A study of naturally occurring cases of ovine foot abscess in New Zealand

A study was made of various aspects of 53 naturally occurring cases of foot abscess in sheep in New Zealand. Radiographic techniques were used to follow the progress of the lesion and from this it was concluded that foot abscess could be defined as an infection of the distal interphalangeal joint. The term foot abscess was considered preferable to the term "infective bulbar necrosis". The attack rate of foot abscess was reported to be higher for rams than for ewes and the condition was less prevalent during summer. Once infection was established in the distal interphalangeal joint a relatively uniform and thus predictable series of events took place that inevitably resulted in some permanent damage and deformity to the digit. If rupture of the axial collateral ligaments occurred, the joint became unstable and the degree of permanent deformity was greater. Treatment with antibiotics did not appear to markedly affect the progress of the lesion or the outcome, once infection had become established in the joint. Although the prognosis for complete recovery was poor, in most cases the foot healed sufficiently after a period of about two months to allow the animal to walk normally.     

A study of naturally occurring cases of ovine foot abscess in New Zealand

A study was made of various aspects of 53 naturally occurring cases of foot abscess in sheep in New Zealand. Radiographic techniques were used to follow the progress of the lesion and from this it was concluded that foot abscess could be defined as an infection of the distal interphalangeal joint. The term “foot abscess” was considered preferable to the term “infective bulbar necrosis”.

The attack rate of foot abscess was reported to be higher for rams than for ewes and the condition was less prevalent during summer.

Once infection was established in the distal interphalangeal joint a relatively uniform and thus predictable series of events took place that inevitably resulted in some permanent damage and deformity to the digit. If rupture of the axial collateral ligaments occurred, the joint became unstable and the de- gree of permanent deformity was greater. Treatment with antibiotics did not appear to markedly affect the progress of the lesion or the outcome, once infection had become established in the joint.

Although the prognosis for complete recovery was poor, in most cases the foot healed sufficiently after a period of about two months to allow the animal to walk normally.     

Analysis of cerebrospinal fluid from field cases of some common ovine neurological diseases.

Analysis of cerebrospinal fluid (CSF) samples from normal sheep and from cases of some common neurological diseases revealed a significant increase (P less than 0.05) in the group mean CSF protein concentration for meningitis, listeriosis and spinal abscess but not for scrapie, spinal injury, ovine pregnancy toxaemia or polioencephalomalacia. The CSF white blood cell count (WBC) was significantly increased (P less than 0.05) in the meningitis group and in those cases of listeriosis which failed to respond to antibiotic therapy. All cases of bacterial infection of the central nervous system (CNS) could be identified by the combined interpretation of the protein concentration and the differential WBC count. It is concluded that CSF analysis is useful clinically in differentiating traumatic from infective spinal lesions and toxic or metabolic lesions from bacterial meningitis in sheep.     

A preliminary study of serum haptoglobin concentration as a prognostic indicator of ovine dystocia cases.

Serum samples were collected prior to the correction of dystocia in 45 sheep and from nine sheep following a normal parturition. Serum samples collected from a group of 16 non-pregnant ewes acted as non-pregnant controls. The mean serum haptoglobin concentration was significantly elevated (P less than 0.01) in those dystocia cases where dead lambs were present in utero compared to those ewes which had live lambs delivered. While the number of cases presented in this study is small, there is an indication that sheep with a serum haptoglobin concentration above 1.0 g/l represent a poor surgical risk. The three ewes which died following a caesarean operation had markedly elevated serum haptoglobin concentrations prior to surgery indicating an inflammatory reaction. Five ewes with a haptoglobin concentration of 0.4 g/l made an uneventful recovery following a caesarean operation.     

Serological study of ovine toxoplasmosis in Colombia: epidemiological study of a field outbreak.

A serological study, using the indirect haemagglutination test, of an outbreak of toxoplasmosis in a flock of blackface sheep is described. The serological aspects of the disease are discussed with reference to this incident, and possible sources of infection are suggested.     

A study of 55 field cases of uterine torsion in dairy cattle

Two-hundred and seventy-three animals were enrolled in a case-case comparison of uterine torsions and other dystocias. The purpose of the study was to describe field cases of uterine torsion and their clinical management, compare them with other types of dystocia attended by field veterinarians, and evaluate the effect of season and housing on the incidence of torsions. Fifty-five cases of uterine torsions representing 20% of the dystocias were diagnosed. Most cases of uterine torsion were successfully corrected and followed by the vaginal delivery of a live calf. When compared with other types of dystocia, cows were at greater risk for uterine torsion than were heifers (OR = 5.2; P < 0.0001), while animals suffering from fetopelvic disproportion or carrying twins were at a lesser risk (OR = 0.05; P < 0.0001 and OR = 0.09; P = 0.007, respectively). Heifers had a lower risk when calving alone in a pen versus a tie-stall (OR = 0.2, P = 0.04). There was no significant effect of season on the risk of uterine torsion.     

A field study of the association between periodontal disease and body condition in sheep

Three farms with a high prevalence of periodontal disease (PD) were selected using data from a December 1983/January 1984 survey. On each of these farms in August 1984, the incisor condition and body condition score of about 50 ewes were noted. Two of the farms and an additional farm with a high prevalence of PD were visited again in August 1985, and on each, incisor condition and body weights of about 150 ewes were recorded. On one farm only was there a significant association between PD and body condition or weight, and it occurred in both years.     

A field study of the association between periodontal disease and body condition in sheep

Three farms with a high prevalence of periodontal disease (PD) were selected using data from a December 1983/January 1984 survey. On each of these farms in August 1984, the incisor condition and body condition score of about 50 ewes were noted. Two of the farms and an additional farm with a high prevalence of PD were visited again in August 1985, and on each, incisor condition and body weights of about 150 ewes were recorded.

On one farm only was there a significant association between PD and body condition or weight, and it occurred in both years.     

A field evaluation of the efficacy of two vaccines against ovine pneumonic pasteurellosis

Two vaccines against pneumonic pasteurellosis were evaluated for efficacy in lambs transported by sea from New Zealand to Saudi Arabia. One vaccine contained whole cell antigens of Pasteurella haemolytica A2 grown under iron restricted conditions. The other contained Pasteurella haemolytica A1 cell surface and leucotoxin antigens. There was no clear evidence of either vaccine leading to a lower pneumonia death or lesion rate than for the control group.     

Lateral fabellar fractures in the dog: A review of eight cases

Fractures of the lateral fabella were recorded in seven medium or large breed dogs. Six dogs had unilateral fractures and one had bilateral fractures. The fractures appeared to occur spontaneously, without external trauma. Four fractures were managed conservatively and four were treated by surgical removal of the fracture fragments. Both treatments were successful in resolving the lameness.     

Hypofractionated radiation therapy in the treatment of canine thymoma: Retrospective study of eight cases

Thymomas are one of the most common tumors of the cranial mediastinum in dogs; however there is limited information available on the use of radiation therapy for treating this neoplasm. Objectives of the current retrospective observational study were to describe outcomes and side effects of a hypofractionated radiation therapy protocol in a group of dogs with confirmed thymoma. A total of eight dogs were included. To generate individualized treatment plans, we designed the planning target volume according to the limits on mean lung dose and the percentage of the total lung volume exceeding 20 Gy (V20). The total administered dose was 48–49 Gy, with one fraction per week for a total of six to seven fractions. After therapy, two dogs achieved complete responses, two achieved partial responses, and the disease remained stable in two. Two dogs died during the radiation therapy protocol and were not classified. The median mean lung dose and V20 were 6.0 Gy (range: 3.1–15.0 Gy) and 12.4% (range: 2.3–27.5%), respectively. The overall response rate was 50.0%, and the median time to response following treatment initiation was 22 days (range: 14–115 days). Acute and late side effects were common in the skin and/or lung and were self‐limiting or asymptomatic. The median survival time was not reached (range: 8–1128 days) and the 1 year survival rate was 75.0%. Hypofractionated radiation therapy was well tolerated in this sample of dogs with thymoma and may be considered when owners decline surgical treatment or the tumor is deemed unresectable.     

Ovine caesarean operations: a study of 137 field cases

Under field conditions a 97.8% success rate was achieved for caesarean operations performed on ewes with live or freshly dead lambs present in utero. Where lambs were in moderate to advanced stages of autolysis and emphysema the survival rate of the dam was 57.1%. Neither the presence of a vaginal prolapse nor abortion appeared to have an influence on the survival rate of the ewe. Interference and trauma to the posterior reproductive tract prior to veterinary examination reduced the success rate of cases. Ewes with a history during gestation of a prolapsed vagina were 10 times more likely to require a caesarean operation to correct the dystocia than normal ewes. A range of haematological variables failed to give an accurate prognostic guide to the outcome of surgery. A caesarean operation is recommended in preference to euthanasia of a ewe that could have been considered a poor-risk surgical case. Fetotomy was not possible in cases where emphysematous lambs were present in utero.     

A comparative study of bovine and ovine Haemophilus somnus isolates.

Bacterial isolates (including 17 Haemophilus somnus isolates and an H. somnus-like isolate) from asymptomatic or diseased cattle and sheep, were evaluated for markers associated with virulence and host predilection. The isolates were separated into 6 distinct biovariants, 3 for sheep and 3 for cattle, based on reactions in a battery of 21 test media. Three bovine isolates associated with disease caused hemolysis of bovine blood. The rest of the isolates did not hemolyze either bovine or ovine erythrocytes. Protein profiles of all H. somnus isolates were similar with the exception of the major outer membrane proteins (MOMPs). The MOMPs of isolates associated with disease in cattle had a relative molecular weight of approximately 41 kDa compared with 33 kDa for the MOMPs of isolates from asymptomatic cattle. The MOMPs from sheep isolates were either slightly higher or lower than the 41 kDa MOMPs of bovine isolates. Major antigens detected by Western blotting were similar in all isolates except the H. somnus-like isolate. An immunodominant 40 kDa antigen was conserved in all H. somnus isolates. Antibodies to this antigen have previously been found to be protective in cattle and may also be protective for sheep. Marked differences between cattle and sheep isolates were revealed by use of restriction enzyme analysis, which separated the isolates into 12 ribotypes and 15 unique DNA profiles. Thus, cattle and sheep isolates in this collection had distinctive differences in biochemical reactions, MOMP profiles, and DNA analyses. Such differences have potential value for epidemiological studies and may also be used to evaluate host specificity of H. somnus isolates.     

Angiostroneylosis in Cornwall: Clinical presentations of eight cases

Clinical signs in eight dogs with Angiostrongylus vasorum infection included chronic cough, dyspnoea, lumbar pain, hindleg paresis/paralysis, abdominal pain, weakness and collapse; two of the dogs were asymptomatic. Thrombocytopenia was present in two dogs and a mild anaemia in one. Thoracic radiographs showed mild right heart enlargement in two out of three dogs and a pneumothorax in one. At post mortem examination in three dogs, the lungs were swollen with a mottled appearance and there was dilatation of the right ventricle. Adult A vasorum were found in the right heart, the pulmonary artery and its branches. Adult worms were also found in the systemic vasculature in one dog, associated with thromboembolism. Treatment with ivermectin in two dogs and fenbendazole in three dogs resulted in the resolution of clinical signs and no demonstrable larvae in the faeces one to two weeks later.     

A retrospective study of dystocia-related vertebral fractures in neonatal calves

Forty-seven cases of neonatal vertebral fractures/luxations occurred in a 21 year period (1967-1987). All of the fractures were located between the 11th thoracic vertebra and the fourth lumbar vertebra; 77% occurred at the thoracolumbar junction. All but one case was associated with a forced extraction, either unspecified (53%), mechanical (28%), or manual (17%).

A weak calf or continuous recumbency since birth was the major clinical sign. Hemorrhage around the kidneys, adrenal glands, and in perivertebral muscles was a consistent necropsy finding and a useful indicator that a thoracolumbar fracture was present. In addition to the vertebral fracture, the prominent necropsy findings were subdural and epidural hemorrhage, myelomalacia, spinal cord compression or severed spinal cord, and fractured ribs. All of the calves died or were euthanized without regaining locomotory function.