Canine babesiosis caused by Babesia canis vogeli in rural areas of the State of Minas Gerais, Brazil and factors associated with its seroprevalence

This epidemiological survey on canine babesiosis was carried out in three distinct rural regions (Lavras, Belo Horizonte and Nanuque) of the State of Minas Gerais, Brazil. Ticks and blood samples were collected during a dry season (Lavras, n = 92; Belo Horizonte, n = 50; Nanuque, n = 102) and the subsequent rainy season (Lavras, n = 71; Belo Horizonte, n = 28; Nanuque, n = 66) from dogs living on farms. Plasma samples were analyzed by the indirect fluorescent antibody test for detection of anti-Babesia canis vogeli antibodies. DNA was extracted from blood of serologically positive dogs and molecular characterization of Babesia species was performed. Rhipicephalus sanguineus, Amblyomma cajennense and Boophilus microplus were the tick species identified in all regions. In Lavras, in addition to those tick species, A. tigrinum and A. ovale were also identified. The most prevalent tick species was A. cajennense (35.3%), followed by R. sanguineus (19%) and B. microplus (4.0%). Dogs living in Nanuque region were more heavily infested with ticks than dogs living in Belo Horizonte and Lavras regions. The overall frequency of anti-B. c. vogeli antibodies in the canine population in rural areas of Minas Gerais was 28.7%, with prevalence rates of 49.0% in Nanuque, 34.0% in Belo Horizonte and 3.3% in Lavras. The age of the animals and tick infestation were associated with seroprevalence of B. c. vogeli. The sequence analysis showed that B. c. vogeli was the only Babesia species present in all three regions. This study showed different rates of prevalence and incidence of canine babesiosis among the three rural regions sampled in Minas Gerais State. The results point to the importance of canine babesiosis in rural areas and to the need for further studies related to its transmission and maintenance in nature.     

Bartonella and Babesia infections in cattle and their ticks in Taiwan

Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n = 254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25 (42.4%) beef cattle and 40 (15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n = 10, 1.9%) or B. bigemina (n = 3, 0.6%).     

Comparison of an amitraz-impregnated collar with topical administration of fipronil for prevention of experimental and natural infestations by the brown dog tick (Rhipicephalus sanguineus).

OBJECTIVE: To compare the efficacies of amitraz and fipronil for prevention of experimental and natural infestations of Rhipicephalus sanguineus. DESIGN: Prospective study. ANIMALS: 30 dogs. PROCEDURE: In 3 trials, dogs were allocated to 3 groups of 10 each. In trial 1, dogs were experimentally infested on day--1, and on day 0 were fitted with an amitraz-impregnated collar, treated topically with fipronil, or not treated. Ticks were counted daily until day 7, when viability of ticks and their progeny was determined. In trial 2, dogs were treated on day 0 and experimentally infested on days 7, 8, 10, and 13. Ticks were counted on days 8, 10, 13, and 18, and viability of ticks and their progeny was determined on day 18. In trial 3, dogs were exposed weekly to a tick-infested environment from day--3 to day 70. Dogs were treated on day 0, and ticks were counted and removed weekly from day 3 to day 77. RESULTS: Fipronil and amitraz were acaricidal and inhibited attachment and feeding. Amitraz had a significantly greater effect than fipronil on numbers of live, feeding ticks, egg hatchability, and larval viability, indicating partial ability to interrupt the tick life cycle. In field conditions, amitraz remained effective over the entire observation period. CLINICAL IMPLICATIONS: Amitraz had stronger and more sustained effects against tick infestation than fipronil.     

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations of brown dog ticks (Rhipicephalus sanguineus) on dogs

Four laboratory studies were conducted to demonstrate that a single topical dose of a novel spot-on combination containing fipronil, amitraz and (S)-methoprene (CERTIFECT?, Merial Limited, GA, USA) is efficacious against the brown dog tick, Rhipicephalus sanguineus. In each study, 6-8 male and 6-8 female purpose-bred, laboratory mongrels, terrier cross or Beagles were randomly assigned to one of two study groups (treated and untreated), based on pre-treatment parasite counts. Starting on the day before treatment, each dog was infested weekly with 50 ticks. Ticks were thumb counted at various time points after treatment and weekly infestations starting as early as 6h and continued at 12, 18 and 24h depending on the study. Ticks were removed and counted at 48 h after treatment and weekly infestations. CERTIFECT provided rapid and excellent control of pre-existing and newly acquired infestations of R. sanguineus with efficacy as high as 93% within the first 12h after a single topical treatment. Excellent control (>96%) of R. sanguineus as early as 18 h, following post treatment infestations was maintained for at least 35 days.     

Study of ehrlichiosis in kennel dogs under treatment and prevention during seven months in Dakar (Senegal)

In Dakar kennels where morbidity and mortality attributed to diseases transmitted by ticks were high, we conducted a field study to assess the prevalence of Ehrlichia canis, Anaplasma platys and Babesia spp. infections in two kennels (n = 34 dogs) and to study the impact of tick protection. The first day of the study, the E. canis PCR were positive in 18 dogs (53%). A. platys was found in one dog and all dogs were negative for Babesia spp. After one month of doxycycline treatment, the number of PCR positive dogs decreased significantly to 2 (5.9%). During seven months, all dogs were treated monthly topically with a novel combination (Certifect^®, Merial) delivering at least 6.7 mg fipronil/kg body weight, 8.0 mg amitraz/kg and 6 mg (S)-methoprene/kg. The number of PCR positive dogs remained stable all over the seven months, with 4 dogs being positive at Day 90 and 2 at Day 210. The combination of treatment and monthly prevention had a significant effect in the two kennels. All dogs remained healthy, which was not the case in previous years.     

Efficacy of a novel combination of fipronil, amitraz and (S)-methoprene for treatment and control of tick species infesting dogs in Europe

Four studies were conducted to show the effectiveness of a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT?, Merial Limited, GA, USA) for the therapeutic and preventive control of Ixodid tick species affecting dogs in Europe: Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus. In each, untreated control dogs were compared to others treated with the novel combination. All dogs were infested with 50 adult, unfed ticks prior to treatment and at 7-day intervals after treatment. Ticks on all dogs were counted at 18, 24 and 48 h after treatment (therapeutic efficacy) or infestation (preventive efficacy). Therapeutic efficacy of fipronil, amitraz and (S)-methoprene was excellent as shown by significant (p<0.05) and greater than 97% and up to 100% reductions in the 48 h tick counts and significant (p<0.05) detachment/death of ticks evident at 18-24h after treatment for all three tick species. Preventive efficacy was demonstrated by significant (p<0.05) and greater than 93% and up to 100% reductions in tick counts at 48 h after repeat infestations out to 35 days after treatment for I. ricinus and out to 42 days after treatment for D. reticulatus and R. sanguineus. The time to substantial disruption of establishment of new tick infestations after treatment was less than 18-24h and was maintained for up to 28 days after treatment of I. ricinus and D. reticulatus infestations, and 4h to at most 18 h and maintained up to 35 days after treatment of R. sanguineus. Similar preventive efficacy profiles for each of the Ixodid species tested suggest that CERTIFECT kills all Ixodid species starting 4h after contact as demonstrated for R. sanguineus.     

Dose determination of a novel formulation of metaflumizone plus amitraz for control of cat fleas (Ctenocephalides felis felis) and brown dog ticks (Rhipicephalus sanguineus) on dogs

A novel spot-on formulation containing metaflumizone and amitraz (ProMeris/ProMeris Duo for Dogs, Fort Dodge Animal Health, Overland Park, KS) was evaluated in a laboratory study to determine the appropriate dose for efficacy against fleas and ticks on dogs for 1 month. Thirty-six Beagles were randomly allocated to six equal groups and individually housed. One group remained nontreated. Another was treated with a placebo formulation (solvents with no active ingredients). Three groups of dogs were treated topically with the metaflumizone plus amitraz formulation (150mg of each of metaflumizone and amitraz/ml), at volumes providing doses of 10, 20 and 40mgeachactive/kg. The final group was treated with a commercial spot-on providing 6.7mgfipronil/kg. All treatments were applied to the skin at a single spot between the scapulae on Day 0. Dogs were infested with 50 adult brown dog ticks (Rhipicephalus sanguineus) on each of Days -2, 5, 12, 19, 26, 33 and 40, and with 100 cat fleas (Ctenocephalides felis felis) on Days -1, 6, 13, 20, 27, 34 and 41. Dogs were examined and parasites "finger counted" on Day 1 to estimate knock down efficacy, and all animals were comb counted to determine the numbers of viable fleas and ticks on Days 7, 14, 21, 28, 35 and 42. There were no significant differences in parasite counts between the nontreated control and the placebo-treated control groups for either fleas or ticks (P>0.05) except for very slight reductions on Day 7 for fleas and Day 14 for ticks, demonstrating that the formulation excipients had no activity. The qualitative finger counts on Day 1 indicated that all of the insecticidal treatments resulted in a noticeable reduction in flea and tick numbers within 1 day of treatment. All of the metaflumizone and amitraz treatments and fipronil resulted in significantly lower flea and tick numbers relative to nontreated controls on all posttreatment count days (P<0.05). For the metaflumizone plus amitraz treatments, mean flea and tick counts for the 10mg/kg dose were significantly higher than those for the 20mg/kg dose (P<0.05) from Day 21 on. There was no significant advantage provided by the 40mg/kg dose over the 20mg dose throughout the entire study (P>0.05). The two higher metaflumizone plus amitraz doses provided >95% control of fleas and >90% control of ticks for at least 35 days after treatment, and this level of control was similar to that of the commercial fipronil product. The 20mg/kg dose was selected as the minimum commercial dose rate to provide effective flea and tick control for at least 1 month following a single treatment.     

Molecular detection of zoonotic tick-borne pathogens from ticks collected from ruminants in four South African provinces

Ticks carry and transmit a remarkable array of pathogens including bacteria, protozoa and viruses, which may be of veterinary and/or of medical significance. With little to no information regarding the presence of tick-borne zoonotic pathogens or their known vectors in southern Africa, the aim of our study was to screen for Anaplasma phagocytophilum, Borrelia burgdorferi, Coxiella burnetii, Rickettsia species and Ehrlichia ruminantium in ticks collected and identified from ruminants in the Eastern Cape, Free State, KwaZulu-Natal and Mpumalanga Provinces of South Africa. The most abundant tick species identified in this study were Rhipicephalus evertsi evertsi (40%), Rhipicephalus species (35%), Amblyomma hebraeum (10%) and Rhipicephalus decoloratus (14%). A total of 1634 ticks were collected. DNA was extracted, and samples were subjected to PCR amplification and sequencing. The overall infection rates of ticks with the target pathogens in the four Provinces were as follows: A. phagocytophilum, 7%; C. burnetii, 7%; E. ruminantium, 28%; and Rickettsia spp., 27%. The presence of B. burgdorferi could not be confirmed. The findings of this study show that zoonotic pathogens are present in ticks in the studied South African provinces. This information will aid in the epidemiology of tick-borne zoonotic diseases in the country as well as in raising awareness about such diseases in the veterinary, medical and tourism sectors, as they may be the most affected.     

Effect of new ethyl and methyl carbamates on biological parameters and reproduction of the cattle tick Rhipicephalus microplus

The effect of carbamates on engorged female Rhipicephalus microplus ticks and larvae was evaluated using the adult immersion test (AIT) and the larval packet test (LPT), respectively. Seventeen synthetic carbamates different from current commercial acaricides were synthesised at the National Autonomous University of Mexico. None of the carbamates had an effect on the percentage of females laying eggs. Six of the compounds inhibited egg laying up to 65.4% and inhibited egg hatching by up to 100% (p < 0.05). Compared to untreated females, eggs produced by treated females had a dark, dry, opaque appearance and were less adherent. Carbamates LQM 934 and LQM 938 had an effect on larval mortality (p < 0.05). Carbamate LQM 934 showed lethal concentrations (LC) of LC₉₀ = 0.76% and LC₉₉ = 0.87%, while LQM 938 showed concentrations of LC₉₀ = 0.267% and LC₉₉ = 0.305%. The compounds were distributed into three classes of acaricidal activity using the AIT or the LPT. These three classes were as follows: (1) compounds having no apparent effect; (2) compounds that inhibit egg laying and embryo development or (3) compounds that exhibit acaricidal activity to larval ticks.     

Prophylactic treatment with flumethrin,a pyrethroid (Bayticol?, Bayer), against Anaplasma phagocytophilum infection in lambs

Backgroud

Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) causes the disease tick-borne fever (TBF) in domestic ruminants and has for decades been one of the main scourges for the sheep industry in the coastal areas of Norway. Current control strategies are based on reduction of tick infestation by chemical acaricides.

Methods

In the present study, we investigated if frequent pour-on applications of pyrethroids would reduce tick infestion rate and seroprevalence of A. phagocytophilum infection in sheep. Forty lambs, one month old, of the Norwegian White Sheep breed were used. The lambs belonged to the experimental sheep flock at the Department of Production Animal Clinical Sciences. None of the lambs had been on I. ricinus infested pasture before turnout (day 0). All lambs were twins and twenty lambs were treated with a pour-on pyrethroid (Bayticol®, Bayer A/S, DK-2300) with a dose of 5 ml on days 0, 14, 28, 42, 56, 70, 84, 98, 112 and 128. Twenty lambs were untreated controls. The lambs were collected every fourteen days on pasture for treatment. In addition, the lambs were examined for ticks, blood sampled, weighed, and rectal temperature was recorded.

Results and conclusion

A significant reduction in tick infestion rate was detected on treated lambs. However, the present results indicate that frequent acaricide treatment does not reduce the seroprevalence to A. phagocytophilum on tick-infested pasture.     

Tick Vaccines and the Transmission of Tick-Borne Pathogens

Ticks transmit pathogens that cause diseases which greatly impact both human and animal health. Vaccines developed against Boophilus spp. using Bm86 and Bm95 tick gut antigens demonstrated the feasibility of using vaccines for control of tick infestations. These vaccines also reduced transmission of tick-borne pathogens by decreasing exposure of susceptible hosts to ticks. The recently discovered tick antigens, 64P putative cement protein and subolesin involved in the regulation of tick feeding and reproduction, were also shown to reduce tick infestations. These antigens, together with the TROSPA receptor for Burrelia burgdorferi OspA were effective against tick-borne pathogens by reducing the infection levels in ticks and/or the transmission of the pathogen. Development of a vaccine targeted at both the tick vector and pathogen would contribute greatly to the control of tick infestations and the transmission of tick-borne diseases. These results have demonstrated that tick vaccines can be developed for control tick infestations and show promise for the prevention of the transmission of tick-borne pathogens.     

Repellency and efficacy of 65% permethrin and selamectin spot-on formulations against Ixodes ricinus ticks on dogs

Two topically applied spot-on products used for flea and tick control on dogs, 65% permethrin (Defend EXspot Treatment for Dogs, Schering-Plough Animal Health Corp., Union, NJ) and selamectin (Revolution [United States] or Stronghold [Europe], Pfizer Animal Health, New York, NY), were evaluated for repellency and efficacy against Ixodes ricinus, the primary vector of Lyme disease in Europe. Eighteen dogs were evenly and randomly allocated to the following treatments: 1) 65% permethrin, 2) selamectin, 3) untreated control. Dogs were treated by topical application of the assigned product in accordance with product label directions on Day 0. At 7, 14, 21, 28, and 35 days after treatment, each dog was exposed for 2 hours to 50 unfed, adult ticks in a cage with a carpet that covered approximately 70% of the floor area. After the exposure period, dogs were removed from the cages and live and dead ticks were counted on the dogs and in the cages. The number of live ticks recovered was reduced by 90.3% to 99.5% for dogs treated with 65% permethrin (P <.0001 versus controls and selamectin), compared with 10.9% to 31.1% for dogs treated with selamectin (P >.05 versus controls). The repellency of 65% permethrin was 63.4% to 80.2% against I. ricinus ticks (P <.0001 versus controls, P <.0007 versus selamectin), compared with 0% to 10.9% repellency for selamectin (P >.05 versus controls).     

The efficacy of eprinomectin extended-release injection against Hypoderma spp. (Diptera: Oestridae) in cattle

The efficacy of eprinomectin in an extended-release injection (ERI) formulation was determined in cattle harboring naturally acquired infestations of first- or second- and third-stage larvae of Hypoderma spp. in three studies conducted according to the same protocol in the USA (two studies) and Germany (one study). Thirty cattle sourced from herds with a history of Hypoderma infestation were included in each study. Cattle were formed into replicates of three animals each on the basis of pre-treatment anti-Hypoderma antibody titers. Within replicates each animal was randomly allocated to one of the following treatments: ERI vehicle (control) at 1 mL/50 kg bodyweight, administered once on Day 0; Eprinomectin 5% ERI at 1 mL/50 kg bodyweight (1.0 mg eprinomectin/kg), administered once on Day 0 (when larvae were expected to be first instars); or Eprinomectin 5% ERI at 1 mL/50 kg bodyweight (1.0 mg eprinomectin/kg), administered once when larvae were second or third instars (study dependent, Day 73, 119, or 140). Treatments were administered by subcutaneous injection in front of the shoulder. In all studies, emerging and/or expressed Hypoderma larvae were recovered, speciated, and counted and viability was determined. Eprinomectin LAI treatment was 100% (p < 0.05) efficacious against first- and second- or third-stage larvae of Hypoderma bovis (two studies) and Hypoderma lineatum (one study). All animals accepted the treatment well. No adverse reaction to treatments was observed in any animal in any study.     

Ornithodoros coriaceus (pajaroello tick) as a vector of bluetongue virus

Preliminary studies demonstrated that the argasid tick, Ornithodoros coriaceus Koch, could become infected with bluetongue virus (BTV). Ticks became infected after feeding through artificial membranes on BTV-infected suspensions of cell cultures, chicken embryos, and sheep blood. Ticks also became infected after natural feeding on viremic sheep (BTV serotype 17) and cattle (BTV serotype 11). Virus was recovered from the hemolymph and salivary glands of ticks which had ingested BTV either through an artificial membrane or by natural feeding on a host animal. Ticks infected with BTV serotype 13 were capable of transmitting the virus to a susceptible cow at 42 days after ingestion of virus-infected cultures, thus demonstrating the potential of the tick to serve as a biological vector of BTV.     

Effect of aqueous extracts of Baccharis trimera on development and hatching of Rhipicephalus microplus (Acaridae) eggs

This study evaluated the effects of aqueous extracts of Baccharis trimera (Less.) DC (Asteraceae), colloquially known as carqueja, on egg production, and hatching rate of larvae of Rhipicephalus microplus. Plant samples were collected in Montes Claros, north of Minas Gerais, Brazil. Adult female ticks were distributed into 24 homogeneous groups of 10. The in vitro test was performed by immersing each group in 10 ml solutions of aqueous extracts at 50, 100, 150, or 200 mg of fresh leaves ml⁻¹. These concentrations were compared with distilled water as negative control and a commercial product as positive control and the tests were repeated four times. The carqueja extract at concentrations of 150 and 200 mg of fresh leaves ml⁻¹ showed 100% efficacy in inhibiting egg hatching and therefore could have potential as an acaricide.     

Effect of heat killed Mycobacterium phlei on body weight gain and management of caecal coccidiosis in broiler chickens

The objective of this study was to evaluate the immunotherapeutic potential of heat killed Mycobacterium phlei in broiler chicken against experimentally produced Eimeria tenella infection. The selected dose of E. tenella oocyst (5 × 10³ sporulated oocysts per bird) was capable of producing a mild form of caecal coccidiosis as observed by significant difference in body weight gain, clinical findings and caecal lesion score. Heat killed M. phlei was fed orally at 10 mg per bird with sterile PBS vehicle at alternate day for four doses. Our study reveals that per day body weight gain was significantly (p < 0.01) higher for healthy control compared to coccidia infected group. The group fed M. phlei along with coccidial challenge showed significantly (p < 0.05) higher body weight gain than infected control group. Heat killed M. phlei feeding also found effective to reduce the caecal lesion score significantly (p < 0.05) in comparison to E. tenella infected untreated group. IgA concentrations in serum and bile at 7-day post challenge of coccidial oocyst was also significantly (p < 0.01) higher in M. phlei fed group when compared to coccidia infected and healthy control group. We concluded that use of heat killed M. phlei has a beneficial role as an immunostimulant against caecal coccidiosis in broiler chicken.     

Efficacy of Strychnos spinosa (Lam.) and Solanum incanum L. aqueous fruit extracts against cattle ticks

The efficacy of Solanum incanum and Strychnos spinosa aqueous fruit extracts was evaluated against cattle ticks in on-station experiments and laboratory tick bioassays. In the on-station experiment using cattle, fruit extracts were applied at three concentrations 5, 10, and 20 % (w/v) and compared with a commercial acaricide, Tickbuster® (amitraz) spray (positive control) and no treatment (negative control). The treatments were applied at weekly intervals for 6 weeks as surface sprays on 32 Mashona cattle in a completely randomized design experiment. Ticks on individual cattle were identified, counted, and recorded daily. Peripheral blood samples were collected for parasite screening. In the laboratory, tick bioassays were conducted at four concentrations, 5, 10, 20, and 40 % (w/v) fruit extracts compared to Tickbuster® (amitraz) spray (positive control) and distilled water (negative control). The extracts were incubated with Rhipicephalus (Boophilus) decoloratus tick larvae and mortalities for each treatment level recorded after 24 and 48 h. The 5 % Solanum incanum treatment had higher efficacy ratio (P?<?0.05) than the other fruit extract concentrations of the same plant species. Efficacy ratio was higher (P?<?0.05) in the 5 % S. spinosa-treated cattle than in the untreated control but lower (P?<?0.05) than that for the amitraz treatment. The bioassays indicated that there was a high efficacy ratio for the lowest fruit extract concentrations when ticks were exposed to acaricidal treatments for 48 h compared to 24 h. Overall, the results indicate that Solanum incanum and Strychnos spinosa individually have some acaricidal effect.     

Tick vaccines and the transmission of tick-borne pathogens

Ticks transmit pathogens that cause diseases which greatly impact both human and animal health. Vaccines developed against Boophilus spp. using Bm86 and Bm95 tick gut antigens demonstrated the feasibility of using vaccines for control of tick infestations. These vaccines also reduced transmission of tick-borne pathogens by decreasing exposure of susceptible hosts to ticks. The recently discovered tick antigens, 64P putative cement protein and subolesin involved in the regulation of tick feeding and reproduction, were also shown to reduce tick infestations. These antigens, together with the TROSPA receptor for Burrelia burgdorferi OspA were effective against tick-borne pathogens by reducing the infection levels in ticks and/or the transmission of the pathogen. Development of a vaccine targeted at both the tick vector and pathogen would contribute greatly to the control of tick infestations and the transmission of tick-borne diseases. These results have demonstrated that tick vaccines can be developed for control tick infestations and show promise for the prevention of the transmission of tick-borne pathogens.     

The prevention of attachment and the detachment effects of a novel combination of fipronil, amitraz and (S)-methoprene for Rhipicephalus sanguineus and Dermacentor variabilis on dogs

A novel combination of fipronil, amitraz and (S)-methoprene (CERTIFECT?, Merial Limited, GA, USA) was evaluated for the prevention of attachment of ticks and its ability to cause detachment of ticks. For the two prevention of attachment studies, 20 purpose-bred beagles were allocated each to two equal groups based on pretreatment tick counts (treated and untreated). Each dog was exposed to 50 adult Rhipicephalus sanguineus and Dermacentor variabilis weekly starting 24h after treatment. In study 1 infestations with R. sanguineus were discontinued after Day 7 but continued to Day 28 for D. variabilis in both studies. Counts of ticks by species were made 2, 4 and 24h after exposure to ticks. Ticks not attaching to dogs were evaluated for viability. For the evaluation of detachment study, 16 purpose-bred beagles were allocated each to two equal groups based on pretreatment tick counts (treated and untreated). Each dog was infested with 50 unfed R. sanguineus and D. variabilis adults on Day -2. Ticks were thumb counted without removal on all dogs on Day -1, and at 4, 12, and 24h after treatment. Ticks were counted and removed at 48 h after treatment. Dogs treated with the novel combination had significantly (p<0.05) lower total numbers of attached R. sanguineus and D. variabilis than untreated controls at 4h through Day 7. For R. sanguineus, percent reduction of attachment at 24h after infestation through Day 29 ranged from 94.5% to 100%. For D. variabilis, the percent reduction of attachment at 24h through Day 22 was above 98.0%. These studies demonstrate that novel combination can disrupt attachment of R. sanguineus and D. variabilis for up to 28 days following treatment. Of those ticks that are exposed to the treatment, even if they do not attach to the dog and remain in the environment, greater than 90% (p<0.05) die within 24h for 2-3 weeks following treatment. Also, for those dogs infested with ticks at the time of treatment, the novel combination causes significant detachment (p<.05) starting at 12h and reaching 98.9% by 48 h after treatment. This product provides an effective means for controlling ticks infesting dogs and limiting the spread of tick transmitted diseases. Additionally, the mortality of ticks exposed to CERTIFECT will reduce infestation of the dog's environment.     

Assessing the efficacy of Duddingtonia flagrans chlamydospores per gram of faeces to control Haemonchus contortus larvae

The aims were (a) to quantify the number of Duddingtonia flagrans chlamydospores per gram of faeces (CPG) recovered from sheep administered with different oral doses and, (b) to describe the relationship between CPG and eggs per gram of faeces (EPG) on the efficacy to reduce Haemonchus contortus infective larvae. Three doses of chlamydospores per kg BW were orally administered during seven days: (T1) non treated control group, (T2) 1 × 10⁶, (T3) 2.5 × 10⁶ and (T4) 5 × 10⁶. Three lambs, infected with H. contortus, were used per group. Faeces were obtained from the rectum of each lamb during the fungal administration period (days 0–6) and for six days after that period. Four coproculture replicates were made from each animal in days 2, 4, 6, 8 and 10. A higher chlamydospore dose produced higher CPG in faeces (p < 0.05), but a clear dose dependent effect was not found either in the larvae reduction or in the CPG:EPG ratio. When ratios were re-analyzed, independently of the treatment groups of origin, a better efficacy was obtained with a ratio from 5 to 10 CPG:EPG and a higher ratio (>10 per egg) showed a lower reduction efficacy (p < 0.05). The binomial analysis showed that for each unit of increment in CPG:EPG ratio there was a reduction of larvae number until a point (between 5 and 10 CPG:EPG) where no further reduction was detected. The surface response test indicated that the number of larvae was reduced by CPG until possible saturation. The highest CPG:EPG ratios did not necessarily improve efficacy of D. flagrans.