Genetic Testing and Genetic Counseling in Pet and Breeding Animals

by Jerold S. Bell, DVM, Tufts University School of Veterinary Medicine  Jerold.Bell@tufts.edu

Genetic testing and genetic counseling are not just for breeding animals. They include; testing for the bleeding disorder von Willebrand’s disease before performing surgery on susceptible breeds, altering diets for pets that are prone to developing bladder stones or crystals, and switching from rapid growth puppy food to lower calorie foods in young, large breed dogs, so that joint tissues can develop at a more uniform rate.

The hallmark of genetic disease is the ability to predict disease before its onset. This allows the possibility of medical or surgical intervention in order to prevent later suffering. Knowledge of breed-related genetic disease and the tests that are available permit early diagnosis and treatment.

Breeders and veterinarians have been utilizing genetic tests since the beginning of domestic animal breeding. Most genetic tests measure the phenotype of an animal, or what you can see. These include radiographs, blood values, eye examinations, skin biopsies, urinalysis for crystals or metabolites, observations on structure or behavior, and ausculting for heart murmurs. Most tests of the phenotype only identify affected individuals, and not carriers. These may, or may not directly relate to the genotype, or the genes regulating the defect.

A test of the genotype is one that assesses the DNA of the animal. These tests can be run at any age, regardless of the age of onset of the disorder. Utilizing polymerase chain reaction (PCR) technology, affected, carrier, and normal individuals can be identified. As the majority of genetic disorders are recessive or have a major recessive component, the identification of carriers is important for effective management.

As additional DNA tests are developed for disorders, the role of genetic counseling becomes more important. Without these tests, the number of individuals that can be identified as carriers is low, even though many may be suspect due to having affected relatives. Breeds have closed gene pools; in other words, the diversity of genes in a given breed is fixed. The number of individuals removed from consideration for breeding based on concerns regarding a specific genetic disease is usually low. While this has slowed the management of genetic disease, it has also prevented genetic drift and diversity problems for pure breeds.

History has shown that breeders can be successful in reducing breed-wide genetic disease through testing and making informed breeding choices. However, there are also examples of breeds that have actually experienced more problems as a result of unwarranted culling and restriction of their gene pools. These problems include: reducing the incidence of one disease and increasing the incidence of another by repeated use of males known to be clear of the gene that causes the first condition, creating bottlenecks and  diminishing  diversity by eliminating all carriers of a gene from the

breeding pool, instead of breeding and replacing them, and concentrating on the presence or absence of a single gene and not the quality of the whole animal.

DNA tests have to be developed specifically for each breed (or group of related breeds that share an ancestral mutation). There are two different types of tests of the genotype; direct gene tests and linkage-based tests. Direct gene tests check for a specific mutation in a defective gene.  The animal either carries the defective gene, or does not.

Linkage-based DNA tests can be developed even if the defective gene causing a disorder has not been identified. Genome research has identified thousands of genetic markers, or “marker-DNA” that are spread across the chromosomes of the species. A linked-marker is a piece of DNA that lies close to the defective gene on a chromosome.

Breeders can use linkage-based genetic tests the same way direct genetic tests are used. The only difference is that you are not directly testing for the defective gene, only an associated marker; so false-positive and false-negative test results can occur.

A genetic crossover between paired chromosomes mixes the genes that an individual receives from its sire and dam. This occurs on a regular basis during the formation of eggs and sperm. As a defective gene and the linked marker are different areas of DNA that lie close together on a chromosome, it is possible that a genetic crossover can occur between them. This would separate the marker from the defective gene and create false positive (testing for the marker without the defective gene), or false negative (testing as normal, but having the defective gene) results. Depending on the relative distance between the marker and the defective gene on the chromosome, researchers can predict the frequency of false results for a linkage-based test; for example: 1 in 100.

If an individual’s linkage-based test for the defective gene is producing false-positive or false-negative results, all of its descendants that inherit this portion of the chromosome will also have false test results. This has been documented with families of Bedlington Terriers tested for the autosomal recessive copper toxicosis gene.

It is obvious that direct gene tests are better than linkage-based tests. However, a test with 90% or 95% confidence is better than no test at all. As genomic research progresses, researchers can identify the defective genes responsible for disorders, and can develop direct gene tests to replace linkage-based tests. The defective gene for copper toxicosis in the Bedlington Terrier has now been identified, and a direct gene test is now possible.

Based on the mode of inheritance of a disorder, and the availability of genotypic or phenotypic genetic tests, breeding management recommendations can be used to prevent or reduce the frequency of carrier or affected offspring. See the article “Breeding Strategies for the Management of Genetic Disorders” in the proceedings for specific recommendations.
Once a genetic test is developed, it allows breeders to positively determine if an individual is a carrier of a defective gene. The typical response of a breeder on finding that their animal is a carrier is to remove it from a breeding program. If a majority of breeders do this, it puts the breed’s gene pool through a genetic bottleneck that can significantly limit the diversity of the breed. The goal of genetic testing is to allow the superior genes of a breeding individual to be propagated, even if the animal is a carrier. One defective gene that can be identified through a genetic test, out of tens of thousands of genes is not a reason to stop breeding. If an owner would breed an individual if it tested normal for a genetic disease, then a carrier result should not change that decision.

Owners of carrier animals who are of breeding quality in other health, temperament, performance and conformation aspects should be bred to normal testing mates. This prevents the production of affected offspring. The breeder should be counseled to test the offspring prior to placement; to determine whether a pet or breeding home is appropriate. The goal is to replace the carrier parent with a quality, normal testing offspring that carries on the lineage of the breeding program.

If the only quality offspring is also a carrier, then breeders can use that offspring to replace the original carrier. The breeder has improved the quality of the breeding stock, even though the defective gene remains in the next generation. The health of the breed does depend on diminishing the carrier frequency and not increasing it. Breeders should therefore limit the number of carrier-testing offspring placed in breeding homes. It is important to carry on lines. A test that should be used to help maintain breed diversity should not result in limiting it.

By breeding and not selecting against carriers, breeders are selecting for a carrier frequency of fifty-percent; higher than most breed averages. Each breeder must assess the frequency of the defective gene in their own breeding stock and determine their own rate of progress. As each breeder reduces the number of carrier breeding stock, the frequency of the defective gene for the breed will decrease.

We know that most individuals carry some unfavorable recessive genes. The more genetic tests that are developed, the greater chance there is of identifying an undesirable gene. Remember, however, that an animal is not a single gene, an eye, a hip, or a heart. Each individual carries tens of thousands of genes, and each is a part of the breed’s gene pool. When considering a mating, breeders must consider all aspects – such as health issues, conformation, temperament and performance – and weigh the pros and cons.

Without tests, the management of genetic disease involves breeding higher-risk animals to lower-risk animals. Occasionally, a breeding male is determined to not carry a defective gene for which there is no carrier test. The tendency is for everyone to breed to this male, as a guarantee against the disorder.  Any major shift in the breeding choices to a limited number of males will restrict genetic diversity, and increase the possibility of propagating additional undetected defective recessive genes in a breeding population. Such genes have become widespread even in populous breeds due to prolific breeding of popular sires.

Breeders are the custodians of their breed’s past and future. “Above all, do no harm” is a primary oath of all medical professionals. Genetic tests are powerful tools, and their use can cause significant positive or negative changes. Breeders should be counseled on how to utilize test results for the best interests of the breed.

This article can be reproduced with the permission of the author. Jerold.Bell@tufts.edu

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The Simple Dollar: A comprehensive listing of pet financial aid organizations for pet owners in need by Brian Robson Learn more

Vaccine Issues and WSAVA Guidelines 2015-2017
Published by DR. Jean Dodds’ Pet Health Resource Blog Learn more…

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Are You Prepared?:  How To Make Your Dog Comfortable in Older Age

Published Spring 2017

Written by Tiffany Cannon

We have 7 dogs in the house right now ranging in ages from 7 months to 10 ½ years. It’s obvious that they have different energy levels but they have different needs on a lot of different levels. As hard as it is to believe, dogs are considered senior somewhere between 7 and 10 years old. Vigilance and close observation will help you know when it’s time to make some changes to keep your best friend as comfortable as possible. 

Diet

Older dogs might have different dietary needs than they did when they were young. If they are particularly sedentary, eating the same food in the same quantity could lead to excessive weight gain. There are several foods formulated specifically for older dogs – some contain supplements that help manage joint health and provide necessary vitamins and minerals. But other foods advertised as ‘for seniors’ might be more marketing ploy than anything else. Consult your veterinarian to help you determine what food might be best suited to your dog’s dietary needs. Your vet might also suggest a supplement containing chondroitin or glucosamine. Finally, older dogs can develop sensitive stomach even when they previously had no problems at all. If you have always fed your dog once per day, it might be necessary to feed your old guy two or three times a day in smaller meals to help ease digestion issues.

Most people agree that table scraps aren’t good for your dog, but they can be even more dangerous for an older dog. Rich, fatty foods can cause all kinds of digestive issues including pancreatitis. Stick to low fat, dog-appropriate treats. 

Soft Bedding

I remember as a teenager when I loved laying on the floor. My brothers and I would play board games at night, lying on our stomachs in the living room, propped up on our elbows playing Monopoly or Battleship. If I tried to lay that way now for any length of time, my back would really start expressing its disapproval! My joints just aren’t what they used to be. Thirty years has taken a toll. I get up more slowly in the morning, stretch a bit to get the blood flowing and definitely prefer a softer bed to keep my back and hips comfortable at night. It’s important to provide soft padded bedding for your older dog too. They’ll sleep more comfortably but hopefully, you will too. Dogs that have comfortable bedding won’t tend to wander as much at night, they don’t need to reposition themselves as often to alleviate pain, they stay asleep and are more rested in the morning. Our old guys deserve comfort.

Home Accessibility

Stairs, jumping on beds and on furniture etc. can begin to present challenges they did not in earlier years. Observing your dog’s movement through the house can sometimes provide your first glimpse into aging behavior.

Older dogs (like older people) have less padding in those joints than they used to. This fact can have a lot of implications for you and your home. Our dogs love to hop up on the couch and lounge there during the day. Our older dogs can still hop up most of the time, but will be hesitant about hopping down. We don’t have any carpet in the den where the dogs stay during the day and it is obviously painful at times when they jump down from the couch to the tile floor. If my oldest girl Truffle sees me in the room, she will move back and forth until I come over and give her a “puppy elevator” ride to the ground.

I think I prefer having a girl who ‘sort of’ knows her limits though to one that still thinks he’s a puppy and tries to jump off the bed or the back of the couch. Older dogs are definitely more susceptible to injuries. If we leave really comfortable beds on the ground, our older girls tend to prefer sleeping on the ground level beds rather than jump on the couch. We have also needed to change up the types of beds we leave on the floor for the dogs. Our dogs have always loved having beds with walls – something they can nestle into and where they can have a built in pillow. We also have raised beds our dogs absolutely love. But arthritis has afflicted our oldest and at the end of an active day, she has trouble throwing her leg up over the wall. Putting down some flat Temper-Pedic-style beds has allowed the dogs to have options to fit their different daily comfort needs.

Slippery floors can be tough for older dogs to navigate as they begin to experience stiffness. If you have tile or hard wood floors, you might consider adding area rugs or runners in areas frequently navigated by your older dog. If you have slippery floors, you need to be especially vigilant with keeping toe nails trimmed as long toe nails exacerbate any traction issues your dog might already be having.

As your dog continues to age, eyesight changes are also common. Dogs who know the layout of their homes well can hide eyesight issues for a long time. If you move any furniture, watch your dog carefully the first few days to see if they are having any difficulties navigating the new configuration in their living space. While normal as part of the aging process, changes in eyesight should be discussed with your vet. Eyesight changes can lead your pup to experience more fear and timidity, especially in unfamiliar places.

Home accessibility is imperative because older dogs can be injured much more easily than flexible, muscular, active young dogs. Slips on the floor or an awkward landing coming off the couch can lead to painful leg and back injuries.

Another place where injuries can easily occur are in the car. Jumping in and out of the car can be even more awkward that jumping off items in the house. It’s also best to buckle up your dog while traveling by car of have him in a crate. We’ve all experienced the sudden stopping situation in traffic where our dog flies forward onto the floor board. This could be very dangerous for our older companions. 

Exercise

Your older Peeb has most likely slowed down a bit, but will still need and appreciate regular exercise. Moderation is key, but exercise will help keep your dog’s appetite stimulated, will help keep muscles and bones strong and gives your dog something to look forward to. Most older dogs will be more appreciative of time to sniff instead of straining at the end of the leash. If you do have an old speed demon, it’s important that you control the tempo. Don’t let your older dog go too fast or too slow. They can overdo it easily in their enthusiasm.

Temperature Control

Dogs become more sensitive to temperature swings as they age. They will appreciate a warm, dry place to snuggle up when the temperature plummets in the winter and might find it more difficult to stay cool in the summer. Older dogs (like older people have a more difficult time regulating their temperature). 

Grooming

Keep it simple and quick! Sacrilegious as it may be, I shave my two oldest girls. They hate being on the grooming table. They hate being brushed, combed, detangled, and having their toe nails trimmed. My oldest has always hated being groomed and has battled me from day one. It’s no surprise that she despises it even more now that she has arthritis. Cricket was a dream on the table as a young dog. But over the last couple of years, she has started fussing anytime we hit a tiny mat that needs to be pulled. Has she become more sensitive to pain in her advanced years or simply less tolerant? No way to know for sure, but she’s given us three litters and 18 babies. If she doesn’t want to be groomed any longer…she won’t be.

However you do your grooming, it remains a very important activity for your aging dog. Grooming provides private time when you can assess the general health of your old friend. This is your opportunity to check for unexpected wear and tear, find signs of a problem before it advances too far and become familiar with the stages of aging so you will be able to recognize changes when they are occurring.

Brush teeth every month to check for signs of decay. Watch for signs that your dog’s mouth is beginning to be painful. If your older dog stops wanting to eat kibble or crunchy treats but will eat soft food, there might be a problem with his mouth or teeth. Give your dog things to chew on such as Greenies, Hooves, Antlers and Bully Sticks which will help naturally keep plaque and tartar from building up. Consider having your dog’s teeth professionally cleaned at the vet when possible. This usually involves anesthesia so it’s important to discuss with your vet whether or not your dog is healthy enough for the procedure.

Trim Toe nails more frequently… Your older dogs aren’t running around like they used to. It seems like our dogs toe nails grow faster in older age…but the simple fact is that our veterans aren’t moving around as much. They don’t cover as much distance, they don’t move as quickly and they aren’t choosing to travel over the same rough terrain they did as youngsters. They are simply no longer being exposed to or experiencing the same surfaces and outdoor settings that naturally served to file down the nails as youngsters. If you take your dog for walks every day and walk your dog on cement, you will not need to trim toe nails as often as someone whose dogs get all their exercise in the back yard. 

Lumps and Bumps

Older dogs sprout all manner of lumps and bumps. Most are harmless and have no medical relevance. But it’s a good idea to investigate if you find that a new lump or bump has popped up in a new place. Skin tags, fatty tumors and cysts can seemingly grow overnight. But these can closely resemble cancerous growth and it’s a good idea for you to regularly check for changes in your dog’s skin. Your vet may want to perform a needle aspiration to determine if the lump is harmless or of concern. If you groom your dog at least once a month, you will have a good baseline of your dog’s “normal” state and will know when something out of the ordinary pops up. Be sure to remember to check in ears, mouth, in between toes and around private parts every time you groom.

Vet Care

If you have always gone to the vet only for an annual checkup, it might be a good idea to switch to a bi-annual visit. Ask your vet if a blood test is recommended. Kidney, liver and many other health issues might be detected at early onset when they will still respond to treatment. With your aging dog, the goal of a vet visit shouldn’t just be about treatment but prevention as well. It’s also important to act quickly when you do notice any issues to allow you to maximize treatment options.

Be Patient

Patience is a virtue and our older dogs will try our patience at times. But it is imperative that we have patience and demonstrate understanding to our old friends. In their advanced years, dogs slow down and take longer to comply with our requests to come. In fact, whether it is from discomfort or simply willfulness, they may ignore you altogether. Our 9 ½ year old Cricket was the only PBGV in my house who actually listened to me reliably and would come when called. Not anymore! She has decided she likes being in the front room where the other dogs aren’t allowed to be except when we are feeding. She stays in the kitchen and stares at the food container in the utility room or she will nestle down in the laundry pile in front of the washing machine. At night, when it’s time for bed, she will now only come willingly when bribed with an appropriate treat. She will not come for a milk bone…leaving her front room requires a piece of chicken or cheese. Any attempt to persuade her by calling is ignored and if you raise your voice to her, she slinks into kitchen and crawls into a crate. Older dogs have a tendency to operate completely on their own agenda.

Other age related issues we have to deal with are problems that are physical in nature. For Truffle, if I am trying to get her attention, I need to waive my arms and not just call her name. She can’t see far away any longer, but she can still pick up movement quite easily. Luckily, we haven’t had to worry about incontinence yet, but it is also a realistic issue that is completely out of our old dog’s control. If your older dog is starting to have accidents in the house, your vet might have something that will help and you will need to go out with your dog more frequently.

Fear Factors

You may notice your old friend is suddenly developing fears of things that never were a concern before. Our old ladies have suddenly developed a fear of thunder. Not unusual for a PBGV…but not normal for my crew. Noise sensitivity is particularly common as a cause for fear and concern. Ironic since this probably develops simultaneous to the beginning of hearing loss. Maybe there’s a connection?

With advanced age seems to develop an awareness that there are things in the world that can be scary and not in our dog’s realm of control. They seem quite aware of the fact that they are not physically up to meet a lot of the potential challenges they could face confidently as youngsters. With this realization, they look to their owners to give them that sense of security. It’s up to us to make our elders feel safe and protected. This might come in the form of a thunder shirt, or a crate kept in a quiet place where the old dog can hide in a safe place if they feel the need.

It is also common for older dogs to develop separation anxiety. 

Privacy & Socialization

Socialization is important for older dogs but so is Privacy! A safe, private area where they can retreat and feel completely confident that they are safe and secure is a must for aging dogs who live in a bustling household. Older dogs need the ability to get away from young and crazy pack members (including other dogs and young children). Place a crate against a wall or in a corner of a quiet room. The top and sides of the crate should be covered with the front door left open. Provide soft bedding for the dog to use for nesting material and make sure the older dog has access to the room throughout the day. We use sheets or towels so our girls can fluff the bedding to their hearts content. If they try to fluff a crate pad, they can inadvertently end up trapped underneath it.

Socialization can also be important. Don’t assume just because your dog wants to observe the action instead of participating that they don’t need socialization at all. It’s good for your elder to meet new dogs and people. This helps to keep them feeling confident and comfortable in new environments.

Training

Spend time teaching your old dog new tricks. They love to learn new things and love to have the personal attention they get when you are spending time teaching them. Be realistic about the types of tricks you want to teach your old dog and limit the tricks to those that don’t involve difficult physical maneuvers. Limit the time devoted to each session so your dog doesn’t tire out or become frustrated. Then spend time doing what they want – sit on the couch, snuggle and take rides in the car or slow walks allowing them plenty of time to sniff.

Feeling the effects of age is an inevitable part of every life well lived. With some planning and preparation, our older dogs can enjoy life well into their middle age and the senior years.

Resources

“10 Ways to Make Your Old Dog Comfortable” by Cynthia Foley, Whole Dog Journal, April 2015

“9 Ways to Make Your Senior Dog’s Life Better” by Lori Tay­lor, I Love Dogs, November 17, 2015

“6 Ways to Comfort Your Senior Dog” by Lisa Spector, Care 2, May 27, 2015

“Old Dogs, New Habits: Ways to Make Senior Dogs More Comfortable” by Gina Spadafori, vetStreet.com, July 5, 2011

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After the disaster: Keeping pets safe when returning home
September 11, 2017 | AVMA@Work Editor  Learn more

Centers for Disease Control & Prevention – What is canine influenza (dog flu)? : Canine influenza (also known as dog flu) is a contagious respiratory disease in dogs caused by specific Type A influenza viruses known to infect dogs. These are called “canine influenza viruses.” No human infections with canine influenza have ever been reported. There are two different influenza A dog flu viruses: one is an H3N8 virus and the other is an H3N2 virus. Learn more

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The 2015 AKC Canine Health Foundation Conference

By Laura Liscum on behalf of the PBGVCA Health Committee

In August, the AKC Canine Health Foundation (CHF) sponsored the 2015 National Parent Club Canine Health Conference in St. Louis. Linda Murray and I attended the conference on behalf of the PBGVCA and the PBGV Health & Rescue Foundation, respectively. We both thought that it was a fabulous experience with excellent talks, abundant opportunities to interact with the speakers, and lots of free dog chow! Here is a synopsis of several presentations that we heard at the conference.

Stem Cells Therapy for Supraspinatus Tendonopathy.
Dogs injure ligaments and tendons while chasing bunnies in the field, running agility courses and roughhousing at doggie daycare. Like their owners, many dogs develop osteoarthritis after years of activity. The traditional surgical repair, medications and rehabilitation therapy have not always restored the injured dog to his/her pre-injury state. Two years ago, we heard Dr. Sherman Canapp describe his remarkable results when traditional treatment approaches are combined with stem cells or platelet-rich plasma therapy. His work continues to look very promising.

This year we heard Dr. Jennifer Barrett from Virginia-Maryland Regional College of Veterinary Medicine. Barrett described her collaborative studies with Canapp using stem cells and platelet-rich plasma to heal 57 agility dogs with shoulder injuries that had been lame for more than a yeardespite treatment with non-steroidal anti-inflammatory drugs, steroids and sessions in rehab. Dogs were treated with stem cells, which are undifferentiated cells that are able to divide and develop into specialized cells that repair and replenish adult tissues. They also treated the dogs with platelet-rich plasma isolated from the canine patient’s blood. Platelets are a natural source of bioactive proteins and growth factors that stimulate collagen formation and healing of tendons and ligaments. In fact, platelet rich plasma is currently being used to treat human and equine athletes. The dogs received pre-treatment analysis of gait and limb movement. Then stem cells and platelets were isolated and injected into the soft tissue lesions, guided by ultrasound.

The dog returned each month for ultrasound gait and limb movement analyses. The site of injury was examined by arthroscopy at 90 days. The outcomes of this study were very encouraging! The AKC CHF is now funding Drs. Barrett and Canapp to conduct the first randomized, placebocontrolled clinical trial of stem cells and platelet-rich plasma for supraspinatus tendon injury. They are having a difficult time enrolling enough dogs for the trial, so if you have an injured dog, please inquire.Puppies

Regenerative Medicine
Techniques to Treat Cartilage Disorders. Complaints about aching joints are not limited to the athletic canine. Couch potatoes can get injured too. In fact, 80 percent of all dogs have orthopedic joint disease at some point. One type of joint disease is called osteochondrosis, in which the joint’s cartilage becomes damaged. If a weakened flap of tissue breaks off, the piece may absorb minerals and harden. Imagine what it would feel like to have a pebble floating around in your joint! Unfortunately, joints do not regenerate healthy tissue very well. Dr. William Saunders, from Texas A&M, described a method for healing degenerated joints in which a plug of tissue is taken out of a non-weight-bearing portion of a dog’s healthy joint and grafted into the same dog’s damaged joint. This autograft can successfully restore function to the formerly damaged joint. However, this is like robbing Peter to pay Paul — the donor site now has a weakened cavity. Dr. Saunders’s goal is to develop a method to strengthen the donor site. His approach is to create replacement plugs made of porous polyethylene glycol and seeded with healthy bone-derived stem cells. In his preliminary studies, he placed these artificial plugs into the donor sites, and the stem cells within the plug populated the joint. This is an important step in bringing the autograft therapy method to the clinic.

Personalized Cancer Treatment.
Most treatment strategies for cancer use a standard approach in which all individuals with a particular cancer are treated with the same standard drug therapy. Unfortunately, this approach fails to take into account the molecular differences between individual cancers. Precision medicine is a new approach in which treatments are selected only after an individual’s tumor has been profiled to find specific gene mutations that led to their cancer.

Dr. Douglas Thamm of Colorado State University is investigating Toceranib, a therapeutic for mast-cell tumors that is used when surgery is not curative. Toceranib, marketed as Palladia, is the only dog-specific anti-cancer drug that is currently approved by the U.S. Food and Drug Administration. It acts by binding to a specific protein in tumor cells. Dr. Thamm hypothesizes that treatment with Toceranib will only be successful on dogs whose tumors are due to mutation of that specific protein. To test this hypothesis, Dr. Thamm has developed a rapid test that can be performed on fine-needle aspirates. The test can rapidly determine whether a dog’s mast-cell tumor has the mutation so that a therapeutic decision can be made within days. This test is the first step toward personalized medicine in the treatment of canine mast-cell tumors.

Atopic Dermatitis and the Mycobiome.
“You’ll Never Walk Alone” is a Rodgers and Hammerstein song from the musical Carousel. When he wrote the lyrics in 1945, Hammerstein had no way of knowing that when you walk through a storm, at least 100 trillion bacteria walk with you. In fact, 90 percent of our body’s cells are bacteria! We truly never walk alone. Fortunately, the microbes that colonize us are non-pathogenic symbiotic bacteria and fungi that are critical for our health. The abundance of these friendly microbes keeps the pathogenic organisms at bay.

Dr. Jan Suchodolski from Texas A&M is studying the canine mycobiome, which is the dog’s fungal community. He has determined that “the skin of dogs is inhabited by much more rich and diverse microbial communities than previously thought.” His recent publication [Hoffman, 2014] showed that each dog has a unique community of microorganisms, and each area of a dog’s skin harbors a unique selection of microbes. Healthy dogs have from 25 to 40 different species in their nostrils and up to 866 species in an ear! The composition of the microbial community did not appear to be influenced by dog age, sex, breed, itchiness, ear problems or indoor/outdoor environment. However, there was a significant difference when healthy dogs were compared to those with atopic dermatitis, or allergies. Dogs with allergies had fewer species of microbes than healthy dogs. Future work is needed to determine whether the reduced diversity of the skin mycobiome in allergic dogs isthe cause of, or the result of, the animal’s hypersensitivity to allergens. It is not known if the skin mycobiome shifts during allergic episodes. Finally, the possibility exists that restoring the microbe community to healthy levels will help treat atopic dermatitis.

Senior Cognition and Brain Aging.
Are you slower to get out of bed in the morning? Can’t remember who that person in front of you is? Finding it harder to negotiate a familiar environment? Have a decreased attention span and a loss of knowledge? Feeling anxious about all of these changes? These are questions that you should be asking your senior dog. From about six years of age on, your dog will begin to exhibit signs of brain aging that are so subtle that you may not notice them. Signs that are severe enough for you to notice include new fears or phobias, separation anxiety, soiling in the house, waking at night, vocalization and repetitive actions. Many owners do not report the first signs of aging to their vet because they think that nothing can be done. But there is evidence that early intervention may help.

Dr. Gary Landsberg from the North Toronto Veterinary Behaviour Specialty Clinic has extensive experience in testing cognition in senior dogs. Senior dogs get Alzheimer’s-like brain changes and have measurable deficits in learning and memory. When cognitive dysfunction is suspected, a vet must first rule out medical issues, and conduct neurological and sensory physical exams. Dr. Landsberg is also director of Veterinary Affairs at CanCog, a contract organization that specializes in non-invasive research on canine cognition and general behavior. His videos of the CanCog Beagle colony illustrated a typical cognitive test. First, let a dog learn a task such as quickly finding the food treat that is under the large box, but never under the small box. Once the task is learned, you present the dog with a reversal task by putting the treat under the small box. Young dogs quickly learn that the task has been reversed, whereas older dogs take significantly longer. But it turns out you can teach an old dog this new trick if you have provided the dog with an enriched environment. Dr. Landsberg said that you should make a senior dog work his/her brain everyday! He cited several pharmaceuticals that he prescribes for dogs that are showing cognitive dysfunction. He said that senior dogs show improvement with the medications individually and do even better when they are in combination. He encouraged owners to ask their vets for help. He also recommended two foods for dogs older than six; they are Hills b/d Canine and Purina Bright Minds (discussed below). Both have additives that help senior dogs maintain learning and memory skills.

Bright Mind Platform.
The brain is the most metabolically active organ in the body. At rest, the human brain uses up to 25 percent of the body’s energy even though it only accounts for 2 percent of the body’s mass. When challenged by a Sudoku puzzle, the energy needs go up. That energy is obtained from glucose that enters brain tissue from the blood. The situation is similar in dogs. Dr. Gary Penn, from the Nestlé Research Center, explained that dogs begin to show behavior signs of aging because their brains lose the ability to metabolize glucose around the age of 7. Investigators at the Nestlé Research Center explored alternative energy sources and found that adding medium chain triglycerides to the food increased the ability of dogs at the CanCog facility to perform cognitive tests. I was so convinced by the evidence that medium-chain triglycerides help maintain cognitive function that I bought a coconut-oil dietary supplement for myself. If only I could remember to take it!

The Human-Animal Bond/Quality of Life Scale.
If you are an avid reader of Saber Tails, that probably means that your passionate relationship to your PBGV(s) governs your life. From the house you buy and the car you drive, to the clothes you wear and places you vacation — PBGVs rule! This extraordinarily close human-animal bond makes it difficult when your dog is terminally ill. The keynote speaker for the CHF conference was Dr. Alice Villalobos, the former president of both the American Associationof Human Animal Bond Veterinarians and of the Society for Veterinary Medical Ethics. Dr. Villalobos has an animal oncology consultation service in Woodland Hills, Calif., and an animal hospice, called Pawspice, in Hermoso Beach, Calif. The Pawspice mission statement says, “Pawspice is committed to the highest standard of compassionate cancer treatment and end-of-life palliative care to advanced stage and terminal pets by providing a unique Quality of Life Care Program.”

According to Dr. Villalobos, we need to be able to distinguish between normal senior life and end of life in our pets. In the past, veterinarians were not trained to give pets palliative care; she is trying to change that. She has developed a quality of life scale that assesses seven characteristics, which are Hurt, Hunger, Hydration, Hygiene, Happiness, Mobility and More good days than bad days. The scale is intended to help caregivers and family to monitor and improve a pet’s well being, and help them know when palliative care and hospice may be warranted, rather than curative treatment. Dr. Villalobos stressed the importance of providing terminally ill pets all necessary medications, effective pain management, adequate nutrition and hydration, proper hygiene, assistance with mobility to maintain muscle mass and healthy joints, and contentment.

The Pawspice website (pawspice.com) has excellent resources for pet owners who are facing difficult end-of-life decisions. Go to the site and click on Library to find articles on Dr. Villalobos’s quality-of-ife scale or to view her seminar at the August 2015 Southern California Veterinary Medical Association Symposium. There is also information on many types of cancer and when it is time for euthanasia.

The 2015 National Parent Club Canine Health Conference also featured presentations on gastric dilatation volvulus (commonly known as bloat), intestinal inflammation, infectious diseases, brucellosis and seizures. You will read about those talks in a future issue of Saber Tails.

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Conditioning Puppies for Hunting

By Mary Fluke, DVM
September 2015

Conditioning puppy for huntsWhen I started hunting with Iris, she didn’t have a clue what she was doing, never went in the cover, just ran the lanes and made no progress until after several hunts when she finally tripped over a rabbit. I’ve watched a lot of novice dogs try to start out in the hunt field and have seen other handlers go through the same frustration that I experienced. For dogs with no experience, whether or not they succeed in the field has more to do with luck and persistence than anything the owner can do to help them. I still remember the moment when I saw the light bulb go off for Iris, when she finally figured out that she could go in the briar patch and rustle up her own bunny and have the fun of following the trail.

Most of us get our puppies from breeders who have the show ring as their main focus. They do a wonderful job of socializing puppies, but hardly anybody makes the effort to condition puppies for hunting. When I decided to breed Iris, I had to come up with a plan to condition the puppies for hunting so they would have a head start in the field.

A few years ago, one of our judges (Sian Kwa) presented a seminar at a hunt on this very topic. She gave a memorable example using a durian (the King of all Fruit, a very stinky sulfurous fruit which tastes like butter if you can overlook the sulfites) to show that things that we smell and taste when we are very young will be familiar forever and have good associations, even though we might not appreciate them so much if we are exposed as adults. Puppies that will be raised for drug detection start playing with plastic cylinders loaded with the smell of illicit drugs while still in the whelping box. Sian, who raises Dachshunds for blood tracking, has her puppies playing with deer feet and eating deer meat as soon as they go on solid food.

I used this information to create a plan for conditioning my puppies for hunting. I started with freeze-dried bunny ears and feet, and also freezedried rabbit jerky. Once the puppies were about three weeks old, I started letting them play with the ears and feet at least once or twice a day. They showed a lot of interest and persistence, and I kept this up until Oak got big enough that one day he swallowed one of the bunny ears whole! After that, I had to be a little more circumspect in how I offered them the bunny bits.

I had taken care of the problem of early exposure to the scent. Now I needed to get the puppies used to going into cover. Fortunately, the puppies were born in the fall so the season was prime for pruning. I used branches to create a brush pile in the back yard. When the puppies were five to six weeks old, I started taking them outside to eliminate after eating and to start walking around on the outdoor surfaces (asphalt and grass). They were interested in the brush pile and played in the edges. I wanted them to be a little more adventurous, so I made a “drag” using a couple of freeze-dried bunny feet tied to a piece of twine. I threaded the twine through the brush pile, and then had a helper release a couple of puppies at a time so they could follow the drag through the brush pile. The puppies had a lot of fun working their way over and through the branches, and the best part was that I could do this in my own back yard, no running grounds required, no hunt field needed. This exercise was tons of fun to do, nothing cuter than puppies worming their way through a brush pile.Puppies going under cover.

One of the beagle guys from our local club was nice enough to fix me up with a San Juan rabbit (halfway between domestic and wild). As the puppies grew up, I gave them the chance to see and smell the rabbit in a cage. Not quite the same as turning puppies loose in a one-acre practice pen like the beagle guys do, but again, I was trying to devise a plan that anybody could do. Domestic rabbits aren’t the same as wild rabbits in terms of smell and behavior, but any rabbit is better than no rabbit — the point is to give the puppy some kind of context to connect “that smell” with “that animal.” The puppies showed some initial fearfulness when they had a chance to get close to the bunny (in a small wire cage on the ground), but they soon got over their caution and started barking and sniffing. One caveat for this exercise is to be careful to avoid the fear period that usually occurs around eight weeks — if the puppy is exposed to the caged rabbit at this critical point, the progress for hunting might be slowed down.
The final exercise was following a trail. I went to a bloodtracking seminar a few years ago and heard a couple of guys from Germany talk about conditioning puppies for following scent trails. One of the presenters said that he used buttermilk to draw a line on the floor, and then let the puppies follow the line — again, easy to do on the kitchen floor where the puppies are being raised. I tried using a drag with bunny “scent in a bottle” and food treats to create trails for the pups to follow, indoors and outdoors.

I am lucky enough to have access to a running grounds, so I had the opportunity to get the puppies on the hunt field by 10 to 12 weeks. They followed me into cover, used their noses consistently and showed wonderful promise as hunting dogs. Three of the pups from that litter have gone on to hunt very enthusiastically, and are well on their way to completing their hunt titles.

So breeders, what the heck, let the puppies play with freeze-dried bunny feet, ears or pieces of a pelt. Feed them some bunny meat, freeze dried or fresh, when they start eating solid food. Puppy buyers, when you get your new PBGV puppy, make a brush pile in your back yard and get some bunny feet to make a drag so you can introduce your new puppy to cover. Take your puppy to a meadow with tall grass, or to the woods with some low undergrowth to encourage exploration and use of nose.

Exposing the puppy to a rabbit might be a little harder from a logistical standpoint, but hopefully you can go to a hunt and participate in a puppy or novice learning experience with a caged rabbit. Use your bunny foot drag to make a trail, and drop a little piece of food every foot or so to get your puppy off to a start on tracking. These exercises are fun and pretty easy to do, even in a suburban environment. (And don’t forget to practice your recall!)

Conditioning puppies for hunting isn’t hard at all. Give it a try!PBGV hunting

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