Seroprevalence and Risk Factors Associated With Corynebacterium pseudotuberculosis Detectable Antibodies in Equids in Alabama

A cross-sectional serological survey was carried out to screen the equine population of the nonendemic state of Alabama for the presence of detectable antibody titers against Corynebacterium pseudotuberculosis. A second objective was to determine the association of detectable titers with risk factors such as exposure to ruminants or previous travel to endemic states. A total of 342 equine serum samples from 40 Alabama counties were analyzed using the synergistic hemolysis inhibition test (SHI). The prevalence of detectable antibody titers (≥1:8) was 52.5% (95% confidence interval [CI], 47%–57.9%). Titers ≥1:128 were detected in 2.63% (95% CI, 1.2%–4.9%), and titers ≥1:512 were detected in 0.3% (95% CI, 0%–1.6%) of the sampled population. In the final generalized linear model, age (P < .001), breed (P = .023), and contact with cattle (P = .05) were associated with increasing SHI titers. Contact with goats was associated in the initial but not in the final analysis (P = .19). Previous travel was not associated with increasing SHI titer (P = .97). The results demonstrated a high prevalence of low detectable titers and low prevalence of titers ≥ 1:128 in a nonendemic population. Further evaluation of SHI cutoff titers and accuracy is warranted to reduce the risk of a false positive diagnosis.     

Complications of Balloon Catheterization Associated With Aberrant Cerebral Arterial Anatomy in a Horse With Guttural Pouch Mycosis

A 3-year-old Quarter Horse gelding was treated for left guttural pouch mycosis by ligation and balloon catheterization of the left internal carotid artery. Catheter advancement was shorter (10 cm) than the normally reported distance (13–15 cm), but was observed endoscopically during placement as it coursed within the internal carotid artery through the guttural pouch. The horse developed a persistently abnormal respiratory pattern after catheter placement, failed to gain consciousness, developed pulmonary edema, and died 5.5 hours postoperatively. Postmortem examination revelaed an aberrant left internal carotid arterial course with location of the embolectomy catheter at the junction of the basilar and caudal cerebellar arteries. Brainstem neuronal necrosis and alveolar and interstitial pulmonary edema were identified on histological examination. Angiography may be used to identify aberrant branching patterns. Failure to identify and occlude aberrant branches may result in fatal epistaxis and Brainstem lesions.     

Urethrotomy and urethrostomy in the dog

An incision, or urethrotomy, is made into the urethral lumen to remove or relieve an obstruction temporarily. When permanent diversion of urine flow proximal to an obstructed, severely damaged, or diseased urethra is required, a urethrostomy is performed. Urethrostomy is also performed to diminish the risk of urethral obstruction due to recurrent urinary calculi that are not likely to be resolved with medical therapy. Whenever possible, to reduce the risk of urethral stricture or recurrent urinary tract infection, urethral surgery is avoided when an obstruction can be relieved by retrohydropropulsion or catheterization. Urethrotomy can be performed in the prescrotal or perineal regions depending on the level of the urethral obstruction. Although urethrostomy can be made in the perineal and antepubic positions, scrotal urethrostomy is the procedure of choice provided the lesion is distal to this area. Specific urethrotomy and urethrostomy procedures are described, including discussion about selection of the appropriate procedure for the urethral problem, patient stabilization considerations, general postoperative management, and risk of complications.     

Thrombocytopenia Associated With Neoplasia in Dogs

Ten percent (214/2,059) of all dogs with cancer at North Carolina State University Veterinary Teaching Hospital had thrombocytopenia. The thrombocytopenia was associated with infectious/inflammatory etiologies in 4%, miscellaneous disorders (therapy, bone marrow failure, disseminated intravascular coagulation) in 35%, and neoplasia without identifiable secondary factors in 61% of cancer-bearing dogs. Classifying these dogs by tumor groups revealed the following proportionate ratios: lymphoid, 29%; carcinoma, 28%; sarcoma, 20%; hemic neoplasia, 7%; multiple, 5%; unclassified, 3%; benign, 3%; brain, 3%; and endocrine, 3%. Dogs with hemangiosarcoma, lymphoma, and melanoma were at increased risk of developing thrombocytopenia. Cytotoxic therapy was the major factor increasing the risk of thrombocytopenia in dogs with melanoma. Golden Retrievers were the only breed recognized with a predisposition to develop thrombocytopenia. If thrombocytopenia is identified in a dog with cancer, we recommend thorough evaluation of the coagulation system before surgery or therapy, and careful consideration of the risks and potential benefits of myelosuppressive or L-asparaginase therapy.     

Siderocytosis Associated With Hypomagnesaemia in Cattle

Sir:- I wish to report the occurrence of siderocytosis (circulating erythrocytes containing free iron)⁽⁵⁾ in cattle with hypomagnesaemia.     

Causes of Encephalitis and Encephalopathy in Brazilian Equids

The etiology of diseases that affect the central nervous system (CNS) of equids was investigated. Samples (n = 218) collected from equids showing clinical signs of nervous or behavioral changes were analyzed, of which 37 (17.0%) were positive for rabies, 13 (6.0%) for the presence of protozoans (one Sarcocystis neurona, 12 Toxoplasma gondii), three (1.4%) for equine herpesvirus type 1 myeloencephalopathy, and 24 (11%) for bacterial encephalitis. Histopathology of the CNS revealed one (0.4%) case of cryptococcal myelomeningoencephalitis and 20 (9.2%) cases of equine leukoencephalomalacia. Central nervous system samples were positive for Sarcocystis neurona and Toxoplasma gondii by nested PCR-ITS1 followed by nucleotide sequencing. Diagnosis of equine herpesvirus 1 was confirmed by cell isolation and polymerase chain reaction followed by sequencing of the GD and polymerase (ORF 30) genes in three samples. No case of equine encephalomyelitis was diagnosed in samples analyzed by isolation in mice, VERO cell cultures, and RT-PCR for the nsP1 gene. Bacterial agents (Staphylococcus spp., Streptococcus spp., Bacillus spp., Enterobacteriaceae spp., Corynebacterium spp., and nonfermenting gram-negative bacillus) were detected in pure or preponderant cultures. Diagnosis was conclusive in 45% of samples, indicating that other infectious and noninfectious etiologies of encephalitis and encephalopathy should be considered for investigation.     

Hypophosphatemia Associated With Enteral Alimentation in Cats

Hypophosphatemia is uncommon in cats, but it has been reported in association with diabetes mellitus and hepatic lipidosis, where it can cause hemolysis, rhabdomyopathy, depression, seizures, and coma. The purpose of this article is to describe 9 cats that developed low serum phosphorus concentrations (<2.5 mg/dL) subsequent to enteral alimentation. Serum biochemical analyses from more than 6,000 cats were reviewed. The medical records of all cats with hypophosphatemia were examined for history of enteral alimentation; diabetic cats were excluded from the study. Nine cats, ranging in age from 3 to 17 years, were identified. All cats had normal serum phosphorus concentrations before tube feeding began. Onset of hypophosphatemia occurred 12 to 72 hours after initiation of enteral alimentation, and the nadir for phosphorus concentrations ranged from 0.4 to 2.4 mg/dL. Hemolysis occurred in 6 of the 9 cats. Hypophosphatemia secondary to enteral alimentation is an uncommon clinical finding in cats. Cats with high alanine aminotransferase activity, hyperbilirubinemia, and weight loss should be closely monitored for hypophosphatemia during the first 72 hours of enteral alimentation.     

Complications Associated with Proximal Duodenal Resection and Cholecystoduodenostomy in Two Cats

Two cats having resections of duodenal lesions involving the major duodenal papilla are described. The operative technique of cholecystoduodenostomy and the postoperative complications are presented. Pancreatic insufficiency and cholangitis developed in both cats and responded to specific treatment. Recommendations for performing successful cholecystoduodenostomy are made.