What is spirocercosis?
Spirocercosis is a parasitic disease of dogs caused by a worm called Spirocerca lupi. This nematode is endemic to tropical regions so that it is present in overseas territories and departments such as Réunion, the West Indies or even Guyana where most stray dogs are infected.
The worm is also rampant in countries around the Mediterranean and in the southern regions of France.
This parasite causes the formation of nodules in the wall of the esophagus, stomach and aortic lesions.Spirocercosis is therefore a serious disease with an often fatal evolution because the lesions caused by the worm are often irreversible and cancerization is frequent.
How can a dog get spirocercosis?
Spirocerca lupi, the parasite in question
Spirocerca lupi is a small nematode (roundworm) that feeds on the blood of its host, which gives it its red color. It parasitizes the lining of the esophagus, stomach and sometimes the aorta of domestic dogs and wild canines such as foxes where it forms nodules in which the worm lives enclosed.
The females of the parasite lay eggs containing larvae which emerge from the nodules pierced by small holes and are eliminated in the dog's stool. These stools are then consumed by coprophagous beetles which play the role of intermediate host of the parasite. Within the body of the beetle, the larva evolves to its infective stage and can contaminate a lizard, batrachian, rodent or hedgehog if they feed on the infested beetle.
Oral contamination
A dog becomes infected by ingesting an intermediate host or a paratenic host of the parasite, that is to say a coprophagous beetle, a lizard, a batrachian, a rodent or an infested hedgehog.
Is spirocercosis transmitted to humans?
Humans can be infested by Spirocerca lupi but very exceptionally if they consume paratenic hosts of the parasite. On the other hand, an infested dog cannot directly infect a human being.
What are the symptoms of spirocercosis in dogs?
The symptoms of spirocercosis are related to the formation of nodules on the walls of the esophagus or stomach. When these are large, they can then obstruct the lumen of the esophagus and cause vomiting and dysphagia or compress neighboring organs such as the trachea and cause breathing problems.The nodules can also develop into cancerous tumors of the esophagus which most often metastasize to the lungs.
It is also possible for the nodules to rupture and cause massive bleeding that will be fatal to the animal.
What treatment for spirocercosis?
Treatments for spirocercosis are complex and difficult because:
- there are very few truly effective drugs against Spirocerca lupi,
- these drugs do not have marketing authorization for dogs, which makes their use tricky,
- and the lesions created by the parasite are often irreversible.
On the other hand, there is a preventive medicine with an A.M.M. in dogs and which must be administered monthly in areas at risk.