Variations in the number of flea species found on a dog reflect the abundance distribution patterns for each species and their associations with host habitat and environmental factors, new research shows.

M. J. Gracia, from the Facultad de Veterinaria, Zaragoza, and associates used data from 744 domestic dogs from 79 localities in Spain to explore the associations between the abundance of flea species, host-dependent factors (sex and age), and host habitat factors including abode (farm, house with garden, apartment), location (urban or rural), the presence of other pets, and dog activity (measured as the frequency with which dogs left their abode).

Furthermore, they considered environmental factors including the time of year and mean annual temperature and rainfall and explored variations in flea community structure at infracommunity and component community levels.

According to the findings, published online on October 18 in Veterinary Parasitology, Ctenocephalides felis was the most abundant (88.02% of fleas identified), followed by Ctenocephalides canis (10.38%), Pulex irritans (1.47%) and Echidnophaga gallinacea (0.13%).

“Overall flea abundance was higher on dogs living on farms than in apartments, as was the abundance of Ct. felis, Ct. canis and P. irritans,” the authors describe. While Ct. felis was more abundant on dogs living in houses than in apartments, the reverse was found for P. irritans.

The investigators observed that overall flea abundance and Ct. canis abundance were highest in rural areas, whereas the presence of other pets sharing the abode was associated with higher overall flea abundance and Ct. felis abundance. Only P. irritans abundance was positively related to the activity of dogs, the report indicates.

Gracia’s team found that Ct. canis and P. irritans abundances were higher during the warm period of the year. “Mean annual temperature was negatively correlated with overall Ct. canis and P. irritans abundances, but positively related to Ct. felis abundance,” the scientists note. Annual rainfall was negatively correlated with Ct. canis and P. irritans abundances, they add.

The analysis further revealed that at the component community level, flea species richness was inversely related to annual mean temperature.

“The structure of flea assemblages on dogs was mainly associated with host habitat and environmental variables, and not with host-dependent variables”, Gracia’s group concludes.

”However”, the researchers add, “a large amount of variation in flea abundance remained unexplained, suggesting the effect of other non-controlled factors.”

References

• Vet Parasitol, available online 18 October 2007.
  Article in Press, Corrected Proof
  doi:10.1016/j.vetpar.2007.10.006