Pain in small animals – its recognition and control

The importance of appreciating the presence of pain in small animals is discussed, and an outline of current concepts in the physiology of pain is presented. The clinical use of therapeutic agents in the control of pain is described. Some discussion on the mechanisms of action of acupuncture is included.     

Estimating adrenal cortical function in dogs with ACTH.

The peripheral blood response to intramuscular injection of 10 units ACTH in dogs was investigated because no experimental evidence for the standardization of this procedure for clinical use was available. Following the injection of ACTH in sodium chloride solution, neutrophilia, monocytosis, eosinopenia, and lymphopenia occurred. With the exception of eosinopenia, the greatest change in the concentration of each cell type in peripheral blood occurred between 2 and 4 hours post injection. The maximum change in eosinophil numbers occurred between 4 and 6 hours post injection. When all cell types were considered, 4 hours post injection was the most suitable time to measure the cellular response in peripheral blood in dogs which respond to ACTH. The data indicate that change in the ratio of neutrophils to lymphocytes (N/L) prior to and at 2 to 4 hours after ACTH injection in normal dogs was a sensitive index of response and occured sooner than eosinopenia. The extent of change in the N/L ratio was such that accuracy in interpretation could be obtained by counting as few as 40 cells.     

Evaluation of reconstitution of immunodeficient mice by partially purified thymic extracts.

Partially purified thymus products were used to evaluate the maturation of T lymphocytes in immunodeficient mice. Three different bovine thymic extracts, designated thymic extracts A, B, and C, were successful in increasing the longevity of conventionally raised nude mice. Daily injection of bovine thymic extracts A, B, and C and mouse thymus extracts failed to mature a population of T lymphocytes and restore the capacity to reject heart allografts. Preincubation of normal syngeneic bone marrow with thymic extract B in vitro before injection into nude mice also failed to reconstitute the host's ability to reject heart grafts. The number of antibody plaque-forming cells of sheep red blood cells in lethally irradiated, bone marrow-reconstituted mice could be increased by preincubating the bone marrow cells with bovine thymic extract fraction B before injection followed by daily injections. A similar but less marked increase in plaque-forming cells was obtained by the daily injection of bovine thymic extract fraction C. Complete functional maturation of T lymphocytes in immunodeficient animals appears to require more than thymic extract stimulation of bone marrow cells or pre-T lymphocytes.     

Nonneurogenic urinary incontinence in a canine female pseudohermaphrodite

Nonneurogenic incontinence was observed in a 1-year-old Pekingese X Poodle with female pseudohermaphroditism. The dog had male external genitalia as well as a well-developed vagina, uterus, and ovaries. Urinary incontinence was caused by an anomalous communication of the prostatic urethra with the vagina. Ovariohysterectomy and surgical correction of the urethrovaginal fistula was followed by remission of urinary incontinence. Subsequently, the dog developed estrogen responsive urinary incontinence. Nonneurogenic incontinence to be a common finding in canine pseudohermaphroditism associated with abnormalities of the vagina or urethra (or both). Surgical correction should be considered to correct anomalous communications between the genital and lower urinary tracts.     

Angiography of the crus penis in the ram and buck during erection

Serial angiography was used to determine blood flow patterns to the penis of rams and bucks. Animals were anesthetized and the internal pudendal artery was catheterized so that contrast medium could be injected toward the crus penis area. By comparing vascular patterns of the ram and buck during erection, it was found that flow patterns of the corpus cavernosum penis (CCP) and corpus spongiosum penis (CSP) were similar for both species. Contraction of the ischiocavernosus muscles occluded the arterial inflow and venous outflow to the CCP, making it a closed system during peak erection. However, during erection, the contrast medium continued to flow into the CSP, showing that it is not a closed system. In the vasodilatation phase, the CSP usually filled before and more intensely than did the CCP.     

Anthelmintic efficacy of thenium closylate-piperazine phosphate combination tablets against Toxocara canis in pups and young dogs

Thenium closylate-piperazine phosphate combination tablets, tablets containing either thenium or piperazine, and control tablets (excipients only) were administered in 2 doses 5 to 7.5 hours apart to weaned pups and young dogs, in critical controlled trials to test efficacy against naturally acquired infections of Toxocara canis. In the 1st trial, the combination tablets produced a mean clearance of 94% from 18 pups. Tablets containing thenium alone showed a mean clearance of 9% from 25 pups, and tablets containing piperazine alone caused a mean clearance of 56% from 16 pups. Clearances, corrected for spontaneous worm losses observed in pups treated with the control tablets, were 90% (combination), 5% (thenium alone), and 52% (piperazine alone). In the 2nd and 3rd trials, efficacy of the combination tablet in 15 pups was 78% when corrected for worm losses in pups which had received placebo (excipient) tablets. Each component in the combination tablet contributed its full single-entity efficacy and, if in combination, synergistic effect between the components.