worms in dogs

Worms in Dogs

Worms in dogs are internal parasites that infest the gastrointestinal tract or other organs. These parasites include roundworms, hookworms, tapeworms, whipworms, and heartworms. 

Each type of worm has its own lifecycle, mode of transmission, and potential health effects on dogs. Roundworms and hookworms are commonly acquired by ingesting contaminated soil or faeces, whilst tapeworms can be transmitted through fleas or infected prey animals. Whipworms are typically contracted by ingesting soil or faeces containing whipworm eggs. Heartworms, on the other hand, are transmitted through mosquito bites and primarily affect dogs in certain regions outside the UK. 

Symptoms of worm infestation can include diarrhoea, vomiting, weight loss, a potbellied appearance, poor coat condition, and general deterioration in health. 

Regular worm count tests and preventive measures are important to keep dogs healthy and minimise the risk of infestations.

Table of Contents

  • How do I know if my dog has worms?
  • How can I check my dog for worms?
  • What are the signs of a dog having worms?
  • Can you visibly see worms in dog's poo?
  • What does dog poo look like if the dog has worms?
  • Do dogs really need worming every month?
  • Do worms make dogs feel unwell?
  • How do dogs get worms in the first place?
  • What food causes worms in dogs?
  • Can dogs get worms from a raw diet?
  • What are the most common worms in dogs?
  • How do I know what kind of worms my dog has?
  • Do I need to go to the vet if my dog has worms?
  • Can dogs get rid of worms without treatment?
  • What happens if worms go untreated in dogs?
  • What kind of worms can humans get from dogs?
  • Can cats spread worms to dogs?
  • Can you tell if a puppy has worms?
  • Do puppies get worms from their mum?

  • How do I know if my dog has worms?

    Worms are not always visible to the human eye and not all dogs with worms will exhibit obvious signs, especially in the early stages of infestation. There are 6 signs that can indicate that a dog has worms.

    1. Changes in appetite: Infected dogs can exhibit a decrease or increase in appetite. Some dogs become less interested in food and experience weight loss, while others have an increased appetite due to the worms consuming nutrients.
    2. Weight loss: Worms can cause weight loss in dogs, especially if the infestation is severe or long-lasting. This weight loss can be accompanied by a visible ribcage or a general decline in body condition.
    3. Poor coat condition: Dogs with worms can have a dull or unkempt coat. Their fur can appear dry, brittle, or lacklustre due to the impact of parasites on their overall health.
    4. Diarrhoea or vomiting: Worm infestations can lead to gastrointestinal disturbances, resulting in diarrhoea and occasional vomiting. However, it's important to note that these symptoms can also indicate other health issues, so proper diagnosis is essential.
    5. Abdominal discomfort: Dogs with worms can experience abdominal pain or discomfort. They can exhibit signs of restlessness, panting, pacing, or sensitivity when their abdomen is touched.
    6. Lethargy and weakness: Dogs with worm infestations can appear lethargic, tired, or weak. They can have reduced energy levels and be less enthusiastic about physical activities.

    How can I check my dog for worms?

    The only way to confirm the presence of worms in a dog is by undertaking a faecal analysis or worm count test.  There are 2 other indicators which can help you determine if a worm count test is required.

    • Observe their behaviour and appearance: These include changes in appetite, weight loss, diarrhoea, vomiting, visible worms in the stool or vomit, and other visible signs around the anus.
    • Examine their stool: Check the dog’s faeces for any signs of worms. Look for small moving threads, rice-like segments, or any other abnormality. You can use a poop scoop, old spoon or a plastic bag to collect a fresh sample for closer inspection.

    What are the signs of a dog having worms?

    There are 3 main physical symptoms dogs can exhibit if they have a worm infestation.

    1. Itching or scooting: Certain types of worms, such as tapeworms, can cause itching or discomfort around a dog’s bottom. They may scoot their rear end along the ground in an attempt to relieve the itchiness.
    2. Visible signs around the anus: In the case of tapeworms, small white or yellowish segments that resemble grains of rice may be seen around the dog's anus or in their bedding.
    3. Digestive issues: Dogs with worms can experience gastrointestinal symptoms, including diarrhoea, constipation, or alternating between the two. The stool may also appear abnormal, with changes in consistency, colour, or the presence of mucus.

    Can you visibly see worms in dog’s poo?

    Yes, in some cases, you can visibly see worms in dog’s poo. The appearance of worms vary depending on the specific type of worm infestation. Not all types of worms are easily visible. Some worms, such as whipworms or lungworms, are much smaller and are usually not visible to the naked eye. Additionally, in the early stages of an infestation, the worm burden might be too low to be noticed.

    • Roundworms: Adult roundworms are long, white or cream-coloured worms that resemble spaghetti. They can sometimes be visible in a dog's vomit, stool, or in the area around the anus.
    • Tapeworms: Tapeworms are flat, segmented worms that can be seen in the faeces or clinging to the fur around a dog's anus. The individual segments, known as proglottids, look like small grains of rice or cucumber seeds. They may also be found on bedding or in the dog's sleeping area.
    • Hookworms: Hookworms are small, thin worms that can be difficult to see with the naked eye. However, in severe infestations, they may be visible in the dog's stool as tiny, thread-like worms or as dark, tarry, and bloody stools.

    What does dog poo look like if the dog has worms?

    Dog poo that contains worms has specific characteristics which indicate the presence of worms. The appearance of the poo varies depending on the type of worms and the severity of the infestation.

    • Presence of worms: You may be able to see worms in the dog's poo. They can appear as long, white or cream-coloured strands (in the case of roundworms) or as small, flat, rice-like segments (in the case of tapeworms).
    • Abnormal colour and consistency: Infected dogs may have poo that has abnormal discolouration, (such as having a pale or darker shade than usual) and/or consistency (the stool may become loose, watery, or even bloody in severe cases).
    • Mucus or other abnormal substances: Worm infestations can lead to increased mucus production in the intestines, which may be visible as slimy or gel-like appearance in the poo.
    • Diarrhoea or constipation: Dogs with worms can experience gastrointestinal disturbances, including diarrhoea or constipation. The stool may be more frequent, loose, or difficult to pass.

      Do dogs really need worming every month?

      No. It is not recommended to deworm dogs every month with chemical wormers without a positive worm count test.  There are 3 points to consider when using chemical worming tablets.

      1. Potential for overuse and unnecessary exposure: Frequent use of chemical dewormers leads to overexposure to the active ingredients, which have potential side effects. Using these products more frequently than necessary can contribute to the development of resistance in the worm population, making the dewormers less effective over time.
      2. Unnecessary stress on the dog's system: Chemical dewormers are designed to kill or expel worms from a dog's system. Using them too frequently puts additional stress on the dog's organs, such as the liver, as these medications are metabolised and eliminated from the body.
      3. Lack of targeted treatment: Deworming your dog without checking if they have worms is an expensive and pointless exercise, plus not all worms require monthly deworming. Different types of worms have varying lifecycles and susceptibility to specific deworming medications. Treating your dog with chemical wormers every month is not necessary if they are not at risk of certain types of worms.

      Do worms make dogs feel unwell?

      Yes, worms can make dogs feel unwell and present with different symptoms. The severity of these symptoms vary depending on the type and number of worms present, as well as the individual dog's immune response and overall health.

        • Nutritional deficiencies: Worms consume nutrients from the dog's body, which can lead to nutritional deficiencies. This can result in weight loss, poor growth (especially in puppies), and a general decline in overall health.
        • Gastrointestinal disturbances: Worms can cause gastrointestinal issues such as diarrhoea, vomiting, or both. The presence of worms in the intestinal tract can disrupt normal digestion and absorption of nutrients, leading to digestive upset.
        • Anaemia: Certain types of worms, such as hookworms, can cause anaemia in dogs. Anaemia occurs when worms feed on the dog's blood, leading to a decrease in red blood cells and oxygen-carrying capacity.
        • Weakness and lethargy: Dogs with worm infestations may experience a decrease in energy levels and overall vitality. They may appear weak, tired, and less active than usual.
        • Itching and discomfort: Certain types of worms, such as tapeworms, can cause itching and discomfort in dogs, particularly around the anal area. This can lead to scooting behaviour or excessive licking of the rear end.
        • Complications and secondary health issues: In severe cases or when left untreated, worm infestations can lead to complications and secondary health problems. These can include intestinal blockage, weight loss, organ damage, and an increased susceptibility to other infections.

      How do dogs get worms in the first place?

      There are 5 common ways in which a dog can acquire worms.

          1. Ingesting worm eggs or larvae: Dogs can become infected with worms by ingesting eggs or larvae present in contaminated soil, water, or faeces. This can happen when dogs explore and sniff around in areas where other infected animals have defecated.
          2. Mother-to-puppy transmission: Puppies can be born with worms or acquire them through their mother's milk. Certain types of worms, such as roundworms, can be passed from an infected mother to her puppies during pregnancy or through nursing.
          3. Fleas and intermediate hosts: Some types of worms, like tapeworms, require an intermediate host, such as fleas or small animals (like rodents), to complete their life cycle. If a dog ingests a flea or prey animal infected with tapeworm larvae, they can become infected.
          4. Contaminated environments: Dogs that spend time in environments where other infected animals have been, such as parks, communal areas, or areas with poor sanitation, are at a higher risk of worm infestation. Worm eggs or larvae present in the environment can be picked up by dogs during their activities.
          5. Hunting and scavenging: Dogs that hunt or scavenge carcasses of infected animals are at risk of contracting worms. Consuming the tissues or organs of an infected animal can lead to worm infestation.

      What food causes worms in dogs?

      No specific food causes worms in dogs. Worm infestations in dogs are typically caused by ingesting worm eggs or larvae present in the environment or through other infected animals. However, certain practices related to food can indirectly contribute to the risk of worm infestations.

      • Raw or undercooked meat: Feeding raw or undercooked meat to dogs, especially if it comes from infected animals, can potentially expose them to parasites such as tapeworms. It's important to handle and prepare raw meat properly to minimise the risk of contamination.  (This should not be confused with feeding raw dog food which is specially prepared to eliminate the danger of transferring parasites to your dog).
      • Contaminated food: If dog food or treats are stored improperly, exposed to moisture, or contaminated by other animals or insects, they can become a source of worm infestation. It's important to store food in a cool, dry place and follow proper food handling and storage practices.
      • Feeding practices: Sharing food or allowing dogs to scavenge from garbage cans, compost piles, or other potentially contaminated sources can increase their risk of ingesting worm eggs or larvae.

      A balanced and nutritious diet supports a dog's overall health, including their immune system, which will help them resist and fight off worm infestations.

      Can dogs get worms from a raw diet?

      The incidence of parasites or worms in raw meat is low, especially when purchasing from a reputable supplier that uses DEFRA licensed manufacturers.  All meat for raw dog food must undergo proper inspection to ensure it is free from worms and parasites. Additionally, it does not contain gastrointestinal (GI) parts, which are more likely to harbour worms.


      Stands for the Department for Environment, Food and Rural Affairs, which is the UK government department responsible for policies and regulations related to the environment, farming, food production, and animal welfare. DEFRA oversees various aspects of animal health and welfare, including regulations for pet food and the safety of products in the market.

      Ensure your raw dog food comes from a licensed manufacturer who is DEFRA licensed and all packs are clearly labelled and sealed.

      While there have been rare instances of parasites or worms transferring from the GI tract to muscle meat, as well as a specific parasite found in raw salmon and other salmonids, these cases are not common. It's important to handle and prepare fresh fish properly and freeze it for a month before feeding it to your dog to reduce the risk of parasites.

      What are the most common worms in dogs?

      There are 5 types of worm prevalent in the UK which are transmitted to dogs in different ways.

      1. Roundworms (Toxocara canis): Roundworms are one of the most common types of worms in dogs. They can be transmitted to puppies from their mother, and dogs can also become infected by ingesting roundworm eggs from contaminated soil or through the consumption of infected prey.
      2. Tapeworms (Dipylidium caninum, Taenia spp.): Tapeworms are typically transmitted through the ingestion of fleas or small mammals that are infected with tapeworm larvae. Dogs can also contract tapeworms by ingesting contaminated food or water.
      3. Whipworms (Trichuris vulpis): Whipworms are found in the large intestine of dogs and can cause diarrhoea, weight loss, and anaemia. They are usually contracted through the ingestion of whipworm eggs present in soil or contaminated faeces.
      4. Hookworms (Ancylostoma spp., Uncinaria spp.): Hookworms are small, blood-sucking parasites that can cause anaemia in dogs. They are usually contracted through the ingestion of hookworm larvae or by skin penetration from contaminated soil.
      5. Lungworms (Angiostrongylus vasorum): Lungworms are becoming more prevalent in the UK. They are transmitted to dogs through the ingestion of infected slugs or snails, or by consuming grass or water (and toys left in the garden) that has come into contact with their slime.

      How do I know what kind of worms my dog has?

      A worm count (also known as a faecal analysis) will identify the species and severity of an intestinal parasite burden

      During a worm count, a small sample of the dog's faeces is collected and examined under a microscope. The sample is usually processed using a flotation technique, which involves mixing the faeces with a special solution that causes the eggs or larvae of the worms to float to the top.

      The sample is then examined under a microscope to identify the type of worms and count the eggs or larvae present.

      Do I need to go to the vet if my dog has worms?

      Not always. You can choose to treat worms naturally or with chemical worming tablets.  Both forms of treatment are available to purchase over the counter.  However, veterinary-prescribed medications are sometimes required to treat heavy worm infestations effectively. Over-the-counter dewormers may not be as effective or may not target the specific worms your dog has.

      Can dogs get rid of worms without treatment?

      It is possible for dogs to naturally eliminate some types of worms on their own, however, it is not recommended to rely solely on the dog's immune system to clear the infestation.

      Limited effectiveness: Dogs may be able to eliminate a small number of worms, especially if they have a strong immune system. However, depending on the type and severity of the infestation, the dog's natural defences may not be sufficient to eliminate all the worms effectively. Some worms, such as tapeworms, require specific medications to be completely eradicated.

      Public health concern: Some worms that affect dogs also pose risks to human health. For example, roundworms can be transmitted to humans, particularly young children, and cause serious health problems. Treating and preventing worm infestations in dogs not only protects their well-being but also helps prevent the transmission of parasites to humans.

      What happens if worms go untreated in dogs?

      Worm infestations can lead to various health problems and complications in dogs. Delaying or avoiding treatment may allow the infestation to worsen, leading to more severe health issues.

      Weight Loss & Anaemia

      Nutrient competition: Worms residing in the dog's gastrointestinal tract feed on the nutrients present in the dog's food. They compete with the dog for nutrients, leading to a decreased absorption of essential nutrients such as proteins, carbohydrates, and fats. This nutrient competition can result in inadequate nourishment for the dog, leading to weight loss over time.

      Intestinal inflammation: Worms such as hookworms and whipworms, attach themselves to the intestinal lining and cause inflammation. This inflammation can disrupt the normal absorption of nutrients from the dog's food, further contributing to malnutrition and weight loss.

      Blood loss and anaemia: Hookworms and whipworms are blood-sucking parasites. They attach to the intestinal wall and feed on blood, which can lead to chronic blood loss. This continuous blood loss can result in anaemia, characterised by a decrease in red blood cells and haemoglobin levels. Anaemic dogs may experience weakness, fatigue, and weight loss.

      Gastrointestinal disturbances: Worm infestations can cause gastrointestinal symptoms such as diarrhoea, vomiting, and poor appetite. These symptoms can lead to decreased food intake and reduced nutrient absorption, resulting in weight loss.

      Metabolic changes: In some cases, severe worm infestations can cause metabolic imbalances in dogs. The presence of a large number of worms can alter the normal metabolic processes, leading to increased energy expenditure and decreased nutrient utilisation. This metabolic disruption can contribute to weight loss.

        Intestinal blockage

        Roundworms: In puppies, a heavy infestation of roundworms can lead to a condition called "ascarid impaction." This occurs when a large number of roundworms gather in the small intestine, forming a mass that obstructs the normal flow of food and fluids. As a result, the intestine becomes blocked, preventing the passage of digested food.

        Whipworms: Whipworms typically reside in the large intestine of dogs. In cases of severe whipworm infestations, a large number of worms can congregate and create a mass that obstructs the passage of stool through the colon, causing partial or complete blockage.

          What kind of worms can humans get from dogs?

          The  transmission of worms from dogs to humans is not common. Practising good hygiene, such as regular handwashing, maintaining a clean living environment, proper disposal of dog poo, and preventive measures for flea control, can significantly reduce the risk of transmission.  There are 3 types of worm that can be transmitted from dogs to human.

          • Roundworms (Toxocara canis, Toxocara cati): The larvae of these roundworms can migrate through the tissues of dogs and form dormant cysts. If humans, particularly children, accidentally ingest the eggs present in soil, sandpits, or contaminated objects, the larvae can hatch in the human digestive tract and migrate through various organs, potentially causing a condition known as visceral larva migrans. Symptoms may include fever, cough, abdominal pain, and liver or lung problems.
          • Hookworms (Ancylostoma caninum, Ancylostoma braziliense): Hookworm larvae can penetrate the skin of humans, causing a condition called cutaneous larva migrans. It typically results in a red, itchy, and winding rash as the larvae migrate under the skin. The most common sites of infection are the feet and hands.
          • Tapeworms (Dipylidium caninum, Echinococcus spp.): While rare, humans can get tapeworm infections from dogs if they accidentally ingest fleas that are carrying tapeworm larvae. Once ingested, the tapeworm can develop in the human intestine, leading to symptoms such as abdominal discomfort, nausea, and weight loss.

          Can cats spread worms to dogs?

          Yes, cats can potentially spread certain types of worms to dogs. The most common worm that can be transmitted from cats to dogs is the tapeworm (Dipylidium caninum). The lifecycle of this tapeworm involves fleas as intermediate hosts. If a dog ingests an infected flea while grooming or through other means, it can become infected with tapeworms. Cats that have fleas and are infected with tapeworms can shed tapeworm eggs in their faeces, which can contaminate the environment and increase the risk of transmission to dogs.

          It's important to note that other types of worms, such as roundworms, hookworms, and whipworms, are typically specific to either dogs or cats and are not commonly transmitted between the two species.

          Can you tell if a puppy has worms?

          There are 5 signs to look for if a worm infestation is suspected in a puppy.. However, it's important to note that not all puppies with worms will display obvious symptoms, especially in the early stages of infestation.

          1. Poor growth or failure to thrive: Worm infestations can impede a puppy's growth and development. If a puppy is not gaining weight or appears smaller and weaker than littermates, it could be a sign of worms.
          2. Pot-bellied appearance: Some worms, such as roundworms, can cause the abdomen to become distended or bloated, leading to a pot-bellied appearance in affected puppies.
          3. Diarrhoea or vomiting: Puppies with worms may experience digestive disturbances such as diarrhoea, which may contain visible worms, or occasional vomiting.
          4. Worms in stools: In some cases, worms or worm segments can be seen in a puppy's stool. Roundworms resemble spaghetti noodles, while tapeworm segments resemble small, white, rice-like segments.
          5. Dull coat and poor overall condition: Worm infestations can affect a puppy's overall health, leading to a dull coat, poor skin condition, and lack of vitality.

          Do puppies get worms from their mum?

          Some puppies acquire worms from their mother before birth or through the mother's milk. Roundworms, for example, can be transmitted from the mother to the puppies through larval migration or ingestion of worm eggs. This is why checking pregnant and nursing bitches for worms with a worm count and treating, where appropriate, is crucial.

          Worm Counts for Dogs

          A worm count for dogs is a diagnostic test performed by a laboratory to assess the presence and severity of internal parasites, specifically intestinal worms, in dogs. 

          This test helps determine the species and quantity of worms residing in the dog's intestines, providing crucial information for appropriate treatment. It is also beneficial for monitoring the effectiveness of deworming treatments and evaluating the risk of transmission to other animals or humans, as certain parasites can be passed between species.

          Regular worm counts should be undertaken every 3-6 months as part of a comprehensive parasite control program, especially for dogs at higher risk or those exposed to environments where parasites are prevalent.

          With wags and woofs,
          Laura, Dolly & Reggie

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