Gastrointestinal Parasites in Dogs: Cause, Symptoms, and Treatment

Gastrointestinal parasites in dogs are parasitic worms that invade the gastrointestinal tract. The most common dog gastrointestinal (GI) parasites are roundworms, hookworms, whipworms, tapeworms, Giardia, and Coccidia. 

Dogs acquire gastrointestinal worms by ingesting parasitic eggs or spores from fleas and their mothers through the placenta or milk. 

Abdominal pain, pot-bellied appearance, diarrhea, vomiting, nausea, appetite changes, weight loss, itchy bottoms, weakness, coughing, and pale gums are signs and symptoms of intestinal worms in dogs. 

Gastrointestinal parasites in puppies are more dangerous than in adults, leading to fatal complications like anemia, malnutrition, or compromised immunity. 

Treating parasites in dogs includes deworming medications, which are used at specific intervals to break down the worms’ life cycles. 

Certain intestinal parasites in dogs present a zoonotic risk, meaning they are transmissible to humans. Regular deworming is critical for preventing dog parasites. 

What are Gastrointestinal Parasites in Dogs?

Gastrointestinal parasites in dogs are an umbrella term for various endoparasitic species living in the dog’s gastrointestinal (GI) tract. GI parasites are popularly called worms. 

“Endoparasites rank among the most common causes of gastrointestinal disease in dogs,” claims a study, “Gastrointestinal Parasites in Young Dogs and Risk Factors Associated with Infection,” published in Parasitology Research in 2023. 

The consequences of worms range from temporary and mild digestive issues in dogs to severe malnutrition and anemia. Puppies are more sensitive to gastrointestinal parasites than adult dogs. 

How is the Gastrointestinal Parasites in Dogs compared to Heartworms in Dogs?

Gastrointestinal parasites in dogs are more common but less damaging than heartworms in dogs when properly managed. 

GI tract worms live in the gastrointestinal tract. Heartworms live in the dog’s heart, lungs, and blood vessels, causing permanent and potentially fatal damage. 

Dogs contract heartworms when infected mosquitoes bite them. A single heartworm lives up to five years once its life cycle begins in the dog.  

What types of gastrointestinal parasites commonly affect dogs?

The types of gastrointestinal parasites that commonly affect dogs are listed below. 

• Roundworms: Roundworms or ascarids are spaghetti-like parasites. Puppies are frequently born with roundworms. 
• Hookworms: Hookworms are blood-sucking worms that attach themselves to the walls of the intestines, leading to anemia. 
• Whipworms: Whipworms are hardy parasites in the first part of the large intestine or cecum. 
• Tapeworms: Tapeworms are flat, segmented, and dangerous types of dog worms that irritate the anus and malnutrition. 
• Giardia: Giardia is a microscopic protozoan that lives in contaminated, stale water and invades the dog’s small intestine. 
• Coccidia: Coccidia are tiny, single-celled protozoan parasites that live in the intestinal wall and cause GI tract irritation. 

1. Roundworms

Roundworms are spaghetti-like, free-living intestinal parasites. Stomach irritation and pot-bellied appearance are telltale signs of roundworms. 

The top two roundworms in dogs are Toxocara canis and Toxascaris leonina. Puppies are born with roundworms, and adults acquire them by eating infected feces. All dogs contract roundworms at specific points in life. 

2. Hookworms

Hookworms are small, thin endoparasites with unique hook-like mouthparts. Hookworms use their mouthparts to attach themselves to the dog’s intestinal wall, unlike free-living worms. 

Common hookworms in dogs are Ancylostoma caninum, Ancylostoma braziliense, or Uncinaria stenocephala. Hookworm larvae migrate via the mammary glands and infect nursing puppies. The larvae burrow through the adult dog’s skin when it comes into contact with infected feces. 

3. Whipworms

Whipworms are thread-like parasites inhabiting the dog’s cecum. Adult whipworms intermittently shed hardy eggs in the environment, spreading infections. 

Trichuris vulpis is the most common whipworm in dogs. The worm’s resilient eggs are found in contaminated soil and water. Anemia and mucus-covered feces or diarrhea are telltale signs of whipworms in dogs. 

4. Tapeworms

Tapeworms are segmented and flattened worms found in the dog’s intestines. The most widespread tapeworm, Dipylidium caninum, is transmitted when dogs ingest infected fleas while grooming themselves. The worm causes stunted growth in puppies. 

A dangerous and common tapeworm is Echinococcus granulosus. The worm is popularly known as the dog tapeworm and has zoonotic potential, using humans as intermediate hosts.  

5. Giardia

Giardia is a single-celled protozoan parasite that invades the dog’s small intestines. Dogs are sensitive to a strain called Giardia duodenalis. The infection with G. duodenalis is giardiasis. The parasite lives in contaminated environments. 

Giardiasis occurs in 45% of the canine population, according to a study, “Subclinical Giardia in Dogs: A Veterinary Conundrum Relevant to Human Infection,” published in Trends in Parasitology in 2014. 

6. Coccidia

Coccidia are tiny-celled protozoan parasites that live in dogs' intestinal walls. The infection, coccidiosis, is caused by various Cystoisospora species. 

Dogs contract coccidiosis from the environment through infected feces or eating infected carrion. Young age and stress make dogs more susceptible. Unusual, fungus-clad diarrhea is a telltale sign of coccidiosis in dogs. 

How do dogs usually get stomach parasites?

Dogs usually get stomach parasites by ingesting worm spores or eggs or from fleas. Puppies acquire gastrointestinal parasites from their mothers. 

Ingesting parasite eggs or spores from contaminated feces, soil, water, or dead animals is a common way to contract worms. 

Certain parasites, such as tapeworms, are transmitted when dogs accidentally swallow infected fleas while grooming. Hookworm larvae burrow through the dog’s skin during direct contact with infected feces. 

Litter dogs pass gastrointestinal worms onto their unborn puppies via the placenta or through the milk in newborns. 

Are certain dog breeds more susceptible to gastrointestinal parasites?

No, certain dog breeds are not more susceptible to gastrointestinal parasites. Breed is not a risk factor for worms. 

GI parasites are associated with other predisposing considerations, like age and lifestyle. For example, worms are more common in puppies and outdoor dogs. 

"The prevalence of gastrointestinal parasites in indigenous breeds is higher than in the exotic breeds," reports a study, "Prevalence of Gastrointestinal Parasites in Dogs from Umuahia City of Abia State," published in the Global Journal of Medical Sciences in 2010.

What Causes Gastrointestinal Parasites in Dogs?

The causes of gastrointestinal parasites in dogs are listed below. 

• Nematodes: Nematodes are structurally simple worms and widespread parasites. Roundworms are the most common GI parasite in dogs from the Nematodes group. 
• Cestodes: Cestodes are flat and ribbon-like worms that parasites in various animal species. Tapeworms are an example of a Cestodes family GI worm in dogs. 
• Protozoa: Protozoa are microscopic and single-celled organisms of various shapes and sizes. Giardia and Coccidia are the top two protozoan gastrointestinal parasites in dogs.

Can Gastrointestinal Parasites Cause Bloating in Dogs?

No, gastrointestinal parasites cannot cause bloating in dogs. Bloating is a term used to describe a condition medically known as gastric dilatation and volvulus (GDV).

GDV occurs when the dog's stomach accumulates liquid or gas, bloats, and then twists on its axis. The exact causes of GDV are not well understood, but it is more common in deep-chested large and giant breeds.

Intestinal parasites cause abdominal enlargement; however, it is not the same as true GDV in dogs.

What are the Common Symptoms of Gastrointestinal Parasites in Dogs?

The common symptoms of gastrointestinal parasites in dogs are listed below. 

• Abdominal Pain: Dogs with intestinal worms develop painful abdomens. A standard sign of abdominal pain in dogs is a hunched position. 
• Nausea: Intestinal worms trigger nausea, which is not dangerous but uncomfortable and affects the dog's appetite. 
• Appetite Changes: Sudden changes in appetite, including increases and decreases, are visible in dogs with GI worms. 
• Itchy Bottom: Dogs with intestinal parasites have itchy posteriors and scoot their backsides on carpets and rough surfaces to relieve the itch. 
• Weakness: Reduced energy levels, sleepiness, and disinterest in daily activities are common dog parasite symptoms. 

How to tell if your Dog has Gastrointestinal Parasites?

You can tell if your dog has gastrointestinal parasites based on early signs. Lack of growth, loss of condition, and a pot-like belly are telltale signs of worms in puppies. 

Initial signs are less noticeable in adult dogs. One indicator is a lack of appetite, while another sign is weight loss fluctuations regardless of appetite. For example, the dog eats well or more than usual but keeps losing weight. 

What are the Signs of Gastrointestinal Parasites in Dogs?

The signs of gastrointestinal parasites in dogs are listed below.

• Diarrhea: Diarrhea is a telltale sign of worms. The diarrhea type depends on the specific gastrointestinal worm and ranges from explosive and watery to dense and blood-tainted. 
• Worms in Stool: A telltale sign is the presence of worms in the dog's stool. The worms resemble little grains of rice or spaghetti-like strings, depending on the parasite type. 
• Vomiting: Vomiting is frequently reported in dogs with gastrointestinal worms. Dogs with heavy infestations expel worms with the vomit. Bloody vomit (hematemesis) is possible. 
• Weight Loss: Dogs with gastrointestinal parasites lose weight because worms rob them of essential nutrients. Reduced appetite, vomiting, and diarrhea contribute to weight loss. 
• Bloated Abdomen: Worms in dogs cause an enlarged abdomen, known as a pot-bellied appearance. 
• Dull Coat: Dogs with GI worms have dull coats that are prone to breaking and have an unkempt appearance. 
• Coughing: Certain gastrointestinal parasites, such as hookworms and roundworms, cause coughing episodes as signs of parasites in dogs. 
• Pale Gums: Pale gums indicate anemia and occur in dogs, more commonly puppies, with severe infestations. 

Can gastrointestinal parasites lead to more serious health issues in dogs?

Yes, gastrointestinal parasites can lead to more serious health issues in dogs. Puppies are more susceptible to complications associated with worms than adult dogs. 

"Intestinal parasites can pose serious health problems in dogs, especially puppies," notes a study "Gastrointestinal Parasites in Shelter Dogs: Occurrence, Pathology, Treatment and Risk to Shelter Workers," published in Animals in 2018.

Severe health issues caused by worms include stunted growth, compromised immunity, anemia, and intestinal obstruction. The complications of GI tract parasites are life-threatening in some cases.

Is it possible for a dog to poop a parasite?

Yes, it is possible for a dog to poop a parasite. Dogs with heavy infestations defecate living or dead gastrointestinal worms. 

The likelihood of pooping a parasite is highest in cases of heavy infestations and shortly after deworming treatments. 

Defecated tapeworms are found in dog poop. The parasites resemble rice grains and are visible in the poop or left behind on the dog's coat, bedding, or carpet.

How Long Can a Dog Live with a Gastrointestinal Parasites?

A dog can live long with gastrointestinal parasites, and the survival time is not fixed. Gastrointestinal worms are not instantly fatal, making it hard to establish critical periods of health decline. 

The impact of the worm infestation depends on the parasite type and load and the dog’s age and overall health. Puppies with gastrointestinal parasites are more at risk of fatal consequences than adult dogs. 

Can Probiotics Help Treat Gastrointestinal Parasites in Dogs?

Yes, probiotics can help treat gastrointestinal parasites in dogs. Probiotics help re-establish a healthy gut microbiome disrupted by worms. 

Certain probiotic strains prevent GI tract worms in the first place, according to a study, “Probiotic Therapy: A Promising Strategy for the Control of Canine Hookworm,” published in the Journal of Parasitology Research in 2013. 

Probiotics are live microorganisms, bacteria, and yeasts that inhabit the dog’s gut and influence benefits. Dog probiotics are available in various forms and are easy to use. 

What are the Best Probiotics for Dogs with Gastrointestinal Parasites?

The best probiotics for dogs with gastrointestinal parasites are listed below. 

• Honest Paws Well Pre + Probiotics: The Honest Paws formula is a chicken-flavored powder produced in the USA with quality probiotics and prebiotic strains. The powder is non-GMO and comes in pre-packed single-dose sachets. 
• Purina ProPlan FortiFlora: FortiFlora is a top-notch dog supplement featuring a single probiotic strain. The product is liver-flavored, packed in individual packs, and rich in vitamins E and C. 
• PetLab Co. Probiotic Chews: Pork-flavored soft chews formulated with eight strains of probiotics and superfoods such as agave, honey, and salmon oil. The dog-friendly flavor makes the chews fit for fussy pets, and the soft texture is enticing for dogs of all ages. 
• Open Farm Probiotic Supplement: Open Farm offers one of the best probiotics for dogs. The product features seven probiotic strains and a delicious pumpkin flavor. Each ingredient in the formula is carefully selected and 100% traceable. 

What are the Treatments for Gastrointestinal Parasites in Dogs?

The treatments for gastrointestinal parasites in dogs are listed below. 

• Dewormer Medications: The cornerstone of treating worms is dewormers, which come with prescription or over-the-counter, in the form of tablets, chews, liquids, or spot-ons. Examples of dewormers are praziquantel, pyrantel pamoate, and febantel.   
• Antibiotics: Certain antibiotics, such as metronidazole, are used with dewormers to treat gastrointestinal parasites. 
• Supportive Care: Supportive care is added to the treatment for parasites in dogs in severe cases. The extent of the care is determined on an individual basis and includes options from special diets to blood transfusions.  
• Pest Control: Treating external bugs, like fleas, is an important aspect of “how to treat parasites in dogs.” Fleas are a source of tapeworms, and the infestation recurs until the source is eliminated. 

Can gastrointestinal parasites in dogs be treated completely?

Yes, gastrointestinal parasites in dogs can be completely treated. Medications that kill worms are efficient, and full elimination is achieved after repeated use. The most popular medication for GI parasites is a dewormer.

Dewormers are administered every two or three weeks to break up the worm life cycle. Gastrointestinal worms in dogs have complex life cycles, including different phases, and the medications work against specific parasitic stages. 

Are over-the-counter medications effective for preventing gastrointestinal parasites in dogs?

Yes, over-the-counter medications are effective for preventing gastrointestinal parasites in dogs. Deworming tablets, chewables, and liquids are available with a prescription or over-the-counter (OTC).

Traditional dog dewormers offer reliability, while natural products have varying effectiveness. 

OTC dewormers for dogs and puppies are safe, but it is best to consult a veterinarian. The vet helps choose the best deworming product and recommends the deworming frequency based on the dog's needs.

Can Gastrointestinal Parasitess in Dogs Resolve Without Surgery?

Yes, gastrointestinal parasites in dogs can resolve without surgery. The treatment of choice for worms is medications. The difference is the type of dewormer drug and its frequency of use. 

Surgery is recommended for dogs with intestinal obstruction due to parasites clumping and forming blockages. Surgeries of the intestines are complex and risky.

What are the Risks of a Dog Dying from Gastrointestinal Parasites?

The risks of a dog dying from gastrointestinal parasites are listed below. 

• Malnutrition: Gastrointestinal worms feed on the dog’s food, depriving it of essential nutrients. Long-term deprivation results in malnutrition. 
• Anemia: Blood-sucking types of gastrointestinal parasites cause anemia or reduced red blood cell counts, which is life-threatening in young puppies. 
• Weak Immunity: Gastrointestinal parasite infestation compromises the immune system and puts the dog at an increased risk of acquiring fatal infections. 

Can gastrointestinal parasites be transmitted from dogs to humans?

Yes, gastrointestinal parasites can be transmitted from dogs to humans. Roundworms are the most commonly transmitted worms. Children are more sensitive to contraction compared to adults. 

The disease caused by the transmitted roundworms is called toxocariasis. Telltale signs include headaches, mild cough, fever, and stomach cramping. 

Washing hands after handling pets and before eating is critical for preventing worm transmission from dogs to humans.

When Should You Seek Veterinary Care for a Dog with Gastrointestinal Parasites Symptoms?

You should seek veterinary care for a dog with gastrointestinal parasite symptoms immediately. Understand the early signs of infestation and call the vet promptly. GI parasites must be swiftly removed to prevent long-term afflictions.

Gastrointestinal parasites are not instantly fatal but require attention. The veterinarian eliminates the worms, provides advice, and makes a deworming schedule to prevent future infestations.