Publishing Author : Jay Gray
Date Published : 26/10/18
Certain issues within Canine Anatomy are more likely in certain breeds of dogs. It is not a universal issue among all canines for the most part, although there are issues that effect a massive array of breeds. The three issues discussed in this paper are Hip Dysplasia, Anterior Cruciate Ligament Injuries and Cervical Spondylomyelopathy (also known as Wobbler’s Syndrome) are all common among larger breed dogs, specifically the Rottweiler.
Rottweiler’s (and other larger breeds) are specifically prone to all three of these issues, but that does not mean that other breeds even of large differences can also be affected. All three issues can affect small breeds, mid breeds and large breeds, they are just less common in breeds like the Rottweiler.
Hip dysplasia is fairly common issues in many larger breeds where the elbow or hip joint has an ill fit where the ball and socket meet. Hip dysplasia can cause mild to severe pain depending on its severity and is almost irreversible except with surgery that can help. Many methods for preventing the issue worsening are practiced commonly.
Anterior Cruciate Ligament (ACL) injuries usually occur after trauma but can occur spontaneously if the dog is predisposed to these issues genetically. In these injuries the ACL is usually ruptured but can be snapped completely showing very obvious symptoms in the dog. ACL reconstruction can be a costly operation that many dogs’ owners dread having to endure. The recovery time is long, the operation is expensive and the chances of re injury are generally high.
Cervical Spondylomyelopathy (Wobblers Syndrome) causes an unsteady gate in dogs. The term is a bit of a catch all term referring to several possible malformations that can cause the symptoms. It is most common in large breed dogs and race-bred horses of Thoroughbred ancestry. There are multiple treatments for wobblers syndrome but very often this is a disease that requires management rather than cure. The severity of the disease will dictate how a professional decides to proceed.
Hip Dysplasia is a canine (genetic) condition where there becomes a tendency to hip laxity especially in later life. The word dysplasia means ‘abnormality of development’ and only occurs because of the genetic morphological incorrectness in the hip. The condition is generally accepted to not be congenital but can become worse with external, environmental influences. The soft tissues that normally stabilise the hip joint are looser than they should be, and this occurs within the first few weeks of a dog’s life. The consequence of this laxity is that the normally congruent ball ad socket becomes considerably less congruent. The ball becomes more flattened and deformed and the socket becomes more and more saucer shaped. All dogs with hip dysplasia develop secondary osteoarthritis of the affected joint and the vast majority of dogs with this condition have dysplasia of both hips rather than just a single side.
The condition is almost always of genetic cause but as stated, environmental factors such as obesity (especially in puppyhood) can influence and accelerate the issue that occurs genetically in the dog. Current estimates state that more than one hundred genes code for hip dysplasia and it is important to remember that environmental factors alone cannot cause hip dysplasia, but they can influence and accelerate the genetic issue into a clinical problem. The most common myth surrounding hip dysplasia is that excessive exercise as a puppy can contribute to the development of a clinical issue but there is no evidence to support this claim.
Hip Dysplasia is the most common orthopaedic condition in dogs and most frequently affects large, rapidly growing dogs (such as the Rottweiler) but other smaller breeds and even cats can also be affected. It is usually diagnosed between 6 and 12 months of age with varying clinical signs presenting themselves. Stiffness, exercise intolerance, difficulty getting up or lying down, problems climbing stairs, gait abnormalities etc. It is extremely rare for dogs to demonstrate overt signs of pain at home due to the natural guarding of the joint but when a veterinary surgeon extends the hips dogs will often show severe pain almost immediately. This pain is caused initially by the repetitive straining of the lax hip stabilisers and micro fracturing of the bone and cartilage surfaces as they rub past one another. As this erosion advances, the pain is the result of the global joint disease known as osteoarthritis.
Diagnosis usually involves a multimodal evaluation process between the owner, the primary care vet and often a specialist orthopaedic surgeon. The primary care vet may recognise an abnormal gait or hip pain during other routine checks. These checks are usually raised by the owner after they notice some of the aforementioned issues. If the primary care vet has a suspicion of hip dysplasia they will likely book for radiographs to take a closer look at the hip joints. Radiographs will show changes in affected dogs, but this is not always the case. Usually, from this point forwards the issue will be referred to a specialist orthopaedic surgeon.
The best treatment for hip dysplasia is dependant on a multitude of factors but the most important of these factors is the severity of the clinical issue. In some dogs, the clinical problem is mild, and the diagnosis of the condition was incidental as part of a screening test for other issues. In other dogs, the clinical signs are dramatically more severe, and treatments will target the current problem alongside the potential problems that the dog is likely to face as tie goes on.
Non-surgical management is the first suggestion, especially for dogs diagnosed as an incidental finding. For clinically affected dogs, the likelihood of a strong response to non-surgical management depends largely on how severe the hip pain is. The cornerstones of non-surgical treatment are body weight management, physiotherapy, exercise modification and medication such as anti-inflammatory pain killers. In the short term, most dogs will see an improvement when they are managed appropriately. Unfortunately, the improvements rarely stretch out over long periods of time and the majority of dogs followed into later life will have ongoing exercise restriction and require medications.
Surgical intervention comes in four common forms. JPS, TPO, THR and FHNE. Juvenile Pubic Symphosiodesis is a surgery involving premature fusion of a part of the pelvis. It is a simple surgery that involves electrical cauterization of part of the pubis and in order to be effective, dogs must be a maximum of five months of age with mild to moderate laxity confirmed using manipulative and radiographic tests. As most dogs do not show signs of issues until at least six months JPS is uncommon. All dogs treated by JPS must be neutered at the same time. Triple Pelvic Osteotomy is a surgery involving the surgical modification of the existing hip joint to improve the capture of the ball. Three cuts are made in the bones around the cup and the free segment is rotated t a point that allows optimal hip capture. The bone fragments are then fixed in position and healing can begin. Healing generally takes 4-6 weeks, and this is only effective in dogs that have hip laxity with no secondary remodelling of the bones or subsequent arthritis. Total Hip Replacement is a considerably more advanced procedure and should only be performed by experienced orthopaedic surgeons. The procedure involves cutting out the entire joint. The ball is replaced with a metal implant and the socket is replaced with a plastic and metal implant. They can be attached to the bone using cement or using a porous coating into which bone can grow. Noel Fitzpatrick is a common practitioner of this coating. The success rate for THR is 90-95% and most dogs are more comfortable within just a few days of surgery. The final option for surgical intervention is Femoral Head and Neck Excision which involves a salvage procedure and is only considered when THR cannot be performed for financial reasons or due to individual anatomy that could preclude it. In this method, the femoral head and neck are completely removed allowing a false joint to form. Pain is relieved by elimination of the bony contact between the ball and the socket. This typically comes at the price of limited function, so the clinical outcome can be unpredictable. Intensive physical therapy is mandatory after FHNE so referral to a chartered physiotherapist is often common.
ACL Injury and Disease
The term ACL is actually a term used in humans and means Anterior Cruciate Ligament. The name for the same ligament in dogs is actually the Cranial Cruciate Ligament (CrCL) but the conditions and injuries are most commonly referred to as ACL, probably for a clearer understanding for owners. For the sake of this paper, the Cranial Cruciate Ligament will be known as the ACL to aid in clarity. The ACL is a band of fibrous tissue that attaches the femur and the tibia. It prevents the tibia from shifting forward relative to the femur and helps to prevent the stifle from over extension and rotation. In humans, ACL ligaments are extremely common in sporting injuries such as football, rugby and even golf but in canines the nature of these injuries is much more gradual and comes in the form of degeneration, almost like a fraying rope. This difference the primary reason that treatment options for ACL damage are fundamentally different to that recommended for humans.
In a large majority of dogs, the ACL ruptures as a result of extensive, long term degeneration, where the fibres within the ligament become weaker over time. The precise cause of this remains unknown to this day but genetic factors are no doubt important and further support the evidence of certain breeds being prone to this issue (Rottweilers, Boxer Dogs, Newfoundland’s, to name a few). The supporting evidence for genetic causal factors was obtained by assessment of family lines, coupled with the knowledge that many animals will rupture the ACL of both knees, often fairly early in their life. Contributing factors such as obesity, confirmation, and inflammatory conditions also play a role in this syndrome.
Limping is usually the initial and most common sign of an ACL injury. It may appear suddenly during or after exercise or it may be progressive and intermittent. Some dogs experience ACL issues in both knees simultaneously and these dogs often find it difficult to rise from the prone position and are often described as having a ‘pottery’ gait. In extreme cases, dogs cannot get up at all and can be erroneously suspected of having neurological issues rather than ACL problems.
Inside the joint, the fraying of the ligament is the catalyst to further events resulting in knee pain and lameness. The early stages of ACL issues often see osteoarthritis present and it is important to accept this because many people view this is something only present in more latent phases. At a critical point in the fraying of the ligament, the ACL loses its mechanical functions and painful lameness is then accompanied by mechanical lameness. At this point, the shape of the top of the tibia begins to have a pronounced backwards slope. The consequence of this slope is that the femur will roll down the slope every time weight is taken onto the affected leg. In dogs without impairment of the ACL this slope will only become a problem if the steepness becomes severe enough. In some cases, the mechanical deficiency can result in trauma to neighbouring structures within the joint. The most commonly affected are a pair of buffer cartilages known as the menisci. The femur can crush and tear these cartilages, particularly those in the medial aspect of the joint.
Diagnosis is usually based on the examination from an experienced orthopaedic surgeon with demonstration of laxity in the joint by manipulation of the knee. Dogs with partial tears or early degeneration can often need further testing such as radiography or MRI scans. Exploratory surgery is often used to confirm the diagnosis of the initial investigation to ensure that the diagnosis is correct.
Non-surgical management is uncommon in ACL injuries except where the risks of GA or surgery are considered excessive. The cornerstones of non-surgical management are much the same as those in Hip Dysplasia. These same techniques are also important in the short-term management of dogs who are following a surgical intervention plan although the surgery itself aims to reduce the restriction of exercise and long-term medication. Dogs over 15kg have a very slim chance of a normal life with non-surgical treatment alone due to the forces acting on the ligament and thus the joint.
Various surgical techniques mimic the procedures used for ACL replacement in humans (these have been used for over five centuries). Prosthetic ligament techniques have also been used for many years and are the simplest techniques that have the ability to return many animals to almost full function. The disadvantage of these techniques is their unpredictability during the early stages of recovery and the mechanical limitations in heavier and more athletic dogs. It is not uncommon for dogs to become transiently lame before improvement occurs.
TPLO and TTL are the two most favoured surgeries to combat ACL injury and disease. Tibial Plateau Levelling Osteotomy involves creation of a radial cut in the top of the tibia. The segment is then rotated until the previous slope in the bone is no longer present. The bones are then fixed in this new position using metal bone plate and screws. Tibial Tuberosity Advancement follows a similar principle as TPLO where a cut is created in the tibia to allow the change in geometry, rendering the ACL redundant. The mathematical principles around TTL are considerably more complex but the basic principle is that an altered direction of traction from the quadriceps produces a force across the knee that neutralises the tendency of the femur rolling down the slope onto the plateau. Both these methods aim to render the tibial plateau perpendicular to the patellar tendon, thus neutralising the tendency of the femur rolling down the slope.
TPLO and TTL are preferential because bone healing is considerably more efficient than ligament healing, so the repairs have a reputation for being much more robust than surgeries designed to replace the ligament itself. Dogs should start weight bearing on the damaged leg within 1-3 days.
As a rule, 90% of dogs return to normal activity after TPLO or TTA surgery meaning the dogs are so normal that the owners are unable to detect any lameness at home. Dogs are expected to return to unrestricted exercise without any requirement for further ongoing medications. Performance dogs such as military, GP or PP dogs are expected to return to normal work after these surgeries. The success rates for TPLO and TTA are almost identical so an osteopathic surgeon will decide the best route to full recovery.
Cervical Spondylomyelopathy (Wobblers Syndrome)
Cervical Spondylomyelopathy is a disease of the spine, within the neck resulting in poor transmission of the nerve signals between the brain and the body. This disease is commonly referred to as Wobbler Syndrome or Wobblers Syndrome. Throughout this paper it will be referred to as CS. There can be a variety of structural issues of the bones in the neck in affected dogs and most frequently these are bony abnormalities with the intervertebral discs which degenerate and protrude directly against the spinal cord. In addition to this, the compression of the cord may be affected by different positioning of the neck itself and as a result, movement in the neck may result in repetitive trauma to the spinal cord. The final common issue of dogs diagnosed with CS is spasms within the muscles in the neck.
Much like the initial two issues discussed in this paper, CS is primarily a genetic issue, but there is argument that dietary factors may be contributory. There is evidence in multiple literatures to suggest that the affected dogs specifically have a reduced size of the neck spinal canal compared to normal dogs of the same breed, which may increase the risk of their development of the disease. In addition to this, increased rotation of the lower neck spine may explain why CS commonly affects this area.
Dogs affected by CS tend to be giant breeds (such as the Rottweiler, Doberman, Great Dane etc) and they can show signs of the syndrome throughout their life. Extremely large breeds such as the Great Dane tend to exhibit symptoms when they are young adults, whereas other breeds like the Doberman are often middle aged when they first develop such symptoms. The most common clinical sign of CS is the ‘wobbly’ gait, where the dogs tend to scuff their feet or stumble when walking. Some dogs also exhibit neck pain although many show no signs of discomfort. Various other diseases show similar symptoms to CS including spinal fractures tumours and other congenital abnormalities.
CS is caused by pathology associated with the intervertebral discs between the bones of the vertebral column. The diagnosis tends to be confirmed using an MRI scan to examine the cord itself and the discs between the cervical vertebrae. A CT scan will then be used to examine the shape of the bones of the column and some dogs will also have adjunctive tests such as blood or spinal fluid collection to help confirm a diagnosis.
The cause and severity of the problem dictates what the best line of treatment is, as well as the suspected duration of the spinal cord compression. Generally, a neurological clinician will advise the most suitable form of treatment based on the dogs individual case and results of the aforementioned tests.
Non-surgical intervention and treatment can allow some stabilisation of the condition in the short term, but it is only recommended for dogs with mild pathology and very slow progression of the disease. Ongoing physical therapy is absolutely vital for treatment of this manner and is facilitated by the support of a chartered physiotherapist and or hydro therapist. As with the two issues mentioned previously, the non-surgical treatment methods are much the same.
Decompressive surgery (otherwise known as a ventral slot) involves the removal of a slice of bone within the casing of the spinal canal, allowing the removal of any bulging or ruptured intervertebral disc material that can be compressing the spinal cord. The procedure is fairly antiinvasive and easy to perform.
Vertebral Distraction-Fusion is a very effective surgical treatment for dogs with CS where compression of the nerve roots is present and pathological instability is suspected. The cervical vertebral distraction-fusion will address the spinal cord compression associated with different positions of the neck and prevent ongoing and repetitive trauma. VDF involves the stretching of the adjacent vertebrae by placing a custom-made titanium bolt called a FITS (Fitz intervertebral traction screw). As the name suggested, the method was founded by the ground-breaking veterinary surgeon, Professor Noel Fitzpatrick. Bone marrow harvested from the humeri encourages permanent biological fusion of the vertebrae and the metalwork. This method has been used in a number of dogs with CS and has successful results. The method is currently only available at Fitzpatrick Referrals, who offer more options within this treatment than anywhere else on the planet. Success rates for surgery largely depend on the duration of the problem and the clinical severity. Dogs able to walk have a vastly better chance than those showing paralysis. High postoperative care regardless is important to avoid complications and allow complete rehabilitation.
All three of these issues are prevalent in many of the large breeds and specifically the Rottweiler. They all carry similarities in their non-surgical intervention methods and in the fact that the earlier the prognosis is made, the better the chance of complete rehabilitation and the dog’s life returning to normal.