Response of triploid Atlantic salmon (Salmo salar) to commercial vaccines

While triploid Atlantic salmon represent a practical and affordable solution to the issues associated with sexual maturation in the salmonid aquaculture industry, empirical evidence suggests triploids are more susceptible to disease and vaccine side-effects than diploids. With vaccination now part of routine husbandry, it is essential their response be studied to confirm their suitability for commercial production. This study tested the response of triploid and diploid Atlantic salmon to vaccination with commercially available vaccines. Triploid and diploid Atlantic salmon siblings were injected with one of three commercial vaccines (or sham-vaccinated) and monitored for performance throughout a commercial production cycle. Sampling at smolt and harvest was undertaken along with individual weight and length assessments through the cycle. Antibody response to Aeromonas salmonicida vaccination was similar in both ploidy, with a positive response in vaccine-injected fish. For both adhesions and melanin, analysis found that higher scores were more likely to occur as the anticipated severity of the vaccine increased. In addition, for adhesion scores at smolt and melanin scores at smolt and harvest, triploids were statistically more likely to exhibit high scores than diploids. Triploids maintained a significantly higher body weight during freshwater and until 11 months post-seawater transfer, with diploids weighing significantly more at harvest. Growth, represented by thermal growth coefficient (TGC), decreased in both ploidy as the severity of adhesions increased, and regression patterns did not differ significantly between ploidy. Vertebral deformity prevalence was consistently higher in triploids (smolt 12.3 ± 4.5%; harvest 34.9 ± 5.9%) than diploids (smolt 0.8 ± 0.5%; harvest 15.9 ± 1.9%), with no significant difference between vaccine groups in each ploidy. This study demonstrates that triploids respond as well to vaccination as diploids and provides further supporting evidence of triploid robustness for commercial aquaculture.

Bilateral hind limb deformities and subsequent medially luxating patellas in a kitten

A 9-week-old domestic long-haired kitten was presented for evaluation of bilateral hind limb deformities. Bilateral hyperextension of the tarsi was diagnosed on physical examination and was treated with physical therapy and splinting. At 4 months of age, the patient was presented with bilateral, medially luxating patellas, which were successfully treated with bilateral chondroplasty and joint capsule imbrication.

A Large Deletion in the NSDHL Gene in Labrador Retrievers with a Congenital Cornification Disorder

In heterozygous females affected by an X-linked skin disorder, lesions often appear in a characteristic pattern, the so-called Blaschko's lines. We investigated a female Labrador Retriever and her crossbred daughter, which both showed similar clinical lesions that followed Blaschko's lines. The two male littermates of the affected daughter had died at birth, suggesting a monogenic X-chromosomal semidominant mode of inheritance. Whole genome sequencing of the affected daughter, and subsequent automated variant filtering with respect to 188 nonaffected control dogs of different breeds, revealed 332 hetero-zygous variants on the X-chromosome private to the affected dog. None of these variants was protein-changing. By visual inspection of candidate genes located on the X-chromosome, we identified a large deletion in the NSDHL gene, encoding NAD(P) dependent steroid dehydrogenase-like, a 3β-hydroxysteroid dehydrogenase involved in cholesterol biosynthesis. The deletion spanned >14 kb, and included the last three exons of the NSDHL gene. By PCR and fragment length analysis, we confirmed the presence of the variant in both affected dogs, and its absence in 50 control Labrador Retrievers. Variants in the NSDHL gene cause CHILD syndrome in humans, and the bare patches (Bpa) and striated (Str) phenotypes in mice. Taken together, our genetic data and the known role of NSDHL in X-linked skin disorders strongly suggest that the identified structural variant in the NSDHL gene is causative for the phenotype in the two affected dogs.

Vertebral Malformation, Syringomyelia, and Ventricular Septal Defect in a Dromedary Camel (Camelius Dromedarius)

An occipitoatlantoaxial malformation and ventricular septal defect (VSD) were diagnosed in a 36-hour-old female camel. Physical examination revealed a firm protrusion of the dorsal aspect of the atlas and axis, tilting of the head to the left, and a grade V/VI systolic murmur. Neurological examination revealed proprioceptive deficits and ataxia of all 4 limbs. Radiographic examination and necropsy demonstrated malformation, fusion of the atlas to the occiput and hypoplasia of the dens of the axis, and subluxation of the atlantoaxial joint. Dorsoventral laxity of the atlantoaxial joint was also present, with compression of the cervical spinal cord. A 1.5-cm-diameter VSD was observed also. Histopathologic examination of the cervical spinal cord revealed a cavity extending from the level of the first to fourth cervical segment, dorsal to the central canal, 5 cm long and 1–2 mm in diameter. The cells around the cavity were positive for glial fibrillary acidic protein and sporadically positive for vimentin. This cavitary structure was consistent with syringomyelia, which was lined by glial cells, surrounded by edematous white matter with Wallerian-like degeneration and with neuronal necrosis in the adjacent dorsal horns.

Surgical stabilization of the atlanto-occipital overlap with atlanto-axial instability in a dog

The atlanto-occipital (AO) overlap in combination with atlanto-axial (AA) instability was found in a dog. We hypothesized that ventral fixation of the AA junction can stabilize the atlas and prevent AO overlap by reviewing our past cases with AA instability. A standard ventral fixation of the AA junction using stainless k-wires and polymethyl methacrylate (PMMA) was performed. The dog fully recovered, and no complication was noted. The results of the postoperative CT imaging supported our hypothesis. The ventral fixation of the AA junction is a feasible treatment option for similar cases, although craniocervical junction abnormalities (CJA) including AA instability are varied, and careful consideration is required for each case.

Rift Valley Fever Vaccine Virus Clone 13 Is Able to Cross the Ovine Placental Barrier Associated with Foetal Infections, Malformations, and Stillbirths

Rift Valley fever virus (RVFV) is a mosquito-borne pathogen that affects domesticated ruminants and occasionally humans. Classical RVF vaccines are based on formalin-inactivated virus or the live-attenuated Smithburn strain. The inactivated vaccine is highly safe but requires multiple administrations and yearly re-vaccinations. Although the Smithburn vaccine provides solid protection after a single vaccination, this vaccine is not safe for pregnant animals. An alternative live-attenuated vaccine, named Clone 13, carries a large natural deletion in the NSs gene which encodes the major virulence factor of the virus. The Clone 13 vaccine was previously shown to be safe for young lambs and calves. Moreover, a study in pregnant ewes suggested that the vaccine could also be applied safely during gestation. To anticipate on a possible future incursion of RVFV in Europe, we have evaluated the safety of Clone 13 for young lambs and pregnant ewes. In line with the guidelines from the World Organisation for Animal health (Office International des Epizooties, OIE) and regulations of the European Pharmacopeia (EP), these studies were performed with an overdose. Our studies with lambs showed that Clone 13 dissemination within vaccinated animals is very limited. Moreover, the Clone 13 vaccine virus was not shed nor spread to in-contact sentinels and did not revert to virulence upon animal-to-animal passage. Importantly, a large experiment with pregnant ewes demonstrated that the Clone 13 virus is able to spread to the fetus, resulting in malformations and stillbirths. Altogether, our results suggest that Clone 13 can be applied safely in lambs, but that caution should be taken when Clone 13 is used in pregnant animals, particularly during the first trimester of gestation.

Experimental Infection of Sheep at 45 and 60 Days of Gestation with Schmallenberg Virus Readily Led to Placental Colonization without Causing Congenital Malformations

BACKGROUND

Main impact of Schmallenberg virus (SBV) on livestock consists in reproductive disorders, with teratogenic effects, abortions and stillbirths. SBV pathogenesis and viral placental crossing remain currently poorly understood. Therefore, we implemented an experimental infection of ewes, inoculated with SBV at 45 or 60 days of gestation (dg).

METHODOLOGY

"Mourerous" breed ewes were randomly separated in three groups: eight and nine ewes were subcutaneously inoculated with 1 ml of SBV infectious serum at 45 and 60 dg, respectively (G45 and G60). Six other ewes were inoculated subcutaneously with sterile phosphate buffer saline as control group. All SBV inoculated ewes showed RNAemia consistent with previously published studies, they seroconverted and no clinical sign was reported. Lambs were born at term via caesarian-section, and right after birth they were blood sampled and clinically examined. Then both lambs and ewes were euthanatized and necropsied.

PRINCIPAL FINDINGS/SIGNIFICANCE

No lambs showed any malformation suggestive of SBV infection and none of them had RNAemia or anti-SBV antibodies prior to colostrum uptake. Positive SBV RNA detection in organs was rare in both G45 and G60 lambs (2/11 and 1/10, respectively). Nevertheless most of the lambs in G45 (9/11) and G60 (9/10) had at least one extraembryonic structure SBV positive by RTqPCR. The number of positive extraembryonic structures was significantly higher in G60 lambs. Time of inoculation (45 or 60 dg) had no impact on the placental colonization success rate but affected the frequency of detecting the virus in the offspring extraembryonic structures by the time of lambing. SBV readily colonized the placenta when ewes were infected at 45 or 60 dg but infection of the fetuses was limited and did not lead to congenital malformations.

Clinical findings and survival in 56 sick neonatal New World camelids

BACKGROUND

Information pertaining to clinical presentation and outcome of neonatal New World camelids (NWC) is limited when compared to calves and foals.

HYPOTHESIS

Values of variables at admission and subsequent treatment would predict survival in sick neonatal NWC.

ANIMALS

Fifty-six client-owned sick neonatal NWC presented over a 10-year period to the Purdue University Veterinary Teaching Hospital.

METHODS

A retrospective study was performed. Inclusion criteria were NWC less than 30 days of age with complete medical records that presented between 2000 and 2010.

RESULTS

The median age at presentation was 1 day (range 1-20). The most common diagnoses were systemic inflammatory response syndrome (50%), congenital defects (41%), ophthalmic lesions (21%), sepsis (16%), and gastrointestinal diseases (16%). Sixty-six percent of NWC survived to discharge. Clinicopathologic findings on admission were variable and not specific for disorders. Factors associated with survival were absence of choanal atresia (P = .001, OR: 55.9 [2.5-1,232]), administration of llama plasma (P = .013, OR: 4.9 [1.4-17.7]), and antimicrobial treatment with trimethoprim-sulfamethoxazole (TMS) (P = .016, OR: 6.5 [1.3-32.2]).

CONCLUSIONS AND CLINICAL IMPORTANCE

The use of antibiotics, particularly TMS, and llama plasma are recommended in sick neonatal NWC. Results from this study could contribute toward defining a NWC-specific sepsis scoring system.

Histological and computed tomographic evaluation of a parasitic conjoined twin in hybrid catfish (Ictalurus punctatus [Rafinesque] X Ictalurus furcatus [Lesueur])

There is growing use of hybrid catfish (Ictalurus punctatus ♀ X Ictalurus furcatus ♂) in commercial aquaculture to utilize hybrid vigour to improve production A conjoined twin specimen found during the course of production studies by the United States Department of Agriculture Catfish Genetic Research Unit (USDA-CGRU) was submitted to the Aquatic Research and Diagnostic Laboratory (ARDL). After preliminary inspection, it was transported to Mississippi State University, College of Veterinary Medicine for further evaluation. The specimen was examined using both computed radiography and computed tomography antemortem. Following humane euthanasia, the specimen was examined both grossly and histologically. Tissues from both fish were also submitted for genetic analysis to determine whether twins were derived from the same egg. This report records the presentation and examination of a pair of conjoined hybrid catfish (I. punctatus X Ictalurus furcatus).

[Diagnostics of genetic malformations in small ruminants]

The epidemic occurrence of the Schmallenberg virus has induced numerous congenital malformations in small ruminants. Because of this high incidence of malformed lambs, an overview of the different causes of congenital malformations is provided. The most frequent infectious and physical causes as well as mineral and vitamin deficiencies and toxic agents which can induce congenital malformations are indicated. This list is supplemented by advice on sampling and laboratory diagnosis for an etiological diagnosis of the malformations.

Epizootic of ovine congenital malformations associated with Schmallenberg virus infection

Epizootic outbreaks of congenital malformations in sheep are rare and have, to the best of our knowledge, never been reported before in Europe. This paper describes relevant preliminary findings from the first epizootic outbreak of ovine congenital malformations in the Netherlands. Between 25 November and 20 December 2011, congenital malformations in newborn lambs on sheep farms throughout the country were reported to the Animal Health Service in Deventer. Subsequently, small ruminant veterinary specialists visited these farms and collected relevant information from farmers by means of questionnaires. The deformities varied from mild to severe, and ewes were reported to have given birth to both normal and deformed lambs; both male and female lambs were affected. Most of the affected lambs were delivered at term. Besides malformed and normal lambs, dummy lambs, unable to suckle, were born also on these farms. None of the ewes had shown clinical signs during gestation or at parturition. Dystocia was common, because of the lambs' deformities. Lambs were submitted for post-mortem examination, and samples of brain tissue were collected for virus detection. The main macroscopic findings included arthrogryposis, torticollis, scoliosis and kyphosis, brachygnathia inferior, and mild-to-marked hypoplasia of the cerebrum, cerebellum and spinal cord. Preliminary data from the first ten affected farms suggest that nutritional deficiencies, intoxication, and genetic factors are not likely to have caused the malformations. Preliminary diagnostic analyses of precolostral serum samples excluded border disease virus, bovine viral diarrhoea virus, and bluetongue virus. In December 2011, samples of brain tissue from 54 lambs were sent to the Central Veterinary Institute of Wageningen University Research, Lelystad. Real-time PCR detected the presence of a virus, provisionally named the Schmallenberg virus, in brain tissue from 22 of the 54 lambs, which originated from seven of eight farms that had submitted lambs for post-mortem examination. This Schmallenberg virus was first reported in Germany and seems to be related to the Shamonda, Aino, and Akabane viruses, all of which belong to the Simbu serogroup of the genus Orthobunyavirus of the family Bunyaviridae. These preliminary findings suggest that the Schmallenberg virus is the most likely cause of this epizootic of ovine congenital malformations, which is the first such outbreak reported in Europe.

Bioindicative potential of shell abnormalities occurring in the clam Macoma balthica (L.) from the Baltic Sea

This study reports the occurrence of shell deformities in the Baltic clam Macoma balthica from the Northern Baltic Sea (Trösa Archipelago, Sweden). The functional significance and the bioindicative potential of observed exoskeleton' anomalies was assessed using a suite of physiological and morphological biomarkers. Analyzed shell deformations (SD) included damages of the dorsal margin visible as shell excavations, destruction of the beak, umbo and hinge ligament and decreased shell' transparency. Deformed clams exhibited worse physiological conditions and increased frequency of micronuclei. Skewed sex ratio towards male domination was observed in all studied populations. Spatial differences in the occurrence of deformed clams are reported, with more than 50% of deformed clams inhabiting polluted locations and 8% the reference station. These results are encouraging for the use of described SDs as initial and cost effective indicators of environmental health.

Perosomus elumbis in a black and white German Holstein calf

Perosomus elumbis is a rare congenital anomaly of unknown aetiology characterized by the aplasia of the lumbosacral spinal cord and vertebrae, mostly associated with multiple other malformations of the hind limbs and the urogenital and intestinal tract. This report describes a stillborn female German Holstein calf showing a complete aplasia of the lumbosacrococcygeal portion of the spinal cord and vertebral column. In addition, both hind-limbs exhibited arthrogryposis and the musculature was completely replaced by adipose tissue. Furthermore, atresia ani and recti, agenesis of one kidney, one adrenal gland, and a hypoplastic and atretic female genital tract were detected. The aplasia of the lumbosacrococcygeal spinal cord and vertebral column and the other associated malformations in the presented case of perosomus elumbis may be the consequence of a combined developmental disturbance of the caudal neural tube, notochord and paraxial and intermediary mesoderm. However, it remains unclear whether the underlying cause is due to an inherited defect or due to an unknown exogenous factor disturbing embryogenesis in a critical developmental period.

Gonadal alterations in male whitefish Coregonus fatioi: no evidence for genetic damage reducing viability in early life stages

In recent years, numerous cases of morphological gonadal alterations in fish have been recorded throughout the world and across a wide range of species. In the whitefish Coregonus fatioi from the pre-alpine Lake Thun (Switzerland), the frequency of gonadal alterations is particularly high and the variety of alteration types large. Little is known about the proximal causes and the direct consequences of these morphological features on population persistence. In particular, the potential for the observed alterations to be the phenotypic expression of reduced genetic quality has not yet been addressed. In this study, we used offspring survival during embryogenesis as a proximate indicator of male genetic quality and tested whether the presence of gonadal alterations in males is an indicator of reduced quality. Embryos resulted from in vitro fertilizations of gametes from 126 males and females. We found no significant correlation between embryo survival and gonadal alteration in adults. Our findings suggest that in C. fatioi of Lake Thun, alterations in gonad morphology are not a phenotypic expression of variation in genetic quality.

Snapping turtles (Chelydra serpentina) as bioindicators in Canadian areas of concern in the Great Lakes Basin. II. Changes in hatching success and hatchling deformities in relation to persistent organic pollutants

Hatching success and deformities in snapping turtle hatchlings (Chelydra serpentina) were evaluated using eggs collected from 14 sites in the Canadian lower Great Lakes, including Areas of Concern (AOC), between 2001 and 2004. Eggs were analyzed for PCBs, PBDEs, and pesticides. Between 2002 and 2004, hatchling deformity rates were highest in two AOCs (18.3-28.3%) compared to the reference sites (5.3-11.3%). Hatching success was poorest in three AOCs (71.3-73.1%) compared to the reference sites (86.0-92.7%). Hatching success and deformity rates were generally poorer in 2001 compared to 2002-2004, irrespective of the study location and could be due to egg handling stress in 2001. Hatching success and deformities were generally worst from the Wheatley Harbour, St. Lawrence River (Cornwall), Detroit River, and Hamilton Harbour AOCs. Associations between contaminant burdens with embryonic development were sufficiently poor that the biological relevance is questionable. Stressors not measured may have contributed to development abnormalities.

A complex malformation in a pig: case report and review of the literature

Congenital defects like myofibrillar dysplasia (splayleg), umbilical and inguinal hernias, cryptorchism, intersexes, and anal atresia occur relatively frequently in swine. On the other hand, some developmental anomalies like double monsters are very rare. The present paper reports a rare case of a congenital complex malformation including polymelia, duplicitas coli partialis et recti, atresia ani et fistula rectogenitalis, duplicitas corpori uteri, cervicis, vaginae et vulvae and duplicitas vesicae, urethrae et renalis. A plausible interpretation concerning the etiology is that the anomalies arose from unequal partial twinning. The pig has been healthy and inconspicuous. Although no anus was formed defecation took place via a fistula to one of the vaginas. Posture and behaviour of the pig were normal. Cytogenetic analysis of blood lymphocytes revealed no numerical or gross structural anomalies. There have been no further piglets with developmental disorders in the same litter, in a second litter of the same parents and in other twelve litters by the same boar.

Results and Evaluation of Thirty Years of Health Recordings in the Norwegian Dairy Cattle Population

The results are based on the Norwegian Cattle Health Recording System, which has been in place for the entire country since 1975. The dairy breeds in Norway consist of 94% Norwegian Red and 4% crossbreeds with Norwegian Red. No other breed consists of more than 0.5% of the total population. During the past 30 yr, there have been 11,563,692 dairy cows within the recording system, corresponding to 8,633,532 cow-years and 8,632,516 calvings. This population consisted of 3,038,675 first-calving cows. Altogether, 8,435,704 different diagnoses were recorded from 4,444,485 different cows each year. The general trend for all recordings was an increase in the incidence rate of all cases from 0.74 per 365 d at risk (cow-year) in 1976 to 1.36 in 1990, and then a decrease to 0.62 in 2002. The corresponding figures for cows treated per cow-year were 0.44 up to a maximum of 0.82, and then a decrease to 0.46 per cow-year in 2002. The most common diseases were acute (severe to moderate) clinical mastitis, chronic (mild) clinical mastitis, ketosis, milk fever, teat injuries, retained placenta, silent heat or anestrous, indigestion, cystic ovaries, and metritis. Clinical mastitis increased from 0.15 cows treated per cow-year in 1975 to 0.44 in 1994, and then decreased to 0.23 in 2002. Ketosis began at 0.10 in 1975, increased to 0.24 in 1985, and then decreased to 0.05 in 2005. For several of the most common diseases, there was a reduction of more than 50% from the 1990s to the years after 2000. Validation processes confirmed that this fluctuation reflected the general trend in the population. The disease recording system also reflected the known outbreaks of bovine respiratory syncytial virus during 1976, 1989 to 1990, and 1995. A marked increase in malformation diagnoses could be seen in 1986 and in 1989 and 1990. These could be related to the Chernobyl nuclear power plant accident in April 1986. The diagnosis that showed the most stability throughout these 30 yr was retained placenta. The 3 main reasons for the large fluctuation for many of the diseases could be the following: a breeding effect, an effect of preventive work, and an effect of changing the therapeutic attitude. Many of the actions taken to bring about improvements would not have been possible without a functioning and practical recording system. Our experience is that an organ-related diagnosis system with up to 60 or 70 different diagnoses will meet the needs of the dairy industry.

Hereditary evaluation of multiple developmental abnormalities in the Havanese dog breed

The Havanese is a toy breed that presents with a wide range of developmental abnormalities. Skeletal defects, particularly osteochondrodysplasia (OCD), are the most frequently observed anomalies. Cataracts, liver shunts, heart murmurs, and missing incisors are also common in this breed. Estimates of heritability and complex segregation analyses were carried out to evaluate modes of transmission for these abnormalities. A moderate heritability was identified and evidence for a single major locus was found. Novel statistical analysis methods were used to identify four traits that co-segregate: cataracts, hepatic abnormalities, OCD, and cardiac abnormalities. A canine-specific microarray was used to identify changes in gene expression in the liver that accompany the aforementioned developmental problems. One hundred and thirteen genes were found to be differentially regulated in the Havanese.

Skeletal and neurological malformations in pigs congenitally infected with Menangle virus

OBJECTIVE

To describe the pathological findings in stillborn piglets and fetuses delivered by sows naturally infected with Menangle virus, a recently recognised Paramyxovirus.

DESIGN

Observations of the gross and microscopic pathology of natural disease.

PROCEDURE

Postmortem examinations were performed on 49 stillborn piglets, 35 mummified or semi-mummified full-term fetuses and 6 aborted fetuses from 20 litters at a 2600-sow intensive piggery in New South Wales during an outbreak of reproductive disease from June to September 1997. Body weights, crown-rump lengths and gross pathological changes were recorded. Tissues, including brain and spinal cord, were processed for histopathological examination.

RESULTS

Litters with reduced numbers of live born piglets had mummified fetuses and stillborn piglets. Affected stillborn and aborted piglets frequently had arthrogryposis, craniofacial and spinal deformities, pulmonary hypoplasia and degeneration of the brain and spinal cord. Intranuclear and intracytoplasmic inclusion bodies were observed in neurones and other cells in the brain and spinal cord in association with extensive degeneration, necrosis, infiltration of macrophages and gliosis.

CONCLUSIONS

In utero infection of piglets with Menangle virus is associated with severe skeletal and neurological malformations.

Correction of angular limb deformity in two subspecies of flamingo (Phoenicopterus ruber) utilizing a transphyseal bridging technique

Three hand-raised American flamingo (Phoenicopterus ruber ruber) chicks and one hand-raised Chilean flamingo (Phoenicopterus ruber chilensis) developed valgus angular limb deformities of the proximal tarsometatarsal bone. All flamingos underwent surgical correction to unequally retard the growth plate using transphyseal bridging. Positive profile pins were placed in the proximal epiphysis and distal to the growth plate in the metaphysis on the convex side of the affected tarsometatarsus. Various banding techniques were used in each flamingo to create tension. Three of the four flamingos responded in 7-14 days with correction or slight overcorrection of the valgus limb deformity. The fourth flamingo's leg deformity did not improve for reasons thought to be related to improper implant placement. Growth plate retardation by transphyseal bridging proved successful in correcting valgus limb deformity of the proximal tarsometatarsus. This technique may be considered as an option for correction of angular limb deformities of the proximal tarsometatarsus in flamingos less than 90-120 days of age.

Effects of Nonadditive Genetic Interactions, Inbreeding, and Recessive Defects on Embryo and Fetal Loss by Seventy Days

Lethal recessive genes that cause early embryo loss are difficult to detect. Nonreturn rate at 70 d after first insemination (NR) was evaluated as a trait of the embryo using 1,739,055 first-service records from 1,251 Holstein bulls represented as both service sires and sires of cows. Effects modeled included herd-year-season, parity of cow, sire of cow, service bull, interaction of service bull with sire of cow, and regression on inbreeding of embryo. Variances of service bull and sire of cow were estimated using REML and estimated effects were removed from the data. Interaction variance was estimated from the residuals using the tilde-hat approximation to REML. An additive relationship matrix was used for sire of cow and a dominance relationship matrix for the interaction term. Service bull effects were assumed constant across time and unrelated. For each 10% increase in inbreeding, NR percentage declined by an estimated 1%. A regression of this size could be explained by > 20% of animals carrying defects that cause early embryo loss. Of the total variance, service bull contributed 0.36%; sire of cow, 0.24% (heritability of 1.0%); and interaction, 0.18% (dominance variance of 2.8%). Numbers of records exceeded 500 for 50 bull pair subclasses. Predicted interactions that included effects of inbreeding ranged from - 3.6% to +2.9%, compared with the mean NR of 56%. The largest negative interactions were not caused by known recessive defects. Complex vertebral malformation generally causes loss of pregnancies later in gestation, and few current bulls carry the gene for deficiency of uridine monophosphate synthase. Further study of the families with largest negative interactions could uncover new recessive defects.

Effects of the polycyclic aromatic hydrocarbon heterocycles, carbazole and dibenzothiophene, on in vivo and in vitro CYP1A activity and polycyclic aromatic hydrocarbon-derived embryonic deformities

Heterocyclic derivatives of polycyclic aromatic hydrocarbons (PAHs) are often significant components of environmental contaminant mixtures; however, their contribution to the toxicity of these mixtures is not well characterized. These heterocycles commonly co-occur in PAH mixtures, which contain agonists for the aryl hydrocarbon receptor (AHR). Our goal for these studies was to explore the effects of two PAH heterocycles, carbazole (CB) and dibenzothiophene (DBT), alone and in combination with a PAH-type agonist for the AHR (beta-naphthoflavone [BNF]) on AHR-mediated cytochrome P4501A (CYP1A) activity and on fish embryotoxicity. Embryos of Fundulus heteroclitus were exposed to CB or DBT, with and without coexposure to BNE Carbazole alone slightly induced, whereas DBT alone slightly reduced, in ovo CYP1A-mediated ethoxyresorufin-O-deethylase (EROD) activity compared to control values. However, exposure to CB or DBT reduced in ovo EROD activity in embryos coexposed to BNE Carbazole and DBT were characterized in vitro as noncompetitive CYP1A inhibitors. Carbazole and DBT enhanced the embryotoxicity of BNF, although neither compound was embryotoxic by itself. The co-occurrence of CB and DBT with PAH-type AHR inducers in contaminated ecosystems may increase the toxicity of PAH-type AHR agonists in these settings and may need to be considered when estimating the embryotoxicity of PAH mixtures.

Potential ecotoxic effects of polychlorinated biphenyls on Xenopus laevis

We examined potential ecotoxic effects of polychlorinated biphenyl (PCB)3, PCB5, Aroclor 1254, and Aroclor 1242 on Xenopus laevis. Tadpoles were exposed to PCBs from stage 46/47 (system of Nieuwkoop and Faber) to the completion of metamorphosis. We demonstrated, to our knowledge for the first time, forelimb malformations caused by PCBs (malformation rate, > 70%). The malformed forelimbs were fixed in the adduction-backward rotation position and could not move. Therefore, malformed male frogs were destined to have no offspring, because they could not grasp the females with their forelimbs to mate. Alcian blue-alizarin red double-staining indicated that the forelimb malformation resulted from the shoulder abnormality. Compared with the normal shoulder joint, the proximal humerus with the humerus inter-rotated 90 degrees in the abnormal shoulder joint. Moreover, testes from more than a third of male frogs with exposed to PCBs exhibited feminization to different degrees at gross morphology and histology, with fewer or abnormal spermatogonia and oocytes. Gonadal abnormalities would lead directly to reproductive dysfunction and population decline. These results suggest that PCBs have potentially ecotoxic effects on amphibian populations. We infer that PCBs could play roles in amphibian malformations and population declines, at least at sites that are polluted heavily with PCBs.

Exposure to 2,4-decadienal negatively impacts upon marine invertebrate larval fitness

Diatoms liberate volatile, biologically active unsaturated aldehydes following cell damage, which negatively impact upon invertebrate reproductive processes such as fertilization, embryogenesis and larval survival. 2,4-Decadienal is frequently identified among the aldehydes produced and is one of the more biologically active. The majority of studies which have examined the toxic effects of diatom aldehydes to invertebrate reproduction have scored egg production and/or hatching success as indicators of biological impacts. There are very few studies which have dealt specifically with the impacts of diatom-derived aldehydes on larval fitness. Larval stages of the polychaetes Arenicola marina and Nereis virens and the echinoderms Asterias rubens and Psammechinus miliaris exposed to 2,4-decadienal at sub 1 microg ml(-1) concentrations suffered reduced survival over the incubation period (day 1-8 post fertilization) with detectable differences for the polychates at a concentration of 0.005 and 0.01-0.1 microg ml(-1) for the echinoderms. Susceptibility of larval N. virens was investigated using stage specific 24 h exposures at 2,4-decadienal concentrations up to 1.5 microg ml(-1). A clear stage specific effect was found, with earlier larval stages most vulnerable. Nectochaete larvae (9-10 d) showed no reduction in survival at the concentrations assayed. Fluctuating asymmetry (FA), defined as random deviations from perfect bilateral symmetry, was used to analyse fitness of larval P. miliaris exposed to 2,4-decadienal at concentrations of 0.1, 0.5 and 1 microg ml(-1). The degree and frequency of asymmetrical development increased with increasing 2,4-decadienal concentration. Equally, as FA increased larval survival decreased. These results provide further support for the teratogenic nature of 2,4-decadienal and its negative impact on invertebrate larval fitness.

[Frequency of congenital anomalies in cattle: results from the practice in comparison with literature]

The study gives a short survey of the literature of frequently observed congenital anomalies in cattle and refers to data on cases of congenital anomalies registered in a veterinary practice over a period of 8 years and in an AI (artificial insemination) station of the Rinder-Union West (RUW) during 4 years. The frequency of congenital anomalies was estimated at 0.013% in the area of the RUW. In the veterinary practice a frequency of 0.51% was found. The most prevalent anomalies were seen in legs (39% in the veterinary practice and 21% in RUW) followed by congenital anomalies of the spine (9% in the veterinary practice and 17% in RUW). Arthrogryposes were most frequent among the anomalies of the legs with 65% (veterinary practice) and 39% (RUW), respectively, of all cases of registered leg anomalies in the respective area. Umbilical hernia and atresia of segments of the intestinum were seen in 8-30% of all registered cases. The frequency of congenital anomalies differed not significantly among paternal half sib groups. A questionnaire was proposed for the registration of congenital anomalies in progeny tests of AI bulls. A series of photographs showing the most prevalent congenital anomalies is supporting the registration form.

Effects of aflatoxin B1 on embryo fetal development in rabbits

Aflatoxin B1 (AFB1), is a food borne mycotoxin produced by fungal species of the genera Aspergillus. To elucidate the teratogenic effects, AFB1 was dissolved in corn oil and given orally to New Zealand White rabbits during 6-18 days of gestation with the dose levels of 0.025, 0.05 and 0.1 mg/kg body weight. To assess pathomorphological features of the anomalies induced by AFB1, the fetal serial sections were histologically examined. There was no maternal mortality in any group. There was non-significant decrease in percent of live fetuses and increase in the percent resorptions and post-implantation losses at 0.1 mg/kg dose group as compared with those of controls. The mean crown to rump lengths of 0.05 and 0.1 mg/kg dose groups were significantly reduced than that of the control. The mean fetal weights were significantly reduced in 0.1 mg/kg dose group than that of other treated groups. The gross anomalies observed included wrist drop and enlarged eye socket whereas, skeletal anomalies were agenesis of caudal vertebrae, incomplete ossification of skull bones and bent metacarpals. The visceral anomalies of microphthalmia and cardiac defects were seen at 0.1 mg/kg dose group. The characteristic histological findings of fetal tissues were distortion of normal hepatic cord pattern and reduced megakaryocytes in liver, fusion of auriculo-ventricular valves, mild degenerative changes in myocardial fibers, microphthalmic eyes and lenticular degeneration. The results of this study indicated that AFB1 was found to be teratogenic in rabbits when given by oral route during gestation days 6-18 and the dose of 0.1 mg/kg could be considered as the minimum oral teratogenic dose. The histological examination of the fetal tissues indicated its importance in identifying the visceral anomalies which were otherwise not visible.

Selenium Toxicity in Breeding Ring-Necked Pheasants (Phasianus colchicus)

A flock of breeding ring-necked pheasants received feed with a high selenium content. Within 4 days of eating the toxic feed, the rate of egg production began to decrease, and bird aggression increased. Approximately 12% of the hens died within a week. Necropsy of the hens revealed colorless fluid around the heart and a friable, but otherwise normal, liver. The rapid onset of the problem and signs noted at necropsy suggested toxicosis. Based on analysis, the feed contained 9.3 ppm of selenium. Selenium toxicity was consistent with the histologic diagnosis of degenerative cardiomyopathy, vacuolar degeneration of hepatocytes, and centrilobular hepatic necrosis. After 8 days, the toxic feed was removed and replaced with fresh feed. Egg production, which had dropped to 50%, returned to normal within 10 days of feed replacement. Hatchability of eggs laid from days 8 to 14 after delivery of the toxic feed was 35%. Approximately 10% of the chicks that hatched had deformed beaks and abnormal eyes. Many of the chicks that died in the shell had deformities, bringing the total to more than 50% of all embryos that developed. The selenium content of eggs that had no embryonic development was 2.05 ppm. Hatchability of eggs laid from days 21 to 28 after the toxic feed was delivered was almost 80%, which was slightly lower than normal. The selenium content of these eggs was 0.30 ppm. These results show the rapid onset and correction of selenium toxicity and suggest that specific embryologic defects are diagnostic for selenium toxicity.

Abortions, stillbirths and deformities in sheep at the Al-Ahsa oasis in eastern Saudi Arabia : isolation of a bluetongue serogroup virus from the affected lambs

A wave of abortions, stillbirths and deformities in sheep occurred at the Al-Ahsa oasis in the eastern region of Saudi Arabia in the second half of 1999. The abortions were recorded in August and September and stillbirths and deformities in neonates were observed in October. Adult sheep were clinically normal. A virus was isolated in chicken embryos, adapted to Vero cell culture and further identified as bluetongue (BT) virus. The virus isolated was not neutralised by the Akabane virus. Reference hyperimmune serum against antibodies to BT virus detected in the sera of the dams gave positive results for BT but negative results for both Akabane and bovine viral diarrhoea virus. It was concluded that the outbreak was caused by a virus of the BT serogroup. The authors present the clinico-pathological and epidemiological situation of the disease outbreak.

Synergistic embryotoxicity of polycyclic aromatic hydrocarbon aryl hydrocarbon receptor agonists with cytochrome P4501A inhibitors in Fundulus heteroclitus

Widespread contamination of aquatic systems with polycyclic aromatic hydrocarbons (PAHs) has led to concern about effects of PAHs on aquatic life. Some PAHs have been shown to cause deformities in early life stages of fish that resemble those elicited by planar halogenated aromatic hydrocarbons (pHAHs) that are agonists for the aryl hydrocarbon receptor (AHR). Previous studies have suggested that activity of cytochrome P4501A, a member of the AHR gene battery, is important to the toxicity of pHAHs, and inhibition of CYP1A can reduce the early-life-stage toxicity of pHAHs. In light of the effects of CYP1A inhibition on pHAH-derived toxicity, we explored the impact of both model and environmentally relevant CYP1A inhibitors on PAH-derived embryotoxicity. We exposed Fundulus heteroclitus embryos to two PAH-type AHR agonists, ss-naphthoflavone and benzo(a)pyrene, and one pHAH-type AHR agonist, 3,3 ,4,4 ,5-pentachlorobiphenyl (PCB-126), alone and in combination with several CYP1A inhibitors. In agreement with previous studies, coexposure of embryos to PCB-126 with the AHR antagonist and CYP1A inhibitor alpha-naphthoflavone decreased frequency and severity of deformities compared with embryos exposed to PCB-126 alone. In contrast, embryos coexposed to the PAHs with each of the CYP1A inhibitors tested were deformed with increased severity and frequency compared with embryos dosed with PAH alone. The mechanism by which inhibition of CYP1A increased embryotoxicity of the PAHs tested is not understood, but these results may be helpful in elucidating mechanisms by which PAHs are embryotoxic. Additionally, these results call into question additive models of PAH embryotoxicity for environmental PAH mixtures that contain both AHR agonists and CYP1A inhibitors.

Uptake and effects on detoxication enzymes of cypermethrin in embryos and tadpoles of amphibians

A number of factors have been suggested for recently observed amphibian decreases, and one potential factor is pesticide exposure. We studied the uptake and effects of environmentally relevant concentrations of the pyrethroid insecticide cypermethrin on two different amphibian species, Bombina variegata and Rana arvalis. The uptake from water of 14C-labeled cypermethrin (0.4 microg/L) by eggs and tadpoles of B. variegata was investigated. After 24 hours of exposure, 153.9 ng cypermethrin/g fresh weight were found in embryos, thus indicating that the jelly mass of the eggs does not act as a sufficient physical barrier to protect embryos from exposure to this compound. Uptake of cypermethrin into tadpoles of both species and in all exposed individuals caused dose-dependent deformities; behavioral abnormalities such as twisting, writhing, and coordinated swimming; and mortality. In tadpoles of B. variegata and R. arvalis, the activity of microsomal and cytosolic glutathione S-transferase (mGST and sGST, respectively) were measured after treatment with cypermethrin. Activities of both GST systems increased significantly with increasing duration and concentration of cypermethrin exposure, with the reaction seeming stronger in B. variegata than in R. arvalis tadpoles. Alpha-cypermethrin--a racemic mixture of two cis isomers of cypermethrin--induced a stronger enzymatic response in the cytosolic fraction of R. arvalis tadpoles than cypermethrin at the same concentration. The observed physical and behavioral abnormities caused by environmentally relevant concentrations of cypermethrin indicate that despite detoxication of the chemical via GST-system contamination of ponds by cypermethrin could result in adverse effects on the development of amphibian embryos and tadpoles.

Frequent and unexplained gonadal abnormalities in whitefish (central alpine Coregonus sp.) from an alpine oligotrophic lake in Switzerland

The occurrence of a large number of whitefish with morphologically altered gonads in Lake Thun (Switzerland) has been reported by commercial fishermen since the year 2000. Macroscopic and microscopic examination of gonads revealed that 35% (281 out of 808) of whitefish from Lake Thun were affected. Frequency of gonadal abnormalities varied significantly with sex, age and ecotype of whitefish. Apparent females (26% [106/408]) showed significantly less gonadal alterations than apparent males (40% [151/225]). Fish with deformed gonads were observed in all age classes from 1 to 6 yr, but were most frequent in the year classes 3+ to 5+. The gonadal alterations showed different frequencies among the 3 ecotypes of whitefish living in the lake: 1 ecotype was less affected (26%) than the other 2 forms (41% and 32%, respectively). The gonadal alterations included adhesions/fusions to the peritoneal wall and the lateral trunk musculature (overall: 5%; in females: 5%; in males: 5%), asymmetry (4%; 6%; 4%), atrophy (4%; 6%; 1%), compartmentations (11%; 4%; 18%), constrictions (3%; 1%; 7%) and hermaphroditism (1.1% of sampled fish, and 10 additional specimens collected by fishermen during the filleting process). In some cases, more than one alteration was observed in the same fish. Hermaphroditism manifested as 3 different types: (1) the lobular type, in which a consecutive sequence of testicular and ovarian lobes are found on the same gonad strand; (2) discrete gonads within one fish, with one gonad strand being ovarian tissue and the other being testicular tissue; and (3) the mosaic type, in which oocytes lie in tissue with normal testicular morphology, or spermatids or sperm are present in ovarian tissue. Several features of the gonadal alterations described in this study of whitefish from Lake Thun have also been reported for whitefish from other areas. However, the Lake Thun situation appears to be unique because of the high prevalence of fish affected and the broad variation of abnormal features. The causes of the frequent appearance of these gonadal alterations in whitefish from Lake Thun remain unclear.

Evaluation of rumen transfaunation after surgical correction of left-sided displacement of the abomasum in cows

OBJECTIVE

To evaluate rumen transfaunation after surgical correction of left-sided displacement of the abomasum (LDA) in cows.

DESIGN

Prospective clinical trial.

ANIMALS

20 multiparous cows with LDA.

PROCEDURES

Cows with LDA were treated surgically (day 0). On days 0 (immediately after surgery) and 1, 10 cows each received 10 L of rumen fluid (transfaunated group) or 10 L of water (control group) via a stomach tube. Postoperative dietary dry-matter intake and milk yield of each cow were recorded daily for 5 days, beginning immediately after surgery. Blood and rumen fluid samples were collected prior to surgery and on days 1, 3, and 5 after surgery. Serum nonesterified fatty acid and beta-hydroxybutyrate concentrations were measured. Volatile fatty acid and ammonia concentrations and pH of rumen fluid were determined. Urine specimens were collected and tested for ketones at 8 AM and 4 PM. Cows with ketonuria were treated with 50% dextrose solution administered i.v. at the time ketonuria was first detected. Cows with ketonuria were treated twice daily until ketonuria resolved.

RESULTS

All cows survived and completed their lactation. Daily and cumulative dry-matter intake and milk yield of cows in the transfaunated group were significantly greater than those of cows in the control group. Cows in the transfaunated group had significantly lower serum concentrations of beta-hydroxybutyrate and significantly lower acetate-to-propionate ratios in rumen fluid on day 1 after surgery, compared with cows in the control group. Cows that received transfaunate required a significantly lower total volume of dextrose administered i.v. than control cows.

CONCLUSIONS AND CLINICAL RELEVANCE

Benefits of rumen transfaunation of cows after surgical correction of LDA included a lesser degree of ketonuria, greater feed intake, and higher milk yield, compared with nontransfaunated cows.

ULTRASONOGRAPHIC DIAGNOSIS OF PORTOSYSTEMIC SHUNTING IN DOGS AND CATS

The value of ultrasonography was evaluated in 85 dogs and 17 cats presented with a clinically suspected portosystemic shunt (PSS). A PSS was confirmed in 50 dogs and nine cats (single congenital extrahepatic in 42, single congenital intrahepatic in 11, and multiple acquired in six). Six dogs and one cat had hepatic microvascular dysplasia, and 29 dogs and seven cats had a normal portal system. Ultrasonography was 92% sensitive, 98% specific, and had positive and negative predictive values of 98% and 89%, respectively, in identifying PSS, with an overall accuracy of 95%. When a PSS was identified with ultrasonography, extrahepatic, intrahepatic, and multiple acquired PSS could be correctly differentiated in 53/54 patients (98%). The combination of a small liver, large kidneys, and uroliths had positive and negative predictive values of 100% and 51% for the presence of a congenital PSS in dogs. The portal vein/aorta (PV/Ao) and portal vein/caudal vena cava (PV/ CVC) ratios were smaller in animals with extrahepatic PSSs compared with animals with microvascular dysplasia, intrahepatic PSSs and those without portal venous anomalies (P<0.001). All dogs and cats with a PV/Ao ratio of < or = 0.65 had an extrahepatic PSS or idiopathic noncirrhotic portal hypertension. Dogs and cats with PV/Ao and PV/CVC ratios of > or = 0.8 and > or = 0.75, respectively, did not have an extrahepatic PSS. Reduced or reversed portal flow was seen in four of four patients with multiple acquired PSSs secondary to portal hypertension. The presence of turbulence in the caudal vena cava of dogs had positive and negative predictive values of 91% and 84%, respectively, for the presence of any PSS terminating into that vein.

Teratogenic versus mutagenic abnormalities in chironomid larvae exposed to zinc and lead

Before chironomid mouthpart deformities can be utilized as indicators of aquatic metal pollution with certainty, it must first be established that deformities are teratogenic and not mutagenic. A laboratory experiment was conducted to assess this question using Zn and Pb as causative agents. Parent populations were reared in sediments spiked with zinc (Zn) or lead (Pb) and their resulting offspring (F1 generation) were reared in clean sediments. The proportions of mouthpart deformities in C. tentans larvae were compared via logistic regression, accounting for time of exposure, between parent and offspring populations. Results indicate that 14% of chironomids from Zn-spiked sediment contained deformed menta and/or mandibles. However, the F1-Zn generation displayed a deformity of 1.7%. Larvae reared in Pb-spiked sediments displayed a deformity frequency of 9% and the F1 generations (F1-Pb a and F1-Pb b) had deformity proportion of 7 and 6%, respectively. We concluded that the deformities caused by Zn stress were morphological because the resulting F1 deformity frequencies declined to control levels. However, deformities caused by Pb appear to be genetic since F1 deformity percentages did not differ from the parent deformity frequency. Because larvae reared in Zn- and Pb-spiked sediments were larger than larvae reared in uncontaminated sediments, we could not conclude that Zn and Pb in the sediments stunted the development of C. tentans.

Abnormal features of Macoma balthica (Bivalvia) in the Baltic Sea: alerting symptoms of environmental adversity?

Recent studies of the Baltic clam Macoma balthica (L.) from the southern Baltic (the Gulf of Gdansk) have revealed striking morphological, histological and cytogenetic features. Strong deformation of the shell, including elongation of the posterior end and the appearance of an easily visible flexure in this part, has been recorded. The population contribution of the deformed blunt shelled ("irregular") clams ranged from 0% to 65% and tended to increase with depth. The morphologically "irregular" clams had higher accumulated tissue concentrations of trace metals (As, Ag, Cd, Pb, Cu and Zn), indicating a different metal handling ability. Adverse conditions in deeper water regions of the Gulf (e.g. hypoxia, hydrogen sulphide, elevated bioavailability of contaminants) have been suggested as inducers of the phenotypical changes (morphological deformation) in part of the population and, in parallel, of the specific physiological adaptations that result in higher metal accumulation in the "irregular" clams. Cytogenetic and histological analyses showed the presence of tumours in gill cells and digestive system of the affected clams, the prevalence of disseminated neoplasia ranging from 0% to 94% depending on the site. The disease was manifested by a modified karyotype (i.e. an abnormal number and morphology of chromosomes), a higher activity of nucleolar organizer regions (AgNORs), and tissue lesions (enlarged cells, actively proliferative with pleomorphic nuclei). Bottom sediments showed acute toxicity and have been proposed as a source of an initialising carcinogenic factor. However, none of the ecotoxicological studies provided was successful in the clear demonstration of a single (or multifactorial) agent that can account for the disseminated neoplasia.

Effects of chlorinated solvents on four species of North American amphibians

Tetrachloroethylene (PCE), a dry cleaning and degreasing solvent, can enter groundwater through accidental leaks or spills, and concentrations as high as 75 mg/L have been reported in Canadian aquifers. Amphibians in wetlands receiving contaminated groundwater may be exposed to PCE and its degradation products, but little information is available on the impacts of these compounds on indigenous amphibian species. Acute (96-h static renewal) exposures to PCE and its major degradation products, trichloroethylene (TCE) and cisand trans-dichloroethylene, were conducted on embryos of four North American amphibian species: wood frogs (Rana sylvatica), green frogs (R. clamitans), American toads (Bufo americanus), and spotted salamanders (Ambystoma maculatum). Subsequently, chronic exposures to PCE and TCE were conducted with the larvae of American toads. Both PCE and TCE were teratogenic to amphibian embryos; median effective concentrations (EC50s) for developmental deformities produced by PCE and TCE exposure for wood frogs and green frogs were 12 and 40 mg/L, respectively. Embryonic survivorship, however, was not compromised at these concentrations. American toads were less sensitive; the EC50 for developmental abnormalities was not attained at the highest test concentrations, 45 and 85 mg/L PCE and TCE, respectively. These results are pertinent in assessing the impact of groundwater pollution on an aquifer-fed wetland.

Two cases of brachymelia in cats

In this report, two cases of brachymelia in related neonatal cats are described. The malformations are described in view of normal limb development, which is illustrated by scanning electron microscopic images. Hypoplasia and aplasia of the distal limb segments were the main disorders in both kittens. Additional malformations in the second case included fusion of the radius and ulna, congenital patella luxation and a shortened tail. Brachymelia and similar cases of feline dysmelia are poorly documented in the existing literature. Possible causes and terminology of these developmental deformations are discussed.

Organismal effects of pesticide exposure on meadow voles (Microtus pennsylvanicus) living in golf course ecosystems: developmental instability, clinical hematology, body condition, and blood parasitology

This is the second of two articles reporting the results of a nonlethal biomonitoring study that quantified the effects of pesticide exposure on meadow voles (Microtus pennsylvanicus) living in golf course ecosystems of the Ottawa/Gatineau region (ON and PQ, Canada, respectively). In the present article, we describe results of measurements regarding developmental instability (e.g., fluctuating asymmetry), congenital birth defects (e.g., skeletal terata), clinical hematology (e.g., differential counts), general body condition (e.g., body mass-length relationships), and blood parasite load (Trypanosoma sp. and Bartonella spp.). Voles were captured during the year 2001 to 2003 at six golf courses and two reference sites. Once voles were fully sedated using isoflurane, blood was collected, radiographs taken, and morphometric measurements recorded. Three animals from each course were euthanized to determine body burdens of historically used organochlorine (OC) and metal-based pesticides. Exposure to in-use pesticides was determined from detailed golf course pesticide-use records. None of the endpoints measured was significantly related to body burdens of OC pesticides and metals historically used, nor did any endpoint significantly vary among capture sites in relation to total pesticide application to the capture site or to the number of days since the last application of pesticide. Based on these findings, it appears that voles from golf courses were no less healthy than their conspecifics from reference sites.

Reciprocal chromosome translocation, rcp(7;17)(q26;q11), in a boar giving reduced litter size and increased rate of piglets dying in the early life

Cytogenetic investigations in a boar causing a 41% reduction in litter size and also producing piglets that died soon after birth revealed the presence of a reciprocal chromosome translocation, rcp(7;17)(q26;q11). The translocation resulted in one extremely small telocentric chromosome marker. Synaptonemal complex analysis of spread spermatocytes by electron microscopy revealed an unusual behaviour of the translocation. This formed not only different types of quadrivalents (78.1% of the cells), similar to those previously found in boars heterozygous for reciprocal exchanges, but also completely or incompletely paired trivalent configurations, plus univalent (21.9%). Association between the sex bivalent and the translocation configuration was observed (18.7%), but testicular histology was normal. Furthermore, the boar with the translocation was found to produce tertiary monosomy and trisomy in some of the liveborn piglets. Some of the tertiary monosomic offspring, which died in the early extra-uterine life, demonstrated ventricular septal defect and cleft palate.

Thyroid hyperplasia and musculoskeletal deformity in a standardbred filly in Ontario

Thyroid hyperplasia and musculoskeletal deformity, described in foals in western Canada, has not been recognized as a common cause of neonatal foal mortality in Ontario. A case is reported from Ontario, with clinical and histopathological findings consistent with the syndrome described in western Canada.