Intervertebral disk disease with spinal cord penetration in a Yucatan pig

A 9-month-old female Yucatan pig was euthanized after acute onset of paraplegia. Gross and microscopic examination revealed dorsal dissection of the nucleus of the L2-L3 intervertebral disk through the annulus fibrosus, extrusion of nucleus pulposus material through the overlying dura mater and into the spinal cord, and associated acute spinal hemorrhage and necrosis. This is, to the authors' knowledge, the first reported case of intervertebral disk disease in swine.

Meningoencephalitis Associated with an Unidentified Apicomplexan Protozoan in a Pacific Harbor Seal

A Pacific harbor seal (Phoca vitulina richardsii) was found on the central California coast with neurologic signs and labored breathing, which were unresponsive to treatment. Necropsy revealed a nonsuppurative necrotizing meningoencephalitis, a multilocular thymic cyst, and nonsuppurative cystitis and renal pyelitis. Microscopic examination revealed protozoans in the brain, thymic cyst, and bladder mucosa. Ultrastructurally, the protozoal tachyzoites were different from those of Neospora caninum, Toxoplasma gondii, and Sarcocystis neurona; the rhoptries were small and had electron-dense contents, and the organism divided by endodyogeny. Specific antibodies were not detected in serum using agglutination (N. caninum, T. gondii) and immunoblot assays (S. neurona). Immunohistochemistry for these organisms was negative. Polymerase chain reaction on brain tissue using specific primers did not amplify T. gondii deoxyribonucleic acid. The meningoencephalitis in this seal thus appears to have been caused by a novel protozoan.

Septic peritonitis due to colonic perforation associated with aberrant migration of a Gasterophilus intestinalis larva in a horse

An adult quarter horse mare was presented with acute colic and fever. Physical examination and abdominocentesis showed septic peritonitis, and the mare was euthanatized. Necropsy and histopathologic examination revealed a focal partial perforation of the right ventral colon, which contained a single bot fly larva, identified as a third-instar larva of Gasterophilus intestinalis. This larva was embedded deep within the muscularis and the submucosa. Although bot fly larvae are known to attach to aberrant sites within the digestive tract, this is the first known report of deep penetration of the colon by a gasterophilus larva, with the resulting leakage of intestinal content leading to septic peritonitis.

Dermatophilus-like infection in beluga whales, Delphinapterus leucas, from the St. Lawrence estuary

Six beluga whales (Delphinapterus leucas) found dead on the shores of the St. Lawrence estuary had multiple slightly depressed greyish round areas randomly distributed over the whole body. Histologically, the surface of these areas was covered with a thick layer of Dermatophilus-like organisms which invaded the stratum corneum. The underlying stratum spinosum had marked spongiosis and vacuolar degeneration. Minimal neutrophilic infiltration was present within the underlying dermal papillae. To the authors' knowledge, dermatophilosis in cetaceans has not been reported previously.

Etiology, forms, and prognosis of gastrointestinal dysfunction resembling vagal indigestion occurring after surgical correction of right abomasal displacement

The objectives of this study were to determine the etiology and types of vagal indigestion (VI) occurring after right displacement of the abomasum or abomasal volvulus (RDA/AV), and the prognosis for each type. Data of cows presented for RDA/AV from a retrospective (n = 288) and a prospective (n = 132) study were used. Vagal indigestion occurred in 39 and 22 cows in each study, respectively. A necropsy was performed in 29 cases. Gastric compartment dilation compatible with VI type III or IV occurred in 23 cases. An abnormal gastric wall was detected in 22 cases. Peritonitis was present in 18 cows. Vagal nerve lesions were present in 5 out of 13 cases studied. Clinical, hematological, and necropsy results suggested a classification of VI with respect to presence or absence of peritonitis. Gastric wall damage, peritonitis and vagal nerve lesions appear important in the etiology. Considering peritonitis occurrence, antimicrobial therapy appears necessary in the treatment of RDA/AV.

Tibial hemimelia, meningocele, and abdominal hernia in Shorthorn cattle

Six genetically related Shorthorn calves were affected with the tibial hemimelia syndrome. The lesions included bilaterally malformed or absent tibia and abdominal hernia in all animals, a long shaggy haircoat, retained testicles in males, and meningocele in three animals. The malformations were similar to those described previously in Galloway calves. Pedigree analysis demonstrated a mechanism by which a recessive allele in a homozygous state could be responsible for the disorder. The condition in these calves was considered the result of a recurrence of a genetic mutation affecting a putative hemimelia locus.

Suprasellar germinoma in three lake whitefish (Coregonus clupeaformis)

Suprasellar germinomas were identified in three wild-caught lake whitefish (Coregonus clupeaformis) from the St. Lawrence River, Quebec, Canada. Histologically, the three tumors expanded the subarachnoid space of the ventral surface of the brain immediately adjacent to the pituitary gland and, in one case, infiltrated the adjacent neuropil. These tumors were characterized by nests and sheets of round cells with a high mitotic rate, separated by a scant amount of loose fibrovascular stroma. The stroma was infiltrated by a moderate number of small mononuclear cells, including rare CD3-immunoreactive lymphocytes. This is the first report of intracranial germinoma in a fish species.

Enterococcus hirae enteropathy with ascending cholangitis and pancreatitis in a kitten

A 2-month-old female Persian cat that had been showing episodes of anorexia and diarrhea for the previous 4 weeks was presented in shock and died 2 days later. Numerous Gram-positive cocci were located along the brush border of small intestinal villi, without significant inflammatory infiltration. Similar bacteria were present within hepatic bile ducts and pancreatic ducts and were associated with suppurative inflammation and exfoliation of epithelial cells. Culture of the liver and lung yielded bacteria identified as Enterococcus hirae. Fecal culture from an asymptomatic adult female from the same cattery also yielded large numbers of E. hirae. To our knowledge, this is the first report of E. hirae enteropathy in a cat and the first report of ascending cholangitis and ductal pancreatitis caused by an Enterococcus spp.

Serologic detection of adenoviral hemorrhagic disease in black-tailed deer in California

An enzyme-linked immunosorbent assay (ELISA) and a serum neutralization (SN) test were developed to measure serum antibodies against the adenovirus causing hemorrhagic disease in free-ranging and captive experimentally-infected black-tailed deer (Odocoilenus hemionus columbianus) in California (USA). There was a strong (rho = 0.874) and significant (P < 0.0001) correlation between ELISA and SN titers, although the SN assay was more sensitive than the ELISA.

The adenovirus that causes hemorrhagic disease of black-tailed deer is closely related to bovine adenovirus-3

DNA sequence data was obtained from an adenovirus previously shown to be the cause of a distinctive, fatal hemorrhagic disease of black-tailed deer in California. A 256 base fragment of the viral hexon gene was amplified by PCR from purified adenovirus preparations. The amplicon then was cloned and sequenced. Phylogenetic relationships with other mammalian adenoviruses were also determined. Although sequence analysis of this portion of the hexon gene indicates that the black-tailed deer adenovirus is closely related to bovine adenovirus-3, the biologic properties of the two viruses are clearly distinct.

Antigenic and nucleotide characterization of a herpesvirus isolated from Pacific harbor seals (Phoca vitulina richardsii)

This report describes the antigenic and nucleotide characterization of a herpes-like virus that has been isolated from the adrenal tissues of neonatal Pacific harbor seals. Infection with this virus has been previously implicated as a major cause of death of animals undergoing rehabilitation. Comparison and phylogenetic analysis of sequenced fragments of the DNA polymerase, glycoprotein B and glycoprotein D genes, and immunofluorescence assay using herpesvirus-specific monoclonal antibodies, demonstrated close similarity of the Pacific harbor seal herpesvirus to European isolates of phocid herpesvirus-1 (PHV-1) and other alpha-herpesviruses affecting terrestrial carnivores.

Meningoencephalitis due to a Sarcocystis neurona-like protozoan in Pacific harbor seals (Phoca vitulina richardsi)

Seven Pacific harbor seals with meningoencephalitis associated with Sarcocystis neurona-like protozoa are described. Six of the 7 seals were free-ranging and were found stranded over an 80-km stretch of central California coastline; the other was captive. All had marked to severe nonsuppurative meningoencephalitis, most severe in the cerebellar cortex. Immunohistochemistry for S. neurona antigens was positive on brain tissue in all cases, revealing numerous merozoites as well as developing and mature schizonts, including rosette forms. Electron microscopy performed on 3 animals revealed merozoites and schizonts consistent with Sarcocystis sp., with the absence of rhoptries in merozoites, lack of a parasitophorous vacuole around schizonts, and division by endopolygeny. Serology using western blotting revealed the presence of anti-S. neurona immunoglobulins in the sera of 4 of 5 seals tested. Four animals also had a concurrent mild to moderate nonsuppurative myocarditis; in 1 seal, rare sarcocysts of undetermined species were present within cardiomyocytes.

Diagnostic features of clinical neurologic feline infectious peritonitis

Feline infectious peritonitis (FIP) is a fatal Arthus-type immune response of cats to infection with FIP virus, a mutant of the ubiquitous feline enteric coronavirus (FECV). The disease may occur systemically or in any single organ system, and primary neurologic disease is a common subset of such manifestations. We examined 16 domestic cats with clinical neurologic FIP and 8 control cats with nonneurologic FIP, with the intention of identifying the ante- and postmortem diagnostic tests that most contribute to accurate diagnosis. Of the 16 cats with neurologic FIP, 15 were less than 2 years of age and all 16 originated from large multiple-cat households. The most useful antemortem indicators of disease were positive anti-coronavirus IgG titer in cerebrospinal fluid, high serum total protein concentration, and findings on magnetic resonance imaging suggesting periventricular contrast enhancement, ventricular dilatation, and hydrocephalus. Postmortem diagnosis was facilitated by FIP monoclonal antibody staining of affected tissue and coronavirus-specific polymerase chain reaction. Most cats with neurologic and ocular forms of FIP had patchy, focal lesions, suggesting that recently developed technologies described in this report may be useful for evaluation of cats with suspected FIP.

Identification of a novel enteric Helicobacter species in a kitten with severe diarrhea

A previously undescribed Helicobacter sp. was recovered from a cat with severe diarrhea. Based upon the absence of any other identifiable cause of diarrhea, this helicobacter may be involved in the development of the disease signs. The organism could not be cultured but was described on the basis of 16S rRNA gene sequence analysis and morphology and appeared to be a new species, with Helicobacter canis being the most genetically similar species. The presence of a diarrhea-inducing helicobacter in a companion animal may pose a risk of zoonosis.

Herpesvirus infection in stranded Pacific harbor seals of coastal California

Histopathological examination revealed multifocal acute to chronic adrenal necrosis in 74 of 162 (45%) Pacific harbor seal pups (Phoca vitulina richardsi) dying during rehabilitation following live stranding along the coast of central and northern California (USA). Necrotic adrenal cells contained amphophilic, smudgy intranuclear inclusion bodies that were stained positive for DNA. Fifty of these seals also had lesions typical of sepsis, bacterial omphalophlebitis, pneumonia or gastroenteritis. Twenty four seals had no lesions other than thymic atrophy and occasional multifocal hepatic necrosis. Prior to death, affected seals had a marked lymphopenia. Electron microscopy revealed unenveloped intranuclear hexagonal to round viral particles approximately 100 nm in diameter, and cytoplasmic enveloped virions approximately 160 nm in diameter. These were morphologically consistent with herpesvirus. Inoculation of phocine adrenal and kidney cell lines with an adrenal tissue homogenate from affected animals produced a cytopathic effect in 5 days. Electron microscopy of cell cultures showing this cytopathic effect revealed similar viral particles to those observed in affected adrenal glands. Cases with characteristic inclusion bodies were observed in 42 of 95 (44%) male and 32 of 67 (47%) female seals. Affected animals had been in rehabilitation 0 to 63 days and were below average birth weight for this species.

Intravascular malignant T-cell lymphoma (malignant angioendotheliomatosis) in a cat

A 7-year-old spayed female Siamese cat was presented with a 7-day history of ataxia, circling to the right, and involuntary micturition and defecation. Cerebrospinal fluid analysis showed increased protein content and relative eosinophilia. At necropsy, there was flattening of the cerebral cortical gyri of the right frontal and parietal lobes, and both kidneys had multiple wedge-shaped cortical indentations. Histologically, the cerebral cortex contained several extensive malacic foci, and the kidneys had multifocal parenchymal degeneration and atrophy. There was multifocal partial to complete thrombosis of renal interlobar arteries and of the right middle cerebral artery and meningeal branches; these thrombi contained large anaplastic round cells, which often invaded the arterial wall. Many smaller vessels within the kidneys and brain were occluded with clusters of similar cells, without thrombosis or vascular wall invasion. The neoplastic round cells had immunohistochemical staining properties of T lymphocytes.

A survey of exercise-induced pulmonary haemorrhage in Quebec standardbred racehorses

Sixty Standardbred horses, aged 3 to 10 years, were examined endoscopically for exercise-induced pulmonary haemorrhage (EIPH) 1 h after racing, on at least 3 occasions. Racing time, finishing position and post exercise venous lactate concentrations were also recorded. Horses positive for tracheal blood on endoscopy were classified as having either grade 1 EIPH (one or a few spots of blood in the trachea), or grade 2 (stream of blood). Air temperature, relative humidity and air pollutant levels were recorded on each examination day. Of the 60 horses, 52 (87%) were EIPH-positive on at least one evaluation out of 3 and 40 of the 52 (77%) showed grade 2 EIPH on at least one occasion. Of the 52 EIPH-positive horses, 52% bled 3 times out of 3, 21% 2 out of 3 and 27% once. When only the first examination was considered, 37 of the 60 horses (62%) were EIPH-positive. There was no significant relation detected between either presence or frequency of EIPH and age, sex, or gait. Horses that showed grade 2 EIPH bled significantly (P = < 0.001) more frequently (mean: 83% of examinations) than horses having shown no more than grade 1 EIPH (47% of examinations). No significant differences could be detected between EIPH-positive and EIPH-negative races in the average racing times, finishing positions and blood lactate concentrations of the 29 horses which showed intermittent EIPH. The proportion of horses showing EIPH on each day where at least 5 horses were examined was correlated with air temperature, relative humidity, and the levels of several air pollutants on those days.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of centrifugation and specimen preparation technique on bronchoalveolar lavage analysis in horses

Bronchoalveolar lavages (BAL) were performed for 6 healthy horses and 8 horses with lower airway diseases (LAD). Total cell and differential counts were performed before and after centrifugation and resuspension of the BAL cells in a small volume of fluid; there was no difference in the total cell counts, but mast cell percentages were significantly (P < 0.05) lower, after centrifugation, in the LAD group. The two specimen preparation techniques compared were cytocentrifugation and centrifugation on microscope glass covers. For both groups of horses, lymphocyte percentages were significantly lower on cytocentrifuged specimens; there was also an increase in the other predominant cell type, i.e. macrophages in healthy horses and neutrophils in horses with LAD. Lymphocyte percentages in healthy horses were higher than those reported in previous studies, possibly because of a long-standing exposure to a high-dust environment. This study suggests that one centrifugation of the BAL fluid does not affect total cell counts, but may cause a decrease in mast cell percentage; cytocentrifugation is associated with a consistent decrease in lymphocyte percentage.

Effects of triamcinolone acetonide on pulmonary function and bronchoalveolar lavage cytologic features in horses with chronic obstructive pulmonary disease

Effects of triamcinolone acetonide (TA) on pulmonary function, bronchoalveolar lavage cytologic features and serum cortisol concentration, were studied in 5 control horses and 5 horses with chronic obstructive pulmonary disease (COPD). In experiment 1, horses were brought in from pasture 3 weeks before administration of 1 injection of TA (0.09 mg/kg of body weight, IM), and were stabled in dusty conditions throughout the experimental period. Measurements of respiratory rate (f), tidal volume, minute ventilation, expiratory-to-inspiratory time ratio, maximal change in transpulmonary pressure (delta PL), pulmonary resistance (RL), and dynamic compliance (Cdyn) were obtained during quiet breathing, immediately before (baseline) and 1, 2, 3, 5, and 9 weeks after administration of TA. Pulmonary airway cells were collected by bronchoalveolar lavage while horses were at pasture, at baseline, and 2, 5, and 9 weeks after TA administration. Serum cortisol concentration was measured before and after adrenocortical stimulation with 100 IU of adrenocorticotropic hormone, 1 week prior to TA administration, and 4 and 8 weeks thereafter. In experiment 2, 4 months after TA injection, pulmonary function measurements were repeated in all horses immediately before and 30 minutes after administration of atropine (0.015 mg/kg, IV), to evaluate the reversibility of airway obstruction. In experiment 1 at baseline, COPD-affected horses had significantly (P < 0.05) higher values than did controls for f, delta PL, RL, and percentage of neutrophils, and had lower values for Cdyn and percentage of lymphocytes and macrophages. There was significant reductions in delta PL and RL, and increase in macrophage percentage after TA administration in COPD-affected horses only.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of stabling on bronchoalveolar cells obtained from normal and COPD horses

Bronchoalveolar lavages (BAL) were performed before and after 3 weeks of housing in 5 horses suffering from COPD and 5 normal horses. In the two groups, the total number of cells recovered remained unchanged after stabling. The most common cell populations in BAL fluid of control animals were alveolar macrophages (46.4%) and lymphocytes (44.9%). The percentage of neutrophils increased after stabling from 8.7% to 27.6%. In COPD horses, lymphocytes predominated (40.7%) in animals at pasture with neutrophils increasing from 29.4% to 71.6% after stabling. After fractionation by Percoll density gradient, alveolar macrophages and neutrophils from normal and COPD horses had a similar density distribution. After stabling, these cells from normal horses were increased in the low density layers, while those from COPD horses were predominantly in the hyperdense layers. Therefore, BAL cells obtained from COPD animals at pasture and after stabling differ from those of control horses in the same environment, not only in their populations but also in their buoyant densities. These differences could be related to different states of cellular activation and perhaps be responsible for disease activity in the COPD horses.

Septic arthritis in 15 standardbred racehorses after intra-articular injection

Case histories, results of synovial fluid analyses, treatment regimens and outcome are described for 15 adult Standardbred horses with confirmed post-injection septic arthritis. Joint sepsis followed injection of corticosteroids, hyaluronic acid, polysulphated glycosaminoglycan, or local anaesthetic. The median interval from injection to appearance of clinical signs was 2.5 days, and median interval from injection to referral was 9 days. The median initial synovial leucocyte count on admission was 57 x 10(9)/litre, but there was a wide range of values (18-258 x 10(9)/litre). The median synovial neutrophil percentage was 95% (77-99%). All bacterial isolates were Gram-positive cocci, 86% of which were staphylococci. All treated horses (12/15) initially received broad-spectrum parenteral antibiotic therapy, and the articulations of all horses except one were lavaged, either with non-surgical through-and-through techniques only (N = 3), or surgically with arthrotomy (N = 1) or arthroscopy (N = 7). The owners of all treated horses were contacted and racing records were consulted. Eleven of 12 horses returned to racing. Outcome was judged as either satisfactory (3/12) if the horse had returned to racing levels similar to or better than before treatment, or unsatisfactory (9/12) if the horse had poorer performance or could not return to racing. The 3 horses with satisfactory follow-up had been treated with arthroscopy and post-surgical closed suction drainage. The results of bacterial cultures suggest that the initial antimicrobial agents used should be effective against penicillin-resistant staphylococci.