The Gold Ears site has been inactive lately, since there have been many changes during the past several months. In May I graduated from WSU and moved to Tacoma and began the long search for a job. In July the entire Gold Ears family had to move to a new apartment due to earthquake renovations in our old building. Now after many months of searching I have been fortunate enough to be offered a position at the Helping Hands Veterinary Clinic in Lynnwood. Gold Ears friend Nicole began working there this summer and when a position became available I was very excited to apply since Nicole had nothing but great things to say about the team there. It’s great to have the opportunity to work with a good friend but I’m even more excited about the direction of the clinic and what the future holds. There have been some very stressful times these past few months but thanks to the Gold Ears friends and family things are now looking up.
The knee is a fairly complicated joint. It consists of the femur above, the tibia below, the kneecap (or patella) in front, and the bean-like fabellae behind. Chunks of cartilage called the medial and lateral menisci fit between the femur and tibia like cushions. Assorted ligaments hold everything together and allow the knee to bend the way it should and keep it from bending the way it shouldn’t.
There are two cruciate ligaments that cross inside the knee joint: the anterior (or, more correctly in animals, cranial) cruciate and the posterior (or, more correctly in animals, the caudal) cruciate. They are named for the side of the knee (front or back) where their lower attachment is found. The anterior cruciate ligament prevents the tibia from slipping forward out from under the femur.
Finding the Rupture
The ruptured cruciate ligament is the most common knee injury in dogs; in fact, chances are that any dog with sudden rear leg lameness has a ruptured anterior cruciate ligament rather than something else. The history usually involves a rear leg that is suddenly so sore that the dog can hardly bear weight on it. If left alone, the leg will appear to improve over the course of a week or two but the knee will be notably swollen and arthritis will set in quickly. Dogs are seen by the veterinarian in either the acute stage (shortly after the injury) or in the chronic stage (weeks or months later). The key to the diagnosis of the ruptured cruciate ligament is the demonstration of an abnormal knee motion called a drawer sign. It is not possible for a normal knee to show this sign.
The Drawer Sign
The veterinarian stabilizes the position of the femur with one hand and manipulates the tibia with the other hand. If the tibia moves forward like a drawer being opened, the cruciate ligament is ruptured.
Another test that can be used is the tibial compression test where the veterinarian stabilizes the femur with one hand and flexes the ankle with the other hand. If the ligament is ruptured, again the tibia moves abnormally forward. If the rupture occurred some time ago, there will be swelling on side of the knee joint that faces the other leg. This is called a medial buttress and is a sign that arthritis is well along.
It is not unusual for animals to be tense or frightened at the veterinarian’s office. Tense muscles can temporarily stabilize the knee, preventing demonstration of the drawer sign during examination. Often sedation is needed to get a good evaluation of the knee. This is especially true with larger dogs. Eliciting a drawer sign can be difficult if the ligament is only partially ruptured so a second opinion with an orthopedic specialist is a good idea if the initial examination is inconclusive.
Since arthritis can set in relatively quickly after a cruciate ligament rupture, radiographs (x-rays) to assess arthritis are helpful. Another reason for radiographs is that occasionally when the cruciate ligament tears, a piece of bone where the ligament attaches to the tibia also breaks off. This will require repair and the surgeon will need to know about it before beginning surgery. Arthritis that has set in prior to surgery limits the extent of the recovery after surgery, though surgery is still needed to slow or even curtail further arthritis development.
How this Happens
There are several clinical pictures seen with ruptured cruciates. One is a young athletic dog playing roughly that takes a bad step and injures the knee while playing. This is usually a sudden lameness in a young large-breed dog. On the other hand, an older large dog, especially if overweight, can have weakened ligaments and slowly stretch or partially tear them. The partial rupture may be detected or the problem may not become apparent until the ligament breaks completely. In this type of patient, stepping down off the bed or a small jump can be all it takes to break the ligament. The lameness may be acute but have features of more chronic joint disease or the lameness may simply be a more gradual/chronic problem.
Larger overweight dogs that rupture one cruciate ligament may rupture the other one. An owner should be prepared for another surgery in this time frame.
What Happens if the Cruciate Rupture is Not Surgically Repaired?
Without an intact cruciate ligament, the knee is unstable. Wear between the bones and meniscal cartilage becomes abnormal, and the joint begins to develop degenerative changes. Bone spurs called osteophytes develop, resulting in chronic pain and loss of joint motion. This process can be arrested by surgery but cannot be reversed.
Osteophytes are evident as soon as 1 to 3 weeks after the rupture in some patients. This kind of joint disease is substantially more difficult for a large breed dog to bear though all dogs will ultimately show degenerative changes. Typically, after several weeks from the time of the acute injury, the dog may appear to get better but is not likely to become permanently normal.
In one study, a group of dogs was studied for 6 months after cruciate rupture. At the end of 6 months, 85% of dogs under 30 lbs of body weight had regained near normal or improved function, while only 19% of dogs over 30 lbs had regained near normal function. Both groups of dogs required at least 4 months to show maximum improvement.
Options for surgical repair will be discussed in the next post.
Since the rest of the Goldears family went to Portland this weekend Sydney decided to head back to Pullman early with Nicole in order to celebrate her sixth birthday with an agility trial. Sydney earned her first leg in novice weavers with a first place finish in her class. She also had some good runs in regular and jumpers, if only those bars would stay up.
Sydney and Indy competed in the Argus Ranch CPE trial January 2nd and 3rd. Indy qualified in Jackpot with a first place run in his height class and the second highest point total in all of level 1. Sydney qualified in Fullhouse and twice in Regular earning her CL1-R title. Sydney will need to work on knocking bars in practice which cost her from qualifying in Jumpers.
Good news! Bridget and Sydney entered in a NADAC trial in Spokane hosted by the HOODOO Howlers and completed their last legs in Touch’n'Go and Tunnelers and earn their TN-O (Open Tunnelers) and TG-N (Novice Touch’n'Go) titles! Being back in Pullman, WA for school this maybe the last trial the team competes in for quite awhile. Unfortunately they could not go 3 for 3, just knocking one bar in their jumpers run… but lets not downgrade their spectacular performance! Great job Bridget and Syd!
On a side note, our friends at Starlight Border Collies also completed their last leg in Touch’n'Go to gain her novice title. Congrats to Nicole and Ella!
Please check out our videos page to see Bridget and Syd’s amazing runs… IN 3-D! Okay, well not in 3-D, but just imagine if it were and put the funny glasses on.
Well, unfortunately this trial didn’t go very well. Neither team was able to come home with a qualifying run. Let me break it down…
Indy started off well though Chauncey did not. And though there were some handling mishaps, its still clear that Indy needs to work on his weave poles.
Sydney broke her sit stay, and Bridget did the right thing by not continuing the course.
Both teams clearly need to work on their tire. Each dog would miss the first obstacle. Syd got a little to excited/agitated and started running across different obstacles, and Bridget was forced yet again to end the run short. Indy decided to end the run early on his own, by running out of the ring – forcing the judge to whistle him out.
We didn’t compete on Sunday, as Chauncey got food poisoning. Though it was a rough day on Saturday, the AKC trial was slightly successful as we were see some improvement in Indy’s temperament around other dogs and in the environment. We might not compete anytime in the near future, but we’ll both be practicing!
Thanks for reading!
It is only a couple more weeks until classes start up again and I have to make the long drive back to Pullman, and go back to long periods of sitting in class. So until that happens I’ve been trying to study for at least a couple hours each day in hopes that I haven’t forgotten everything I’ve learned in my first two years. I know studying during summer vacation is pretty nerdy but third year is supposed to be the most difficult. Strange how it seems they say that about every year we are about to start. In any case the subject I was studying today is toxicology so I thought I would discuss 3 of the toxins from my notes.
Recently, word has spread that feeding grapes and raisins to dogs can be toxic. The first time I heard this I have to admit I was skeptical. It seems like whenever you hear that something is “bad” for your dog they can never tell you the why or how. So when we learned about grapes/raisins in class I was happy to finally have some solid information on the subject. Grapes/raisins are potential toxins that affect the kidneys. The problem is that there is no dose response recognized. What this means is that you or even your veterinarian cannot tell whether your dog will get sick by the amount of grapes/raisins your dog has consumed. Even more interesting is that not all dogs exposed become ill. The mechanism of action is also unknown at this time, i.e. how/why they damage the kidneys. If your dog is affected the signs will be pretty non-specific: vomiting characteristically occurs within 2 hours of ingestion, anorexia, diarrhea, depression, lethargy, and abdominal pain.
Cyanobacteria is another potential toxin that I had not heard about until veterinary school. Cyanobacteria, also known as blue-green algae, despite the name can be seen in many different colors ranging from black to pink. It may be found in salt or freshwater when the specific environmental conditions are in place for it to grow and to produce toxins. Not all cyanobacteria are toxic but all animals including humans are susceptible to the toxic producing variety making it a public health concern. Depending on the strain of cyanobacteria the liver or the nervous system may be affected. If your dog is affected, signs may include vomiting, abdominal pain, diarrhea, muscle rigidity, tremors, and paralysis. These signs would occur fairly soon after exposure within 1-4 hours. You can see some good pictures of cyanobacteria by searching in Google images. Since this is a public health concern if you suspect a bloom of cyanobacteria the Public Health department should be notified so they can test the suspected water.
The last potential toxin I’m going to discuss is Xylitol. This toxin is a sugar substitute that is now found in a wide variety of products including gum, toothpaste, mouthwash, candy, and sugar substitutes used for baking. Over-consumption can cause a severe hypoglycemia (low blood sugar) in dogs. Some dogs may even develop liver failure. The signs of hypoglycemia will generally develop 30-60 minutes after ingestion and include weakness, seizures, and vomiting.
These are just three examples of toxins that I felt are fairly unknown to the majority dog owners but can be very harmful. If you think your dog has fallen victim to, or is experiencing any of the signs indicated here you should consult your local vet as soon as possible.