Dogs can be infected by roundworms (hookworm and ascarids) or tapeworms. The worms either attach to the intestine of the dog and suck blood, (hookworms) or compete with the dog for food (tapeworm) Puppies are more susceptible to worms and show symptoms more readily than adult dogs, but all ages are affected and should be treated.
Ascarids and hookworms can also infect humans, posing a threat to human health.
Puppies may be infected with roundworms in utero; the larvae pass to the unborn puppies from the pregnant bitch. In addition, an infected lactating bitch can transmit the roundworm larvae to the puppies through her milk.
The eggs hatch in the dogs’ environment, in warm damp conditions. The larvae are swallowed by the dogs, or in the case of hookworm, they may penetrate the skin and migrate to the intestine, causing dermatitis of the skin. The larvae mature into adults, mate and the female lays her eggs which are passed out in the faeces. The eggs hatch into larvae, beginning the cycle again.
The larva of the hookworm of dogs and cats is a particularly unpleasant little creature. It is passed out in the dog’s faeces, hatches and lives in sand or soil, in warm, damp conditions and infests humans, by burrowing into the skin. It migrates aimlessly around under the skin, causing extreme irritation and sometimes severe pain. It is known as ‘sandworm’ in man and is very difficult to kill.
The symptoms of roundworm infestation may include:
• Digestive upsets
• Anaemia – from blood loss
• Poor coat
• Failure to grow in puppies
• Weight loss in adults
It is important to know that dogs may show none of the above symptoms, but will still be carrying a worm load and be able to transmit worms to other animals and to humans. For this reason it is important to treat all animals in the household on a regular basis, whether or not symptoms of infestation are visible.
Regular dosing of all animals in the household and by daily collection and disposal of dog faeces, by burning or composting.
Tapeworm (Dypilidium Caninum)
The flea is the intermediate host of the dog tapeworm; therefore flea control is essential to control infestation. (See Flea Control in Dogs) The danger with the dog tapeworm is that children may easily become infected by accidentally swallowing the flea host.
The tapeworm eggs in the dog’s environment are eaten by the flea and form cysts which remain inside the adult flea. If a dog swallows the flea, the tape cyst hatches and the small tapeworm attaches to the wall of the dog’s intestine. It feeds off the food in the dog’s gut, increasing in size to 50cm. As the tapeworm matures, it develops detachable body segments containing male and female sexual organs. Eggs are formed in these segments, which detach from the body of the tapeworm and are deposited in the faeces. These segments are mobile and can actually crawl spontaneously out of the anus. The segments drop into the environment, dry out and release the eggs, which are eaten by a flea, beginning the lifecycle again.
Symptoms of tapeworm infestation may include:
• Weight loss and unthriftiness as the tapeworm competes for food
• Staring coat
• Abnormal appetite
• Abdominal pain
• “Riding” on their hindquarters over a carpet or grass, caused by irritation of the anus.
• In extreme cases, blockages of the intestine.
• Regular dosing with an approved product
• Collection and disposal of dog faeces
• Control of fleas.
Puppies should be dosed 6 – 8 weeks after birth, then again at 3, 6 and 9 months.
Adult dogs should be dosed 4 times a year.
Ref: Handbook on Stock Diseases, Monnig and Veldman