye. Many are intestinal worms. Signs and symptoms vary depending on the type of worm. Most manifest as gastrointestinal complications and weakness. Amongst the most common worms are roundworms, tapeworms, whipworms, and heartworms. Less common worms include the screwworm and lungworm.
Toxocara canis (dog roundworm) is a helminth parasite of dogs and other canids. The name comes from the Greek word “toxon”, which means bow, and the Latin word “caro”, which means flesh. Dog roundworms are dioecious, meaning that males and females are distinctly different from each other. Males of the species are 4-6 cm long, smaller than the 6.5 – 15 cm female. Females have large ovaries which can contain 27 million eggs. Dog roundworm eggs are brown and spherical or oval-shaped. The surface is granular and thick, measuring between 72 – 85 μm. This gives them resistance to most weather and chemical conditions.
For puppies under three months, these larvae hatch within the small intestine and enter the bloodstream. They migrate through the liver, ending up in the lungs. Once in the lungs, the worms then migrate up the trachea. This causes coughing and the puppy swallows the larvae back down to the small intestine. For dogs older than three months, the larvae enter somatic sites in the body like the kidneys, muscles and mammary glands where they mature. This is particularly worrisome for pregnant dogs.
Dog roundworms infect a developing fetus and encyst in the dam’s mammary glands, where they are passed on through the milk. When she has been infected once, a female dog infects her future litters. This happens even if she does not encounter an infestation again. Puppies contract the dam’s dormant larvae. Dog roundworm infections are usually asymptomatic. In most cases the only defining symptom is diarrhea. In severe cases, massive infection with dog roundworm causes vomiting, flatulence, poor growth rate in puppies, and an enlarged abdomen.
Dirofilaria immitis (dog heartworm) is a parasitic roundworm that causes dirofilariasis. Dog heartworm was once confined to the United States.
The first and second larval stages develop within the body of the mosquito. By the third larval stage, the mosquito must locate a host and deliver a bite. This deposits the larvae beneath the skin of the animal. After one to two weeks of development, the fourth stage migrates into the muscles of the abdomen and chest. 45 to 60 days after the migration, the fifth and final molt occurs. The heartworm enters the bloodstream to migrate into the pulmonary artery. Over the next three or four months, the heartworm grows. Lengths of 30 cm for the female and 23 cm for the male are possible. Seven months after the initial infection, the heartworms are mature and will mate. Females give birth to live young. The young, called microfilariae, circulate in the dog’s bloodstream for up to two years. In this time, mosquitos will ingest them and the cycle repeats.
Most dogs show little or no signs of heartworm infestation. However, more active dogs or those with a heavy infestation will show the characteristic signs. The signs of heartworm include a cough, exercise intolerance, weight loss, fainting and coughing up blood. The most severe cases result in congestive heart failure. In rare situations, migrating heartworm larvae can end up in unusual sites such as the brain, eyes or leg arteries. This results in worrisome symptoms like seizures, blindness, and lameness.
Two common tapeworm species that infect dogs are Dipylidium caninum (flea tapeworm) and Echinococcus granulosus (dog tapeworm). Fleas transmit Dipylidium caninum. Microscopic flea larvae ingest tapeworm proglottids found in the environment or in dog feces. As the flea matures, it remains an intermediate host for the tapeworm, which is in its cysticercoid form at this time.
Dogs ingest the infected flea whilst grooming. Within the small intestine, the cysticercoid develops into its adult form. One month later it reaches maturity. Mature flea tapeworms reach up to 46 cm to 60 cm. The mature flea tapeworm goes on to produce proglottids that detach from the tapeworm. The cycle begins again. Infections with Dipylidium caninum tend to be asymptomatic. Dogs may attempt to relieve anal pruritis by scraping their anal region against the floor. Mild gastrointestinal discomfort may occur. The most obvious symptom is the presence of proglottids in the feces. Freshly-passed proglottids are motile.
Sheep transmit Echinococcus granulosus. Consuming infected offal can lead to infection, however, the infection is dependent on several factors. Dog tapeworm infections are asymptomatic for years. The dog tapeworm causes cysts in organs like the liver lungs, spleen, bone and even the brain. Ruptured cysts produce symptoms such as fever, eosinophilia, urticaria and potentially anaphylactic shock.
Ancylostoma caninum is a hookworm that infects the small intestine of dogs. It requires warm and moist conditions and prefers tropical climates. Hookworm infects dogs without ingestion. It exists in the warm, damp soil and can penetrate the skin. This usually occurs through the dog’s paw pads. Once they attach to the intestines, they feed on the mucosal lining and blood. At this stage, the symptoms include lethargy, weakness, pale gums, the roughness of the coat, and potential black stools.
Hookworms are often fatal for puppies. Acute anemia is characteristic of the infection. Anorexia, emaciation, and weakness develop in chronic cases. Hemorrhagic enteritis with ulceration is seen in fatal cases. The surviving puppies develop some immunity to hookworms. Future infections are less severe. Bitches must be free of hookworms before breeding.
Ancylostoma caninum causes cutaneous larva migrans in humans. Hookworms usually fail to penetrate all the way through human skin. The result is a range of uncomfortable symptoms. Itching, redness, and lesions appear until the larva dies. Dogs also contract this disease but the name is reserved for human cases. In dogs, the larvae are more likely to survive. Once they burrow through the skin they make their way into the intestines. This results in hookworm infection.
Trichuris vulpis is a whipworm that infects at least 14.3% of shelter dogs in the United States. The whipworm has a variable size, growing anywhere from 30 – 50 mm in length. Adult whipworms lay eggs in the large intestine. Another dog ingests the eggs in feces, which go on to invade the intestinal cells.
As they grow, whipworms live within the colon, cecum, and rectum, releasing eggs after about three months. Adult whipworms consume the dog’s blood, mucosal epithelium, and tissue fluids. Severe infection by Trichuris vulpis causes dehydration, weight loss, anemia, and bloody diarrhea.
Symptoms of Worms in Dogs
Depending on the type of worms your dog has, the symptoms will vary. However, there are several non-specific signs you can refer to when considering if your pet is struggling with worms:
- Weight loss
- General irritability
- Dull coat
- Appetite Changes
Your pet will suddenly eat more to make up for the lack of nutrients caused by the worms. Your dog may also reject food. This typically comes down to discomfort from gastrointestinal upset. The most obvious sign of worms in dogs is the presence of proglottids in the feces.
Specific Worm Symptoms
Proglottids are segments of the tapeworm. These segments contain reproductive organs. They can survive and move briefly after breaking away from the body and may move around in the feces. Dried segments will appear like white rice grains or sesame seeds in the stool. Adult worms also appear in feces and vomit. Adult hookworms and roundworms appear as off-white or tan, elongated parasites.
Hookworm infestations manifest some specific symptoms. At the site, there is dermatitis with papules and erythema. Lesions can be seen and are most common on the feet. Respiratory diseases also occur in puppies with severe infestations of hookworm. Respiratory symptoms indicate anemia which is caused by blood loss.
Diagnosis of Dog Worms
Canine worms are diagnosed under a microscope. The process is called fecal flotation with centrifugation. The Companion Animal Parasite Council recommends that all dogs are tested with this method. Fecal tests for specific parasites combined with flotation aids in the identification. It especially helps in situations where few worms are present. Worm eggs float readily in most flotation solutions. Some eggs are morphologically distinct. For example, Toxocara canis has a dark embryo and a rough outer shell wall. However, other worms are not as easily identified. Sedimentation is more suitable for heavy worm eggs. Diphyllobothrium spp. eggs do not always float.
Your veterinarian will ask you for a stool sample. Even when your dog is not suffering any symptoms of canine worms, it doesn’t hurt to bring a sample to your vet during your pet’s annual examination. Ideally, the fecal sample is no more than 24 hours old. Any clean container with a tightly-fitting lid is suitable. This includes jars and plastic tubs.
Heartworms are detectable in a blood test. The American Heartworm Society states that many dogs show few symptoms of heartworms, but the earlier treatment begins the higher the recovery rate. That’s why annual testing for heartworms is one of the best ways to prevent a serious infection.
Best Dog Worm Treatments
It’s vital that you regularly treat your dog for worms. Puppies and children are especially at risk of contracting worms. Always consult your veterinarian on the best worm treatment for your pet. There are many types of medication that prevent and treat canine worms.
When using pet store products, always double-check the dose and read the manufacturer’s instructions. Your dog’s size and weight are likely to be a factor in the dose. Effective flea and tick treatment will also help to eliminate some types of worms.
There are many treatments available on the market for dog roundworms. Nursing dams are treated for roundworms at the same time as their puppies. Puppies often contract roundworms from their mother. Approved canine-safe products for use on roundworms include:
- Pyrantel Pamoate
- Panacur C (fenbendazole)
- Trifexis® (milbemycin oxime/spinosad)
- Iverhart Max® Chewable Tablets (ivermectin/pyrantel/praziquantel)
Only a drug called melarsomine dihydrochloride approved by the FDA for the treatment of heartworm in dogs. This drug must be injected by a veterinarian. Melarsomine is an adulticide and cannot affect juvenile heartworms. Because of this, several other medications are administered to improve the chances of recovery. This includes providing heartworm preventative medication and doxycycline. Over the course of the treatment protocol, adult heartworms will die within 1 to 3 months. Cage rest and limited exercise during the recovery period decrease the risk of complications. You will need to give preventative medication year-round for the rest of your dog’s life.
Long-term use of heartworm preventative medication is not enough to treat heartworm. In fact, continuous use will cause additional damage to the lungs and heart as the adult worms infecting them will continue to grow and breed. Yearly testing is important for this reason. The American Heartworm Society states that dog owners should administer preventative medication every month of the year to kill any heartworm larvae before they can grow and become a problem.
95-98% of dogs successfully beat heartworm with the right treatment. However, the condition is distressing and dangerous for your dog. Make sure you protect your pet so that treatment won’t be necessary.
- HEARTGARD® Plus (ivermectin/pyrantel)
- NexGard SPECTRA® (afoxolaner/milbemycin oxime)
- Interceptor® (milbemycin oxime)
Most dog dewormers on the market will treat flea tapeworms in dogs. However, Echinococcus granulosus (dog tapeworm) has a more guarded prognosis due to the rupture of cysts. Routine complete blood counts are required for your veterinarian to successfully treat this specific tapeworm. Your vet will identify the exact tapeworm species infecting your pet and the treatment depends on which type it is.
- Bayer Tapeworm Dewormer (praziquantel)
- Sentry HC WormX Plus (pyrantel pamoate)
- Drontal® Plus (febantel/pyrantel pamoate)
Several dewormers are effective at treating hookworms in dogs. In severely affected dogs, medication is combined with supportive therapy to help the dog’s chances of survival. This involves keeping the dog warm, providing electrolytes and fluids, iron supplements and blood transfusions. The most popular dewormers for hookworms include:
- Droncit® (praziquantel)
- Interceptor ® Plus (milbemycin oxime)
- Drontal® Plus (febantel/pyrantel pamoate)
- Sentinel® Spectrum® (milbemycin oxime/ lufenuron/praziquantel)
Most broad-spectrum dewormers will treat whipworm. Check the manufacturer’s instructions before using any of these products. Whipworm eggs are extremely hardy. They last up to five years in the environment. This means that whipworms have a high re-infection level. For this reason, treatment is continued for up to three days.
- Coraxis® Topical Solution (moxidectin)
- Interceptor ® Plus (milbemycin oxime)
- Drontal® Plus (febantel/pyrantel pamoate)
Home Remedies to Treat Worms in Dogs
Canine worms are partially manageable at home. Although it may be tempting to try these options instead of seeking veterinary help, it’s vital that you provide your dog with the correct medication as soon as possible. Untreated worm infestations cause discomfort and illness in dogs. Worms will not subside on their own.
Raw carrots are a healthy and enjoyable superfood for your dog. While carrots are safe and non-toxic, you must cut or grate carrots into small pieces if you want to use them. This helps to prevent choking. Carrots are a great way to help your pet get rid of worms. They contain insoluble fibers like lignin, cellulose, and hemicellulose, which promote regular bowel movements. The coarse texture of carrots helps to scrape canine worms away from the mucosal lining that they attach to. These two factors combined allow for easier passage of intestinal worms from the body.
Carrots are best given in moderation. The average dog will eat one or two baby carrots a day with no problem. The carrots are best chopped or grated into fine pieces to prevent choking. Grated or chopped carrots can be sprinkled on top of your dog’s meal. Always ensure that the carrots are clean.
Monitor your dog closely after feeding them carrots. If your dog has a concerning change of stool habits, revert back to the original diet. This includes constipation and diarrhea. Chunks of carrot are sometimes found in the stool. This indicates that your dog was not able to digest the carrot properly. You will need to use smaller pieces or stop using carrots. Carrots cause orange stool. This is because of the beta carotene found in carrots.
Garlic is used to treat intestinal parasites. This is because of its antihelminthic effects. Researchers have found that treatment with garlic reduces worm load in mice. It also works as an expectorant, meaning that it helps to bring mucus and phlegm out of the airway. Unfortunately, unlike raw carrots, garlic does come with some risks.
Garlic contains aliphatic sulfides. In excess, aliphatic sulfides will reduce the number of red blood cells in your pet’s blood. This is hemolytic anemia. For this reason, the ASPCA considers garlic toxic to dogs. Be sure to consider both the pros and cons of using garlic before offering any to your dog. Some experts recommend using one crushed garlic clove to be given per day for large dogs. Garlic powder is also an option.
Cloves are an aromatic spice with antihelminthic properties. In one study, clove extracts were more effective at killing earthworms than garlic. They are also effective at removing giardia and coccidia. However, like garlic, cloves can be toxic to your pet when given in large doses. Cloves contain a compound called eugenol. Eugenol is hepatotoxic. Overdose is a possibility, causing several symptoms like bloody urine, diarrhea, dizziness, and convulsions.
Experts suggest that one clove should be given per day for a week. Do not give cloves to pregnant dogs as it causes miscarriage. If you wish to try using cloves, use them sparingly and always monitor your pet for signs of illness. Discontinue use immediately if you are concerned at all about your pet’s well-being.
Pumpkin seeds contain biochemical compounds called cucurbitacins. Cucurbitacins have antihelminthic properties. They paralyze the worm’s muscles. This causes it to detach from the intestinal lining. Most current studies about the effectiveness of whole pumpkin seeds have focused on birds rather than dogs, but the results are still promising. Some owners report success after using this method.
The seeds are most effective against tapeworms and roundworms. To try giving your dog pumpkin seeds, you can offer a quarter of a teaspoon per ten pounds of body weight once a day. Always use raw, organic seeds and avoid salted seeds where possible.
Oregon grape root, also called mountain grape, is an evergreen shrub with several beneficial properties. Its root contains berberine, a substance with antimicrobial and antihelminthic qualities. Unlike garlic and cloves, Oregon grape root is not toxic to dogs. However, you cannot use this herb for pregnant dogs or dogs with liver disease. To administer Oregon grape root extract, you can offer doses of half a tablespoon up to three times a day. Do not exceed this amount.
Dogs infected with intestinal worms will struggle to derive enough nutrition from their food. In severe cases, your dog loses weight as the canine worms steal nutrients and break down the intestinal lining. Giving digestive enzymes during treatment, as directed by a veterinarian, will help your pet to derive more nutrition from their food until they have recovered.
If you decide to supplement your dog’s treatment with digestive enzymes, it’s important to consider the pros and cons. Some veterinarians suggest that supplementing your dog will suppress their natural enzyme production, leading to a dependency on the supplements.
Preventing Worms in Dogs
Prevention is always better than treatment, especially when canine worms are involved. Luckily most types of parasitic worm infections are easy to treat. Here are some of the most common methods of canine worm prevention.
Preventative medications are vital for your dog’s protection. A highly effective way to combat worms is through regular use of a dewormer. Dogs over 6 months of age should be treated every 3 months for life. Flea treatments are easy to use and help to prevent intestinal worms. Tapeworms can be transmitted through flea bites, so preventing flea infestations is a good way to reduce the risk of your pet getting canine worms. Spot-on flea treatments are given every 3 months along with a dewormer.
As well as maintaining your dog’s dewormer and spot-on flea treatment protocol, it’s also vital to upkeep good hygiene. Regularly clean up your dog’s feces to reduce the risk of coprophagia, and monitor your dog when out on walks to ensure that they don’t eat any feces on the way. Bathing and grooming your dog as required will help to remove infected soil and stool in your dog’s coat. This reduces the risk of egg ingestion.
Worms in Dogs – FAQs
Have any unanswered questions? Feel free to consult our FAQs section. Here we answer the most common questions about worms in dogs.
How Do You Get Rid Of Worms In Dogs?
Canine worms are primarily treated through deworming medication. This medication is designed to paralyze and kill any worms that infect your dog. Some treatments can be bought in pet stores. Others are only given as prescriptions. Some owners opt to use home remedies alongside veterinary treatments. If you choose to do this, it’s always best to ask your veterinarian for guidance before starting any supplementary treatments. Administering too much of your home remedy will make your dog feel worse. This is especially true for garlic and cloves, which are toxic to dogs in excess.
Can You Get Worms From Your Dog?
You can contract tapeworms, roundworms, and hookworms from your dog. Humans accidentally consume worm eggs in a few ways. Worm eggs stick to the dog’s fur, especially around the rear end, and are accidentally ingested if you touch your nose or mouth after petting. Picking up infected stool without washing your hands afterward also leaves you at risk. If your dog brings fleas into the house, the chances of contracting tapeworms increases. Occasionally, children will ingest an infected flea and get tapeworms this way. Children are more likely to catch worms. This is especially a problem if they play in your dog’s living space.
Cutaneous larval migrans (CLM) is contracted from canine hookworms. CLM manifests as red, “creeping” lesions on the skin. Fortunately, the larvae cannot penetrate the basement membrane of the skin. This keeps the disease confined to the skin’s outer layers. Sites most frequently affected by CLM are the feet, hands, and knees.
How Did My Dog Get Worms?
Your dog can contract worms from several sources. Amongst the most common reasons are; the ingestion of infected feces, through flea bites, through mosquito bites, and direct contact with infected dogs. If you have more than one dog, it’s possible for both to get worms. This is because contact with an infected dog can pass on eggs. If your pet has fleas the likelihood of them having tapeworms increases. To recap how your dog catches worms:
- Ingesting contaminated feces
- Eating contaminated soil
- Consuming infected prey
- Eating infected offal
- Mosquito bites
- Flea bites
- Eating fleas
- Drinking contaminated milk
- In-utero from the mother
- Direct contact with infected dogs
Can You Get Roundworms From Your Dog Licking You?
Roundworms are passed from your dog to you through licking. This is because your dog has ingested infected feces or soil. Your dog will also contract roundworms by licking infected dogs. In either scenario, the eggs of the roundworm are left on your skin after your dog licks you. When you touch your nose or mouth the eggs are ingested. This leaves you vulnerable to roundworm infection. Hookworm and giardia are also transmitted through licking.
Not every lick will give you worms. Not every play session puts you at risk of catching them. But if you know your dog has worms, it’s best to stop them from licking you until they’re better.
How Long Does It Take For Worms To Leave Your Dog?
Most canine worming treatments get to work quickly. Efficient treatments kill worms in 2 to 6 hours. A wait of 12 hours is more common. One treatment often isn’t enough to completely eliminate worms. Roundworms and hookworms continue to enter the intestine after deworming. You will not always see dead worms in the stool. This is because they are digestible. Worms, if passed, will be present in the stool for a week or two. If the treatment is successful these worms will be dead. Re-infection is possible for any type of worm.
To conclude, canine worms are a common problem for pet owners. Preventative measures should be used to stop dogs from getting parasitic worms. Worming dogs every month is the best way to prevent infection. Flea treatment also helps to prevent tapeworms in dogs. Most treatments start to work after 12 hours.