1. The Importance of Worming
1. Helminths are divided in to three groups:
a) Flukes : infect livers of cattle and sheep (Trematodes)
b) Tapeworms/Flatworms : eg Dipylidium caninum (Cestodes)
c) Roundworms : eg Toxocara canis. (Nematodes)
In general intestinal worms may cause :
a) loss of condition b) poor growth rate
c) diarrhoea , vomiting d) impaction of the gut in severe infestation.
* infection of the adult may be asymptomatic.
3. Toxocara canis is a zoonotic parasite.
4. Nematode eggs are produced by the adult worm and pass out with the faeces of the host. After the egg hatches there are four larval stages before the adult worm develops. The larva may develop inside the egg – normally the second or third stage larvae are infective.

2. a) Intermediate host – development occurs inside the host.
5. Life Cycles may be “Direct or Indirect”
a) The Direct lifecycle has a single host which is infected when the host ingests an infective larva.
b) The Indirect life cycle has an intermediate host in which larval development occurs. The final host ingests the intermediate host to be infected.
6. Types of host :
a) Intermediate host – development occurs inside the host.
b) Final host - the parasite sheds eggs which pass out with the faeces.
c) Paratenic host - no development of the parasite inside the host
7. Methods of infection :
a) Ingestion of infective larvae .
b) In-utero : from the dam to the foetus, through the placenta.
c) Ingestion of infective larvae in the dam’s colostrum or milk.

3. The Life Cycle of Toxocara canis

4. Life Cycle of Toxocara canis
The adult dog passes T. Canis eggs in its faeces These develop in to the infective stage in the environment (2nd larval stage). 3. In the adult the larvae penetrate the gut wall. In the puppy the larvae migrate from the liver to the lung tissue, up through the airways where irritation in the trachea causes coughing, swallowing and migration down the oesophagus in to the stomach and intestines. These will develop in to adult nematodes within 3 weeks. 4. During gestation, hormonal changes in the bitch stimulates migration of the larvae encysted in her gut muscles. This happens after 42 days gestation and the larvae will cross the placenta and infect the puppies before parturition. Infection of the puppies is also possible through the dam’s colostrum and milk. 5. Infection may occur through ingestion of a paratenic host eg mouse. 6 Humans are an accidental host and infection may occur through poor hygiene when children are handling the puppies.
In the 3 week old pup the adult nematode may release several thousand eggs per 1 gram of faeces.

5. Treatment / Prevention
Treat bitch with Fenbendazole (Panacur) prior to whelping from the 42nd day of gestation. This will kill the migrating larvae. Continue until 2 days post whelping or
2. Treat the puppies and dam, starting at 14 days post parturition. eg 2, 4, 6, 8 weeks post parturition.

6. Dipylidium caninum : Tapeworm
The head or scolex has suckers and hooks to cling on to the intestinal wall.
The segments or proglottids mature, fill with eggs and separate from the tapeworm. They pass out with the faeces.
The segment full of eggs looks like a grain of rice or a cucumber seed.

7. Signs of infection
Poor growth, weight loss, anaemia.
Abdominal pain.
Worm segments in the faeces.
“Scooting”
Gut impaction
Often asymptomatic in the adult.
Treatment
Treatment of the dog with worm tablets eg Drontal, must be combined with effective destruction of the flea infestation on the dog and around its environment.

9. Vaccinations
1. The dam’s colostrum will provide passive immunity for 5-7 weeks. The antibody level will be higher if the dam has been vaccinated just before mating.
2. Vaccinating before 6 weeks will not be effective as the pups antibodies will “neutralise” the antigens in the vaccine.
3. Generally it is recommended to vaccinate at 8 and 10 weeks. The second vaccination will ensure that a strong active immunity is present.
4. It will still be another 2 weeks after the second vaccine before the full immunity is established.
5. Vaccination (Puppies) will protect against :
a) Distemper (Hardpad) b) Infectious Canine Hepatitis c) Parvovirus
d) Leptospirosis (Zoonotic) e) Para-influenza
Cats
a) Feline Infectious Enteritis b) Feline Infectious Respiratory Disease (Cat Flu) c) Feline Chamydia Virus d) Feline Leukaemia (at risk cats)
Rabbits must be vaccinated against Viral Haemorrhagic Disease and Myxomatosis ( combined vaccine now available at 5-6 weeks old.

11. USA Vaccination Regime – this may include rabies