Chlorpyrifos intoxication in a bull

A mature Brangus bull received the recommended dose of chlorpyrifos and became dull and inappetent 3 days later. Clinical findings included weakness, dehydration, rumen stasis, and rumen distention with fluid and gas. Blood cholinesterase activity was 25% of normal. The bull's condition improved after treatment with pralidoxime, antimicrobials, electrolyte solutions, vitamins, and adsorbents. Five weeks later, the bull had gained weight, the blood cholinesterase activity was 70% of normal, and the results of a semen evaluation indicated he was a satisfactory potential breeder.     

Narcolepsy in a Brahman bull

Behavioral, electrophysiologic, and pharmacologic tests were performed on a 2 1/2-year-old Brahman bull suspected of having narcolepsy. Placement on a tilt table or electroejaculation induced apparent sleep and cataplexy. Electrophysiologic recordings during the episodes revealed the low-voltage, high-frequency electroencephalogram, reduced electromyogram amplitude, and rapid eye movements in the electrooculogram associated with rapid eye movements sleep. Physostigmine salicylate appeared to elicit and potentiate the episodes, whereas atropine sulfate and imipramine reduced or blocked them. The combined results of the tests supported the diagnosis of narcolepsy.     

Intracranial lymphosarcoma in a Holstein bull

A 2-year-old Holstein bull was examined because of decreased appetite. Clinical signs included head tilt, circling, head pressing, ptosis, hypesthesia of the face, and dysfunction of the parasympathetic component of cranial nerve III. Necropsy revealed intracranial lymphosarcoma.     

Laryngeal granuloma in a bull.

Dyspnea in an adult bull caused by a large laryngeal granuloma was corrected by use of a surgical technique that allowed resection of the mass without ventral laryngotomy. Endoscopy was used for visualization of the mass during the oral surgery. The technique may be performed in the field.     

Type-I diabetes mellitus in a bull

Although metabolic disorders are a frequent concern in cattle, they are not commonly recognized in bulls. The combination of hyperglycemia, acetonemia, ketonuria, and glycosuria in a bull was highly suggestive of diabetes mellitus. This uncommon diagnosis was confirmed by results of intravenous glucose tolerance testing. Results of the test and serum insulin values were further able to classify the disease in this bull as type-I diabetes mellitus.     

Primary mandibular hemangiosarcoma in a bull

Disseminated pulmonary and subcutaneous-muscular hemangiosarcoma at the left hemimandible was diagnosed postmortem in a 2-year-old Jersey bull that presented with a 7-day history of facial swelling from suspected traumatic injury. Hemangiosarcoma is uncommon in cattle and has never been reported to affect the bones of the skull.     

Bilateral cryptorchidism in a bull.

Clinical and pathological observations were made on a case of bilateral cryptorchidism in a bull. Sexual libido could not be assessed because the bull was housed alone. The location of the intraabdominal testes indicated that surgical castration would necessitate a flank laparotomy incision.     

Preputial foreign body in a bull

A preputial foreign body caused severe preputial swelling and depression in a 4-year-old Shorthorn bull. Disruption of the preputial epithelium by the foreign body resulted in abscess formation lateral to the prepuce. A patent urethral fistula, probably a complication of prior fibropapilloma excisional surgery, was also detected on the distal portion of the glans penis. Foreign body removal, antimicrobial administration, and warm hydrotherapy resolved the swelling and abscess. Electroejaculation was used to extend the penis and to minimize preputial adhesions. Breeding soundness examinations were used to evaluate breeding potential.     

Progressive ataxia in a Charolais bull

A 20-month-old Charolais bull was referred for evaluation of progressive hind limb ataxia. Clinical findings suggested a neuroanatomic lesion caudal to T2. Postmortem histologic examination revealed multifocal, acellular, pale, eosinophilic plaques throughout the cerebellum, which were diagnostic for the disease progressive ataxia of Charolais cattle. This disease is presumed to have a hereditary transmission and is not commonly recognized in the United States.