Age of sexual maturity and factors associated with neutering dogs in the UK and the Republic of Ireland

BACKGROUND

Surgical neutering of dogs is common, however the average age that dogs reach sexual maturity, are neutered, and dog owners' attitudes to neutering in the UK and the Republic of Ireland have not been explored in a longitudinal study.

METHODS

Owner-reported data on the timing of the first oestrus, timing of neutering and the reasons given for neutering dogs by 12 and 15 months of age were summarised. Factors associated with neutering at 15 months and factors associated with intention to neuter were quantified using multivariable logistic regression.

RESULTS

At 15 months of age, 90.0% (n = 207/230) of unneutered females had had their first oestrus. By 7, 9, 12 and 15 months of age, 22.1% (n = 131/593), 32.2% (197/593), 45.4% (n = 269/593) and 59.9% (n = 352/593) of dogs were neutered, respectively. Breed purity, dog's source, owners' intentions to neuter and the number of dogs in the household were associated with neuter status at age 15 months. Dog's sex, Kennel Club registration, dog's source, dogs intended to be working dogs and previous dog ownership were associated with intentions to neuter. Preventing puppies was the most common reason for neutering.

CONCLUSION

Understanding factors that shape owners' intentions to neuter can inform owner-vet discussions regarding whether to neuter a dog and the optimal age for doing so.

Puppy acquisition: factors associated with acquiring a puppy under eight weeks of age and without viewing the mother

Background

Puppy acquisition decisions may impact upon the health and behaviour of these dogs in later life. It is widely recommended by welfare organisations and veterinary bodies that puppies should not leave maternal care until at least eight weeks (56 days) of age, and that when acquiring a puppy it should be viewed with its mother.

Methods

Owner-reported prospective data were used to explore risk factors for puppy acquisition age, and whether the mother was viewed during acquisition, within a cohort of dog owners participating in an ongoing longitudinal project.

Results

A quarter (461/1844) of puppies were acquired under eight weeks of age and 8.1 per cent were obtained without viewing the mother (n=149). Only 1.6 per cent of puppies were obtained under eight weeks of age and without the mother being seen (n=30). Multivariable logistic regression analysis revealed that owners who intended their puppy to be a working dog, visited their puppy prior to acquisition, and/or obtained a puppy of unknown breed composition had increased odds of acquiring a puppy under eight weeks of age. The odds also increased as the number of dogs in the household increased but decreased as annual income rose. Owners who visited their puppy prior to acquisition, obtained a Kennel Club registered puppy, viewed the puppy’s father, and/or collected their puppy from the breeder’s home had decreased odds of acquiring a puppy without viewing the mother.

Conclusion

Targeting interventions towards identified owners who are more likely to acquire a puppy against current recommendations could help reduce these types of acquisitions.

Pericellular colocalisation and interactive properties of type VI collagen and perlecan in the intervertebral disc

The aim of this study was to immunolocalise type VI collagen and perlecan and determine their interactive properties in the intervertebral disc (IVD). Confocal laser scanning microscopy co-localised perlecan with type VI collagen as pericellular components of IVD cells and translamellar cross-bridges in ovine and murine IVDs. These cross-bridges were significantly less abundant in the heparin sulphate deficient Hspg2 exon 3 null mouse IVD than in wild type. This association of type VI collagen with elastic components provides clues as to its roles in conveying elastic recoil properties to annular tissues. Perlecan and type VI collagen were highly interactive in plasmon resonance studies. Pericellular colocalisation of perlecan and type VI collagen provides matrix stabilisation and cell-matrix communication which allows IVD cells to perceive and respond to perturbations in their biomechanical microenvironment. Perlecan, at the cell surface, provides an adhesive interface between the cell and its surrounding extracellular matrix. Elastic microfibrillar structures regulate tensional connective tissue development and function. The 2010 Global Burden of Disease study examined 291 disorders and identified disc degeneration and associated low back pain as the leading global musculoskeletal disorder emphasising its massive socioeconomic impact and the need for more effective treatment strategies. A greater understanding of how the IVD achieves its unique biomechanical functional properties is of great importance in the development of such therapeutic measures.

The effect of silica nanoparticulate coatings on serum protein adsorption and cellular response

Serum protein adsorption on colloidal silica surfaces was investigated using a quartz crystal microbalance with dissipation (QCM-D) monitoring. The amount of serum proteins adsorbed on colloidal silica-coated surfaces was not significantly different from the control silica surfaces, with the exception of 21nm colloidal silica which experienced significantly less (P<0.05) fibrinogen adsorption compared with control silica. The adhesion and proliferation of human endothelial cells (C11STH) on nano-scale colloidal silica surfaces were significantly reduced compared with control silica surfaces, suggesting that the conformation of adsorbed proteins on the colloidal silica surfaces plays a role in modulating the amount of cell binding. Fibronectin is one of the main extracellular matrix proteins involved in endothelial cell attachment to biomaterial surfaces. There was reduced binding of a monoclonal anti-fibronectin antibody, that reacted specifically with the cell-binding fragment, to fibronectin-coated colloidal silica surfaces compared with control silica surfaces. This suggests that the fibronectin adsorbed on the colloidal silica-coated surfaces was conformationally changed compared with control silica reducing the availability of the cell-binding domain of fibronectin.