Cranial cruciate ligament injuries are a common orthopaedic condition in dogs (Budras et al., 2007). The cranial cruciate ligament runs between the femur and tibia and stabilises the stifle joint by preventing the femur from sliding forwards during weight-bearing. The cranial cruciate ligament also limits medial rotation of the tibia when the stifle joint is flexed (Evans and deLahunta, 1996).
Cranial cruciate ligament rupture is one of the most common orthopaedic conditions in dogs (Budras et al., 2007). Cranial cruciate ligament rupture or tearing can be extremely painful and if untreated can cause meniscal tears and potentially osteoarthritis (OA) (Beetem, 2012). There is vast research on the contributing factors and recommended treatments.
Certain breeds appear to be more susceptible than others, one paper which looked at 426 dogs found that the breeds most commonly presenting with cranial cruciate ligament disease were Labrador Retrievers, 16%, Rottweilers, 15%, Golden Retrievers 12% and Boxers, 9% (Guthrie et al., 2012). Another study found that there were cellular differences between the cranial cruciate ligament in Labrador Retrievers who are prone to cruciate injuries and Greyhounds who are not (Smith et al., 2012).
Another contributing factor to cranial cruciate ligament injuries is conformation. Dogs with cow hocks and/straight hindlimb conformation (reduced stifle and hock angle when viewed from the side – image below) are predisposed to cruciate ruptures (Roush, 2013).
When rehabilitating cruciate injuries it is important to increase the muscles that surround the stifle joint. Building these muscles can also help as a preventative measure to reduce the strain on the cruciate ligaments. There are studies to support this theory which show a correlation between decreased quadriceps muscle mass and cruciate disease (Mostafa et al., 2010; Adrian et al., 2013).
If you are concerned about your dog, consult your veterinary surgeon who will be able to advise you.
Increasing Hindlimb Strength
When walking, many dogs will pull themselves along with their chest and front legs which results in the back legs doing less work. Over time, the back end loses strength and the front end gains strength making the dog even less likely to recruit the muscles of the pelvic limb which could increase the strain on the joints, tendons and ligaments. A simple way of encouraging your dog to use his backend is to walk him slowly. If your dog pulls on the lead this will also increase the weight carried on the front legs and reduce the weight carried behind, to address this, the use of a headcollar or harness rather than a collar may help. Slow lead walking doesn’t sound like hard work but it is likely that when you walk your dog, he is trotting which is easier than walking. During trot each limb spends less time on the ground and momentum carries them forwards. Slowing the pace to a walk means that each limb has to be in contact with the ground individually and therefore take more weight which will increase muscle strength over time!
Another simple exercise that you can add into your walks is a sit to stand transition. Going from a sit to stand requires the muscles that support the joints to work particularly the gluteals, hamstrings and quadriceps which support the joints of the pelvic limb. When performing this exercise it is important that the dog sits with both legs tucked under his bottom, not with one leg out to the side. If your dog tends to sit consistently with one leg out it may be worth monitoring and if it continues getting your vet to have a look.
Adding these two simple exercises into your dog’s routine will help to build muscle over his back legs to reduce strain on his joints and his front legs. If you have any concerns/queries ask your vet or contact your local veterinary physiotherapist who can give you specific advice for your dog.
Adrian, C.P. Hausseler, K.K, Kawcak, C. Reiser, R.F. Riegger-Krugh, C. Palmer, R.H. McIlwraith, C.W. Taylor, R.A. 2013. The Role of Muscle Activation in Cruciate Disease. Veterinary Surgery. 42 765-773
Beetem, J. 2012. Canine Rehabilitation: Getting Orthopaedic Patients Back on Their Feet. Firstline. dvm360.com
Budras, K.D. McCarthy, P.H. Fricke, W. Richter, R. 2007. Anatomy of the Dog. 5th Edition. Hannover, Germany, Schlutersche
Evans, H.E. deLahunta, A. 1996. Miller’s Guide to the Dissection of the Dog. 4th Edition. Philadelphia, US. W.B. Saunders Company
Guthrie, J.W. Keeley, B.J. Maddock, E. Bright, S.R. May, C. 2012. Effect of Signalment on the Presentation of Canine Patients Suffering From Cranial Cruciate Ligament Disease. Journal of Small Animal Practice. 53 273-277
Mostafa, A.A. Griffon, D.J. Thomas, M.W. Constable, P.D. 2010. Morphometric Characteristics of the Pelvic Limb Musculature of Labrador Retrievers with and without Cranial Cruciate Ligament Deficiency. Veterinary Surgery. 39 380-389
Roush, J.K. 2013. Canine Cranial Cruciate Disease. Today’s Veterinary Practice.
Smith, K.D. Vaughn-Thomas, A. Spiller, D.G. Clegg, P.D. Innes, J.F. Comerford, E.J. 2012. Variations in Cell Morphology in the Canine Cruciate Ligament Complex. The Veterinary Journal. 193 561-566