CRANIAL CRUCIATE LIGAMENT RUPTURE

08.08.2010 1 comment »

First, the Basics

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.

UKC WASHINGTON CLASSIC 2010

04.07.2010 No comments »

Indy competed in the UKC conformation show at Argus this Friday and Saturday. He was handled by Nicole and won 4 best of breeds and one Herding Group 2nd. Not bad for his first conformation show in nearly two years.

LEWISTON WOOFF TRIAL

21.03.2010 No comments »

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.

NEW PUPPY TUCKER

06.02.2010 No comments »

No big updates in terms of the team, all the pups are doing just dandy (if not a little bored).  But just wanted to give a big shout-out to the newest Overbey, an English Springer Spaniel named Tucker.

Here are couple of pictures of the big guy.  He is only 5-6 months old, and I am sure he is already a handful.

Poking up to say hello!

I am a pretty big deal.

I think he is a little 'Tucker-ed' out... get it?

ARGUS CPE TRIAL

09.01.2010 No comments »

TheResults

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.

HOODOO HOWLERS NADAC TRIAL

01.09.2009 No comments »

TheResults

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.

OLYMPIC KENNEL CLUB AKC AGILITY TRIAL

20.08.2009 No comments »

TheResults

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…

Jumpers:
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.

Standard:
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!

UNCOMMON TOXINS

11.08.2009 1 comment »

OffCourse

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.

NADAC RAT RESULTS

27.07.2009 No comments »

TheResults

Well the results are in from today’s NADAC Rainier Agility Team (RAT) Trial, and there is some good stuff to talk about.  Both teams worked really hard today and luckily came away with ribbons!  I think we found A LOT of things we need to work on, but overall I think it was a good day for the Gold Ears team – especially considering the heat/temperature we had to battle!

Indy & Chauncey (1/6):
1 Qualifying Run in Novice Tunnelers – placing 3rd.

Sydney & Bridget (3/4):
2 Qualifying Runs in Open Tunnelers – placing 2nd and 3rd.
1 Qualifying Run in Novice Touch’N'Go – placing 2nd.

Indy and Chauncey’s day wasn’t nearly as successful as Syd and Bridget’s but for only his 2nd trial, we will take it in stride and hopefully build on it for the upcoming AKC Trial.  Rather than working on anything in specific, Indy’s problem was more the atmosphere of the trial and his issues with other dogs and distractions.  Its also important to note that Indy would have qualified in his 1st Round of Novice Tunnelers if Chauncey had not made a handling error.

Now on to the better news, Syd and Bridget qualified in 3 of their 4 runs.  They both did a really great job, and we can see some real improvement in Syd – especially in her sit-stays.  Hopefully this is just the beginning and will translate into some great results at the upcoming AKC trial.

We updated our videos page to include the qualifying tunnelers for today, please feel free to enjoy!

That is all for now – you stay classy San Diego?

SCREENING HIP DYSPLASIA

23.07.2009 2 comments »

OffCourse

The 2009 AVMA convention was last weekend and I was fortunate to be able to attend several lectures given by Dr. Randall Fitch. These lectures were focused on localizing lameness in primarily the rear limb. I wish that they would have focused more on sports medicine as originally advertised, but we can’t have everything we wish for. During one of the lectures Dr. Fitch showed several pelvic radiographs from a bitch that was evaluated as OFA Excellent but turned out to be severally dysplastic.

This caught my attention since Indy, our gold border collie, has recently turned 2 years old and is now eligible to have his OFA radiographs submitted. There are two most popular screening organizations in the U.S. is the OFA and PennHIP. There is a lot of animosity and debate between the two groups as to which is the superior method and this doesn’t appear to be ending any time soon.

OFA has been around for a longer time period and is the more popular method of screening. Dogs must be at least 24 months of age to be certified and it is recommended that they be sedated for the procedure but it is not required. Radiographs are taken with the dogs lying on their backs with their rear legs extended and rotated slightly inward. When submitted the radiographs are subjectively measured on 7 points that takes into account evidence of hip laxity, osteoarthritis, or both. From this subjective evaluation the hips are rated into the seven different phenotypic classifications: excellent, good, fair, borderline, or mild, moderate, and severely dysplastic. These seven levels are used to help owners make informed decisions for breeding purposes. An advantage of OFA screening is that any veterinarian can take the radiographs and submit them as long as they are good quality. Also if the veterinarian is willing to take the radiographs without anesthesia they can be significantly cheaper then PennHIP. This is not advisable since tense muscles can make the radiographs appear better then they actually are. The OFA also maintains easily accessible records of all the submitted radiographs, which can be helpful when potential buyers are researching breeders.

PennHIP was developed to quantitatively assign a measure to hip joint laxity, the Distraction Index (DI). Since it has been recognized that there is a correlation between joint laxity and the development of osteoarthritis. PennHIP radiographs can only be taken by a certified veterinarian, which limits the availability of the procedure. Three views are taken and the dog must be under anesthesia or heavy sedation. The first view is the traditional rear limb extended view just like for OFA screening. The next two views, the compression and the distraction are done with the legs in a neutral or normal stance position while the dog is laying on it’s back. These are used in the measurement of the DI. The compression view is obtained by placing downward and inward pressure on the femur in order to place the femoral head into the acetabulum (hip socket). This allows for a visual evaluation of how well the femoral head fits into the acetabulum basically showing ideal congruency if no OA is present in the joint. The third view is the distraction view. A distractor is used to act as a fulcrum to displace the femoral heads from the acetabulums. The distractor is placed between the femurs with the rods placed over the femoral heads. Force causes the femur to distract from the acetabulum based on the inherent laxity of the joint. The DI is calculated and is given as a unit-less number between 0 and 1. As this number increases the joint is considered to have more laxity, and subsequently is more susceptible to arthritis. The laxity of the joint is the amount of displacement of the femoral head. Studies have shown that dogs that have DI <0.30 are virtually at no risk to develop arthritis. DI’s >0.30 are susceptible to arthritis. PennHIP screening can be performed as early as 4 months of age. Each report also contains a percentile ranking of the dog amongst others of the same breed. PennHIP advises that dogs below the 50th percentile of their breed not be used for breeding.

Canine hip dysplasia continues to be a very prevalent disease in the canine population despite many years of working to decrease its occurrence. This is evidence of a screening method that is not accurate enough and has a low heritability. Which is the case with the OFA technique, which has been the most commonly used means of evaluating the dog for hip dysplasia for over 40 years. Despite this time, the prevalence of the disease has only decreased slightly. False negative results in the test are likely the main cause of the slow progress; i.e. dogs been graded acceptable when they are in fact dysplastic. The PennHIP technique has been found to have a negligible number of false negatives thereby minimizing the number of dogs with the genotype for hip dysplasia to be used in selective breeding programs. This is the main factor in decreasing the prevalence of the disease in the canine population. I believe, as more veterinarians are able to perform this screening technique the more popular it will become, and real progress can be made in eliminating hip dysplasia.