Alpha and gamma herpesvirus detection in two herds of farmed red deer (Cervus elaphus) in New Zealand.

CASE HISTORY: In September 2004 two hinds on Farm 1 were observed with epiphora and keratoconjunctivitis, and corneal scarring. A low pregnancy rate in some hinds had been recorded that year. In the same year six yearling deer were observed on Farm 2 with keratitis, uveitis and corneal scarring. CLINICAL AND PATHOLOGICAL FINDINGS: On Farm 1, conjunctival swabs and blood samples were collected from the hinds with ocular lesions, and from 24 other hinds. The two affected hinds were immunosuppressed with dexamethasone for 7 days. Conjunctival, nasal and vaginal swabs were collected daily before euthanasia and necropsy on the eighth day. Subsequently, another five non-pregnant hinds were similarly immunosuppressed and necropsied, and the reproductive tracts of 20 non-pregnant hinds were collected following slaughter. Semen samples were collected from four stags implicated with reproductive failure. On Farm 2, conjunctival swabs were collected from six hinds with ocular lesions and from 14 unaffected deer. Viral culture, consensus primer PCR and sequencing for specific herpesviruses was carried out on conjunctival swabs, buffy coat from blood samples, semen and reproductive tracts. Necropsy samples were also examined using gross pathology and histopathology. On Farm 1, a type 2 rhadinovirus (CvRhV) was detected in the conjunctiva of one hind with keratoconjunctivitis using PCR. Following immunosuppression, gross vesicular and histological vaginal lesions typical of infection with alphaherpesvirus were observed in samples of vaginal tissue from the same hind. Buffy coat, vaginal and lumbar spinal nervous tissues were also positive for cervid herpesvirus 1 (CvHV-1) using PCR. Herpesviruses were not detected in reproductive tracts, ocular or semen samples of the other deer. CvRhV was detected in buffy coats from four other hinds and in a conjunctival swab from one hind, all without ocular lesions, using PCR. On Farm 2, conjunctival swabs from two deer with keratitis were culture positive for CvHV-1. Two culture-negative conjunctival samples from deer without ocular lesions were positive for CvHV-1 by PCR. In two other affected animals, presence of CvRhV was confirmed by PCR and sequencing. DIAGNOSIS: Infection with CvHV-1 associated with keratitis and vulvovaginitis, and CvRhV infection in deer with and without ocular lesions. CLINICAL RELEVANCE: CvHV-1 is a likely cause of keratoconjunctivitis and possibly reproductive tract pathology in deer. Investigation of ocular lesions and reproductive failure in farmed deer should include CvRhV and CvHV-1.

Efficacy of tropicamide, homatropine, cyclopentolate, atropine and hyoscine as mydriatics in Angora goats.

AIM: To document the efficacy of five commercially available mydriatics for their potential for diagnostic and therapeutic use in Angora goats. METHODS: Over 8 weeks, the mydriatic effects of 1% tropicamide, 2% homatropine, 1% cyclopentolate, 1% atropine and 0.25% hyoscine were evaluated. Given as block treatments, drugs were applied randomly to one eye of 10 Angora goats, and the contralateral eye served as a control. Vertical and horizontal pupil diameters were measured to document onset of effect, time to reach a difference of 5 mm in the vertical/horizontal pupil diameter between eyes, time to maximum pupillary dilation, and duration of mydriatic action. RESULTS: Onset of mydriasis for all drugs occurred within 15 minutes. Time to reach a difference of 5 mm in the vertical pupil diameter between eyes was shortest for 1% tropicamide and 0.25% hyoscine (0.5 h), then 2% homatropine and 1% atropine (0.75 h), and longest for 1% cyclopentolate (1.5 h). The maximum vertical pupillary dilation occurred earliest with 1% tropicamide and 1% atropine (2 h), followed by 0.25% hyoscine (3 h), 2% homatropine (4 h), and latest with 1% cyclopentolate (8 h). The duration of vertical dilation of the pupil was shortest with 1% tropicamide (6 h), then 2% homatropine (12 h), 1% cyclopentolate (12 h), 1% atropine (24 h), and longest for 0.25% hyoscine (96 h). The time to reach maximum horizontal dilation of the pupil in treated eyes was shortest with 1% cyclopentolate (1 h), followed by 1% tropicamide (1.5 h), 0.25% hyoscine (3 h), 2% homatropine (3.5 h), and 1% atropine (4 h). The duration of horizontal pupil dilation was shortest with 1% tropicamide (4.5 h), and longest with 0.25% hyoscine (48 h). CONCLUSION: All five mydriatics induced clinical dilation. Tropicamide (1%) had the shortest duration of effect, but gave incomplete dilation. Good dilation was achieved with 1% cyclopentolate and 2% homatropine, but took too long to reach maximum dilation for routine mydriasis. The largest vertical dilation of the pupil was achieved with 1% atropine and 0.25% hyoscine, but pupils remained dilated for more than 24 h. CLINICAL RELEVANCE: For routine mydriasis in goats, it is recommended that 1% tropicamide be used, though there may be incomplete dilation. For a longer duration of mydriasis, such as in the treatment of anterior uveitis, 1% atropine or 0.25% hyoscine would be the drugs of choice.

In vitro analysis of antiangiogenic activity of fungi isolated from clinical cases of equine keratomycosis.

OBJECTIVE: The goal of this project was to explore the possibility that fungal organisms produce metabolites that inhibit angiogenesis. Procedures Fungal cultures were obtained from cases of keratomycosis, grown in Sabouraud's dextrose broth, and sterile filtered for use in experiments. The Matrigel assay was used to screen the filtrate samples for antiangiogenic activity. Matrigel is a basement membrane matrix that supports the differentiation of human umbilical vein endothelial (HUVE) cells into a capillary-like network of tubules. HUVE cells were cultured using standard techniques and passaged at confluence, with all cells being used at passage 3-6. HUVE cells (40 000 cells) were pipetted into each well of a 24-well tissue-culture plate coated with Matrigel. An aliquot of fungal media filtrate was added to each well and the plates allowed to incubate for 18 h, at which time they were evaluated for tubule formation. RESULTS: Two fungal isolates showed inhibition of tubule formation. The addition of 100, 200 and 400 &mgr;L of the fungal media filtrate from the first isolate (Fusarium sp. 99A34574) produced a consistent and dose-dependent inhibition of tubule formation. The second isolate (Aspergillus sp. 271599) did not show inhibition of tubule formation with 100 or 200 &mgr;L added to the wells, however, it did show inhibition at 400 &mgr;L/well. The remaining three isolates did not cause inhibition at any concentration. CONCLUSIONS: Our findings suggest that certain fungal organisms produce metabolites that inhibit tubule formation in vitro, and that these metabolites may play a significant role in altering the host vascular response to fungal infections of the cornea.

Equine infectious keratitis.

Corneal ulcers are one of the most common ocular disease presentations in the horse. With the use of correct diagnostic techniques and selection of an appropriate treatment regimen, most cases result in a satisfactory outcome. The eye does not respond well to inflammation, and in complicated ulcers, this should be managed aggressively using systemic NSAIDs with a high priority assigned to removing the infectious agent. Care needs to be taken to avoid topical or systemic corticosteroid use for the treatment of equine ocular disease, however, unless the clinician is completely sure that the corneal disease is not caused by an infectious process. The use of combination corticosteroid-antibiotic ophthalmic preparations without an appropriate treatment rationale can result in doing more harm than good. It is important to have a treatment plan and to monitor the elected treatment regimen. The clinician should decide on some objective criteria at initiation of treatment so that any changes are made rationally. This approach should also include consideration of early referral of the eye's care to a veterinary ophthalmologist.

Efficacy of ivermectin against benzimidazole-resistant Nematodirus spathiger in sheep.

Eighteen helminth-free lambs were randomly allocated to six groups of three. Each lamb was dosed with 3300 infective larvae pooled from two isolates of Nematodirus spathiger known to be benzimidazole resistant. One lamb from each group was treated with oral ivermectin, one with oral oxfendazole and one left untreated 21 days after infection. All lambs were humanely killed 14 days later and small intestine worm counts performed. No Nematodirus were found in the ivermectin-treated lambs. Nematodirus numbers were reduced by 13% in oxfendazole-treated lambs relative to the control lambs.

Evaluation of the efficacy of doramectin against an artificial infection of Dictyocaulus viviparus in calves.

Three groups of eight Friesian calves, reared parasite-free, were experimentally infected with 1000 infective larvae of Dictyocaulus viviparus. Two groups were injected subcutaneously with 1% doramectin at 0.2 mg/kg body weight, one group 5 days after infection and the other 25 days after infection. A third group served as untreated controls. Faecal samples were examined for lungworm larvae on days 28, 32, 33, 34 and 35 after infection; the calves were killed and necropsied 39 or 40 days after infection and any lungworms present recovered and counted. Doramectin proved 100% effective against both 5-day-old and mature D. viviparus infections.