Haematobia thirouxi potans, two methods described for laboratory rearing, adult flies can be fed either on a bovine calf or on bovine blood in vitro

Parafilaria bovicola, field survey of insect vectors collected from cattle, bleeding-point on cows and prepatent period studies, experimental infection of laboratory-raised Musca autumnalis with third-stage larvae, transmission of third-stage larvae to calves (clinical and pathologic findings)

A successful attempt was made to mechanically transmit bovine leukosis virus (BLV) from a BLV-infected cow with a normal lymphocyte count to sheep by inoculation with horse fly (Tabanus abactor) mouthparts. After interrupted natural feeding, horse flies were anesthetized with CO2. Mouthparts were severed and pooled into a tissue grinder containing medium. Five inocula containing the mouthparts of 10 flies each, and 5 inocula containing the mouthparts of 20 flies each, were prepared and inoculated SC in the right axilla of 10 BLV antibody-negative sheep. Five additional sheep served as controls. Serum samples were collected at 2-week intervals and tested by agar gel immunodiffusion for BLV antibodies. One sheep injected with 20 mouthparts developed antibodies to BLV at 10 weeks after inoculation. Six months after inoculation with fly mouthparts, 1 BLV antibody-negative sheep was randomly selected from each treatment group and injected, in the left axilla, with 3 ml of blood from the donor cow to confirm susceptibility of the sheep. All 3 sheep developed antibodies to BLV within 4 weeks.

helminth parasites and Oestrus ovis in Karakul sheep, seasonal incidence determined by slaughter of successive groups of tracer lambs each exposed on pasture for 33 days, recommended deworming programme, importance of moving sheep to new pastures immediately after deworming

attempts to transmit Anaplasma marginale to cattle with field collections of Hippobosca rufipes were unsuccessful, 1 of 3 attempts to transmit organism with Stomoxys calcitrans was successful

Antiparasitic efficacy of ivermectin against migrating Gasterophilus intestinalis was evaluated in 36 treated and 24 nontreated (n = 12) or vehicle-treated (n = 12) ponies experimentally and naturally infected with G intestinalis and naturally infected with G nasalis. Each pony was experimentally infected with 500 G intestinalis lst instars in 2 divided doses on days -14 and -7 before treatment. On day 0, ivermectin was administered at the rate of 200 microgram/kg of body weight by IV (n = 12) or IM injection (n = 12) or given as an oral paste (n = 12). Ponies were euthanatized and necropsied 21 days after treatment. In each nontreated or vehicle-treated pony, late lst-, lst- to 2nd-instar molt, and early 2nd-instars of G intestinalis were found in the mouth, and 2nd- and 3rd instars of G intestinalis and 3rd instars of G nasalis were found in the stomach. Bots were not found in any ivermectin-treated pony and, thus, ivermectin was 100% effective against oral and gastric stages. Adverse reactions were not observed in ponies given ivermectin by IM injection or orally, but 1 pony given the vehicle IV and 1 pony given ivermectin (in the vehicle) IV had an anaphylactic reaction, resulting in death of the ivermectin-treated pony. It was speculated that the adverse reaction was caused by histamines released in response to vehicle components given by IV injection.

Parafilaria bovicola, general appearance, size, developmental times, and site of development of each larval stage in potential vector flies (Musca xanthomelas and M. lusoria)