Journal Roundup May 2003

Many complementary and alternative therapies have little or no evidence to support their use. However, a new study by Chiu et al¹ shows evidence of a physiologically measurable effect. Rats were given true and sham acupuncture and electroacupuncture, and the effect on the hypothalamus measured using MRI. True electroacupuncture enhanced the primary response of the hypothalamus in contrast to the control groups. The authors note that this is a preliminary study, and recommend further work in this area is carried out.

            It has been noted in the past that human and equine athletes have a high incidence of gastric disease. Davis et al² studied a group of racing Alaskan Sled dogs, and found they had a higher incidence of gastric ulceration, erosion or haemorrhage than a historical control group. They believe that as with other species, elite canine athletes have a higher incidence of gastric disease.

            Lymph node palpation is often used as a means of checking for metastasis of neoplasia. Williams and Packer³ looked at the association between lymph node size and metastasis in dogs with oral malignant melanoma. They found that about half of the dogs had no cytological or histological evidence of metastasis, although half of these did have lymph node enlargement. 40% of dogs with normal-sized lymph nodes did have evidence of metastasis. The authors conclude that lymph node size alone is insufficient for accurate clinical staging of oral malignant melanoma in dogs. Fortunately, a new test shows promise for the detection of metastatic melanoma. Catchpole et al⁴ have developed a PCR assay for detection of metastatic melanoma in lymph node aspirates, which shows a good specificity for this type of cancer. In combination with cytological analysis, this increases the chance of discovering the presence of metastasis.

            Remaining with oncology, cyclophosphamide is a commonly used chemotherapeutic for treatment of lymphosarcoma. One common problematic side effect is sterile haemorragic cystitis. Charney et al⁵ examined risk factors for development of this problem. They found that dogs treated with frusemide were significantly less likely to develop the cystitis. Dogs with previous immune-mediated disease were more likely to develop the condition.

            Cytological analysis is a convenient, minimally invasive way of obtaining a preliminary diagnosis in various conditions. Cohen et al⁶ evaluated the sensitivity and specificity of the procedure by comparing cytological diagnoses to histological diagnoses. The results showed a surprisingly low correlation, with sensitivity of cytology between 33 and 66%. The technique was most accurate for cutaneous and subcutaneous lumps and least accurate for liver lesions. The technique was also more accurate for neoplastic conditions compared to dysplastic or hyperplastic conditions.

            Surgery is a mainstay of cancer therapy. Lascelles et al⁷ describe a combined dorsolateral and intraoral approach for the resection of tumours in the maxilla in the dog which are caudal to the third premolar. The only intraoperative complication was blood loss. A recurrence rate of 50% was seen.

            Good surgical practice dictates the wearing of surgical gloves for sterile procedures. Character et al⁸ examined the integrity of gloves after use by electrical resistance testing. 23% of gloves had defects, 84% of these resulting from operations lasting more than 60 minutes. The authors recommend double gloving or regloving every 60 minutes for prolonged procedures.

            Acepromazine is probably the most commonly used pre-medication for anaesthesia in veterinary practice. Its effects include vasodilation leading to arterial hypotension, which could potentially compromise renal function. Bostrom et al⁹ studied the effects of intramuscular ACP compared to saline before thiopentone/isoflurane anaesthesia. They found that, although the mean arterial blood pressure was lower in the dogs pre-medicated with ACP, there was no significant difference in GFR or other renal parameters. The authors conclude that ACP may protect renal function despite lowering arterial blood pressure.

            Lufenuron has been suggested as a useful treatment for ringworm. DeBoer et al¹⁰, examined 3 groups of cats, one treated with lufenuron orally, one with lufenuron by injection and one set untreated controls. After 4 months, these cats were exposed to cats mildly infected with M canis. They found that cats treated with lufenuron had lower infection scores compared with control cats, and a more prolonged initial progression phase of the infection. However, the drug did not prevent infection, and once established, the infection resolved in approximately the same amount of time in the treated and untreated groups.

            Methimazole has recently been licensed as a treatment for hyperthyroidism in cats. Trepanier et al¹¹ studied the efficacy and safety of the drug when used once or twice daily in a randomized non-blinded clinical trial. They found that serum thyroxine was significantly higher in the once daily treated group, and that only 54% of cats treated once daily were euthyroid, compared with 87% of cats treated twice daily.

            Finally, metronidazole is a useful drug with indications for the treatment of giardiasis, anaerobic infections and inflammatory bowel disease. However, it can have side effects when given at higher dose rates. Evans et al¹² investigated the use of diazepam as a treatment for metronidazole toxicity. They found that diazepam given as an initial iv bolus, then by mouth three times daily for 3 days resulted in a markedly shorter response and recovery time than dogs treated without this drug.   

1. Chiu et al 2003, Can Vet J; 67: 94

2. Davis et al 2003, J Vet Int Med; 17, 311

3. Williams & Packer 2003, JAVMA; 9, 1234

4. Catchpole et al 2003, AJVR; 64, 544

5. Charney et al 2003, JAVMA; 10, 1388

6. Cohen et al 2003, JAVMA; 7, 964

7. Lascelles et al 2003, JAAHA; 39, 294

8. Character et al 2003, JAAHA; 39, 311

9. Bostrom et al 2003, AJVR; 64, 590

10. DeBoer et al 2003, JAVMA; 9, 1216

11. Trepanier et al 2003, JAVMA; 7, 954

12. Evans et al 2003, J Vet Int Med; 17, 304

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