Cynara RRs - Ridgeback Health

Rhodesian Ridgebacks are generally quite healthy but may suffer from certain problems including allergies, autoimmune thyroiditis, dermoid sinus or cancer. All breeds, including mixed breeds, have health problems. A few breeds have many serious problems. Take time to research and study potential health issues of any breed you are considering before purchasing. More owners and conscientious breeders are testing their dogs for health problems and are brave enough (about 25%) to allow the Orthopedic Foundation for Animals (OFA) to post both good and bad results online. The OFA database is located at www.offa.org. Don't forget to ask about the parents, siblings and grandparents health records. A $400 dog could easily cost you $3000 if treatment becomes necessary for a serious inherited disease like hip dysplasia, congenital heart disease, von Willebrand's disease, etc. A puppy produced by several generations of health tested and disease free ancestors has significantly lower odds of inheriting a disease that will break your heart and pocketbook.

CANCER

As of June 2008, cancer is the leading cause of disease-related death in dogs. In humans, cancer is the second most common cause of death. There are several types of cancer, as with people. Rottweilers are one of the breeds at high risk of developing osteosarcoma and lymphoma cancer. Ridgebacks do get these types of cancer but it isn't a great concern.

Lymphoma is the 3rd most common type of cancer in dogs. Within 4-8 weeks after the dog is diagnosed, most dogs die from masses that grow and spread. The masses also called solid tumors are caused by cancer cells invading the lymphatic system, lymph nodes, spleen and thymus. Lymphoma is classified as a hematopoietic tumor, meaning it begins from bone-marrow derived cells. There are two types of lymphoma. Hodgkin's disease and non-Hodgkin's disease. Recent statistics show non-Hodgkin's disease if 5 times more common than Hodgkin's disease. Doctors have broken down non-Hodgkin's lymphoma into over 30 subtypes. Researchers have found huge differences in which breeds of dogs have naturally occurring canine lymphoma.

Osteosarcoma is a fast-spreading, painful bone caner which occurs frequently in several large and giant breeds, strongly suggesting that genetics play a role. About 8,000 to 10,000 dogs are affected each year with osteosarcoma. Kenine Comstock, Ph.D., research investigator at the University of Michigan, says, "Breed is the most clear-cut risk factor. A combination of genetic factors and environment is likely to cause osteosarcoma. A dog may inherit a susceptibility to the disease, however, it is possible that he will only develop the cancer if exposed to something in the environment." Researchers continue to study, hoping to unravel the genetics behind canine cancer.

CATARACTS

CERF = Canine Eye Registration Foundation. Board-certified veterinary ophthalmologists are used to conduct CERF eye tests. CERF exams should be given annually until the age of 7 or even older for better records.

Cataracts are the most common treatable form of blindness in dogs. Some dogs test normal when young and then develop cataracts from ages 4-6 years. It is recommended that breeders do not breed dogs affected with cataracts.

The canine eye has a clear lens inside that is used for focusing. A cataract is an opacity that forms on the lens, inhibiting light from reaching the retina. Cataracts may begin as small cloudy sections of the lens that do not impair vision. Typically the opacity grows to cover the entire lens and functional vision is lost. Cataracts may develop in one of both eyes quickly over the course of several weeks or slowly over several years. Cataracts also can occur as a secondary complication to eye disorders such as progressive retinal atrophy (PRA), glaucoma and inflammatory uveitis. Even traumatic injuries or metabolic disorders like diabetes can lead to cataracts. There are dogs diagnosed with cataracts who never lose their eyesight because the cataracts stop growing.

"Posterior Polar Subcapsular (PPS)" - A slow developing opacity in the central (polar) posterior (back part) of the lens. It often shows up in dogs at about 18 months of age. PPS cataracts are presumed to have a recessive mode of inheritance. This means a dog needs to inherit the gene mutation from both parents to be affected. Carriers, as opposed to affected dogs, inherit only one PPS gene. Normal dogs have no gene mutations for PPS. Researchers are trying to develop a genetic test {as of July 2007} to identify carriers, affected and normal dogs.

"Unilateral cataract" - A cataract that occurs in only one eye. The other eye usually remains normal.

Some types of cataracts are known to be hereditary, and many others are believed to be hereditary.

For most dogs, if the dog is in good health, surgery can remove the cataract(s) if it becomes necessary. The success rate for cataract surgery is currently over 90 percent {as of July 2007} thanks to more sophisticated equipment and better surgical techniques. The same procedure used for removing human cataracts is used for canines. With phacoemulsification the veterinarian makes a small incision through which a probe is used to break up the cataract with ultrasonic vibration. Then the entire lens is removed and replaced with an artificial lens called an intraocular lens.

After the surgery owners need to follow up by giving their dog non-steroidal anti-inflammatory drugs for several weeks after the surgery to control inflammation.

DEGENERATIVE MYELOPATHY (DM)

Degenerative Myelopathy is caused by an autoimmune disease attacking the nervous systems of patients, leading to progressive neural tissue damage. The disease causes advancing weakness and muscle atrophy and ultimately leads paralysis and death. DM has been recognized for more than 35 years. The original studies on DM found it to be similar to Multiple Sclerosis in human beings. However in January 2009 it was announced researchers have found that the genetic mutation responsible for DM in dogs is the same mutation that causes amyotrophic lateral sclerosis (ALS), the human disease also known as Lou Gehrig's Disease. Currently there is no treatment known that will stop or slow progression of DM. Dog owners are forced to put their dogs to sleep when they can no longer use their rear legs, control their bladder and other symptoms of paralysis cause a shut-down of their system.

Researchers have discovered a genetic mutation which greatly increases a dog's risk of developing DM. A DNA test developed in July 2008 by the University of Missouri determines how many copies a dog has of the mutated or abnormal gene. N = Normal. A=Abnormal Dogs with 2 mutated copies of the gene are "At RISK - A/A" for developing DM. "Carriers - A/N" have 1 mutated copy and one normal copy of the gene. The best result is "Normal - N/N" where the dog has 2 normal and zero mutated copies of the gene. Carriers and Normal dogs are highly unlikely to develop DM. Research is ongoing to determine why only some of the dogs testing A/A are affected by DM as they reach a certain age. One line of thought believes DM is jump started by some type of medical stressor.

This disease is fatal to dogs and there is no known cure but preventing DM is simple. Test your dog before breeding. Only breed Normal dogs to Normal dogs or Carriers. It's not recommended but you can breed Normal to At-Risk dogs. Don't breed Carriers to other Carriers or to At Risk dogs. Normal dogs can only transmit the normal gene to its offspring. Carriers can transmit either the normal gene or the mutated gene to its offspring. Since At Risk dogs have 2 copies of the mutated gene A/A, they must pass one of the mutated gene to their offspring. Cost of a DNA test for degenerative myelopathy is $65.00. The fee includes test supplies, lab work and posting the results to the OFA database.

As the table below shows - if you breed a normal dog to a carrier some of the pups could be normal and some could be carriers. There are 3 possibilities when you breed two carriers together: normal, carrier or at-risk. Two At Risk dogs are always going to produce At-Risk puppies. If all dog owners test before breeding, this disease could be a thing of the past in only 3 or 4 generations.

	Dam N/N	Dam A/N	Dam A/A
Sire N/N	Pups N/N	Pups A/N Pups N/N	Pups A/N


Sire A/N	Pups A/N Pups N/N	Pups A/A Pups A/N Pups N/N	Pups A/A Pups A/N


Sire A/A	Pups A/N	Pups A/A Pups A/N	Pups A/A

As of 9/16/08 all 5 of Cynara's Ridgebacks have had their DNA tested for the gene associated with Degenerative Myelopathy susceptibility. Four of them are N/N and one is A/A and could develop DM around 9 or 10 years of age. Statistics posted on the OFA website as of 1/4/2010 show 1068 Ridgebacks (the most of any breed) have been tested for DM. Compared to some of the other breeds doing extensive testing, Ridgebacks have the lowest percentage of At Risk dogs. The last column shows mixed breed dogs. Data doesn't lie and these stats should help bust the myth that mixed breed dogs are always healthier than pure bred dogs.

DYSPLASIA

Large breeds are more prone to having hip and elbow dysplasia than small dogs who commonly suffer from patellar luxation. OFA considers two years old to be the best age to perform x-rays and evaluate them for dysplasia. This is the main reason many breeders refuse to breed their dogs under the age of two.

Elbow Dysplasia - A degenerative joint disease that is evaluated through a lateral radiograph (x-ray).

Hip Dysplasia - A malformation of the hip socket and femur bone. Can cause debilitating orthopedic problems. It can be diagnosed by pelvic radiograph (x-ray). When sent to the OFA, the x-ray is evaluated by three veterinary radiologists to determine if the hips are excellent, good, fair, mildly dysplastic, moderately dysplastic and severely dysplastic.

Luxation of the Patella - A deformity of the hind leg that allows the kneecaps to dislocate, which leads to lameness. A veterinarian can determine if a dog suffers from patellar luxation by performing a physical examination.

HYPOTHYROIDISM

Hypothyroidism is becoming too common in Ridgebacks. Many breeders are now working extremely hard to eliminate it from their breeding lines. When breeding two dogs it is understood that neither are perfect. Breeding is a delicate balancing act of determining what you want to improve in the next generation and what problems you can let slide until next time. Breeding away from diseases that cripple dogs like hip/elbow dysplasia and degenerative myelopathy are a higher priority than hypothyroidism which can be controlled with medicine. However, after many generations of allowing Ridgebacks with hypothyroidism to be bred, it is time for breeders to make eliminating it a priority.

Statistics gathered by OFA from Jan. 1974 thru Dec. 2007 show there have been 1886 evaluations (tests) on Ridgebacks. Sadly Ridgebacks are rated #6 out of 74 breeds who have had at least 50 evaluations. 10.7% were positive for autoimmune thyroiditis and 11.8% were equivocal (not normal and not autoimmune). Some breeders have their dogs tested but choose not to share the results with OFA. The lab at Michigan St. Univ. has processed 2155 evaluations. 15.4% of Ridgebacks were positive for autoimmune thyroiditis and 5.5% were equivocal. MSU has Ridgebacks rated at #15 out of 140 breeds tests. English Setters have the highest rate of thyroid disease in both OFA and MSU statistics.

Four of Cynara's five Ridgebacks have had their thyroid tested and the results submitted to OFA. Dozer has been tested twice because one of his older brothers went from normal, to equivocal and then became autoimmune at 6 years old. Dozer tested normal both times. Trouble will be tested when she turns a year old. Hunter is the only one of our 4 Ridgebacks to test positive for autoimmune thyroiditis. He was neutered soon after and never sired any puppies.

MEGAESOPHAGUS

The mode of inheritance for megaesophaegus in Ridgebacks isn't known for sure but is believed to be a simple recessive -- which mean both parents have to be carriers in order for one of their puppies to be born with it. Most puppies eventually die when born with megaesophagus so vets usually recommend putting them to sleep to prevent pain and suffering. This isn't common in Ridgebacks but it does exist in certain lines. There isn't a test to determine if a dog is a carrier before breeding so the only way to know is when one of the offspring is born with it.

PARVOVIRUS

[As of June 2008] In 1978 a new viral disease popped up. The virus caused fear and panic because so few dogs had immunity, an entire kennel could be killed within a few weeks of the first dog exhibiting symptoms. Veterinarians were swamped with dogs suffering from continuous vomiting and explosive diarrhea. The virus was named canine parvovirus 2 (CPV-2). It took doctors years to create a vaccine to provide immunity against parvo. Since 1978 two similar strains of parvo were identified. The were named CPV-2a & CPV-2b. In 2006 a new strain, CPV-2c, was found in the US.

After almost a generation of being able to protect our dogs against parvo with proper application of vaccines CPV-2c has changed its genetic makeup just enough where the vaccines aren't giving total immunity anymore. Ridgebacks, especially puppies are very susceptible to parvo. Parvovirus is extremely hardy and tough. It can last for up to 7 months in the environment especially in feces of infected dogs makes it almost impossible to eliminate. One of the methods used, in addition to vaccines for the sire and dam, to protect puppies is to limit their contact with the outside world. Cynara's Ridgebacks did not visit any dog shows, dog parks, or pet food stores where the virus could be picked up from the time Katie was bred until the pups received their first round of shots at 6 weeks of age. Potential puppy buyers were asked to remove their shoes and wash their hands before entering the whelping room.

Dogs are infected by oral ingestion of the virus. It immediately starts multiplying (sci-fi fans can visualize replicators or tribbles) in the lymph nodes in the throat and begins to enter the bloodstream. It attacks the cells lining the intestine which causes the the intestine to weaken and allows bacteria to escape into the body. The bacteria causes a life-threatening infection called septicemia. Vomiting is the first sign of trouble. Once the vomiting starts it seldom stops. To make matters worse, a foul-smelling diarrhea begins within hours of the vomiting further weakening the dog or puppy by causing dehydration. If the septicemia develops the puppy goes into shock and dies. Mortality ranges from 10-35%. The younger the dog the higher the death rate. Vets try to save the dogs by giving them IV fluids, antibiotics and medicines to stop the vomiting. Drastic treatment can include blood transfusions.

According to the experts, Chlorine bleach is 100% effective against the virus. Mix 1 part bleach with 30 parts water. Spray or mop the surface to be disinfected, like kennel floors, crates, and whelping boxes and allow it to air-dry. Then spray or map it again. To help prevent the virus from spreading, some breeders put a shallow pan of the bleach water in front of kennel and entry doors so everyone entering must step into the water. Keep kennels, yards, dog runs and rooms clean. Pick up dog poop and dispose of it properly. Stay away from unknown dogs. The most important preventive, even against CPV-2c is vaccination. Bitches should be vaccinated (no longer than 2 1/2 years) before breeding so they can pass on vital immunity to the pups through the colostrum when the pups first nurse.

TICK DISEASES

Lyme Disease - One of the biggest tick-transmitted threats in many parts of the United States, Lyme disease can cause fever, lameness, loss of appetite, and swollen or painful joints in pets. If left untreated, the problems can spread to the heart, joints, and nervous system.

Rocky Mountain Spotted Fever - A serious infection that can be transmitted by infected ticks throughout the country, it can cause arthritis, bruising, decreased appetite, fever, and swollen or painful joints in pets. One of the most discussed symptoms is bleeding from the eyes. However RMSF seems to respond to treatment much easier and faster than dogs with Ehrlichiosis. Hunter was unlucky enough to catch both RMSF and Ehrlichiosis. We caught it early during a routine check-up and managed to cure Hunter with only one month of Doxycycline.

Ehrlichiosis - In pets, this potentially chronic infection can cause appetite and weight loss, bleeding, depression, and fever. Three of my dogs have had Ehrlichiosis. There is an over population of deer in our area whom run across our yard and drop ticks--lots of ticks. The vet usually recommends we give 200mg Doxycycline Hyclate pills twice a day (90 lb dogs) for 4 weeks. Chisum had a relapse after a few months (or else he was bitten again) and had to be treated for another month.

After the bouts with both RMSF & Ehrlichiosis we started using K9 Advantix by Bayer. It is expensive and has to be reapplied about every 4 weeks in the Oklahoma woods but none of the dogs have caught any more tick diseases. They still get a few ticks but by the time we find them, the ticks are dead.

LINKS

http://www.hemopet.com/ - HEMOPET established the first private non-profit animal blood bank 1991. HEMOPET's licensed full-service blood bank provides state-of-the-art blood components and supplies for transfusions to veterinary clinics nationwide. This is where I now send serum for the thyroid panel for the dogs OFA tests.

LINKS

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