Fibrosarcoma adjacent to the site of microchip implantation in a cat

A 14-year-old spayed female domestic shorthair cat presented with an interscapular mass. A computed tomography scan, biopsy, and histological examination revealed a fibrosarcoma adjacent to a pet identification microchip. Because the cat was previously vaccinated at this site, it is not possible to establish definitive causation of the fibrosarcoma, but this is the first report of a tumor in the vicinity of a microchip in a cat. Microchip-associated tumors have been reported in rodents and dogs. Veterinarians should be aware that because inflammation may predispose felines to tumor formation, separation and observation of vaccination and implantation sites are indicated. Adherence to American Association of Feline Practitioners (AAFP) vaccination guidelines and monitoring of microchip implantation sites are recommended.     

Spinal cord injury resulting from incorrect microchip placement in a cat

A 2-year-old, male neutered domestic shorthair cat was presented for investigation of an acute onset of tetraparesis immediately following the implantation of a pet identification microchip. A left-sided C6-T2 spinal segment localisation was suspected from the neurological examination, with spinal cord trauma being the primary differential diagnosis. Myelography demonstrated obliteration of the contrast columns by the microchip at the C5-C6 intervertebral disc space. A dorsal laminectomy was undertaken and the microchip was successfully removed. Eleven months after the surgery, the cat was able to weight bear in all limbs but with mild residual paresis in the left thoracic limb.     

Pituitary responsiveness to GnRH in mares following deslorelin acetate implantation to hasten ovulation

The present experiment characterized the pituitary responsiveness to exogenous GnRH in the first 10 d after ovulation following commercially available deslorelin acetate implantation at the normal dosage for hastening ovulation in mares. Twelve mature, cyclic mares were assessed daily for estrus and three times weekly for ovarian activity starting May 1. Mares achieving a follicle at least 25 mm in diameter or showing signs of estrus were checked daily thereafter for ovarian characteristics. When a follicle >30 mm was detected, mares were administered either a single deslorelin acetate implant or a sham injection and then assessed daily for ovulation. On d 1, 4, 7, and 10 following ovulation, each mare was challenged i.v. with 50 microg GnRH, and blood samples were collected to characterize the LH and FSH responses. The size of the largest follicle on the day of treatment did not differ (P = 0.89) between groups. The number of days from treatment to ovulation was shorter (P < 0.001) by 2.0 d for the treated mares indicating a hastening of ovulation. The size of the largest follicle present on the days of GnRH challenge was larger in the treated mares on d 1 (P = 0.007) but smaller on d 10 (P = 0.02). In addition, the interovulatory interval was longer (P = 0.036) in the treated mares relative to controls by 4.4 d. Concentrations of FSH in plasma of the treated mares were lower (P < 0.05) than control concentrations from d 3 to 12; LH concentrations in the treated mares were lower (P < 0.05) relative to controls on d 0 to 5, d 7, and again on d 20 to 23. Progesterone values were the same (P = 0.99) for both groups from 2 d before ovulation though d 23. There was an interaction of treatment, day, and time of sampling (P < 0.001) for LH and FSH concentrations after injection of GnRH. Both the LH and FSH responses were suppressed (P < 0.009) in the treated mares relative to controls on d 1, 4, and 7; by d 10, the responses of the two groups were equivalent. In conclusion, deslorelin administration in this manner increased the interovulatory interval, consistently suppressed plasma LH and FSH concentrations, and resulted in a complete lack of responsiveness of LH and FSH to GnRH stimulation at the dose used during the first 7 d after the induced ovulation. Together, these results are consistent with a temporary down-regulation of the pituitary gland in response to deslorelin administered in this manner.     

Studies on the pathogenesis of equine tendonitis following collagenase injury

The histological and morphological characteristics of the scar tissue formed during healing after traumatic equine tendon injury have been compared with those of scar tissue produced in response to an enzyme-induced pony tendon injury. Several techniques are currently in use in the treatment of equine tendon sprain and this work formed part of a study of their respective efficacy. It was concluded that the enzyme-induced lesion is resolved by a reparative process very similar in its prognosis and extent to that following a naturally occurring tendon sprain. It may therefore justifiably be used as a model of naturally occurring tendon sprain in the comparative study of treatment methods.     

Hypothalamic-pituitary axis deficiency following traumatic brain injury in a dog

Objective – To describe endocrine dysfunction associated with traumatic brain injury in a dog.
Summary – A 12-week-old dog presented with traumatic brain injury and did not respond to traditional supportive care. Continued hypothermia, electrolyte derangements, hypotension, and hyposthenuria prompted screening for and detection of several hypothalamic-pituitary disorders including: hypoadrenocorticism, central diabetes insipidus, hypothyroidism, and growth hormone deficiency. Electrolyte abnormalities, urine osmolarity, and blood pressure improved with treatment for the associated disorders.
New or Unique Information Provided – This is the first report of generalized hypothalamic-pituitary dysfunction or panhypopituitarism following traumatic brain injury in a dog.     

Prevention of tetanus in man and animal following injury]

The effect of heterologous and homologous antitoxin is the same if an equal amount of antitoxin is present in the organism. In man there are no circulating antibodies in the blood after the first injection of the toxoid because there is no natural immunity against the tetanus antigen. After the second injection, man develops the same immunity as animals. Large antitoxin doses protect people for a longer period than small doses. Normally 3,000 I. U. of the heterologous antitoxin protects people for 2 to 3 weeks. In man and sheep 2 ml of the adsorbed vaccine produces an earlier and longer-lasting immunity than 0.5 ml. Simultaneous active and passive prophylaxis is superior to passive prophylaxis alone. To achieve a long-lasting active immunity, 2 ml of the vaccine should first be injected and a booster dose 7 to 10 days later, and again 6 to 12 weeks after the first dose. Immediate vaccination against tetanus following an injury will not protect a person who has not been vaccinated previously, as the active immunity will start too late.     

Presumptive acute lung injury following multiple surgeries in a cat

A 12-year-old, 3.5-kg spayed female domestic shorthair cat had a tracheal mass identified as malignant B-cell lymphoma. The cat had tracheal resection and subsequently developed laryngeal paralysis. Due to multiple episodes of respiratory distress the cat subsequently had tracheal surgeries. Finally, the cat had a sudden onset of severe respiratory distress and collapsed. Computed tomography imaging and arterial blood gas analysis supported a diagnosis of acute lung injury.     

Imaging diagnosis--polioencephalomalacia in a calf.

A 2-month-old mix-breed calf developed acute blindness and ataxia. Serum thiamine concentration was deficient. In antemortem magnetic resonance imaging there were laminar T2-hyperintense regions extending along the cerebral cortex that primarily affected the gray matter. The lesions were relatively symmetric between the left and right hemispheres but no abnormalities were present at the frontal lobes. At necropsy, laminar autofluorescence of the cerebral cortex was observed under ultraviolet exposure at 365 nm, consistent with a diagnosis of polioencephalomalacia. Polioencephalomalacia in the bovine species is compared with that in other species, namely humans, dogs, and cats.     

Cervical injury following a horse kick to the head in two dogs

Two dogs were presented to North Carolina State University Veterinary Teaching Hospital following blunt trauma to the head delivered by a horse kick. On presentation, both dogs had resolving clinical signs directly related to the head trauma, but both also had compromise to their upper airway as a result of indirect injury to the soft tissues of the neck, visible on plain radiographs. One dog made a full recovery following a period of assisted ventilation. The other dog was euthanized at the request of the owner. These injuries illustrate the importance of evaluating the cervical spine and soft tissues of the neck following blunt trauma to the head.     

Surgical implantation of electroencephalographic electrodes in the dog.

A simple surgical technique for implanting chronic electroencephalographic electrodes in the skull of the dog was devised to obtain electroencephalograms from nonsedated and nonanesthetized dogs frequently. Orthopedic screws were used as implant electrodes and for securing the recording assembly over the frontal sinus. The electrode assemblies have been tolerated well for as long as 10 months in 17 of 20 dogs and have given reliable and satisfactory electroencephalograms for computer analysis and have been virtually free of all physiologic and motion artifacts in all dogs, with minimal use of physical restraint.