Congenital hypotrichosis in a Percheron draught horse

A blue roan Percheron foal was born with poorly circumscribed patchy alopecia of the trunk and legs. Teeth and hoof development were normal. Alopecia was progressive, becoming almost complete by 1 year of age. Histopathological findings in a skin biopsy obtained at 7 months of age were consistent with severe follicular hypoplasia. Sebaceous glands, epitrichial sweat glands and arrector pilae muscles were normal. The horse is alive and otherwise well at 6 years of age, although adult stature is considered small for this breed. The clinical history and histopathological findings are most consistent with a form of congenital hypotrichosis.     

Serologic and histologic diagnosis of toxoplasmic abortions in sheep in Oregon

Between 1983 and 1989, we examined 586 fetuses and dead lambs submitted to a diagnostic laboratory in Oregon. Toxoplasmosis was diagnosed in 74 (12.6%), campylobacteriosis in 89 (15.2%), chlamydiosis in 75 (12.8%), miscellaneous infections in 153 (26.1%), noninfectious causes in 37 (6.3%), and undetermined causes in 158 (27.0%). Detection of Toxoplasma gondii agglutinating antibodies (greater than or equal to 20) in body fluids or heart serum was considered specific for the diagnosis of toxoplasmosis in ovine fetuses or lambs. Toxoplasma gondii antibody titers (reciprocal) in 285 fluids from fetuses or dead lambs were less than 20 (64.5%), 20 (4.5%), 40 (1.7%), 80 (0.7%), 160 (2.1%), 320 (1.7%), 640 (4.9%), 1,280 (2.8%), 2,560 (4.5%), 5,120 (3.8%), 10,240 (2.1%), and greater than or equal to 20,480 (6.3%).     

Pathology of Campylobacter jejuni abortion in sheep

Campylobacter jejuni was inoculated intravenously into pregnant ewes on gestation days 114 and 123 to reproduce ovine abortion. All ewes aborted 7-12 days post-inoculation. High numbers of C. jejuni were isolated from ewe tissues (caruncle, bile, cecal feces), fetal tissues, and placenta. C. jejuni colonies were identified in caruncles and placenta by light microscopy and immunoperoxidase techniques. Histologically, inoculated ewes had a severe purulent endometritis with vasculitis. Placentas from inoculated ewes and field cases showed necrosis and purulent inflammation; however, placentas from inoculated ewes had large numbers of bacterial colonies compared to few bacteria found in field cases. Histologically, only one fetus from the inoculated ewes showed lesions (purulent bronchopneumonia), whereas all fetuses from field cases had a distinct bronchopneumonia, and one fetus showed multifocal hepatic necrosis. These results suggest that C. jejuni (serotypes Penner 1 and Lior 2) is an important abortifacient organism for sheep.     

The economic implications of potato response to irrigation: Results from 1985 field tests in Maine

The economic value of potato yield and quality response to supplemental irrigation were shown to be dependent on the potato cultivar and the market destination. The results of on-farm tests in Aroostook County, Maine indicate the value of this response ranged from — $257.18 to $1057.46 per hectare in 1985. The annual variable and ownership costs, excluding the value of management time, of center pivot irrigation systems were estimated to be from $226.67 to $387.02 per hectare in 1985 and were found to be dependent on the long-term system plans of the producer as well as on the standard components of cost. The managers’ time commitment was found to be quite large both in the planning stages and in the first year operation of the systems.     

Efficacy of a vaccine to prevent Chlamydia- or Campylobacter-induced abortions in ewes

In a sheep flock, Chlamydia psittaci, Campylobacter fetus, Ca jejuni, and Salmonella dublin caused abortions. A vaccine that contained C psittaci type I from 2 sources: a cow with pneumonia and an aborted ovine fetus, Ca fetus, Ca jejuni, and 4 strains of K99 Escherichia coli was given to 240 ewes before they were bred. All fetuses, placentas, and lambs, that died within 36 hours of birth were examined for infectious agents. Of 55 abortions, 30 (55%) were caused by Chlamydia or Campylobacter spp; 25 of the 30 (83%) abortions took place in the nonvaccinated group (n = 240). Forty-five more lambs survived in the vaccinated group than in the nonvaccinated group. Abortion rates for Chlamydia and Campylobacter spp (2.1 vs 10.4% in vaccinated and nonvaccinated groups, respectively) were significantly different (P = 0.003). Abortion rates for S dublin were not significantly different between groups. The Salmonella epizootic was controlled quickly by sanitation and treatment procedures. The vaccine was at least 80% efficacious against Chlamydia and Campylobacter spp and appeared to be protective.     

Measurement of IgG concentration in ovine fetal fluids: a useful diagnostic test

The Veterinary Diagnostic Laboratory at Oregon State University received 172 aborted ovine fetuses during the 1985-1987 lambing seasons; from 120 of these, body fluids were evaluated for IgG levels. Fifty-two (43%) of the fetal fluids had immunoglobulin G (IgG) levels greater than 15 mg/dl. Forty-five (87%) of the fluids with elevated IgG levels were confirmed or presumed toxoplasma or chlamydia abortions. A mean fetal fluid IgG concentration of 111.5 +/- 78 mg/dl was found for the 26 toxoplasma abortions; for the 19 chlamydia abortions, a mean IgG concentration of 109 +/- 91 mg/dl was found. Antibody titers equal to or greater than 1:40 against Toxoplasma gondii were detected in 23 fetal fluids. Fetal fluid IgG concentration less than 15 mg/dl was found to be associated with bacterial organisms (i.e., Campylobacter sp.) as the confirmed or presumed cause of abortion. These results suggest that measurement of fetal fluid IgG concentration is a useful, supportive diagnostic test in determining the cause of ovine abortion, and should be included as a routine laboratory procedure for ovine abortion diagnosis.     

Megaesophagus in 15 Llamas: A Retrospective Study (1985–1993)

Megaesophagus was diagnosed in 15 llamas on the basis of survey and contrast radiography. Age of onset ranged from 13 months to 9.5 years. Clinical signs varied, with salivation being the most common; regurgitation or dysphagia were noted in only 33% of the cases. Duration of the disorder ranged from 1 week to 5 years. Organophosphate toxicity was the cause of megaesophagusin 1 llama. While most cases were of unknown etiology, the 3 with histological abnormalities included 1 with vagal neuropathy and 2 with a degenerative myopathy of esophageal muscles. The causes in most were undetermined.     

Hemorrhagic enteritis caused by Clostridium perfringens type C in a foal

A 4-day-old foal died with bloody diarrhea. Using a mouse neutralization test, Clostridium perfringens type C was isolated from intestinal contents, and alpha and beta toxins were identified. About 4 m of the jejunum had severe necrohemorrhagic enteritis. Microscopically, large, rod-shaped, gram-positive bacteria were seen on necrotic intestinal villi by use of Brown and Hopp's stains.     

Pentatomid host suitability and the discovery of introduced populations of <Emphasis Type="Italic">Trissolcus japonicus</Emphasis> in Oregon

Trissolcus japonicus is an egg parasitoid of Halyomorpha halys, brown marmorated stink bug, a severe agricultural pest in the USA. T. japonicus is being evaluated in quarantine as a classical biological control agent to manage H. halys populations in the USA. To determine T. japonicus’ potential for successful management of the pest, we performed a series of no-choice and paired-host-range tests, evaluating parasitism and host recognition in ten nontarget insects. In laboratory no-choice tests, T. japonicus successfully parasitized egg masses of seven Pentatomidae native to Oregon in addition to H. halys. Mean parasitism proportions of egg masses were greater than 40% in two species, B. dimidiata and H. abbreviatus, and were statistically similar to parasitism of H. halys. However, paired-host tests identified higher proportions of parasitized H. halys egg masses compared to four other pentatomids. T. japonicus was equally attracted to volatiles produced by H. halys and other pentatomids but demonstrated significantly longer arrestment response time on surfaces with H. halys contact kairomones. Although host acceptance patterns were similar between stink bug species, our results suggest a greater potential for parasitoid development in H. halys eggs compared to the native pentatomids. During host-range testing, we detected field populations of T. japonicus at 11 sites in Portland, OR, indicating an unintentional introduction and establishment. Further work is needed to characterize its nontarget activity and dispersal patterns in areas where H. halys causes economic damage in Oregon.