AVOID EXPENSIVE, PAINFUL CRUCIATE LIGAMENT RUPTURE
Early spay/neuter is one of the primary indicators of a potential for a “blown knee” in our dogs, according to Dr. Marty Greer, DVM. The cruciate ligaments in the stifle joint of the dog serve as a hinge when working properly. When these ligaments are stretched, frayed or torn, the dog will be painful, limping, or “off” on a rear leg. Environmental factors such as overweight and lack of condition also can contribute as causal factors, Greer adds.
TRAUMA NOT ALWAYS THE CAUSE
WHILE TRAUMA HISTORICALLY HAS BEEN CONSIDERED THE PRIMARY CAUSE OF THIS SITUATION IN THE DOG, GREER SAYS SHE SEES MORE AND MORE DOGS WITH NO KNOWN INJURY SUFFERING FROM A DAMAGED JOINT.
“… THERE’S A HUGE INCREASE IN INCIDENCE OF CRUCIATE RUPTURES IN DOGS THAT ARE SPAYED AND NEUTERED WHEN THEY’RE YOUNG,” GREER SAID. “AND BECAUSE THERE’S BEEN A BIG MOVEMENT TO EARLY SPAY AND NEUTER FROM THE RESCUE ORGANIZATIONS AND THE HUMANE SOCIETIES FOR REASONS OF POPULATION CONTROL, THEY’VE PUT OUR DOGS AT INCREASED RISK. INADVERTENTLY, THEY DIDN’T SET OUT TO DO THAT, BUT INADVERTENTLY, THEY SET OUR DOGS UP FOR FAILURE IN THE DEVELOPMENT OF THEIR JOINTS. SO, WHEN A DOG IS SPAYED OR NEUTERED WHEN THEY’RE REALLY YOUNG, THEIR GROWTH PLATES STAY OPEN LONGER. WE KNOW THAT FROM LLAMA’S. WE KNOW THAT FROM HUMAN EUNOCHS … SO, IF YOU WALK DOWN THE AISLE IN A HUMANE SOCIETY AND YOU SEE A LONG LEGGED SKINNY STRAIGHT KNEED BLACK 60-POUND DOG, ODDS ARE PRETTY GOOD THAT IT’S A MALE THAT WAS NEUTERED WHEN HE WAS 3, 4, 5 WEEKS OLD, MAYBE TWO OR THREE MONTHS OLD. BUT WE DO KNOW THAT THE INCIDENCE IS MUCH, MUCH INCREASED IN DOGS THAT ARE SPAYED AND NEUTERED REALLY EARLY. SO THAT’S ONE FACTOR THAT REALLY NEEDS TO BE TAKEN INTO ACCOUNT.”
Anterior Cruciate Ligament (ACL) Rupture
Rupture of the anterior or cranial cruciate ligament is more common after gonadectomy than in intact dogs (Whitehair et al. 1993; Duval et al. 1999; Slauterbeck et al. 2004). Breeds at risk for rupture of the ACL include the Akita, American Staffordshire terrier, Chesapeake Bay retriever, German shepherd dog, golden retriever, Labrador retriever, mastiff, Neopolitan mastiff, Newfoundland, poodle, rottweiler and St. Bernard (Duval et al. 1999; Harasen 2003). Other risk factors include obesity and abnormal angulation of the stifle (Ragetly et al. 2011). One could argue that increased risk of ACL injury after gonadectomy is because of decreased athleticism and obesity in gonadectomized animals but the trend stands even in studies that statistically compensated for these effects in dogs. Joint laxity may differ under varying hormonal stimuli, suggesting one possible cause‐and‐effect mechanism. Another hypothesis is increasing stifle angulation with asymmetry of growth plate closure in the femur and tibia.
Tick borne diseases that can cause joint inflammation are another area Greer notes that may cause complications. Often times, a dog will not have a fully ruptured ligament, but these important sort of elastic bands in the joint will have frayed or “stretched.” Treating these dogs with crate rest, testing for tick borne diseases and treating with a prophylactic course of Doxycycline that both treats tick borne diseases and confers some anti-inflammatory process in the joint is Greer’s recommendation.
Patellar luxation is a genetic disorder that serves as complicating factor for potential injury to the knee joint as well, according to Greer.
Surgery to repair a torn cruciate ligament is expensive and requires the best orthopedic surgeon you can find, Greer said. But it isn’t an emergency situation. If you suspect a cruciate injury,
- Keep the dog quiet and crated.
- Take it to your veterinarian for diagnosis.
- Research the best surgeons available in your area.
- Be diligent about maintaining *strict* crate rest during recovery.
We hope you enjoy today’s podcast with Dr. Greer. For more information on this topic, visit:
VETERINARY VOICE: HEALTH TESTING 101 – DR. MARTY GREER
Dr. Marty Greer, DVM, JD returns to our Veterinary Voice series to talk about health testing for our breeding programs.
Using testing to improve our dogs’ overall health involves looking at both “phenotype” — diseases we can test for with xrays, blood or other physical exam — and “genotype” — those diseases identified by DNA testing.
Dr. Greer also provides some great input on the various DNA tests cropping up all around us. These tests, all spinning off from the identification of the canine genome, provide breeders, exhibitors and pet owners with a plethora of options for naming everything from the mixture of breeds in a shelter dog to the specific heritable genes for deadly diseases.
One of Greer’s primary points, which we’ll touch on again next week in our podcast with Dr. Jerold Bell, is that these health testing options provide breeders with the ability to *expand* their gene pools. Scientifically identifying a dog as a carrier and another as a non-carrier of a specific disease gene, for example, enables breeders to breed those two individuals with the assurance that none of the resulting progeny will be affected by the disease in question.
Many of our dogs are impacted by polygenic diseases, in other words something like hip dysplasia, for which there is no DNA test because it is predicated on more than one simple gene pair. Nonetheless, the future of breeding healthy dogs is made profoundly more “user friendly” with the available testing protocols for those who use them wisely.
“So, the tricky part, and I think the really hard part for people that as breeders are running these tests are for them to try and decide how to use that information in their breeding program,” Greer said. “… I see a lot of breeders who are so distraught about finding a genetic defect in their dog or in their line of dogs that they will throw out a whole line of dogs genetically. They will just stop breeding that whole line and it is narrowing and bottlenecking our gene pools even further than a lot of the breeds already are. So, we have to be really careful how we interpret and use those results.”
Greer goes on to discuss various health concerns and how those should apply to making breeding decisions.
“So, I tend to rank, personally, genetic diseases on a ranking of one, two and three, because you can’t treat them all the same,” Greer said. “So, things like an umbilical hernia, or an extra eyelash, you fix it once surgically, it is corrected. …the reality of it is those are not life-threatening diseases … Ranked two are things like allergies and thyroid disease, which require chronic medications. They always have to be on medication for those diseases if they have them. … And then ranked three are the things that are life-threatening, life-altering, life-changing diseases, and those are arthritic changes like hip dysplasia, seizures that are life-threatening, and, frankly, bad temperament in my opinion has the same categorization because some of those dogs have such bad temperaments that they bite people and that’s life-changing, life-altering and life-threatening. … I want to kind of frame it so people understand that not all not genetic diseases are the same, not all should be treated equally, and we have to really be thoughtful about how we use this information in breeding programs.”
The judicious and thoughtful use of health testing results and criteria in breeding healthy dogs presents almost a continuum of application in Greer’s experience. Potentially unhealthy dogs with no testing on one end and dogs with extensive testing but a potentially limited gene pool which may entrench diseases at the other end of the spectrum.
“…the Dandie Dinmonts, the Otterhounds, these people with small gene pools can serve as models for other breeds,” Greer said, “because even Labradors and Golden Retrievers are narrowed pools compared to what we have seen in the past. So, absolutely we need to be looking at these kinds of opportunities to perpetuate our genetics and not breed ourselves into such a bad corner that we end up with everything having a genetic disorder that is insurmountable, because some of these diseases are pretty serious and they become very ubiquitous in a breed.”