Pesky Parasites – Endoparasites and your dogThe most common endoparasites that dogs can be susceptible to are also roundworms and tapeworms. Your pet may not show signs of infection with mild burdens, however with heavy burdens they may experience weight loss, vomiting, diarrhoea and failure to thrive.
Some of these worms can cause infections in humans and we advise it is important to regular treat your dog to prevent these parasites.
There are two common roundworms in dogs Toxocara canis and Toxascaris leonina. Eggs are passed in the faeces and are able to remain viable in the environment for several years. Infection to other animals may either be through ingestion of eggs from contaminated ground or ingestion of an intermediate host (e.g. mouse or bird) that are infected. Toxocara canis can also be passed from mother to the puppies via the placenta or milk, the worms will migrate through the tissues including the liver and lungs before entering the intestines where it will become an adult worm.
Hookworms (Ancylostoma Caninum) are more common within other countries throughout the world. These worms are able to hatch into larvae on the ground and penetrate skin on contact. They can also be passed onto the puppy via the placenta or milk from the mother. They can cause signs of emaciation, blood loss, diarrhoea, dehydration and failure to thrive. Uncinaria Stenocephala is also a hookworm associated with dogs but it causes less clinical disease.
These tapeworms will tend to be referred to a resembling a ‘grain of rice’. Tapeworms are long flat worms consisting of many segments and mature segment holding eggs will be released from the end of the tapeworm and passed in the faeces. These ‘grains of rice’ may be visible around the animal’s anus, in the faeces or on the pet’s bed. Dipylidium caninum has an intermediate host of the flea and your cat could become infected through the ingestion on a flea. Taenia is morely commmonly seen in cats but dogs can also become infected through the ingestion of an infected intermediate host such as a mouse or bird.
Adult Whipworm (Trichuris vulpis) live within the large intestine and will attach to the gut wall by burrowing their heads into the gut lining. They can reach up to 2-3 inches in length and dogs become infected by ingesting the egg stage of the lifecycle. Older dogs are more at risk of having a whipworm burden. Signs of a burden may include bloody diarrhoea, anaemia, dehydration and tiredness. By keeping up with regular worming and cleaning up after your dog you will minimise the risk of exposure.
Heartworms (Dirofilaria) are associated more with dogs that travel abroad. They are transmitted by mosquitos and are very thin, thread-worms reaching up to around 30cm long. Symptoms of infection can vary from mild signs such as an occasional cough, coughing more regularly when exercising; to more severe signs as losing weight, laboured breathing, finding exercise difficult, and most can develop caval syndrome where the sheer number of worms can block the flow of blood into the heart.
Our general advice regarding worming of your dog, is that puppies should be wormed every 2 weeks from 3 weeks of age until 8 weeks, then it is recommended to treat monthly until 6 months of age. After 6 months, worming will depend on certain factors such as outdoor access, scavenging, and the presence of children or other vulnerable people with the household. These individuals should be treated more regularly as they will be classed as a higher risk and it is also advised to use a product to treat against fleas to minimise the risk of tapeworm.