Differences in the behavior of Rhipicephalus sanguineus tested against resistant and susceptible dogs

Abstract

To ascertain whether brown dog tick Rhipicephalus sp. infests resistant (beagle) and susceptible (English cocker spaniel) dogs differently, five animals of each breed were maintained in a kennel whose walls were infested with 7,000 larvae, 320 nymphs, 80 males and 80 females, in 3 infestations, at 10-day intervals. Five times more ticks were found on cocker spaniels (498) than on beagles (96). Substances were collected by rubbing pieces of clean flannel on the dogs for 15 min and these were tested for arrestment and attractiveness of ticks. Three choices were offered: cocker extract vs. control; beagle extract vs. control, and cocker extract vs. beagle extract. When allowed to choose between substances rubbed from dogs and a control, more ticks were arrested by extracts from the cockers than from beagles. In the arrestment tests with only a choice between substances from dogs of each breed, more ticks were arrested by cocker substances. To test for attraction, capsules containing adsorbent were used and the tests were carried out in a Y-olfactometer. Fifteen males and 15 females were tested, for each treatment. In the olfactometer, the ticks were not attracted to the odor of either breed, however the odor of the Beagle was apparently repellent. These results indicate that R. sanguineus can use substances from the dogs to differentiate susceptible English Cocker Spaniels from resistant Beagles.

Identification of non-host semiochemicals for the brown dog tick, Rhipicephalus sanguineus sensu lato (Acari: Ixodidae), from tick-resistant beagles, Canis lupus familiaris

“…On the other hand, in the olfactometer, arthropods are guided by anaemotactic stimuli, directly influenced by the presence of chemicals in the vapour phase (Ferreira et al, 2001;McMahon et al, 2003;Vilela and Lucia, 2001), thus confirming the repellent property of the compounds. It is noteworthy that the percentage of repellency observed in the Y-tube olfactometer using the 2-hexanone:benzaldehyde mixture was similar to that observed by Louly et al (2010) when testing crude beagle extracts.…”

“…In the arena, when ticks were able to choose between substances collected on the skin from dogs, they were attracted by semiochemical produced by English cocker spaniel and deterred by the substances from beagles. At the same way, in the Y-olfactometer they were repelled by the odour of beagles (Louly et al, 2010).…”

“…Since production of semiochemicals is thought to be under genetic control , it can be inferred from the data in the present study that the differential production of semiochemicals by beagles and cocker spaniels is a consequence of genetic differences between the two breeds. Avoidance of the beagle breed is biologically important for R. sanguineus s.l., since only 5% of larvae and 50% of nymphs reach ecdysis when fed on resistant beagles, compared with 100% of both stages reaching ecdysis when fed on susceptible animals, for example English cocker spaniels (Louly et al, 2010). Thus, non-host semiochemicals appear to act as reliable signals of host unsuitability that mitigate the risk of reduced ecdysis.…”

Lack of acquired resistance in dogs to successive infestations of Rhipicephalus sanguineus ticks from Brazil and Argentina

“…Moreover, mongrel dogs (Chabaud 1950;Garin and Grabarev 1972;Theis and Budwiser 1974;Bechara et al 1994;Szabó et al 1995) and, as demonstrated in this study, dogs of the Dachshund breed do not seem to develop resistance to R. sanguineus ticks. These findings were also corroborated by Louly et al (2007Louly et al ( , 2010, who observed that English Cocker Spaniel dogs are more susceptible to R. sanguineus than mongrel dogs, and that Beagle dogs are naturally more resistant to R. sanguineus than English cocker spaniel dogs, respectively. Differences in the ability of different breeds to acquire natural resistance to ticks were also reported in cattle to R. microplus (de Castro and Newson 1993) and in goats to R. appendiculatus (Gopalraj et al 2013).…”

“…The studies that demonstrated resistance to R. sanguineus in dogs used the Beagle breed as an experimental model (Inokuma et al 1997;Jittapalapong et al 2000;Louly et al 2010). Moreover, mongrel dogs (Chabaud 1950;Garin and Grabarev 1972;Theis and Budwiser 1974;Bechara et al 1994;Szabó et al 1995) and, as demonstrated in this study, dogs of the Dachshund breed do not seem to develop resistance to R. sanguineus ticks.…”