Dogs can get worms in a variety of ways. Worms are internal parasites that live in a dog’s intestines and feed off of partially digested food. There are several different types of worms that commonly infect dogs, including roundworms, tapeworms, hookworms, and whipworms. Worms can pose serious health risks to dogs if left untreated, so it’s important for dog owners to understand how their pets can get worms and take steps to prevent infestations. Let’s take a closer look at the most common worm species, how they infect dogs, and what you can do to make sure your furry friend stays worm-free.
What are the most common types of worms in dogs?
Here are the primary internal parasites that infect dogs:
Roundworms – Roundworms are extremely common in puppies and young dogs. Their scientific name is Toxocara canis or Toxascaris leonina. They live in a dog’s small intestine and can grow up to 7 inches long. Roundworm eggs are passed in dog feces and become infectious after a few weeks in the environment. Dogs usually get roundworms by ingesting contaminated soil, feces, or infected rodents. Roundworms can also be transmitted from mother to puppy before birth or through nursing.
Tapeworms – Tapeworms attach themselves to a dog’s intestinal wall by hooking onto it with mouthparts. Tapeworm segments containing eggs break off and pass out in the dog’s feces. Their scientific name is Dipylidium caninum. Common intermediate hosts include fleas, mice, and other small mammals. Tapeworms are transmitted when dogs swallow infected fleas during grooming or eat infected hosts.
Hookworms – Hookworms bite into the intestinal lining and feed on blood. Their scientific names are Ancylostoma caninum and Uncinaria stenocephala. Hookworm eggs pass out in the feces and hatch into larvae in the environment. Dogs get infected by ingesting larvae, often from contaminated soil. Hookworm larvae can also burrow through the skin and migrate to the intestines.
Whipworms – Whipworms get their name from their whip-like shape. They embed their head into the intestinal wall. Their scientific name is Trichuris vulpis. Whipworm eggs are passed in feces and need several weeks in warm, moist soil to become infective. Dogs get whipworms by ingesting the larvae, usually through grooming or contaminated food/water bowls.
So in summary, dogs can get intestinal worms by ingesting contaminated soil, feces, food/water, fleas, or infected rodents. Worm larvae can also penetrate the skin and migrate to the gut. Puppies are especially prone to roundworms.
How do puppies get worms?
Puppies are extremely susceptible to a variety of worms due to their underdeveloped immune systems and curiosity about the environment. Here are some key ways puppies get infected with worms:
- From their mother – Puppies can get roundworms across the placenta before birth or through nursing milk. The larvae migrate to the intestines and mature into adults.
- Ingesting feces or soil – Puppy behaviors like eating feces or soil expose them to worm eggs and larvae. Their undeveloped immunity allows the worms to establish infection.
- In utero infection – Some worms like hookworms and roundworms can infect unborn puppies if the mother dog has worms during pregnancy.
- Dormant larvae – Larvae ingested by the mother dog can encyst in tissues and reactivate during pregnancy, infecting the puppies.
- Nursing – Puppy nursing can transmit worm larvae that are shed in the mother’s milk.
- Rodents – Eating infected rodents and their feces is a common source of tapeworms and roundworms.
- Fleas – Puppies can easily pick up tapeworms by ingesting fleas during grooming.
Because of these risks, most veterinarians recommend worming puppies starting at 2-3 weeks of age, then repeating the medication every 2-4 weeks until they reach adulthood around 6 months old. Puppies should also receive regular fecal tests to check for worm eggs. Keeping the environment clean and preventing access to feces are also critical to avoid reinfection.
How do adult dogs get worms?
While puppies are very prone to worms, adult dogs can also pick up worm infections through:
- Contaminated environment – Older dogs can ingest worm eggs or larvae when digging, sniffing, or consuming feces, soil, grass, etc.
- Eating rodents – Hunting and consuming infected mice, rats or other small mammals is a common source of tapeworms and roundworms.
- Fleas – Tapeworm transmission through fleas is common in adult dogs during grooming.
- Raw meat – Eating raw, undercooked meat may contain worm larvae.
- Daycare/boarding – Greater exposure to feces and soil where other dogs eliminate.
- Immune deficiency – Weakened immunity can lead to reactivation of dormant larvae.
- Transplacental – Some worms can be passed to unborn puppies from infected mothers.
While adult dogs have a more developed immune system than puppies, they are still susceptible to worm infections from their environment and behaviors. Annual fecal testing and routine worm prevention helps keep adult dogs parasite-free. Promptly picking up feces in the yard also reduces exposure.
What are the most common ways dogs get worms?
Based on the information above, here are the most frequent transmission routes for worms in dogs:
- Ingesting contaminated soil or feces
- Eating infected fleas
- Consuming infected rodents
- Transmission from mother before birth or through nursing
- Eating raw meat containing larvae
- Inactive larvae reactivation due to weak immunity
Exposure to contaminated feces, soil, and invertebrate hosts are the most preventable causes of worms. Good hygiene practices like prompt fecal removal, flea/pest control, cooking meat fully, and avoiding access to feces/soil are key to reducing risk. Annual deworming and fecal testing are also recommended, especially for puppies and high-risk adult dogs.
What environments are high risk for worms?
Certain environments pose greater risks for worm exposure and transmission:
- Dog parks and daycares – Lots of dog feces and greater chance of contamination.
- Humid, warm climates – Ideal conditions for parasite eggs and larvae survival.
- Yards without prompt feces removal – Allows worm stages to accumulate and become infectious.
- Households with puppies or immunocompromised dogs – Higher risk populations.
- Kennels and shelters – Dogs from multiple sources interacting in a confined space.
- Hunting/wooded areas – More exposure to wild hosts like rodents.
- Beaches and sandboxes – Sand and soil easily contaminated by feces.
- Unhygienic living conditions – Fecal accumulation indoors.
Reducing feces exposure is the key to making any environment lower risk. Prompt waste cleanup, pest control, hygiene practices, and anti-parasitic treatments greatly reduce the threat of worms. Risk is highest anywhere large numbers of dogs congregate and defecate freely.
What are the symptoms of worms in dogs?
Worms can live in a dog’s intestines without causing obvious symptoms. But in some cases, pet owners may notice these signs of an active worm infestation:
- Diarrhea
- Vomiting
- Weight loss
- Pot belly appearance
- Dull hair coat
- Coughing
- Intestinal blockages or pain
- Slow growth in puppies
- Visible worms in vomit or stool
- Anemia from blood loss in hookworm infection
Puppies experience more noticeable symptoms and serious impacts from worms since their bodies are still developing. Adult dogs often display fewer overt symptoms, but worms can still cause internal damage. Tapeworms may also be spotted crawling around the anus or in stool. Any symptoms or signs of illness in a puppy require immediate veterinary inspection for worms and prompt treatment.
How do vets test dogs for worms?
Veterinarians use several methods to check dogs for worm infections:
- Fecal examination – Microscopic inspection of a stool sample for parasite eggs. The most common diagnostic test.
- Fecal flotation – Using a solution to float and separate parasite eggs from feces to aid identification.
- Fecal smear – Placing a thin layer of stool on a slide for examination of worm eggs, larvae, or adults.
- Fecal antigen testing – Detecting antigens from worm digestion in feces.
- PCR testing – Detecting worm DNA in feces through polymerase chain reaction methods.
- Blood tests – Checking for antibodies or antigens in the blood indicating worm infections.
- Endoscopy/biopsy – Directly visualizing worms in the GI tract through endoscopy. Biopsy can confirm parasite species.
Fecal tests looking for eggs/larvae are the standard first step. Blood work and other advanced diagnostics help confirm the type of worm present if feces alone isn’t definitive. Puppies should have fecal exams every 2-4 weeks. Annual screening is recommended for adult dogs, along with any time symptoms develop.
How are worms treated and prevented in dogs?
There are several highly effective deworming medications veterinarians prescribe to eliminate worms from dogs. Preventive drugs are also administered routinely to kill larval stages and prevent new infestations.
Deworming Medications
Common medications for treating active worm infections include:
- Fenbendazole – Kills roundworms, hookworms, whipworms, and tapeworms.
- Pyrantel pamoate – Treats hookworms and roundworms.
- Praziquantel – Eliminates tapeworms.
- Milbemycin oxime – Used against roundworms, hookworms, and heartworm larvae.
- Ivermectin – Broad spectrum dewormer effective against many species.
Treatment is typically repeated 2-4 weeks after initial deworming to kill newly hatched worms. Puppies usually need multiple rounds of deworming spaced 2 weeks apart until fecal tests are negative.
Preventive Medications
Monthly to semi-annual preventives are given based on risk, including:
- Heartworm preventives (like ivermectin) that also treat intestinal worms.
- Topical treatments effective against fleas, heartworms, and intestinal parasites.
- Oral treatments that prevent heartworms, fleas, and worms.
Prevention is key to keeping susceptible puppies worm-free. Annual or biannual deworming is recommended for adult dogs based on exposure and test results. Prompt treatment of active infections protects the dog’s health and prevents environmental contamination.
Are worms contagious to humans?
Some dog worms can be transmitted to humans and cause significant illness:
- Roundworms – Humans can accidentally ingest infective eggs that dogs pass in feces. The larvae migrate through tissues and cause a disease called visceral larva migrans.
- Hookworms – Hookworm larvae can penetrate human skin from contaminated soil. They migrate to the intestines causing cutaneous larva migrans.
- Tapeworms – Direct contact with infected dog feces can transmit tapeworm eggs and cause infection when accidentally ingested.
- Whipworms – Humans can ingest whipworm eggs from the environment and develop an intestinal infection.
Children are at greatest risk due to more frequent hand-to-mouth contact and outdoor play. Prompt removal of dog feces prevents contamination that could be transferred through oral contact or bare skin. Deworming dogs, good hygiene, and cleanliness greatly reduce risk of human infection.
Conclusion
Dogs acquire intestinal worms through ingestion of parasite eggs or larvae from contaminated surroundings. Puppies are very susceptible due to their immature immunity and curious behaviors. While adult dogs are less prone to worms, they can still become infected from hunting, grooming, or environments like dog parks. Reducing exposure to feces, prompt deworming of puppies, and periodic prevention in adults are the keys to keeping dogs worm-free and reducing human infection risks. With some diligent hygiene and preventative care, both our furry friends and family members can avoid the discomforts and health hazards caused by worm infections.