Responses of ponies to equid herpesvirus-1 Iscom vaccination and challenge with virus of the homologous strain

An experimental (Iscom) vaccine previously shown to protect hamsters from lethal challenge with equid herpesvirus-1 (Ehv-1), was tested in horses. Vaccination with Ehv-1 Iscoms induced serum antibodies to the major virus glycoproteins gp10, 13, 14, 17, 18 and 21/22a, whereas antibody responses to gp2 were weak or absent. High levels of virus neutralising antibody of long duration were induced, but did not prevent challenge infection with virus of the homologous strain. However, in the vaccinated ponies there was a significant reduction in clinical signs, nasal virus excretion and cell associated viraemia compared with age-matched unvaccinated controls. There was a strong correlation between pre-challenge levels of serum virus neutralising antibody and the duration and total amount of virus excreted from the nasopharynx.     

Palatal erosion and oronasal fistulation following covered nasopharyngeal stent placement in two dogs

Treatment options for dogs with nasopharyngeal stenosis include fluoroscopic placement of metallic stents. Reported complications include entrapment of hair and food, obstruction and persistent nasal discharge. Two toy breed dogs were examined for persistent nasal discharge and halitosis at 4 and 20 months after placement of permanent metallic stents for acquired nasopharyngeal stenosis. Full thickness defects were found in the palate of both dogs, with extensive communication between the mouth and the nasal passages. Portions of the metal stent were observed within the lesion in both patients. Additional treatment was declined by the owner of one dog; the stent was removed through the fistula in the other dog. Palatal erosion with secondary oronasal fistulation is a potential complication of nasopharyngeal stent placement in dogs.     

Prospective trial of autologous conditioned plasma versus hyaluronan plus corticosteroid for elbow osteoarthritis in dogs

This prospective, randomized, double-blinded trial compared outcomes in dogs with bilateral elbow osteoarthritis (OA) treated with hyaluronan plus methylprednisolone (HA + S) or autologous conditioned plasma (ACP^®; Arthrex). An investigator blinded to the treatments graded lameness (0–4) before and 6 months after a single injection with either HA + S or ACP. Clients were blinded to treatment and completed a validated survey before and 1, 6, 12, and 24 weeks after injection. Ten dogs (5 per group) completed all parts of the study. Pre-treatment lameness grades were 1.2 ± 0.97 for HA + S and 1.8 ± 1.1 for ACP and were not different between groups. Post-treatment lameness grades were 0.4 ± 0.55 for HA + S and 0.8 ± 0.64 for ACP with significant (P < 0.05) improvement with either treatment but without differences between groups. Client-based assessments demonstrated improvements in activity, lameness, and pain with HA + S and ACP. These data suggest that both treatments have beneficial effects for dogs with bilateral elbow OA.     

IgM responses in chicken serum to live and inactivated infectious bronchitis virus vaccines.

Intramuscular (i.m.) administration of infectious bronchitis virus (IBV) oil-emulsion vaccine (OEV) to IBV-primed or unprimed chickens resulted in the production of zero or minimal concentrations of IBV-specific IgM in the serum, as measured by enzyme-linked immunosorbent assay of gel chromatography fractions. Live-attenuated infectious bronchitis (IB) vaccine given i.m. or by eyedrop stimulated the production of IBV-specific IgM in similar amounts following inoculation by both routes. These levels were comparable to those found in earlier studies following intranasal inoculation with a virulent strain of IBV and confirm that the detection of IBV-specific IgM is a valuable aid to the diagnosis of recent infection. As expected, administration of live-attenuated IB vaccines i.m. or by eyedrop protected the respiratory tract against challenge with virulent virus 24 days later; however, OEV given i.m. did not.     

Synchronization of estrus in beef cattle with norgestomet and estradiol valerate

Fifty-six cows received a norgestomet implant and an injection of norgestomet and estradiol valerate; half (n = 28) received 500 IU equine chorionic gonadotrophin (eCG) at implant removal, 9 d later. A third group (n = 25) received 2 doses of cloprostenol (500 micrograms) 11 d apart. Estrous rate was higher (P < 0.05) for cows given norgestomet and estradiol plus 500 IU eCG (75.0%) than for those receiving cloprostenol (44.0%); for those receiving norgestomet and estradiol alone, it was intermediate (67.8%). Pregnancy rates to artificial insemination (after estrus or timed) were higher (P < 0.05) for cows given norgestomet and estradiol than for those given cloprostenol (23 of 28, 82.1% vs 13 of 25, 52.0%), and intermediate (67.8%) for those given norgestomet and estradiol plus eCG. In a second experiment, for heifers treated with norgestomet and estradiol plus eCG (n = 15) or with 2 doses of cloprostenol (n = 16), estrous rates were 66.7% vs 56.2% (P > 0.5), ovulation rates were 100.0% vs 81.2% (P = 0.08), intervals from implant removal or cloprostenol treatment to estrus were 48.0 +/- 4.4 hours vs 61.3 +/- 7.0 hours (P = 0.12) and to ovulation were 70.4 +/- 4.4 hours vs 93.2 +/- 7.5 hours (P < 0.01), respectively; pregnancy rates were 41.7 and 35.7%, respectively (P > 0.5). Norgestomet and estradiol were as good as (heifers) or superior to (cows) a 2-dose cloprostenol regimen. In cows given norgestomet and estradiol, injecting eCG at implant removal did not significantly improve estrous or pregnancy rates.     

Rickets in yearling steers wintered on a swede (Brassica napus) crop

Rickets was diagnosed in a group of 80 yearling Angus steers wintered for three months on a crop of swedes (Brassica napus) in the Kimbolton area. Growth rate was poor and several steers developed lameness during the final three weeks on the crop. Five animals were euthanased after developing bone fractures. Necropsy of two animals revealed soft ribs, enlarged costochondral junctions and irregularly thickened growth plates in long bones. Histologically there were islands of hypertrophic cartilage within metaphyses and disruption of metaphyseal trabeculae. Thickened, irregular, trabeculae were sometimes lined by wide osteoid seams. Phosphorus deficiency was considered to be the most likely aetiology of the osteodystrophy. The dry matter content of the swedes was only six percent, and in order to satisfy their phosphorus requirements each steer would have had to ingest approximately 330 kg of swedes per day. Rickets is an uncommon disease of grazing animals in New Zealand and to our knowledge this is the first report of its occurrence in cattle.     

Ultraviolet light and mating behaviour in domestic broiler breeders

1. The perception of UVA light (320 < lambda < 400 nm) by domestic fowl may be an adaptation to naturally lit habitats and may still be functional in farmed varieties, although not utilised owing to the absence of these wavelengths in commercial house lighting. One function may be the mediation of sexually related signalling or communication. 2. In experiment 1, two groups of 41 adult broiler breeders (four cockerels, 37 hens) were kept under conventional fluorescent light, with or without fluorescent UVA supplementation amounting to 16.9% of the total spectral power output of the luminaires. Each light environment was approximately iso-illuminant as perceived by the birds. The two groups were exposed to the light environments alternately for five 2-day periods in a cross-over design. Mating behaviour, production measures and time budgets were recorded on the second day of each period. 3. A UVA-enriched environment increased the number of attempted matings (1.27 vs 0.99 matings/cockerel.h) and locomotion (5.3 vs 3.7 min/bird.hour). 4. In a second experiment, 10 hens were allowed to choose between four cockerels lit under different power levels of UVA (1.6%, 14.6%, 43.5%, 57.5% of the total spectral power output of the luminaires) in a four-armed maze. Again, each light environment was approximately iso-illuminant as perceived by the birds. Each hen was allowed to make one choice per day over four days, with the position of the cockerels and the UVA levels interchanged each day. This schedule was repeated with the same hens for two other groups of four cockerels. 5. At a distance of no less than 60 cm from the cockerel, the hens spent most time inspecting whichever cockerel was lit by 1.6% or 14.6% UVA (1.33 vs 1.37 vs 1.22 vs 1.16 log seconds/hen.choice, respectively for increasing UVA level). Similarly, when allowed to approach closer to the cockerels, the hens spent most time in the arm which contained a cockerel lit by 14.6% UVA light, (1.62 vs 1.88 vs 1.69 vs 1.51 log s/hen.choice, respectively for increasing UVA level). 6. UVA is clearly implicated in the transmission of sexual signals or communication which may have implications for the welfare and production of broiler breeders.