- New research finds that smaller, fatter dogs with longer backs are at greater risk of slipped discs
- Short-legged dwarf dogs are affected, including Dachshunds, Pekingese, Shih Tzus, Basset Hounds and dwarf cross breeds
Breeding dogs to be longer in the body and shorter in the leg is putting them at greater risk of painful and debilitating slipped discs a study conducted by a BBSRC-funded PhD student reveals.
'Long-and-low' dwarf breeds are particularly prone to the condition according to the study from the Royal Veterinary College (RVC), published in the journal PLoS ONE.
The study shows that very long Miniature Dachshunds, whose backs are two-thirds longer than their shoulder height, have double the risk of slipping a disc by the time they reach five years old, compared with the shortest individuals of the same breed.
The researchers examined 700 dogs of diverse breeds referred to the RVC's Queen Mother Hospital for Animals over the course of a year, of which 79 dogs suffered the relevant type of slipped disc. Having a longer and lower body shape was the biggest risk factor, but small body size and being overweight also made dogs more vulnerable to the condition. Most of the affected dogs had long and low body shapes, although Jack Russell Terriers and Cocker Spaniels were also affected for reasons yet to be understood.
Dwarf breeds (such as Dachshunds and Basset Hounds) have been bred to have long and low body shapes, partly driven by the formal descriptions of each breed's characteristics, known as 'Breed Standards'.
Dwarf dog breeds have abnormal cartilage, making them prone to a certain type of slipped disc. In these dogs the normal shock absorbing gel, which is encased in 'discs' between the bones of the spine, degenerates and hardens. A disc can then rupture and the hardened material bursts out, pressing painfully on the spinal cord and causing nerve damage.
PhD student Rowena Packer from RVC, who carried out the study, said: "We regularly see some of the longest dogs come into the hospital for their first, second or even third slipped disc. Unfortunately this disorder is so common in some of the longest breeds, that it could almost be regarded as 'normal', however breeders and vets should not become desensitised to this serious condition, and must work together to reduce its occurrence as it causes huge distress for both the dog and owner."
When slipped discs happen, they are usually sudden, with the dogs in obvious pain and sometimes unable to move their hind legs. Many of these dogs must be cared for as long term paraplegics with some relying on wheels to support them as they move around. Some dogs undergo major spinal surgery followed by a lengthy stay in a cage while they heal. Other dogs are so severely affected that they have to be put down.
Dr Charlotte Burn, who led the research, said: "The 'sausage dog' shape is highly distinctive of these breeds, but these results show that our demand for longer and lower dogs needs to be reined in. In this context, shorter backs are safer backs."
"We were also surprised that smaller dogs were at more risk, but this is likely because the human environment is larger relative to their body size, making things like jumping down a step, or into a car, more dangerous for them."
Veterinarians Drs Anke Hendricks and Holger Volk, both from the Royal Veterinary College, emphasised the importance of keeping your dog lean and in good body condition. "Breeders, veterinarians and researchers need to work together to use the findings of this study to improve the body shape of those lovely dogs to reduce the risk of this serious condition. Embracing the results with an open mind to improve the wellbeing of human's best friend is of vital importance."
Dr James Kirkwood, Scientific Director of the Universities Federation for Animal Welfare said: "This important research clearly illustrates the potential dangers to animal welfare associated with breeding dogs for body shape or other characteristics to meet arbitrary preferences about appearance rather than for good health, welfare and fitness. It shows the way for making great and long-lasting improvements to the welfare of these dogs."
Notes to editors
To read 'How long and low can you go? Effect of conformation on the risk of thoracolumbar intervertebral disc extrusion in domestic dogs', visit: http://dx.plos.org/10.1371/journal.pone.0069650
Photographs of affected dogs can be provided on request.
About Royal Veterinary College
The Royal Veterinary College is the UK's first and largest veterinary school and a constituent College of the University of London. It also provides support for veterinary and related professions through its three referral hospitals, diagnostic services and continuing professional development courses. www.rvc.ac.uk
The Universities Federation for Animal Welfare (UFAW) is an internationally recognised, independent scientific and educational animal welfare charity. It works to improve knowledge and understanding of animals' needs in order to achieve high standards of welfare for farm, companion, research, captive wild animals and those with which we interact in the wild. UFAW improves animal welfare worldwide through its programme of awards, grants and scholarships; by educational initiatives, especially at university and college level; by providing information in books, videos, reports and in its scientific journal Animal Welfare. UFAW provides information on welfare aspects of a wide range of genetic diseases of companion animals at www.ufaw.org.uk/geneticwelfareproblems.php.