Evaluation of a Burdizzo Castrator for Neutering of Dogs

A Burdizzo castrator was evaluated for the neutering of dogs. Histological and morphological changes of spermatic cells and peripheral serum testosterone after challenge with a GnRH-analogue (gonadorelin) were assessed. There was a control group (G1), a surgically castrated group (G2) and a Burdizzo group (G3) divided in two, G3a receiving two crunches in each spermatic cord and G3b receiving one crunch in each spermatic cord. Sixteen days after application of the Burdizzo blood samples were taken from the dogs at 30 min interval during 2 h; after the second sample the dogs were treated with 1 mug/kg body weight of gonadorelin i.v. The same protocol of gonadorelin challenge was performed in G1 and G2 dogs. The G2 dogs were surgically castrated after the second blood sample, before the gonadorelin treatment, and the G1 dogs after the last blood sample. The excised gonads were examined histologically, and sperm smears were prepared from the caudae epididymidis. The testes and plexus pampiniformis of the G1 and G2 dogs had a normal histological appearance, and they had morphologically normal epididymal sperm cells. In all G3 dogs, there was an acute fibrosis with an inflammatory reaction in the plexus pampiniformis. The testes from the G3a dogs showed diffuse areas of infarction and degeneration of the parenchyma. Similar but less diffuse lesions were seen in group 3b dogs. The deferent ducts from all G3 dogs showed vasitis and/or sperm granulomas. Azoospermia or sperm malformations were observed in the epididymal smears from the G3 dogs. Testosterone concentration in the G1 dogs increased after gonadorelin application (p < 0.0001). The G2 dogs had basal testosterone levels after castration (p < 0.001) and did not respond to gonadorelin. Groups 3a and b showed a slight but non-significant increase in testosterone concentration after gonadorelin challenge, supposedly due to the reduction of testicular blood flow and loss of testicular interstitial tissue.     

Evaluation of Efficacy and Safety of Zinc Gluconate Associated with Dimethyl Sulphoxide for Sexually Mature Canine Males Chemical Neutering

The aim of this research was to evaluate the efficacy of zinc gluconate associated with dimethyl sulphoxide (DMSO) for chemical neutering in canine males. Fifteen sexually mature male dogs were divided in two groups, named control and treated. An injection was administered to both testicles, at a concentration of 26.2 mg zinc gluconate per ml and 0.5% DMSO in the treated group (11 dogs). The control group was given injections of saline solution (four dogs). Clinical examination and blood collection for a haemogram were done both before and after drug injection. There were 12 spermograms performed to analyse sperm motility, sperm vigour, ejaculate volume, testicle size, pathology and sperm concentrations. Libido was also measured. An ultrasound examination and histopathology were performed at the end of the experiment. Dogs’ libido after chemical injection was reduced by over 50%. The spermogram analysis showed final mean results of 14.54% for sperm motility, 0.72 of sperm vigour and 37 150 per million spermatozoa per millilitre, values considered below the necessary levels at which fertilization can occur. Ultrasound and histopathology analyses of testicles for the treated group revealed more intense injuries when compared with the control group, with compromised testicular parenchyma and a decrease of germ cell number leading to total atrophy, indicating that the treatment reduced the fertilizing potential of male dogs, promoting a possible subfertile status.     

Behavior of dogs

The present results of comparative ethology in different dog breeds make plain their very variable demands in social life as in other environmental criteria. Dog breeds differ as greatly in behaviour characteristics that environmental demands in dogs are less to be described as "species typical" rather than as breed specific. Characteristics in behaviour that are typical of certain dog breeds could be proved especially in the following fields: 1. Ontogeny of behaviour does not develop in a "domestic dog typical" way, rather it is characterized by significant differences among dog breeds concerning the rate of development of certain behavioural characters and physiological processes (both relative retardation and relative acceleration compared to the ontogeny of behaviour in wolves). 2. There are breed typical differences in expressive behaviour and in communication. 3. Dog breeds show differences in social behaviour and bonding behaviour toward humans.