Hip Dysplasia

Hips: What we can do

Hip and elbow dysplasia are big topics when it comes to our giant breed dogs. Both breeders and owners want our dogs to have the healthiest joints possible so they can live long and comfortable lives. However, current methods of health screening of breeding dogs limit us greatly as to what we can do regarding hip dysplasia. In a limited gene pool like the Pyrenean Mastiff, we have to operate with the theory of “breeding up”. This means we may take a dog who does not have a passing hip score and breed it to a dog with a passing hip score in hopes of improving the hips in offspring without losing valuable genetic material. (See PMUSA Breeding Guidance for appropriate pairings.) Because joints are polygenetic, and we currently have no way to identify which genes cause hip and elbow dysplasia, we are limited to doing our best in other ways to encourage healthy joints. In this article we are going to discuss some ways both breeders and owners can help encourage healthy joints.

Encouraging good joint health starts with the breeder! The very first thing breeders are encouraged to do is to radiograph the parents before breeding. As mentioned, in our breed we operate with the theory of breeding up. If we don’t know what our dog’s hips look like, then we don’t know if we are breeding two severe dogs together. Knowing what we are working with is one of the biggest pieces of the puzzle. While two excellent-rated dogs can produce a severe puppy, we are still trying to stack the deck in our favor with the diagnostic tools available. In addition to doing radiographs on parents, the next thing breeders need to consider is how puppies are reared! Hip and elbow dysplasia can develop due to environmental factors, as well as the genetic component. Consequently, how and where puppies are reared is extremely important. “The most critical period for proper growth and development of the hips and elbows in dogs is from birth to 8 weeks of age, so the type of exercise the puppies are exposed to is most important during this time.” (Beuchat PhD, 2015)

What Breeders Can Do

Environmental factors breeders need to consider regarding hip and elbow dysplasia include surfaces puppies walk on, exercise and diet. Joint laxity is the primary factor in environmental-based hip dysplasia. That is when the femoral head is not seated tightly in the acetabulum. This can be caused by trauma such as a fall or high impact activity, “overloading of the joint by weight, lack of muscle strength, or adductor forces.” (Beuchat PhD, 2015) We are going to break down each of these items and how breeders can help prevent these environmental factors from impacting puppies.

It is important to rear puppies on non-slip surfaces to prevent legs from splaying and slipping which can cause trauma to the tendons and the sensitive cartilage that has not calcified. This starts from day one! Having a surface that is grippy in the whelping box will help puppies move around properly and help with muscle development. The grippy surfaces should continue the entire time puppies are in the breeder’s care. Options for surfaces include fleece vet bedding, rugs, and rubber mats. Muscle development is extremely important to create stability within the joint because the muscles will help with protecting the joint as the puppy ages and keeping it in place. We will discuss later how muscle development also aids in preventing further degeneration of the joint.

"There is no evidence that a primary defect of bone exists but rather the disease is a failure of the muscles and other soft tissues to hold the hip joint in full congruity. This is further supported by the fact that bony dysplasia can be increased, decreased, or prevented by controlling the degree of joint instability and incongruity. No other malformations are associated with the disease. A causal relationship between muscles and soft tissue defects or pathologic changes other than lack of muscle mass or strength has not been established... Hip dysplasia is a concentration of factors from a pool of genetic weaknesses and environmental stresses that fall into a programmed pattern of progressive remodeling and degenerative joint disease." (Riser 1985)

Keeping puppies at a healthy weight is extremely important in ensuring the joints are not overloaded with weight. Keeping puppies lean while they grow is a necessity, many people want their giant breeds to be “big” but it is important to maintain slow and steady growth until growth plates close around the age of 2. “​Puppies that weigh more at birth as well as those with higher growth rates (so they get heavier sooner) have a higher risk of degenerative changes in the hip joint.” (Vanden Berg-Foels et al 2006)

“As this graph shows, puppies kept on a restricted diet (gray line) have a dramatically lower risk of dysplasia and it develops much later in life than in puppies kept on normal rations (black line).” (Smith et al 2006)

Diet fed to puppies is also extremely important as well as the weight of the puppy. It used to be believed that a high protein diet would cause rapid growth in dogs. However, studies indicate that “[H]igh protein intake is less important for development of normal hip joints than previous studies might indicate.” (Richardson DVM, 1992) Excess calcium intake has been highly associated to skeletal disease. “Chronic, high calcium intake in large breed dogs has been associated with hypercalcemia, concomitant hypophosphatemia, rise in serum alkaline phosphatase, retarded bone maturation, higher percentage of total bone volume, retarded bone remodeling, decrease in bone resorption cells, and retarded maturation of cartilage with disturbances in endochondral ossification (articular and epiphyseal).Clinical diseases associated with these changes are osteochondrosis, retained cartilage cones, radius curvus syndrome, and stunted growth.” (Richardson DVM, 1992) It is also important when monitoring weight in puppies that they are not overly underweight as the lack of nutrition can also impact skeletal growth and lead to skeletal diseases and stunted growth.

The last factor that is imperative to control with puppies while they are with the breeder is the type of exercise. A study done in 2012 by the American Journal of Veterinary Research showed that there was a high risk of hip dysplasia in puppies under 3 months who were exposed to daily use of stairs. This study also noted that it is important that puppies be allowed outdoor exercise on soft ground in moderately rough terrain to decrease the risk of hip dysplasia. Age-appropriate exercise is important to help develop muscle tone; but over exercising a young puppy or exposing them to any impact exercise can be detrimental. “On the other hand, dogs from 12-24 months old that regularly chase a ball or stick thrown by the owner have a higher risk of developing dysplastic hips.” (Sallander et al 2006)

What Owners Can Do

Once puppies leave their breeder after 8 weeks, it becomes the owner’s responsibility to monitor weight and exercise! While the highest impact is during the first 8 weeks, changes can still happen to the sensitive joints and growth plates after 8 weeks. Many of the things that owners need to take into account are similar to what a breeder must consider, including age-appropriate exercise and diet.

Weight management is extremely important when it comes to growing joints, your puppy should never be overweight. Weight management is important for preventing hip dysplasia and managing a dog who may already have hip dysplasia. It is important to find a food that is formulated for All Life stages or for large breed puppies. Ideally you want calcium to phosphorous ratios of the food to be between 1.2:1 and 1.5:1. Any higher than this is too much calcium and can lead to issues noted previously.

It is extremely important to manage your puppy’s exercise. High impact activities should be avoided, and this includes stairs every day, jumping in and out of the car or jumping off other objects. You should avoid forced exercise such as taking your dog running or jogging until their growth plates have closed. Most exercise after your puppy comes home should be self-directed play. This allows puppies to exercise at their own pace. After 3 months of age and prior to 6 months, you can start to introduce stairs. Make sure they have good footing on stairs, so they do not fall or slip while on the stairs. You can now start working on short sessions of exercise for 10-minute intervals with your puppy. Around 6 months of age, the first growth plates are starting to close. At this point you can do leashed walks up to 15 minutes, begin doing jumps as long as they are low impact, and introduce swimming. While swimming sessions should be kept short, at this age it is an amazing activity to do to help with muscle development. Later we will discuss other benefits of swimming. Between 18 months and 2 years the majority of the growth plates are closed and you can begin training for longer jogs, hiking, and swimming. Your puppy can now do higher impact activities such as agility training. It is important to remember that if you plan to do agility or other sport activities that you condition your dog properly to prevent soft tissue injuries just like you would as a person.

Lastly, as the owner, it is important to consider when you plan to alter your puppy. Hormones are extremely important to proper growth and development. While many veterinarians push for early spay and neuter, it has become known in recent studies that early spay/neuter is detrimental to joint health. Many of our club breeders will recommend not to alter prior to 18 months. The reasoning behind this is to ensure growth plates have closed before hormones are removed. Without hormones, “the long bones grow beyond their intended length and interfere with the normal size and mechanical relationship between bone and joint. This abnormal relationship can lead to a variety of orthopedic issues, including an increased incidence of cranial cruciate rupture, hip dysplasia and patellar luxation.” (1991, Salmeri KR) Other studies showed an increase in chances of mast cell tumors, lymphosarcoma, lymphoma, hemangiosarcoma, and osteosarcoma.

Preventative measures that owners can do to help avoid hip dysplasia and ensure that your puppy has good muscle development include physical therapy exercises and stretches, swimming and free exercise. Swimming and free exercise are straight forward. Swimming is a great activity for your dog that relieves pressure on the joints while allowing your dog to work muscles they may not work during their typical day. When it comes to hip dysplasia, the muscles in the rear legs need to keep moving. A dog who may have a mild case of hip dysplasia may guard this area which in turn causes muscle atrophy and results in further deterioration. If the muscles are kept strong in the rear, it will help prevent laxity. Free exercises are exercises that your dog may do running in the yard of their own free will. This is unleashed exercise where you as a person do not control what they are doing. The reason this is important is because it is beneficial for your dog to get full leg extension while running on their own to again help prevent atrophy in the muscles that surround the hips. Allowing them to run on various terrains is even more beneficial; softer terrain works the tendons and ligaments so that they are stronger as your dog navigates shifting and balancing while playing.

In Conclusion

It is important to remember that the vast majority of hip dysplasia cases rarely result in surgery. A dog can live a completely normal life with moderate and mild-rated hips. When it comes to environmental factors, both the breeder and owner have an impact on what can happen to hips. While the breeder has the most vital period of time, so much can still happen after a puppy goes home that could result in hip and or elbow dysplasia. It is important for both the breeder and owner to do their best to manage your pup’s weight, environment, muscle development, diet and exercise so that we can ultimately have the best outcome regarding hips and elbows.

References:

Beuchat, Carol PhD, The 10 most important things to know about canine hip dysplasia, The Institute of Canine Biology, 2015.

Giroux, Phyllis, Helping Dogs with Hip Dysplasia, Whole Dog Journal, 2019.

Richardson, Daniel C., The Role of Nutrition in Canine Hip Dysplasia. Veterinary Clinics of North America: Small Animal Practice. 1992:Volume 22:Number 3:529-539.

Salmeri KR, Bloomberg MS, Scruggs SL, Shille V. Gonadectomy in immature dogs: effects on skeletal, physical, and behavioral development. J Am Vet Med Assoc 1991;198(7):1193-1203.

See Spot Run: Veterinary Rehabilitation and Hydrotherapy, Exercise Guidelines for Puppies, 2019.