Hypokalemia, muscle weakness, and recumbency in dairy cattle.

Seventeen cases of severe hypokalemia (serum or plasma potassium < or = 2.1 mEq/L) in association with profound muscle weakness and recumbency in lactating dairy cattle were included in a retrospective study. The cattle were from 15 different farms.

Presumed clostridial and aerobic bacterial infections of the cornea in two horses.

Microscopic examination of Gram-stained tissue specimens collected from severe corneal ulcers in 2 horses revealed large gram-positive rods suggestive of Clostridium spp. Clostridium perfringens was isolated from specimens collected from horse 1; anaerobic organisms were not detected in specimens from horse 2. Aerobic bacterial culture revealed Aeromonas hydrophila and Enterobacter cloacae in specimens collected from horses 1 and 2, respectively.

Ocular manifestations of equine motor neuron disease.

The characteristics of the ocular manifestations of equine motor neuron disease (EMND) are described. Forty-two horses with histories, clinical signs and necropsies compatible with EMND were the subjects of this study. Ophthalmoscopic lesions that varied in severity were found in 40 of 42 horses and appeared as a distinct pigmented reticulated pattern at the tapetal-nontapetal junction or throughout the fundus, depending upon severity.

Tumors of the eye and ocular adnexal tissues.

This article reviews options in dealing with tumors of the cornea and conjunctiva, nictitating membrane neoplasms, and eyelid neoplasms. Orbital tumors, optic nerve and other intraocular tumors are also discussed.

Clinical appearances, healing patterns, risk factors, and outcomes of horses with fungal keratitis: 53 cases (1978-1996).

Objective: To compare initial clinical appearances, healing mechanisms, risk factors, and outcomes of horses with fungal keratitis.

Design: Retrospective analysis.

Animals: 52 horses (53 eyes) with fungal keratitis.

Paraneoplastic pruritus and alopecia in a horse with diffuse lymphoma.

An 8-year-old castrated male Paint Horse was referred because of generalized pruritus, alopecia, and intermittent fever. Results of gross evaluation of the skin and microscopic evaluation of skin scrapings were inconclusive. Histologic examination of skin biopsy specimens revealed vasculitis.

Concurrent abomasal displacement and perforating ulceration in cattle: 21 cases (1985-1996).

Objective: To evaluate the association of physical examination and clinicopathologic findings with surgical findings in cattle with concurrent abomasal displacement and perforating ulceration, to determine short- and long-term survival rates in these cattle, and to determine whether degree of peritonitis (focal vs diffuse) influences survival rates.

Design: Retrospective study.

Animals: 21 cattle with concurrent abomasal displacement and perforating ulceration and 42 cattle with uncomplicated abomasal displacement.

Ocular lesions in horses with lymphosarcoma: 21 cases (1977-1997).

Objective: To determine the most common ocular lesions in horses with lymphosarcoma.

Design: Retrospective study.

Animals: 79 horses histologically confirmed to have lymphosarcoma.

Cholelithiasis and cholecystitis in a dairy cow.

A 9-year-old Holstein cow was evaluated for colic and decreased milk production of 2 days' duration. Preoperative serum biochemical results suggested hepatic damage and cholestasis. On the basis of persistent signs of abdominal pain that were nonresponsive to analgesics, exploratory laparotomy was performed.

Evaluation of itraconazole-dimethyl sulfoxide ointment for treatment of keratomycosis in nine horses.

Objective: To evaluate the efficacy of itraconazole-dimethyl sulfoxide ointment for treatment of keratomycosis in horses in the northeastern United States.

Design: Prospective clinical trial.

Animals: 9 horses (10 affected eyes).

Multicentric schwannomas causing chronic ruminal tympany and forelimb paresis in a Holstein cow.

A nine-year-old Holstein cow that developed recurrent ruminal tympany and an abnormal forelimb gait and posture ultimately became recumbent and unable to rise, and was euthanased. A postmortem examination demonstrated numerous schwannomas affecting peripheral nerves and several thoracic and abdominal viscera.

Corneal concentrations and preliminary toxicological evaluation of an itraconazole/dimethyl sulphoxide ophthalmic ointment.

The objectives of this study were to determine the concentration of itraconazole achieved in corneal tissue and aqueous humour after topical application of a 1% itraconazole ointment: to determine the effect of including dimethyl sulphoxide (DMSO) in the ointment on achievable ocular tissue itraconazole concentrations; and to assess if any gross or histopathologic ocular toxicity results from the topical application of 1% itraconazole with or without the addition of DMSO. The experimental trial consisted of 6 horses considered to have normal eyes. Each horse had one eye treated with 0.

Ocular emergencies.

Most ocular and orbital injuries or acute ocular inflammation in horses result in similar signs of adnexal swelling, photophobia, blepharospasm, and lacrimation. It is hoped that detailed examination and the suggestions in this article will enable veterinarians attending horses having ocular emergencies to arrive at a correct diagnosis and appropriate therapy.

Lack of residual lung damage in horses in which Rhodococcus equi-induced pneumonia had been diagnosed.

The effect of prior Rhodococcus equi-induced pneumonia on pulmonary health was investigated in 5 horses (< 24 months old) using endoscopy, radiography, hematologic and bronchoalveolar lavage analyses, and pulmonary function testing. Rhodococcus equi-induced pneumonia had been diagnosed in principal horses when they were foals. Diagnosis was based on positive results of transtracheal aspiration and thoracic radiography at the time of initial clinical examination.

Diaphragmatic herniation causing respiratory signs in a heifer.

A diaphragmatic hernia was found in a pre-partum dairy heifer that was exhibiting signs of respiratory disease. Ruminal tympany was included in the history although this was not a feature of the disease on admission. Diagnosis was made by auscultation and confirmed by radiology and during elective Caesarean section to remove the fetus.

Clinical manifestations of leukocyte adhesion deficiency in cattle: 14 cases (1977-1991).

In Holstein cattle, an inherited disease has been recognized recently in which leukocytes lack surface glycoproteins termed beta 2 integrins, which are important in cell adhesion processes. This disease is the homologue of leukocyte adhesion deficiency in human beings and has been termed bovine leukocyte adhesion deficiency. The molecular basis of this disease is failure to produce normal CD18.

Motor neuron degeneration in a horse.

A 9-year-old Quarter Horse mare was examined because of progressive weight loss, weakness, muscle atrophy and tremors, and behavioral change. Selenium and glutathione peroxidase assays, blood lead analysis, erythrocyte transketolase analysis, pseudorabies and Borrelia burgdorferi serology, electromyography, and CSF analysis were performed. Motor neuron degeneration was diagnosed by microscopic examination of neural tissues.

Oropharyngeal abscessation in two cows secondary to administration of an oral calcium preparation.

This paper describes two cases of infection of the soft palate and pharyngeal wall in cattle. The infections were secondary to trauma and laceration received during treatment with an oral calcium preparation which was given to treat post-parturient hypocalcemia. Clinical signs included dehydration, depression, pseudoptyalism, and fetid breath.

Retinal and optic nerve diseases.

Basic knowledge of the normal appearance and variations of the equine fundus coupled with frequent practice in ophthalmology will allow equine practitioners to be confident when assessing the equine fundus during ophthalmic examinations. Once the normal variations are mastered, appreciation of retinal, choroidal, optic nerve, and vitreal abnormalities is possible. Congenital and acquired lesions of the equine retina, optic nerve, and vitreous are discussed and illustrated.

Selective IgM deficiency and abnormal B-cell response in a foal.

Selective IgM deficiency was diagnosed in a 3-month-old Standardbred colt that was referred for chronic respiratory tract disease. Immunoglobulin quantification revealed normal IgG and IgA concentrations, but undetectable IgM concentration. Stimulation of blood lymphocytes with the T-cell mitogens concanavalin A and phytohemagglutinin yielded results within the normal range.

Hyperkalemic atrial standstill in neonatal calf diarrhea.

Hyperkalemia has been associated with cardiac abnormalities and muscular disorders. Hyperkalemia is a common problem associated with the acid-base and electrolyte disturbances that occur in neonatal calves having acute diarrhea. Occasional calves with acute neonatal diarrhea, metabolic acidosis, and hyperkalemia have cardiac rate or rhythm abnormalities.

Chronic frontal sinusitis in dairy cattle: 12 cases (1978-1989).

Chronic frontal sinusitis in 12 dairy cattle most often was associated with a history of dehorning, in which the sinus was entered (67%), or with respiratory tract disease (25%). The most common organisms isolated were Actinomyces pyogenes and Pasteurella multocida. Signs of infection did not develop for months in some cattle and were often intermittent.

Factors associated with the risk of developing sarcoid tumours in horses.

A retrospective case-control study was conducted to identify risk factors in horses associated with the development of the common skin tumours known as sarcoids. The study involved 503 sarcoid cases diagnosed (January 1980-December 1989) at New York State College of Veterinary Medicine and a similar number of controls (non-sarcoid cases). Data on age, breed and sex of cases and controls were obtained from computerised records.

Thoracotomy in adult dairy cattle: 14 cases (1979-1991).

Fourteen cows were subjected to thoracotomy as an aid in the treatment of either septic pericarditis (n = 7) or unilateral pleuritis (fibrous or purulent; n = 7). Thoracic lesions were primary in 4 cows, secondary to traumatic reticuloperitonitis in 9 cows, and secondary to extension of a liver abscess in 1 cow. Thoracotomy was performed on 9 cows under local anesthesia.