Parasites Every Dog Owner Should Watch Out For

Dr Amelia Bunker, Resident Veterinarian - Knose Pet Insurance

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Dr. Amelia Bunker

Dr. Amelia Bunker (BVSc), our resident veterinarian at Knose, blends her passion for animal care with her expertise in veterinary science. Her journey from mixed practice clinics to insurance expert motivates her dedication to animal welfare, both in her professional role and as a pet owner.

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At some point in their lives, dogs will be exposed to or get infected by parasites. These parasitic insects and worms can be found everywhere, making them difficult to control. 

Although some pet parents may think of this as normal and though it’s true some dogs may show mild symptoms, when parasitic infections are left unnoticed and untreated, it can lead to serious diseases that can impact your dog’s quality of life and potentially affect you and your family’s health as well. 

Here are some of the common parasites found in dogs that you need to be familiar with. 


Fleas are perhaps the most common cause of parasitic dog infections in Australia. Although outdoor dogs are more prone to fleas, almost any dog can get them. Even worse, your dogs can carry fleas inside your home where they can settle on your dog’s bedding, in carpets, on your floorboards, and on sofas.

Fleas are common in the warm spring and summer months. When left untreated, one female flea can produce up to 1,000 fleas in just 21 days. Infestation can be difficult to control, and throughout the course of treatment, you may see new fleas reappearing. 

Constant itching, biting, and scratching are the most notable signs of a flea-infected dog. A flea infection can cause anywhere from mild symptoms to allergic dermatitis or anemia, which can be life-threatening. Puppies are particularly vulnerable to anemia and blood loss. 

Fleas are also responsible for transmitting tapeworms in both dogs and cats and can cause allergic reactions in people. 


The paralysis tick (Ixodes holocyclus) is a serious threat to your pet’s health. They like the humid environment and are usually not found in cooler climates. They are usually seen in the warmer months but can be seen all year round.

Paralysis ticks have a toxin that causes a progressive paralysis starting from the hind limbs working its way up to the head. Often the first sign you will see will be your dog looking a little wobbly and unsteady on their feet. This progresses to vomiting, coughing, trouble swallowing and breathing.

If you have found a tick on your dog and your dog is showing any signs of tick paralysis, even if it is mild, it is extremely important that you take them to your vet to be given anti-serum. Even once treated it can take 48 hours for the toxin to be eliminated from your dog.

It is important if you live in an area known to have paralysis ticks that you give your dog a preventative medication to help deter them. 

Learn more about how you can prevent ticks in your dogs through our vet-designed Knose wellness plans. 


Three in every ten dogs and seven in ten puppies are infested with roundworms, making it one of the most common types of parasitic worms. 

Roundworm females can lay up to 300,000 eggs per day, and because they can spread easily, they can be difficult to control. Infested dogs can spread tiny eggs into the environment through their waste. 

Some dogs can get infected if they swallow these eggs whenever they sniff or lick soiled substances or accidentally eat rodents or other animals that carry the roundworm larvae.

Adult dogs can pass these worms to their puppies during pregnancy and via its milk when nursing.

Adult roundworms live in the affected dog’s intestines. Although some infected dogs may not show any signs, those with severe infections, especially puppies, may show signs of colic and lethargy, diarrhoea, vomiting, weight loss, dull hair, and a potbellied appearance. The dog may develop cough if the roundworms move into the lungs.

You may notice the adult roundworms in your dog’s feces or vomit. They will appear white or light brown and may be a few inches long.

Roundworm infection can also put humans at risk especially when in contact with contaminated soil or dog feces, which can cause eye, lung, heart, and other neurologic symptoms. 


Hookworms are similar to roundworms in that they infect a dog’s digestive system and feed on blood, which can lead to ulcers and blood loss. A dog can become infected when it swallows hookworm larvae from infected soil or waste. 

Hookworm-infested dogs have a very poor appetite. That’s why they’d lose weight and look unhealthy. Their nostrils, lips, and ears will be pale. If hookworm larvae get into the lungs, this can lead to coughing as well as other symptoms such as dark stools, diarrhoea, and constipation. 

Hookworms are a serious threat to dogs, especially young puppies. Although symptoms can be mild in older dogs, blood loss can turn chronic, and anemia and weight loss can lead to further problems and may end a dog’s life.  


Named after the shape of their bodies, whipworms can attach themselves on the large intestines and feed on blood. They are one of the most common causes of diarrhoea in adult dogs and puppies. Dogs can get infected when they come into contact with infective whipworm eggs from the waste of infected dogs. These eggs can survive in the environment for up to five years. 

Infected dogs do not show any clear signs, but when this becomes severe, a whipworm infestation can lead to weight loss, bloody diarrhoea, and severe anemia, which can be life-threatening.  


Heartworms are transmitted by mosquitoes, which can spread from an infected host to your dog. Adult heartworms are found in the heart, pulmonary artery, and adjacent large blood vessels of infected dogs. 

Heartworm larvae, which is deposited by a mosquito bite, then migrates to your dog’s heart chambers or into the lung vessels. Once the worms have matured, they affect the blood flow, causing the right side of the heart to work much harder to push blood towards the vessels. 

Heartworm symptoms progress slowly. You’ll notice your dog gets tired easily, show shortness of breath, or coughing after exercise. Infected dogs will be resistant to exercise and fatigue after moderate activity, show a decreased appetite, and weight loss. 

In more advanced stages, you can observe coughing and fatigue even when your dog is at rest. When left untreated, this eventually causes heart failure.


Rat lung worm (Angiostrongylus cantonensis) is a parasite that lives in snails and slugs and can be significantly harmful to pets, and humans, if eaten. Most dogs are very curious about anything that moves in the garden and tend to find these little creatures rather fun to play with!

If your dog eats a snail or slug that is infected with rat lung worm this can lead to pain, swelling and inflammation of the spinal cord. In severe cases there is also inflammation of the brain that can be life-threatening. Initially, your dog will usually show signs of a painful back and be reluctant to walk. If treated early enough, your dog should make a full recovery.

Conclusion: Keep Your Dog Parasite-Free

It can be difficult to fully protect your dog from all kinds of parasites, and one is bound to infect them at some point in their lives. But regular vet visits and getting yourself familiar with the associated risks can help you spot these symptoms early on so you can keep your dog happy and healthy. 

Veterinarians also recommend getting your dogs checked for parasites during their sixth-month check-up to ensure they are vaccinated and have no current infections that could turn into serious and life-threatening illnesses later on. 

Subscribing your dog to a pet wellness plan gives them access to a preventative healthcare regime that includes vaccinations, health checks, and budget-friendly treatment options that can protect them parasites and other common illnesses. 

They are tailored by your vet for your pet’s needs and give you some peace of mind.  Ask your vet about Knose Wellness Plans today! 

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