Nutrition and behavior in senior dogs

With increasing age, some dogs develop a neurogenerative disease that is commonly referred to as canine cognitive dysfunction syndrome (CDS). Diagnosis of CDS can be clinical or based on laboratory tests. The main behavioral changes associated with CDS are disorientation, altered interactions with people or other animals, sleep-wake cycle alterations, house-soiling, and changes in activity level. Ruling out medical conditions that can cause similar changes in behavior is important when performing a clinical diagnosis. Management of CDS includes dietary and pharmacological intervention. Dietary treatment of CDS has been based on the use of antioxidants and mitochondrial cofactors, and recent work has shown that long-term supplementation with medium-chain triglycerides can improve cognitive function in aged dogs. CDS must be considered an animal welfare issue and the implications of this are discussed in this article.     

Salivary cortisol and behavior in therapy dogs during animal-assisted interventions: A pilot study

Animal-assisted interventions (AAIs) have been associated with positive effects on human psychological and physiological health. Although the perception of quality standards in AAIs is high, only few investigations have focused on potential welfare implications for therapy dogs linked to their performance in AAIs. The standardized program “multiprofessional animal-assisted intervention (MTI)” has been carried out in adult mental health care, significantly improving patients' prosocial behaviors. In the present study, we monitored salivary cortisol and behavioral measures in therapy dogs that participated in MTI group therapy sessions in an in-patient substance abuse treatment facility. Work-related activity (lay, sit, stand, walk, and run), behavior (lip licking, yawning, paw lifting, body shake, tail wagging, and panting), response to human action (taking food treats and obeying commands), and salivary cortisol levels were analyzed over the course of 5 subsequent MTI working sessions in experienced therapy dogs (N = 5), aged 5.4 ± 2.8 years (mean ± standard deviation). Salivary cortisol levels decreased from presession to postsession in sessions 1, 2, and 3. However, only in session 4 and 5, postsession cortisol levels were significantly lower than presession levels (P = 0.043). There was no difference between salivary cortisol levels sampled on a nonworking day at home and work-related levels sampled at the therapy site. None of the behavioral parameters varied significantly over the course of the 5 MTI sessions. Both lip licking (P = 0.038) and body shake (P = 0.021) were positively correlated with the decline in cortisol during session 5. The study results suggest that trained dogs are not being stressed by repeated participation in in-patient substance abuse therapy sessions. Further investigation into the effects of animal-assisted therapy on dogs' physiological markers and behavior is warranted.     

Suspected air embolism through the thoracic ventral internal vertebral venous plexus during hemilaminectomy in dogs

Venous air embolism entering via the ventral internal vertebral venous plexus was suspected during thoracic spinal surgery in two dogs. In both cases, air was seen bubbling from a pool of blood on the floor of the vertebral canal accompanied by sudden cardiopulmonary disturbances: low end‐tidal carbon dioxide pressure, tachycardia and reduction in oxygen in the blood. One dog became dyspnoeic and one died.     

Importance of bringing dogs in contact with children during their socialization period for better behavior

Much attention has been given to the role that dogs play in the social, physical, and psychological development of children. Furthermore, dogs are now playing a new important role in animal-assisted education (AAE). However, some dogs have difficulty getting along with children. The aim of this study was to demonstrate how dogs' contact with children during and after their socialization period influenced their responses toward children. In total, 31 pet dogs were divided into three groups. Group 1 dogs had been in contact with children during the canine socialization period (between 3 and 12 weeks of age); Group 2 dogs had been in contact with children after this socialization period; Group 3 dogs seldom had contact with children. As soon as a child entered the room, the dog was presented three stimuli by the child over the course of several intervals. The dogs' responses were evaluated by analyzing behavior and heart rates. The dogs that had been in contact with children during their socialization period did not show aggressive behavior or excited behavior toward the child in our test. Moreover, their heart rates were significantly decreased even during the last stimulus, which involved the child running around the dog while calling its name. This study suggested that the dogs having contact with children during socialization period might not show inappropriate responses toward children and could be suitable for taking part in AAE.     

Effects of various sedatives on air cystometry in dogs

The effects of various sedatives on air cystometry in dogs were investigated. Oxymorphone plus acepromazine, xylazine alone, atropine plus xylazine, and diazepam plus ketamine were compared for interference with the detrusor reflex, adequacy of patient restraint, and development of adverse side effects. Atropine plus xylazine was the best of the 4 drug combinations tested, because it had the least interference with the detrusor reflex, bradycardia did not develop, and excellent restraint was obtained. Pain and hematuria were common whenever intravesicular pressure exceeded 40 cm of H2O, yet pressures that high were rarely necessary to stimulate the detrusor reflex.     

Identifying animal welfare impacts of livestock air transport

Air transport of livestock occurs frequently from most Australian major cities. The total journey time starts with road transport from the farm or pre-export facility to the departing airport where livestock are crated, and ends with the unloading of animals at the premises or farm in the importing country. We reviewed the literature regarding airfreight and conclude that there was minimal information on current practices within this industry, particularly for procedures after arrival at the Australian airport, and during the on-board phase.     

Effect of cisplatin on bone transport osteogenesis in dogs

OBJECTIVE: To document effects of cisplatin on regenerate bone formation during the distraction and consolidation phases of bone transport osteogenesis. ANIMALS: 10 skeletally mature hounds. PROCEDURES: Bone transport osteogenesis was performed to reconstruct a 3-cm defect in the radius of each dog. Five dogs were randomly selected to receive cisplatin (70 mg/m2, IV, q 21 d for 4 cycles), and 5 were administered saline (0.9% NaCl) solution. Bone mineral density was measured by use of dual-energy x-ray absorptiometry (DEXA) on days 24, 55, and 90 after surgery. Dogs were euthanatized 90 days after surgery. Histomorphometry was performed on nondecalcified sections of regenerate bone. Bone mineral density and histomorphometric indices of newly formed bone were compared between groups. RESULTS: Densitometric differences in regenerate bone mineral density were not detected between groups at any time period. Cisplatin-treated dogs had decreased mineralized bone volume, decreased percentage of woven bone volume, decreased percentage of osteoblast-covered bone, increased porosity, and increased percentage of osteoblast-covered surfaces, compared with values for control dogs. Lamellar bone volume and osteoid volume did not differ significantly between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Regenerate bone will form and remodel during administration of cisplatin. Results of histomorphometric analysis suggest that bone formation and resorption may be uncoupled in cisplatin-treated regenerate bone as a result of increased osteoclast activity or delayed secondary bone formation during remodeling. These histomorphometric differences were modest in magnitude and did not result in clinically observable complications or decreased bone mineral density as measured by use of DEXA.     

Morphology and behavior of primary ocular melanomas in 91 dogs

Primary ocular melanocytic neoplasms from 91 dogs were divided into two groups by histologic criteria. Seventy-five were benign and composed of spindle-shaped and large polyhedral melanocytes similar to those of human ocular melanocytomas. Fifty-nine of these originated in the uvea where most resulted in uveitis, glaucoma, or hyphema prior to enucleation. None metastasized. Nineteen melanocytomas were limbal tumors. None metastasized, but three of nine incompletely excised tumors were found within the anterior chamber 2 to 3 years after the initial removal. Sixteen uveal melanocytic neoplasms were histologically malignant. Three had confirmed metastases, all within 3 months of enucleation. Cell type or pattern of growth within the globe were not predictive of biologic behavior. Our data suggest that the mitotic index is the best criterion for histologic identification of ocular melanomas with high metastatic potential. We propose that the classification of primary ocular melanomas be simplified to include only two categories: melanocytoma (benign) and melanoma (potentially malignant). Further behavioral data may justify a grading scheme for melanomas based upon mitotic index.     

Effect of inspired air heat and humidification on anesthetic-induced hypothermia in dogs

Dogs were evaluated for efficacy of inspired air heating and humidification in maintenance of body temperature during general anesthesia. Three separate trials were conducted: (i) a control group without thermal support (n = 5), (ii) a group supported only by a heated humidifier device placed in the inspiratory limb of an anesthesia circle delivery system (n = 7), and (iii) a group supported by combination of inspired air humidification and recirculating water blanket (n = 7). A significant difference (P greater than 0.4) was not noticed in temperature changes between control and humidifier-supported groups. A significant advantage (P less than 0.05) was noticed between the combined support and the humidifier or control groups. Seemingly, during general anesthesia, use of combined thermal support is significantly better than airway humidification for maintenance of normothermia in the dog.     

Postnatal development of nutrient transport in the intestine of dogs

OBJECTIVE: To measure nutrient absorption by the intestine during postnatal development of dogs. ANIMAL: 110 Beagles ranging from neonatal to adult dogs. PROCEDURE: Rates of absorption for sugars (glucose, galactose, and fructose), amino acids (aspartate, leucine, lysine, methionine, and proline), a dipeptide (glycyl-sarcosine), and linoleic acid by the proximal, mid, and distal regions of the small intestine were measured as functions of age and concentration (kinetics) by use of intact tissues and brush-border membrane vesicles. Absorption of octanoic acid by the proximal portion of the colon was measured in intact tissues. RESULTS: Rates of carrier-mediated transport by intact tissues decreased from birth to adulthood for aldohexoses and most amino acids but not for fructose and aspartate. Kinetics and characteristics of absorption suggest that there were changes in the densities, types, and proportions of various carriers for sugars and amino acids. Saturable absorption of linoleic acid in the small intestine and octanoic acid in the proximal portion of the colon increased after weaning. CONCLUSIONS AND CLINICAL RELEVANCE: Rates of absorption decreased between birth and adulthood for most nutrients. However, because of intestinal growth, absorption capacities of the entire small intestine remained constant for leucine and proline and increased for glucose, galactose, fructose, aspartate, and proline but were less than predicted from the increase in body weight. Although postnatal ontogeny of nutrient absorption was consistent with changes in the composition of the natural and commercial diets of growing dogs, rates of amino acid and peptide absorption were lower than expected.