New World screwworm (NWS) myiasis is an infestation by Cochliomyia hominivorax larvae that consume the living tissue of warm-blooded animals, including humans. Domestic dogs are among the potential hosts of these flies that lay their eggs on the edges of wounds. NWS myiasis cases can be fatal if untreated. Treatment with parasiticides must be fast-acting, long-lasting and show 100% efficacy, since open wounds can be reinfested. Afoxolaner is a molecule from the isoxazoline family with proven ectoparasiticide action against fleas, ticks and mites in dogs. Fourteen healthy client-owned dogs, naturally infested by C. hominivorax larvae, were treated with afoxolaner (NexGard®) as per label recommendations, providing at least the minimum dosage of 2.5 mg/kg. Maggot infestations were classified as light (fewer than 10 larvae), mild (from 10 to 20 larvae) or severe (more than 20 larvae), according to the number of larvae found in the wound and/or collected from the ground after treatment. Twenty-four hours post-treatment, infested lesions were carefully inspected and collected larvae were counted and classified as live or dead. All maggots were identified as second and third instar larvae of C. hominivorax and were found dead within 24 h after treatment, demonstrating 100% larvicidal efficacy against C. hominivorax.

The cattle tick, Rhipicephalus microplus, causes significant economic losses to the cattle industry. Tick control is predominately achieved via pesticide applications. However, alternative control methods such as vaccines are needed due to the tick's capacity to quickly develop pesticide resistance and to combat tick-borne diseases. We used an in silico reverse vaccinology approach to evaluate and rank open reading frames (ORFs) from the tick's transcriptome for their potential use as anti-R. microplus vaccine antigens. We manually annotated the 200 highest ranked antigens and selected 10 transcript ORFs as vaccine antigen candidates for expression in Pichia pastoris or insect cells. Six of the ten candidate antigens could be successfully expressed and purified in vitro as recombinant proteins with > 1 mg quantity. RT-PCR confirmed the expression of all six transcripts in tick RNA. However, only three of the six transcripts' corresponding ORFs could be confirmed as present in tick tissue protein extracts. Only four of the six vaccine candidate antigens were successfully expressed and purified in sufficient quantity (> 10 mg) for immunogenicity and efficacy trials in cattle. These four were designated BI-TS002, BI-TS004, BI-TS008, and BI-TS009 and sufficient annotation existed that showed sequence similarity to serine‑rich adhesin for platelets, glycine-rich cell wall structural membrane protein, SWM-1 tick serine protease inhibitor, and venom-like dermonecrotic toxins from ticks and spiders, respectively. Cattle immunized with BI-TS004, BI-TS008 and BI-TS009 yielded a statistically significant difference in antibody response post-immunization. This difference was noted on Days 42, 56, 70, and 84 post-immunization for BI-TS008 and BI-TS009, but only on Day 56 for BI-TS004. BI-TS008 and BI-TS009, were formulated with adjuvant and cattle stall tests conducted over a 175 day period to evaluate efficacy against R. microplus infestations. Both an adjuvant only negative control group and a positive control group using the commercially available GAVAC anti-tick vaccine were used. Efficacy was determined by comparing number of engorged adult female ticks, total egg mass weight, and egg hatchability produced from the immunized group to corresponding data from the adjuvant only negative control group. Thus, effects on engorged adult tick number, reproductive capacity, and fertility were measured. Both initial (designated Phase 1 and calculated from tick collections of Days 60-94 days post-first immunization) and long-term (designated Phase 2 and calculated from tick collections of Days 152-175 post-first immunization) efficacies were determined. The overall Phase 1 trial efficacies of BI-TS008, BI-TS009, and GAVAC were 68.3 %, 48.5 %, and 70.7 %, respectively. The overall Phase 2 trial efficacies of BI-TS008, BI-TS009, and GAVAC were 64.4 %, -30.1 %, and 45.1 %, respectively.

Bovines are suitable hosts and can be affected by fly infestations. Flies pose a significant threat to cattle livestock in Latin America (LA), causing substantial economic repercussions to animal production (reduced productivity, veterinary expenses, and decreased animal welfare) and damage to human health. The most important flies affecting cattle in Argentina, Brazil, Colombia, Mexico, and Uruguay are Haematobia irritans, Dermatobia hominis, and Cochliomyia hominivorax. Due to production losses and the consequent economic costs associated with these flies, control measures must be implemented, primarily relying on insecticidal products. However, decision-making for preventing and treating animals with insecticides varies due to differences in environmental conditions across countries and regions, production systems, animal populations, infestation levels, animal welfare, and the prevalence of myiasis, among other factors. Although insecticides remain the most effective option for fly control in cattle, resistant populations have developed, rendering them less effective. To overcome fly resistance to insecticides, non-chemical (mechanical, environmental, biological, and genetic) methods are being integrated into alternative control and eradication strategies. The use of integrated livestock fly control contributes to safeguarding animal, public, and environmental health. This review is designed to support individuals and institutions, both civil and governmental, addressing the ongoing challenge posed by flies affecting livestock.

Leptospirosis is a potentially fatal zoonosis caused by Leptospira bacteria. Some animal host species are adapted to specific serovars being potential carriers and environmental dispersers. From 2009 to 2011, 45 wild mammals (39 opossums Didelphis albiventris, four porcupines Sphiggurus villosus, one coypu Myocastor coypus and one capybara Hidrochoerus hidrochaeris) found by citizens in anthropic areas of Monte Mor municipality were captured, restrained and had sera samples collected for Leptospira antibody detection. The samples were titrated by the microagglutination technique (MAT) for different serogroups. A total of 35.56% (16/45) animals were reactive for Leptospira antibodies for 11 different serogroups. The most frequent serovar, among the 12 identified, was Icterohaemorrhagiae (6/16), followed by Gryppotyphosa (4/16) and Pyrogenes (2/16). Didelphis albiventris, the most abundant species in the study, had a prevalence of 35.9% (14/39) for Leptospira antibodies, while S. villosus had 0% (0/4), M. coypus (1/1) and H. hydrochaeris (1/1) 100%. Among the seropositive D. albiventris, 35.71% (5/14) and 28.57% (4/14) seroreacted for Leptospira interrogans species, serogroups Icterohaemorrhagiae and Gryppotyphosa respectively, indicating environmental contamination by these bacteria and the possibility of exposure and infection of humans and domestic animals in the studied area.

Lutzomyia longipalpis is the main vector of Leishmania infantum, the agent of canine and human visceral leishmaniosis in the Americas. Considering that the dog is the main domestic host of the parasite, repellent treatment is a measure that might contribute to the prevention of canine visceral leishmaniosis. The repellent efficacy of a single treatment of a new spot-on topical combination of fipronil and permethrin (Frontline Tri-Act®, Merial, now part of Boehringer-Ingelheim) to repel Lu. longipalpis sand flies was evaluated. Sixteen healthy Beagle dogs, eight females and eight males, weighing 8.4–14.4 kg, and 2 to 4 years-old were included in the study. Animals were blocked on decreasing body weight and randomly allocated within the blocks to one of two treatment groups of eight animals each. Dogs in Group 1 were untreated and Dogs in Group 2 were treated with a combination containing 67.6 mg/ml fipronil + 504.8 mg/ml permethrin (Frontline Tri-Act®) once on Day 0. Sand fly exposures were performed on Days 1, 14, 21 and 30 with Lu. longipalpis female sand flies. After 65 (± 15 min), sand flies were assessed for engorgement status. The percent repellency of the treated group compared to the untreated control group was 95.7, 94.3, 81.7 and 72.2% for exposure days 1, 14, 21 and 30, respectively. The two treatment groups were significantly different for all exposure days (P ≤ 0.016 for days 1, 14, 21 and 30). No adverse reactions were observed during the study. A single topical administration of a new combination of fipronil and permethrin demonstrated a significant repellent effect against Lu. longipalpis bites as soon as it was applied on the dogs and its repellent efficacy lasted for 4 weeks with results greater than 80% for 3 weeks. The results suggest that in endemic areas the regular application of the new combination could contribute to protect dogs from Leishmania infection and therefore serve as an additional tool for the prevention of canine visceral leishmaniosis.