Diffusion weighted magnetic resonance imaging is a feasible method for characterizing regional lymph nodes in canine patients with head and neck disease.

In dogs diagnosed with solid tumors, regional lymph node involvement or evidence of distant metastasis can predict worse prognoses and significantly decreased survival. Lymph node size alone has been shown to be insufficient as a predictor for the accurate clinical staging of some canine neoplasia. However, certain regional lymph nodes (including those of the oral cavity) are difficult to access for routine tissue sampling. Diffusion weighted magnetic resonance imaging (MRI) has demonstrated the ability to differentiate metastatic from inflammatory/benign lymph nodes in clinical studies with human cancer patients through the calculation of quantitative values of diffusion termed apparent diffusion coefficients (ADC). The objective of this prospective, exploratory study was to evaluate diffusion-weighted MRI and ADC as potential methods for detecting metastatic lymph nodes in dogs with naturally occurring disease. We hypothesized that diffusion-weighted MRI would identify significantly different ADC values between benign and metastatic lymph nodes in a group of canine patients with head or neck disease. Our study population consisted of eight client-owned canine patients, with a total of 20 lymph nodes evaluated (six metastatic, 14 benign). Our results demonstrated that two of four observers identified a significant difference between the mean ADC values of the benign and metastatic lymph nodes. When data from all four observers were pooled, the difference between the mean apparent diffusion coefficients values of the benign and metastatic lymph nodes did not reach significance (P-value = 0.0566). Findings indicated that diffusion-weighted MRI is a feasible method for further characterizing enlarged lymph nodes in dogs with head and neck disease, however measured ADC values did not differ for benign vs. metastatic lymph nodes in this small sample of dogs.

Leiomyosarcoma of the Wing in a Vieilott's Fireback Pheasant (Lophura rufa).

A 15-year-old, female Vieilott's fireback pheasant (Lophura rufa) presented with a 2-day history of a drooping right wing. Examination revealed severe soft tissue swelling in the area extending from the right shoulder to the humeral-radio-ulnar joint with associated bruising and feather loss. Results of a complete blood cell count revealed marked heterophilia and lymphocytosis, and results of serum biochemical analysis showed severe increases in creatine kinase and aspartate aminotransferase activities, hypoproteinemia, and hypoalbuminemia. Radiographs revealed osteolytic lesions of the right humerus with pathologic fractures and circumferential soft tissue swelling. Although surgical wing amputation was successful, the bird died the next day while being treated. The mass was diagnosed histologically and immunohistochemically as a leiomyosarcoma. This is the first neoplasia of any kind reported in this species, to our knowledge, and one of the very few reports of smooth muscle neoplasms affecting the limb of a bird.

Computed tomography findings in a 5-year-old Australian Cashmere goat (Capra hircus) suffering leukoencephalomyelitis due to caprine arthritis encephalitis virus.

Computed tomography was used to aid in the antemortem diagnosis of leukoencephalomyelitis in a goat infected by caprine arthritis encephalitis virus (CAEV). Imaging results were corroborated by histologic examination. This report discusses various methods of imaging the nervous system and their potential for use in the antemortem diagnosis of CAEV neurologic changes.

Résultats d'une tomodensitométrie chez une chèvre cachemire de l'Australie(Capra hircus)âgée de 5 ans souffrant d'une lymphoencéphalomyélite en raison du virus de l'arthrite caprine. La tomodensitométrie a été utilisée pour faciliter le diagnostic antemortem de la lymphoencéphalomyélite chez une chèvre infectée par le virus de l'arthrite-encéphalite caprine (VAE). Les résultats de l'imagerie ont été corroborés par l'examen histologique. Ce rapport discute les diverses méthodes d'imagerie du système nerveux et leur utilisation potentielle pour le diagnostic antemortem des changements neurologiques du VAE.(Traduit par Isabelle Vallières).

Advances in equine ultrasonography.

The many advancements in ultrasound technology, including spatial compounding, harmonic imaging, multidimensional and extended field-of-view images, and improvements in transducer capabilities, are used to enhance the ultrasonographic examination of the equine patient. The improvements in software and hardware capabilities help overcome artifacts, improve image quality, and allow better documentation of the examination for follow-up studies. In addition, the ability of smaller, more portable machines to produce better images is ideal for the ambulatory practice setting.

Effect of topical application of 1% diclofenac sodium liposomal cream on inflammation in healthy horses undergoing intravenous regional limb perfusion with amikacin sulfate.

OBJECTIVE: To determine whether topical application of 1% diclofenac sodium cream would decrease inflammation at sites of IV regional limb perfusion (IVRLP) in healthy horses. ANIMALS: 6 healthy adult horses (12 forelimbs). PROCEDURES: Bilateral IVRLP with 2.5 g of amikacin sulfate was performed twice in each horse, with 24 hours between each session. Horses were treated with topical 1% diclofenac liposomal cream (treated limbs) or a placebo cream (control limbs). All injection sites were evaluated before the first IVRLP session and 24 hours after the second session by means of ultrasonographic examination by a trained ultrasonographer who was unaware of the treatment received. Circumferential measurements and subjective visible inflammation scores were recorded by a veterinarian who was also unaware of treatment received. RESULTS: After IVRLP, control limbs had a significantly greater increase in subcutaneous thickness, compared with treated limbs. Ultrasonographic and visual assessment scores were significantly higher in control versus treated limbs. The mean change in limb circumference was greater, but not significantly so, in control limbs, compared with treated limbs. CONCLUSIONS AND CLINICAL RELEVANCE: Topical application of 1% diclofenac sodium liposomal cream to sites of IVRLP in healthy horses decreased inflammation as judged by visual assessment and ultrasonography. Decreased inflammation may allow extended use of IVRLP and may result in a reduction in pain in treated horses.

Thyroid scintigraphy in veterinary medicine.

Thyroid scintigraphy is performed in cats and dogs and has been used to a limited degree in other species such as the horse. Thyroid scintigraphy is most commonly used to aid in the diagnosis and treatment management of feline hyperthyroidism but is also used in the evaluation of canine hypothyroidism and canine thyroid carcinoma. This article reviews the normal scintigraphic appearance of the thyroid in the cat, the dog, and the horse and the principles of interpretation of abnormal scan results in the cat and the dog. Radioiodine is the treatment of choice for feline hyperthyroidism, and the principles of its use in the cat are reviewed.