Search Results
Introduction Ticks are recognized as important vectors of disease for humans, domestic animals, and wildlife. 1 , 2 The geographic range of many tick species has expanded due to human and pet travel, movement of wildlife hosts, and the
infested with ticks, the bobcat was afebrile (rectal temperature, 38.5°C [101.3°F]), and all palpable lymph nodes were considered to be of normal size. The remaining physical examination findings were unremarkable. Blood was collected for point
T icks are common ectoparasites on horses in the United States. 1 In the United States, over 15% of equids and 29% of equine operations have reported tick infestations. 2 In particular, the blacklegged tick ( Ixodes scapularis ) poses
Ixodes scapularis , the black-legged tick, is abundant in parts of the northeastern and upper midwestern United States and is expanding geographically into previously uninfested areas. Invasion of I scapularis results in increased risk of
tick feeding. However, other modes including vertical or horizontal merozoite spread (eg, blood transfusion/ingestion, wounds, or saliva) must be considered. 1 Neonatal dogs infected with large Babesia spp typically present with severe acute
Introduction The expansion of tick-borne disease in populations of domestic dogs is a one health issue that poses a significant and increasing health threat to canids and to humans. 1 Dogs can be infected with numerous tick-borne zoonoses and
Abstract
Objective—To determine whether the geographic distribution of deer ticks (Ixodes scapularis) was associated with the distribution of dogs seropositive for various tick-transmitted disease organisms (ie, Borrelia burgdorferi, Rickettsia rickettsii, the human granulocytic ehrlichiosis [HGE] agent, Ehrlichia canis, and Bartonella vinsonii subsp berkhoffii).
Design—Serologic survey.
Sample Population—Serum samples from 277 dogs in animal shelters and veterinary hospitals in Rhode Island.
Results—Overall, 143 (52%) dogs were seropositive for B burgdorferi, 59 (21.3%) were seropositive for R rickettsii, 40 (14.4%) were seropositive for the HGE agent, 8 (2.9%) were seropositive for E canis, and 6 (2.2%) were seropositive for B vinsonii. Regression analysis indicated that the natural logarithm of nymphal deer tick abundance was correlated with rate of seropositivity to the HGE agent and to B burgdorferi but not to rate of seropositivity to R rickettsii, E canis, or B vinsonii. Percentages of samples seropositive for B burgdorferi, R rickettsii, the HGE agent, and E canis were significantly higher for samples from the southwestern part of the state where ticks in general and deer ticks in particular are abundant than for samples from the northern and eastern portions of the state, where ticks are relatively rare.
Conclusions and Clinical Relevance—Results suggested that all 5 disease agents are in Rhode Island and pose a risk to dogs and humans. Knowledge concerning tick distributions may be useful in predicting the pattern of disease associated with particular tick species and may aid diagnostic, prevention, and control efforts. (J Am Vet Med Assoc 2001;218:1092–1097)
Abstract
Objective—To determine whether use of topical flea and tick products increases the risk of transitional cell carcinoma (TCC) of the urinary bladder in Scottish Terriers.
Design—Case-control study.
Animals—87 adult Scottish Terriers with TCC (cases) and 83 adult Scottish Terriers with other health-related conditions (controls).
Procedure—Owners of study dogs were recruited through private veterinary practices and the Scottish Terrier Club of America. History of exposure to flea and tick products 1 year prior to diagnosis of TCC for case dogs and during a comparable period for control dogs was obtained through a questionnaire. Risk of TCC associated with exposure to flea and tick products was determined by means of univariate and multiple logistic regression analysis.
Results—After adjustment for host factors, Scottish Terriers treated with topical spot-on flea and tick products containing fipronil or imidacloprid did not have an increased risk of TCC, compared with Scottish Terriers that had never been exposed to any flea and tick products. The risk of TCC associated with use of older topical flea and tick products such as shampoos, dips, powders, sprays, and collars could not be evaluated because of the low number of owners in the study population that had used such products.
Conclusions and Clinical Relevance—Results suggest that use of topical spot-on flea and tick products does not increase the risk of TCC in Scottish Terriers. ( J Am Vet Med Assoc 2004;225:389–394)
Abstract
Objective—To compare the efficacy of collars impregnated with 9% amitraz or 9% amitraz and 0.5% pyriproxyfen (PPF) for control of newly established tick infestations by Rhipicephalus sanguineus, Ixodes ricinus, and Ixodes scapularis in dogs and determine whether egg production by surviving female ticks was decreased.
Design—Prospective study.
Animals—72 dogs.
Procedure—Dogs were fitted with 1 of 3 test collars impregnated with amitraz, amitraz and PPF, or only excipients (untreated controls). In 3 trials corresponding to each of the 3 tick species, dogs were infested with 150 unfed adult ticks on days 8, 10, 13, and 18. The number of feeding female ticks was recorded on days 10, 13, 18, and 28. Surviving females were weighed and permitted to oviposit under controlled conditions.
Results—Collars impregnated with amitraz and PPF decreased tick loads as efficiently as collars containing amitraz alone. Inclusion of PPF into the collar did not significantly decrease the efficacy of amitraz. The few female ticks that survived after feeding on dogs treated with collars containing PPF were unable to oviposit.
Conclusions and Clinical Relevance—Collars impregnated with amitraz were efficient in preventing tick infestations in dogs but did not inhibit oviposition in the few surviving female ticks. Incorporation of PPF into the amitraz-impregnated collar resulted in impairment of the reproductive ability of ticks. (J Am Vet Med Assoc 2005;226:221–224)
Abstract
Objective—To evaluate the pathogenicity of 4 strains of the entomopathogenic fungi Metarhizium flavoviride var flavoviride and Metarhizium anisopliae var anisopliae in vitro against the bovine tick Boophilus microplus.
Sample Population—300 B microplus females were used for each series of 5 conidial suspensions of the 4 fungal strains; a control group of 60 females was treated with sterilized water.
Procedure—For each fungal strain, sporulating cultures were used to produce conidial suspensions containing 104, 105, 106, 107, and 108 conidia/ml. A bioassay was performed by immersing B microplus females in conidial suspensions; the procedure was repeated with a new group of 60 females for each dilution (a total of 300). A control group was immersed in the same volume of sterilized distilled water. Ticks were maintained at 27 C and 80% relative humidity for 7 days, and the following variables were evaluated: weight before egging, egging weight, percentage eclosion, reproductive efficiency, and percentage control.
Results—A low index of eclosion was found in the treated groups, with a progressive decrease in percentage eclosion (control = 100%) with increased conidial concentration. The highest level of effectiveness of biocontrol was detected in groups treated with concentrations of 107 and 108 conidia/ml.
Conclusions and Clinical Relevance—Strains of the entomopathogenic fungi M anisopliae var anisopliae and M flavoviride var flavoviride were effective as biological control agents against B microplus, with M flavoviridestrain CG-291 being the most effective. The pathogenicity of these strains and the development of an application method for this fungus for control of ticks may result in improved animal productivity and a reduction in environmental pollution through the use of fewer chemical insecticides. (Am J Vet Res 2001;62:1478–1480)
