Dr Mokshata Gupta
Parasites are the common cause of disease in your dogs. Most of the pet owners are familiar with the external parasites like fleas and ticks, but they do not realize that intestinal parasites can also be a terror for your pet’s health. –by Dr Mokshata Gupta, Dr Tanmay Mondal, and Dr Asmita Singh
Intestinal parasites are those that live inside the gastrointestinal tract of the host. It includes roundworms, whipworms, hookworms, tapeworms, giardia and coccidia. These parasites can cause malnutrition, weight loss, vomiting, diarrhoea, and anemia. Besides making your pets sick, many of these parasites can affect you and your family too. Dogs can contract intestinal parasites via different routes. They are usually transmitted when your pet accidentally ingests parasite eggs or spores in contaminated soil, water, feces or food. Puppies, on the other hand, usually get intestinal parasites from their mother. Transmission can occur in-utero or from nursing. These parasites bite, irritate, jump and suck your precious pet’s blood. They live on their skin, swim through their bloodstream and spread in their intestinal tract or other body parts. By early treatment, most of the parasitic infections aren’t life-threatening and can be easily treated with medication.
Adult dog or pup, you need to buckle up!
A few of the intestinal parasites do not cause health issues. But, some like roundworms and tapeworms absorb nutrients through their skin and do not normally injure your pet’s intestine. Others, like hookworms, chew and erode the lining of your pet’s intestine. Strongyloides tunnels through the lining causing inflammation. The giardia blocks nutrient absorption and produces a mild toxin whereas coccidia enters and destroy the villi.Your pet has great potential to drive away certain parasitic organisms. But when their number is high, your pet’s health will suffer. The presence of diarrhoea reduces absorption of nutrients. The irritation in the intestine reduces appetite and causes vomiting and burrowing parasites cause blood loss and anemia.
Intestinal parasites are always worse when they affect young puppies. Their age is directly related to the severity of the infection. That is because growing puppies have much higher nutrient requirement and their inflamed intestines cannot absorb nutrients. Their ulcerated intestines also leak precious blood. In addition, they do not move far from their whelping area, so they are repeatedly exposed to parasite eggs. Some parasites, like hookworms and roundworms, readily move from infected mothers to their babies while they are still in the womb.
Adult Dogs
Adult dogs are more resistant to various intestinal parasites. But, during unhygienic environment and lower immunity, they too can become seriously ill. Age-related resistance is greatest against roundworms and coccidia, whereas whipworms and hookworms can cause health problems at any age. Much of age-related immunity is acquired by prior exposure to these common parasites. So dogs who have not been exposed previously may react as seriously as puppies if they suddenly consume intestinal parasite eggs.
Magic of Prevention: The superpower of Three Ms
When it comes to internal parasites, prevention and early detection are vital. Whenever you get a new pet to the family, schedule a vet appointment at the earliest for a thorough physical examination as well as getting the vaccinations. To avoid parasitic problems in your pet, always think of Three Ms:
1. Medicate with preventives. There are effective treatment options available for your infested pets. Although intestinal parasites are treatable, but the best way to protect your pets is to keep them on parasite preventatives and have their stool checked at least once a year.
2. Monitor your pet with annual screening tests from your veterinarian. Observe your pet regularly and make note of any changes in his skin and coat, grooming behaviour (such as increased itching or scratching) or appetite. In some cases, symptoms are not always visible, so, annual check-ups are important.
3. Maintain a clean environment for your pet. Make sure bedding, food and water dishes, coats, etc., are cleaned on a regular basis. Keep them away from garbage, dead animals, and other dogs or cats that may be infected. Remove feces at least once a week from wherever your dog eliminates so as to prevent their exposure.Severely affected pets often require hospitalisation, supportive care and medications to soothe and protect their digestive system. Iron supplements are greatly helpful. In some severe cases, pups and debilitated adults can only be saved by blood transfusions.
Different types of internal parasites
Horrors of hookworms
Adult hookworms are quite small and barely visible to the naked eye. The hookworm attaches to the intestinal wall of the dog and feeds on tissue and blood. Its eggs are laid in their digestive tract and pass into the environment via feces. Larvae hatch out from eggs after about 10 days and live in the soil. These larvae can infest your dog by means of contact and penetration of the skin or through swallowing after sniffing or licking contaminated areas. In young puppies, they severely damage the small intestine, but in puppies over three months of age, many of these ingested larva are trapped and remains dormant in the muscle and connective tissue.Your pet with heavy infestation of hookworm can become quite ill. Through their feeding activity, these parasites cause internal blood loss. They are a serious threat to young puppies as they can induce bloody diarrhoea and severe anemia which can be fatal. In older dogs, blood loss may be more chronic, and the dog may additionally lose weight. It can also cause weakness and vomiting of varying intensity.
Rescue against roundworms
Roundworms and tapeworms are the major parasites you are likely to see in your pet’s stool. Roundworms are highly prolific and females can lay up to 300,000 eggs per day. They have no mouth, so they do not chew and damage the puppy’s intestinal lining or cause anemia like hookworms do. If your pet is infested with hookworms, they will shed its microscopic eggs via their droppings into the environment, where they become infective after 2 to 3 weeks. Other dogs become infested as they swallow these eggs when they sniff or lick soil or other substances contaminated by feces. They may also get infected if they eat rodents or other small mammals that carry roundworm larvae. Dogs become infected by eating roundworm eggs – not larva. Puppies get infected while still in the womb or from suckling milk from mothers who harbor the parasites. Adult roundworms live in the dog’s intestines and many dogs do not show any sign of illness. Puppies bred in unsanitary conditions are more likely to have these parasites in large numbers. Small puppies with large numbers of roundworms have a typical pot-belly and suffer with diarrhoea and vomiting. Their hair coat is poor and scurfy and their body growth is slow. Immature worms can also affect their respiratory system as they pass through their lungs, leading to coughing and pneumonia.
Guard against giardia
Next to roundworms, giardia is the most common intestinal parasite. Dogs and even humans can contract giardia by coming into contact with infected feces or contaminated water. Most of the dogs never show symptoms or develop diarrhoea. Other symptoms include abdominal pain, nausea or vomiting.
Be careful of coccidia convoy
This particular parasite has adapted to live within the body. The more common form affects the intestines and can cause weight loss, watery or mucous-like diarrhoea and dehydration or your pet may not show any signs of infection. One rare form of coccidian affects the liver and can cause appetite loss, diarrhea, liver failure or in severe cases, death.
Like most of the parasites, they go hand-in-hand with poor sanitation, crowding, and stress. As the dogs mature, the incidence of coccidiosis decreases significantly. Coccidia can transfer from one pet to another pet via fecal contamination and oral ingestion.These organisms invade the lining of the dog’s intestine causing inflammation and diarrhoea, indistinguishable from giardia. They are only life-threatening in infant and debilitated animals where the diarrhoea can lead to serious dehydration and colic.
Stay strong against strongyloides
This parasite can be a problem when dogs are kept in very unsanitary conditions. It multiplies rapidly at higher temperatures and in mud. The most common season for this parasite is summer and rains. They are often missed on routine fecal floatation because they sink to the bottom of the container, unlike the parasite eggs that float to the surface. They can occasionally be found on direct microscopic examination of the stool. When they assume their parasitic form the larva drill into dogs through their skin, once in the pet, they migrate to the lungs, up through the trachea and are swallowed. During this migration, they cause pneumonia when their number is very large. In heavy infections, young dogs develop diarrhea and weight loss. Dogs with a few parasites might not show any signs or symptoms.
Whipworms woes
Whipworms live in the dog’s large intestine and thus, do not cause the violent diarrhoea and illness. Generally, they do not pass large numbers of eggs, so their presence can be missed in fecal examination. It often takes repeated fecal flotation to find them. Your dog may become infested by swallowing infective eggs in soil or other substances that has been contaminated by dog feces. These eggs are particularly resistant in the environment and can survive for at least five years. The dogs infested with a few whipworms may not show the signs of illness. However, some do develop colitis that causes repeated urgency to defecate. When infected dogs pass stool, it is often coated with mucus and occasionally streaked with bright blood. The blood remains bright red because it’s originated low in the intestine, as opposed to the blood of hookworm disease that is originated higher up. Severe infestation causes bloody diarrhoea and anemia that can be fatal if not treated on time. Chronic infestation causes progressive weight loss.
Be cautious: Not just your pet, even you and your family can be at risk

  • The most common human problem associated with intestinal dog parasites is cutaneous and visceral larval migrans. This problem occurs when parasitic larva penetrates human skin or when parasitic eggs are accidentally ingested.
  • Humans can be infested with hookworms too, when coming into contact with soil that contains hookworm larvae. These larvae may penetrate the skin and cause skin condition, including an itching sensation at the point of entry and visible tracks on the skin where the worm is burrowing.
  • Giardia is a common cause of human diarrhea. Most cases occur due to contaminated drinking water or eating raw salads, but there is probably the potential of catching it from infected dogs as well. It is unclear whether the common strains of giardia found in dogs have the potential to cause disease in humans. So, be safe, wear gloves and take simple precautions when you have contact with dog stool.
  • Strongyloides infection, commonly known as Threadworm is very rare in well-kept dogs. But when it is in the pet and its environment, it can jump to humans and vice-versa. These problems are more common in children, due to their less-developed immune systems, their less developed hygienic habits and the likelihood that they will play in contaminated areas. Adults may be exposed during certain activities like gardening.
    Keeping your pets safe will in turn keep you and your family safe from infections and diseases.

(Dr Mokshata Gupta and Asmita Singh are PhD Scholars from Division of Animal Nutrition, ICAR- Indian Veterinary Research Institute, Izatnagar, Bareilly; and Dr Tanmay Mondal is PhD Scholar from Division of Physiology & Climatology, ICAR- Indian Veterinary Research Institute, Izatnagar, Bareilly)
Bring up the germ shield and keep your pooch safe

  • Do not let your pet roam free outdoors unsupervised.
  • Do not take your pet to areas frequented by dogs whose parasite status is unknown.
  •  Hire pet sitters rather than boarding your dog at kennels or animal hospitals.
  •  Do not bring additional pets of unknown parasite status into your household until they have been wormed several times and their fecal status is negative.
  •  Remove stool promptly. Wear gloves, bag it and place it in a trash can outside your home.
  •  Keep your pets from chewing on objects that cannot be easily sanitized or come directly from the store.