For Monday’s Marvels we would like to introduce the dog’s thymus. We don’t hear much about this organ of the lymphatic system, other than perhaps when there are problems associated with it. Simply because it’s an organ that’s not that popular, we thought that it would be interesting learning more about it and how it affects our dog’s bodies. Our references point to some intriguing tasks carried out by this organ that make our dog’s bodies so interesting to learn about. So here’s what our dog’s thymus has to say.
Let Me Introduce Myself!
Hello, it’s your dog’s thymus talking today! You may not know me well as I am not so popular as other organs such as the liver, heart or stomach, but don’t let my lack of popularity belittle my role in ensuring your dog stays healthy and happy. I play some quite important roles that help orchestrate the immune system so everything runs smoothly and your dog’s body is protected from the harm of any foreign invaders. As a lymphoid organ, I am responsible for the development and deployment of special types of white blood cells the help maintain your dog’s immune function. I am located just above your dog’s heart and right below the trachea. I am born relatively large, but as it happens in humans, I tend to shrink in size with age.
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I protect the fortress from invaders.
I am an Instructor
My main function is to educate. My trainees are certain blood cells of your dog’s immune system which are known as “T cells.” T-cells are born in your dog’s bone marrow, but then are sent to me for their education, (hence their “T” name.) What do I teach these cells? I coach them on how to distinguish cells that are part of your dog’s body and those who aren’t supposed to be there. Just imagine your dog’s immune system as being protected by a fortress surrounded by walls and many troops. Sometimes, among the troops, there may be invading soldiers who dress up like the troops and try to infiltrate in hopes of gaining access to the fortress. My job is teaching my troops how to identify these invaders so they can be captured and removed before they do harm.
Meet My Troops
Interested in getting more acquainted with my troops? I have different types of soldiers that help protect my fortress and engage in different tasks. My “helper T cells” work hard cooperating with other types of white blood cells so to develop a strong immune response. My “killer T cells” are specifically trained to detect those foreign invaders such as harmful bacteria. While I try to do my best in training these latter soldiers, not all of them excel in their tasks. In this unfortunate instance, they aren’t given a second chance to make up for their mistakes. I must promptly take action because their mistake can be costly to your dog’s body. So I fire them on the spot and they are gone once and for all. Finally, I have a team of “suppressor T-cells” meant to keep things under control. You see, when invaders arrive, they stir up quite a conflict and things can get out of hand. Their job is to keep things under control.
Puppy’s Best Friend
We love puppies as much as you do. Remember how I mentioned that I am born relatively large and then shrink in size with age? Well, there’s a good reason for this. My role is most important during puppy hood, when puppies need to rely on the immune system the most. When puppies are born, they really don’t have much immunity, so my role is to help kick start the immune system to help these vulnerable beings.
I also play a role in what is known as “adaptive immunity“, also known as “acquired immunity.” I help make sure that those vaccinations protect your puppy as they should. You see, certain memory t-cells have the uncanny ability to remember exposure to certain foreign invaders. So let’s say the puppy is given a vaccination against distemper. The soldiers with the good memory will remember the distemper antigens so that should these antigens show up in the system, they can fight them promptly and efficiently so your dog can survive and thrive for as long as there is protection (something to obviously discuss with your vet!)
Disclaimer: The article is not intended to be a substitute for professional veterinarian advice, diagnosis, or treatment. If your dog is sick, please see your vet.
Puppy accidents: no matter what your breeder and that promising book you have purchased have told you, they will occur in your home sooner than later. Potty training puppies as with potty training children, takes patience and time, so unless you won a stuffed puppy at some carnival game, those bladder and bowels will empty no matter how assiduously you stick to a puppy potty training program. As with many things in life, if it sounds too good to be true, it likely isn’t true at all, and new puppy owners often learn this the hard (and often frustrating) way.
Breeders can start the ABCs of potty training.
Housebroken Puppies Ready for New Homes!
Yes, it’s true that many breeders implement some preliminary potty training basics when the puppies are in their care, but don’t expect to have all the homework done when your puppy comes home. Puppies have a hard time generalizing what they have learned in the breeder’s home. Just because a puppy was housetrained in the breeder’s place doesn’t necessarily mean he’ll be able to transfer the skill into a totally new context without help, explains Nicholas Dodman, in the book Puppy’s First Steps. It would be more realistic if certain breeders would explain that their puppies were introduced to potty training and that the new puppy owners must continue the training from day one, and that yes,they should expect some accidents along the way!
Potty Train Your Puppy in Under One Week!
Also, misleading is a new trend of books, e-books and videos making promising statements such as “How to potty-train a puppy under 7 days.” Sure, this is an effective sales pitch, who wouldn’t dream of a puppy who learned how to potty outside in just under a week? So new puppy owners purchase the book, try to adhere to the program and then get upset when they notice it isn’t working its magic. We can almost hear them say something in the terms of “What? It’s day 8 and the puppy had an accident?” Turns out, titles like these will only lead to frustration.
A formula for for failure?
Use this Formula for Success!
Another common misleading statement that can lead to problems is suggesting the “puppy month’s plus one rule.” This is something we hear trainers often repeat “ad nauseam” to their clients. The rule dictates the frequency a puppy should be taken out by calculating the puppy’s age in months and then adding one. So if say the puppy was 3 months, you would add 1 and therefore the puppy should be taken out every four hours. This leads to frustrated puppy owners when they discover that their puppies are unable to make it for the whole four hours. Unfortunately, potty training is not math, and equations as such will not work thier magic. For instance, if the puppy had some rough play time, he’ll likely guzzle down a lot of water, and then in an hour or two, the Niagara falls will open, leading to “unexpected messes.” Also, young pups need to be taken out after they wake up from a nap or after playing. Last time we checked, puppy bladders didn’t have a counter, so it’s not like the puppy’s bladder is counting down the minutes with the predictability of a kitchen timer.
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Aunt Mary knew it all.
Aunt Mary’s Training Was Easy as Pie!
Last but not least, be wary of aunt Mary who says her puppy was so smart she was potty trained in under 10 days. She may not truly recall how long it really took (things from the past often seem far easier than they really were) or she may have missed some piddles. It’s not uncommon to hear some people say “Oh, our Betsy was potty trained in what, 2 weeks?” and then the daughter remarks: ” but mommy, did you forget all those accidents we found later when we moved the couch?” It’s quite easy to miss little sprinkles from pint-sized dogs like Chihuahuas and toy breeds, versus the Lake Michigan-like puddles of a mastiff or great dane!
The Physiology Behind Puppy Accidents
Potty training puppies is not something that will happen overnight. Puppy owners need to be patient, understanding and learn effective methods to help their puppies succeed. Understanding better the physiology behind puppy accidents, can help new puppy owners understand why it’s so unrealistic to expect puppies to be potty trained in under a week and why certain mathematical formulas should be restricted to fixed variables that are constant versus things that are unpredictable and so variable such as puppy bladders and bowels!
Don’t blame me, I got no control!
No Sphincter Control
In dogs, and any living being equipped with a bladder, urine is constantly accumulating. At a certain point, when the bladder is full and reaches its threshold, special stretch receptors in the bladder wall activate. This triggers the contraction of muscles of the bladder wall (detrusor muscles) which give the dog the sensation of having to urinate. When dogs acknowledge this sensation, they may go to the door and bark to ask their owners to be let out. Control of the muscular sphincter found around the neck of the bladder allows them to hold the urine. Then, once out, they can can relax the sphincter and urinate.
In young puppies, when the bladder wall contractions take place, they are unable to control their muscles of their sphincter so emptying of the bladder occurs at this point. So the moment they realize they need to go, their bladders are already emptying. At what age do puppies attain sufficient muscle tone to allow them to control things a bit more? Stanley Coren, in his book “Born to Bark: My Adventures with an Irrepressible and Unforgettable Dog” claims that full control isn’t reached until the puppy is 5 to 6 months. So let’s do some real math here. If most puppies are 8 weeks when they go to their new homes, how can they be already house trained? And how can they be possibly be house trained in under one week?
Food equals poop!
The Gastrocolic Reflex
One main reason why the month plus one rule is faulty is the way a pup’s gastrocolic reflex works. Right after a meal, a dog’s gastrocolic reflex will increase the motility of the colon. This causes the rectum to fill up which stimulates the smooth muscle of the internal anal sphincter and the striated muscle of the external anal sphincter, explains Katherine A. Houpt in the book “Domestic Animal Behavior for Veterinarians and Animal Scientists.”
This means that shortly after eating, most puppies will have a need to defecate, which can set a puppy (whose owner adheres to the puppy moth plus one rule) to failure. You can almost hear frustrated new puppy owners make statements as such: “I just sent my puppy out at 5PM, my puppy had the opportunity to defecate, but he didn’t. I then served him dinner when we came back in, and just an hour later, he had an accident on the carpet! Arrgh.. wasn’t he supposed to be able to hold it for 4 hours?” Being aware of the gastrocolic reflex can help new puppy owners attain success because they’ll send their pups out after their pup’s schedule meal times, which is when they’re more likely to defecate. Other times pups should be taken out is after a nap, Soon, puppies will learn to associate going outside with the act of eliminating, a win-win situation for all!
Did you know? The veterinary term for the excretion of urine is “micturition.”
References:
Katherine A. Houpt, Domestic Animal Behavior for Veterinarians and Animal Scientists
Thomas Colville DVM MSc, Joanna M. Bassert, VMD Clinical Anatomy & Physiology for Veterinary Technicians, Mosby 2002
Nicholas Dodman, Puppy’s First Steps, Houghton Mifflin Company, Boston New York, 2007
What’s more surprising than a dog breed that sports six toes, the ability to close his ears and an amazing flexibility which allows him to bend his head backwards to touch the spine?
No, we are not talking about some science fiction creature or some odd being popping out of a Steven Spielberg’s film, we’re talking about a real dog breed originating from the remote islands of Norway that was selectively bred to perform some quite interesting tasks! So let’s take a closer look into how this fellow turned out being the amazing creature he is, shall we?
Norwegian lundehund
Nice to Meet You!
The Norwegian lundehund is categorized as a spitz-type dog, basically a dog boasting a thick, long coat with a pointed muzzle and often blessed with a tail that curls over the back. If we take a look at the meaning of this breed’s name we can find some clues as to what he was selectively bred for. In Norway, the word “lunde” means puffin, a species of bird found on coastal cliffs or offshore islands. The word “hunde” instead means dog. From these elements we can therefore deduce that this breed was bred to hunt for puffins and their eggs, a line of work that goes as far back as 1600. This bird’s meat was used for food and their feathers were used to make feather beds that were often exported to nearby locations.
Puffins over cliffs.
A Flexible Body
Amazed by the acts of contortionists you have seen at Cirque du Soleil? Norwegian lundehunds are the contortionists of the canine world. Since puffins live on rocky coasts and narrow passages in the island of Værøy, Norway, the lundehund’s body had to adapt to be capable of accessing these areas where man could not reach. Their superior range of motion allowed them to fit and turn around in narrow spaces. Here are some amazing capabilities: their head can bend backwards along their spine, a quality known only to reindeer, their shoulders allow a peculiar rotary movement and their front legs can extend flat to the side allowing them to hug the cliffs. Don’t expect judges though to ask for proof of flexibility in the show ring; these dogs won’t be able to do a demo as they would need to be sufficiently relaxed!
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Shut Those Ears!
Another interesting feature is this breed’s ability to shut their ears by folding them forwards or backwards. This feature allowed the lundehund to protect his ears from dirt and debris when walking through narrow cliff passages. According to the American Kennel Club standard, the ear leather should be capable of being folded and turned up, backward or at right angles, allowing the lundehund’s ear openings to be clamped shut.
The six toes of the lundehund
The Extra Toes
Ernest Hemingway had an obsession with polydactyl cats, but if he liked dogs, the lundehund would have made a good conversation piece at his place. The term polydactyl simply means ” having extra toes.” While several dogs have four toes on their front feet and four on the rear, this breed has a minimum of six toes on each foot and elongated rear foot pads, meant to grasp steep vertical cliffs, as he hunted for puffins in their rugged and inaccessible nesting locations. According to breed standard, the extra toes consist of one three-jointed toe and one two-jointed toe which gives the foot an overall strong appearance.
Puffins are now protected species.
On the Brink of Extinction
While lundehunds were used for many centuries to hunt puffins, their numbers declined dramatically as nets for hunting the birds were crafted in 1850 and puffin birds became a protected species. To make matters worse, several outbreaks of canine distemper taking place during World War II, and then again, in 1963, further decreased their numbers to only 6 specimens. Nowadays, their numbers have risen and there were an estimated 1400 lundehunds in 2010 with about 600 found in Norway and about 350 in the United States.
A new interest in this breed has revamped in the airport of Tromsø where they are being considered by Norwegian Air Traffic and Airport Management as a possible solution to fight airplane bird strikes by allowing them to search for bird eggs around the airport. Pretty amazing fellows, aren’t they?
References:
American Kennel Club, Official Standard of the Norwegian Lundehund, retrieved from the World Wide Web on Jan 9th, 2016
Norwegian Lundehund Club of America, Homepage, retrieved from the World Wide Web on Jan 9th, 2016
A black cat with raised hackles is a staple of Halloween decorations, but did you know that dogs have the ability to raise their hackles too? The action of raising hackles is known as piloerection, literally meaning raising of hairs. Cats are known to raise their hackles, but so do porcupines with their thick hairs when they’re frightened by predators. In some sort of way, the action is similar to when we get goosebumps, and as the popular expression goes, our “hairs stand on end. ” So in this Fascinating Friday, we’ll be taking a look as to why dogs raise their hackles.
Skin anatomy and skin follicle, Wikipedia Commons Public Domain
A Lesson in Anatomy
Dogs are equipped with hair follicles that are attached to special muscles called the “arrector pili” which are confined to the dog’s neck, back and tail. When the dog is in a normal, relaxed state, the hair follicles stay at a 30 to 60 degree angle compared to the skin.
Let the muscles contract though and those hair shafts will literally stand up, explains Karen L. Campbell, a board-certified veterinarian specializing in internal medicine and dermatology in the book “The Pet Lover’s Guide to Cat and Dog Skin Diseases.”
Getting Worked Up
Raised hackles in dog
The arrector pili muscles are innervated by the sympathetic branch of the autonomic nervous system. In our canine companions, contraction of these muscles is elicited by the release of epinephrine as it occurs when the animal feels afraid or excited, further adds Dr. Campbell. The contraction is involuntary, and thus, not under the dog’s conscious control as it’s part of the dog’s fight-or-flight reaction. It can also be seen in animals that are aroused, anxious, uncertain or surprised by the sudden appearance of an unexpected stimulus. An overstimulating play session may also cause raised hackles in dogs while playing.
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There are chances that based on the area of raised hairs, one may deduce information pertaining the dog’s emotional state. Raised hackles by the shoulder area may denote fear, while hackles raised by the tail area may suggest confidence, and in both shoulder and base of tail, they may suggest an ambivalent emotional state and conflict, (Karen London, 2012). Most likely, just as in the cat and in the porcupine, the action of raising those hackles has some adaptive function meant to make the dog appear larger than he really is. But wait there’s more! Alexandra Horowitz in her book “Inside of a Dog, What Dogs See, Smell and Know ” on page 110, explains that those hairs may also release the odor of skin glands located at the base of the hairs.
Raised hackles during rough play
Not Necessarily Aggression
It’s not correct to make unfounded claims that dogs who raise their hackles are aggressive. First of all, it’s wrong to label dogs as aggressive from the get-go, as dogs aren’t always in a constant state of aggression. It’s more correct to say that dogs may act aggressively in certain scenarios versus “dogs are aggressive.” Also, one must identify the stimulus that triggered the hackles to rise in the first place and take note of the accompanying body language before drawing conclusions. The fallacy of stating that dogs who raise hackles are aggressive is counterproductive, as it labels dogs through mere speculation and assumptions. If you are uncertain as to why your dog may raise his hackles, consult with a veterinary behaviorist.
Getting Warmed Up
Warm coats have replaced our fur.
The sensation of cold has been associated in several animals with the activation of the sympathetic nervous system causing the contraction of the arrector pili muscles. The piloerection in this case is meant to trap air and create a layer of insulation. As the hairs thicken, the amount of subcutaneous fat also increases. In us humans, cold still triggers goose bumps, causing the characteristic bumps and the rising of the hair shafts. Charles Darwin in the book “The Expression of the Emotions in Man and Animals ” classified the appearance of goose bumps as a vestigial reflex though, consideringthat ithas lost its original function since we’re no longer covered in hairs.
In dogs, Steven R. Lindsay in his book “Handbook of Applied Dog Behavior and Training, Procedures and Protocols” discusses about a possible interesting relationship between reactive emotional states and the process of heat production. The findings of several studies conducted on rats found a correlation between psychological stressors and temperature elevations. These increases in temperature may therefore turn out being a useful, non-invasive tool for evaluating the presence of psychological distress in dogs, he suggests.
Did you know? You’re not imagining things when you notice more hair loss in your dog during stressful situations. What happens is that hairs that are in the telogen phase (the resting phase) are more likely to fall out when the arrector pili muscles contract as it happens in stressful situations such as being at the vet, explains board-certified veterinary dermatologist Karen L. Campbell in the book “The Pet Lover’s Guide to Cat and Dog Skin Diseases.”
References:
Alexandra Horowitz in her book “Inside of a Dog, What Dogs See, Smell and Know”, Simon &Shuster, Inc, New York, Ny
Darwin, Charles. (1872) The Expression of the Emotions in Man and Animals John Murray, London
Karen L. Campbell “The Pet Lover’s Guide to Cat and Dog Skin Diseases”Elsevier Health Sciences, 2006
It’s Talent Thursday, and learning to associate words with certain items is certainly an impressive talent, especially when it comes to dogs! How many words can a dog learn? Rico, the border collie, has shown the ability to learn over 200. Juliane Kaminski from the Max Planck Institute for Evolutionary Anthropology along with colleagues, has studied this remarkable border collie. The results of the study clearly demonstrated that Rico was capable of getting 37 out of 40 items correctly! In order to properly study this dog, a scientific approach was needed to rule out other phenomena which could have explained this dog’s ability to discriminate words from one another.
Beware of the Clever Hans Effect!
Ruling Out the Clever Hans Effect
One phenomenon to rule out included the dog’s reliance on subtle cues sent from the owner. Dogs are very attentive to our body language, so it’s easy for them to select certain items simply because we are moving our heads in that direction or looking at the item. We may do this unintentionally, but dogs feed into these cues.
Many years ago, a horse going by the name of Clever Hans, was found to be capable of resolving arithmetic calculations. The horse was asked to solve a math problem and he would tap his hoof to give the answer. After an investigation conducted in 1907, psychologist Oskar Pfungst proved that the horse wasn’t actually counting, but was actually responding to involuntary, subtle cues sent out by his trainer! Turns out the horse was quite sensitive to the building tension of his trainer when he was asked to solve a math problem and the release of tension when he got to the correct number. This release of tension therefore informed the horse that it was time to stop tapping his hoof. Because of this phenomenon, now, people studying animal cognition refer to it as “The Clever Hans effect.”
Out of Sight
So in the study of Rico, the border collie who knew 200 words, it was important to rule out the Clever Hans effect. This was done by asking the dog to fetch the toy by its name with the owner in another room. This prevented the dog from reading the owner’s cues (such as looking at a particular item) and would have proven that this dog was actually capable of fetching the correct toy because he really associated the word with that particular toy. The results revealed that Rico was actually, capable of understanding words and his vocabulary proved to be quite broad when compared to the vocabulary of parrots, apes, sea lions and dolphins!
Proof of Fast Mapping
So if Rico wasn’t relying on any subtle cues sent by his owner, how was he capable of learning so many words? Turns out, he was utilizing the same mechanism humans use known as “fast mapping.” Fast mapping is a mental process where concepts are learned based on a single exposure. Children during the language acquisition phase, learn many words each day by relying on this mechanism.
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To prove that Rico was capable of learning based on a single exposure, a novel item was introduced among familiar ones in a single exposure. Rico was then asked to retrieve the new object by using the novel word. So Rico went off to select the toy, and possibly, through a process of elimination, determined that the novel word must have been used to refer to the novel toy.
Referent Selection and Retention
In order to learn through fast mapping, two conditions needs met: referent selection and referent retention. In referent selection, the dog must associate a word with a particular item; whereas, in referent retention, the dog must be able to store the word in his memory for later use. After learning a new word after only one exposure, Rico was tested a month later to see if he retained the understanding of that word. Surprisingly, Rico was able to correctly retrieve the item as much as 50 percent of the time, a success rate that matches that of a 3-year-old child!
Rico’s behavior was quite remarkable indeed. Further proof of understanding words was proved by other dogs with an even more vast knowledge of words. Betsy, another border collie, showed she was capable of understanding over 340 words, but as of 2010, Chaser, another border collie beats all with a vocabulary of an astounding 1022 words! Yes, you read right, that’s 1022 words!
This can make us wonder if border collies have superior cognitive abilities when it comes to understanding the meaning of words. If we think of it, this breed was selectively bred to herd and throughout the years has shown a remarkable ability to understand voice commands and whistles, so perhaps, there may be a genetic predisposition at play. Yet, with the right training, any dog regardless of breed can learn the meaning of words if you know how to teach them.
Words From Rover’s Perspective
As much as the behaviors of Rico, Betsy and Chaser are impressive, they are still a far cry from the way humans perceive words. Humans have the cognitive ability to perceive abstract concepts such as the words love, friendship and sincerity. Dogs on the other other hand, are more down to earth, and mainly learn words that are under the form of objects or actions.
Even though your dog may seem to understand a sentence such as ” do you want to go out?” and gets all excited when he hears that as it’s always followed by you walking by the door and opening it, he may not understand more complex concepts or phrases such “you can’t have the cookie now” as the word “now” or “can’t” isn’t understood, but since the word cookie may be, likely your dog may get all excited and then feel frustrated when he doesn’t get the cookie.
Your dog may not know an impressive number of words compared to Rico, Betsy or Chaser, yet consider that many dogs respond to cues present in their environment which often speak for themselves. For instance, the noise of the leash becomes synonymous with walk, the noise of the food bag becomes synonymous with dinner, when you wear your shoes, your dog knows that means you’re heading out, when you grab the car keys it likely (and hopefully!) means car ride and when your dog hears your keys making contact with the key hole it means you are returning home. So now that you know that dogs respond best to concrete concepts such as the names of objects or action words, it’s time to put your dog to test and enroll him in a program that extends his vocabulary!
Today we decided that the dog word of the day is “crabbing.” What is crabbing and how does it relate to dogs? According to the American Kennel Clubs glossary it’s a dog’s movement with the body kept at an angle to the line of travel. As the word implies, the movement is likely inspired by the way crabs move in a sideways fashion. The term is also used in aviation to refer to the maneuvering action of aircraftwhen dealing withcrosswinds so to compensatefordrift. Also known as sidewinding (in this case likely inspired by the movement of the sidewinder rattlesnake), this type of movement is frowned upon in the show ring because it interferes with a dog’s ability to trot in an efficient manner with little effort.
A Doberman trotting
The Correct Trot
In order to better understand crabbing, one must first better understand how a dog trots.
When a dog trots, the legs move diagonally in two beats with legs working as a pair. First, two legs diagonal to each other (right front, left rear) are lifted, while the other two are touching the ground, and then, the other opposite two legs diagonal to each other ( left front, right rear) are lifted while the other two are on the ground.
To trot effectively, it’s important that the legs land without touching each other. To avoid this, the dog must have enough reach in the front to move the front legs out of the way so there’s enough space for the rear to legs to move forward, without the dog risking stepping on himself.
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A Matter of Alignment
In an ideal situation, dogs should be moving in parallel planes. This means that as a judge looks at a dog moving towards him/her, the front leg as it’s lifted should block the view of the rear leg on the same side.
When this happens, it’s said that dog is “moving in the same planes.” In a normal trotting situation, the paw prints of the hind feet follow along the track left by the front feet.
A great example of this comes from Dr. Carmen Battaglia. She claims that when cars move in the snow, the front and back tires leave only two trails in the snow despite the fact that cars have four wheels. This is because the car’s front and rear wheels are moving on the same plane.
Moving Like a Crab
When legs end up touching each other, this interference causes the dog to adjust his gait, swinging the rear legs to one side, thus, causing the crabbing gait. By crabbing, dogs avoid kicking their front legs with their rear legs.
When this happens though the dog’s spinal column is not pointing in the direction of travel; rather, it deviates at an angle, explains Robert Cole in the book “You be the Judge – the Brussels Griffon.”
Affected dogs will therefore not move on a parallel plane but in an oblique line, and the judges notice it as the front leg doesn’t block the view of the rear leg on the same side. Dogs who are crabbing or sidewinding therefore have difficulty moving in a straight line.
A dog trotting with little effort
What Causes Crabbing in Dogs?
It’s often a matter of some structural deficiency or other proportional discrepancy, according to GrendsLori Kennels, a kennel specializing in breeding Great Pyrenees in Michigan.
Over or under angulation, short backs, sway backs are a few examples. It can also sometimes be seen in dogs with congenital orthopedic problems, nutritional deficiencies, some type of injury or a neurological disorder (such as lack of proprioception), so it’s worthy to see a vet for a thorough assessment.
Holistic veterinarian Dr Cathy Alinovi suggests seeking chiropractic care. In the show ring, crabbing is frowned upon because this interference leads to inefficient movement that wastes energy and is tiring to the dog.
“Crabbing” may be temporarily seen in young dogs, mostly when they go through the lanky phase of development and their back legs are slightly longer than the front or it can stem from lack of coordination. These youngsters may temporary move in a diagonal fashion to avoid stepping on themselves, but as they further develop, this movement may correct itself with early intervention.
If your puppy is running sideways or your dog is crabbing, consult with a vet for an assessment. For dogs who walk crooked only occasionally, it may be worth it to record the behavior as it occurs and show it to a vet.
A video is often worth a thousand words! Below is a video of a dog crabbing.
References:
Peak Performance EBook: Coaching the Canine Athlete By Canine Sports Production
What are exactly senses and how do they relate to dogs? If we look at our reference book “Clinical Anatomy & Physiology for Veterinary Technicians, p. 269:” it says that senses are “extensions of the central nervous system” that allow it to monitor what’s going on inside and outside of the dog’s body. Generally, when an internal or external stimulus is detected by the dog’s sensory receptors, a nerve impulse travels to the dog’s central nervous system and then it’s interpreted as a sensation that may generate a response. How many senses do dogs have though? So here’s our Tuesday Trivia question for today:
How many senses do dogs have?
A: Less than 5
B: 5
C: More than 5
And the answer is……
Answer: if you answered A, which is less than 5, you have missed out several important senses. If you answered B and said 5, you may likely think you got it right, as traditionally most of us grew up knowing that there are 5 main senses, but there are actually many more! So the correct answer is C, more than 5. Let’s take a closer look at them, shall we?
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A Dog’s Five Special Senses
These are for a good part the senses we are mostly accustomed to, the traditional ones we grew up knowing from studying them in classes. What these special senses have in common is that the sensory organs are located in the dog’s head. Even though these senses are the ones we most commonly think of, by limiting ourselves to these, we fail to give our dog’s bodies full credit for all of the amazing things they’re capable of doing. Here’s a quick rundown of them:
Sense of Taste: also known as the gustatory sense, your dog has several sensory receptors in his dog’s mouth which are commonly known as “taste buds.” Most of these are located on the tongue, but some are also found in the lining of the dog’s mouth and throat. When these receptors are stimulated, they generate nerve impulses to the brain which are interpreted as taste.
Sense of Smell: also known as the olfactory sense, your dog has several sensory receptors in his nose that generate nerve impulses to the brain and are interpreted as odors. A dog’s sense of smell is surely remarkable compared to ours and plays an important role in his perception of the world. If you’re guilty of yanking on your dog’s collar the moment he stops to sniff the fire hydrant, it’s time to start seeing things more from your dog’s perspective. Next time, as you walk towards the hydrant, ask your dog to heel a few steps and then reward him by telling him to “go sniff!” the fire hydrant. Your dog will be grateful for that and you can take a moment to admire this amazing sense.
Sense of Hearing: also known as the auditory sense, your dog’s hearing system converts vibrations of air molecules into nerve impulses that are interpreted by the brain as sounds. Does your dog sometimes barks at night and you can’t find a good reason why? Most likely, your dog has a good reason to bark as he can hear sounds that our ears cannot detect. If he does it quite often, it’s not a bad idea to check your attic, deck, basement or yard for any unwanted critters.
Sense of Vision: when it comes to vision, dogs have less visual acuity, color and depth perception compared to us humans, but they’re good at sensing movement even in dim light. When the photoreceptors of a dog’s eyes detect a stimulus, they generate nerve impulses that are interpreted by the brain as images.
Sense of Equilibrium: we’re not used to including this sense with the usual ones we’re most accustomed to, but it’s a sense and and as such deserves its spot among the other dog’s senses that originate from the dog’s head. We often take this sense for granted, but it’s thanks to this sense that our dogs are capable of maintaining their balance. The equilibrium receptors in this case are found in the dog’s inner ear and they collaborate with the eyes and several other sensors called proprioceptors that provide information about the dog’s position in space.
A Dog’s Five General Senses
As the name implies, general senses are senses that are distributed throughout our dog’s bodies other than being restricted to the head. When we think about a dog’s senses, we often think about the sensory organs that we are used to seeing on our dog’s bodies such as the dog’s nose, ears and eyes, but that’s just half of the story as there are several more! Several fall under the visceral category, meaning that they are interior, within the dog’s body. Here’s a quick rundown of them.
Sense of touch: also known as tactile sense, this sense tells the dog that something is in contact with the surface of his body. Special touch receptors located on the dog’s skin inform the dog’s brain about several sensations such as pressure, vibrations, and texture. The skin is the dog’s largest organ and it’s meant to protect his internal body from potential dangers of the external world.
Sense of Temperature: dogs also have several temperature receptors which are meant to inform the dog’s central nervous system about the body’s temperature so the body can make adjustments to return it within normal range. The dog’s temperature control system may therefore attempt to correct any conditions of hypothermia (low body temperature) or hyperthermia (high body temperature).
Sense of Pain: dogs have several pain receptors, known as nociceptors, which are located on the surface of the body and inside of the body. These pain receptors are found scattered almost everywhere on the dog’s body so the central nervous system can be alerted and measures can be taken to protect it. Sadly for many years, pain perception in dogs was underestimated, but nowadays a better understanding of ways dogs manifest pain proves they feel pain just as we do.
Sense of Inner Body: also referred to as “visceral sensations” under this category are found some miscellaneous senses of things happening internally. A deficiency of water elicits the sensation of hunger. A deficiency of nutrients elicits the sensation of hunger. Internal organs that are hollow have stretch receptors meant to inform about a sensation of fullness (think a full bladder eliciting a need to urinate) or pain (think the a bubble of gas in the intestine or the pain of a urinary stone).
Sense of Proprioception: we may not be too familiar with our dog’sproprioception sense, but our veterinarian certainly is and even more are veterinarians specializing in neurology. Dogs have several stretch receptors located in their muscles, tendons, joints and ligaments that are meant to inform the central nervous system about their whereabouts, including position, contraction of muscles, tension on ligaments etc. In other words, they help your dog know exactly where his body parts are, relative to their other body parts. When neurologists must evaluate dogs for neurological problems they’ll often lift the dog’s foot so that it’s upside down and evaluate how long it takes for the dog’s nervous system to detect the abnormality and adjust the foot’s position.
So here you have it, 10 senses, which include 5 special senses and 5 general senses. There may be even more though if you talk to a neurologist. Quite amazing, huh? But wait, this isn’t limited to only dogs! For the human version of this article read “How Many Senses Do You Really Have?” And just between us, let’s not forget about “sense of humor” and “common sense“! Just joking of course, haha!
Reference:
Clinical Anatomy & Physiology for Veterinary Technicians, Thomas Colville DVM MSc, Joanna M. Bassert, VMD, Mosby 2002
Today we’ll be sharing some interesting discoveries pertaining a marvelous organ that is often underestimated, the dog’s liver.
For those folks who loved reading stories from Reader’s Digest around the mid 80s’ may remember the author J.D. Ratcliff who wrote compelling articles featuring organs as if they were talking in first person.
We thought it would be fun to share some interesting discoveries of our dog’s bodies in a similar fashion on a weekly basis.
So we got our dusty veterinary textbooks out and visited several websites that are posted in the reference section. So here come some interesting facts about a dog’s liver, inspired by Ratcliff’s style and presented under the “I am Rover’s Liver” format.
Let me Introduce Myself!
Hello, it’s your dog’s liver talking. As an organ, you likely don’t know me well as I am tucked deep within your dog’s abdomen, right under the ribs, but don’t expect me to make my presence much relevant even when I am not doing well. I am notorious for causing vague symptoms that may mimic many other conditions. But first let me introduce myself.
My name is liver, and just from the origin of my name, you can tell a whole lot about me. My name comes from the Old English word “lifer” which most likely refers to life. In German, the liver is called “die Leber” and the word “leben” is a German verb that means “to live.”
Even our English word “life” has quite a close resemblance to the Old English word “lifer.” Perhaps, that’s because I sure play a great role in your dog’s life and the life of any living being who hosts me, as I am a vital organ that carries out a wide range of functions which are necessary 24 hours a day.
OK, I’m not that good looking even when served on a plate!
I was once considered the largest organ of your dog’s body, but now that many physiologists claim that the skin is an organ too, what can I say, the skin has outranked me, but I come right after with a honorable second place.
From an aesthetic standpoint, my appearance is not much candy for your eyes, as you may attest when you chop up liver treats for your dog’s training sessions.
I am a basically a brownish/red colored blob with several lobes. The real beauty of me relies in my “intelligence” in carrying out many complex tasks. This is not an understatement!
According to veterinarian Race Foster, I am capable of performing more than 1,000 different tasks! It would take a whole book to list them all, so I’ll try to make it short and sweet for you. My main tasks include metabolizing food, storing items for later use and disposing of stuff that aren’t needed or that are potentially toxic. Here’s a rundown of them.
I’m a Filtration System
Loads of blood comes in and out of me on a continuous basis. I am technically a sponge saturated with blood, squeeze me and I’ll secrete droplets of blood. Blood is delivered to me via the hepatic artery which supplies me with oxygen-rich blood straight from the heart that keeps me healthy and happy, but the great majority of the blood supplied to me comes from the portal vein which carries particles of digested food straight from the small intestine.
When blood makes it into my filtration system, I sort it into various components: things that are helpful, things that should be disposed of and things that should be stored for later use, yes, just like dogs who bury bones!
I’m a Chemical Processing Factory
After your dog eats his chow, I start working on breaking down and processing all the fats, carbohydrates and proteins. For example, I transform carbohydrates into glucose, break down the amino acid building blocks of protein so to separate the nitrogen and help in the digestion of fats by secreting bile.
I basically work extra hard in processing all the good stuff that comes in and transform them into easy-to-assimilate forms that the rest of your dog’s body can easily utilize.
When I secrete bile, a substance that aids in your dog’s digestion of fats, the bile is stored in the gallbladder and released into your dog’s small intestine via the bile duct. Bile also helps wipe out bilirubin, which is the residue of old, broken down red blood cells that need to be discarded.
If you ever wondered why your dog’s poop is brown, it’s thanks to the presence of bilirubin which is orange/yellow in color. If I get ill, I no longer can effectively get rid of bilirubin which is why dogs suffering from liver disease sometimes get yellow skin (jaundice) and may have gray-colored stools.
But wait, there’s more. I also make a protein known as albumin, which prevents fluids from the dog’s blood vessels from seeping out. When I get ill though, I may fail to produce enough albumin and fluids may start leaking out into tissues causing ascites, which shows up as abdominal distention.
And what about my ability to manufacture blood clotting factors? If you accidentally cut your dog’s quick as you clip his nails, it is thanks to me that he doesn’t bleed to death. Should I get sick for some reason though, I might be unable to produce these important clotting factors which can make your dog bleed more easily.
I’m a Garbage Disposal
Along with breaking down those carbs, fats and proteins your dog eats, I also try my best to also metabolize any crap I am exposed to such as harmful substances that are added to processed dog foods nowadays. I can do this though only up to a certain extent.
Remember those infamous pet food recalls from 2005/2006 that killed hundreds of dogs? The foods in that case were contaminated with aflatoxins and I couldn’t always keep up and work hard enough to excrete these, so sadly in such cases, I ended up raising the white flag and failing.
Along with getting rid of harmful substances, I am also responsible for metabolizing medications your dog takes. What I do is try to make them easier to excrete. Please make sure you follow your vet’s dosing instructions to a T and read the accompanying package inserts for symptoms suggesting liver or other problems.
If your dog is taking certain drugs that may impair my functionality, your vet may recommend routine blood work just to make sure I am doing OK.
Not all the stuff I dispose of come from bad stuff your dog ingests, some stuff are just part of the body’s normal functioning as in the case of proteins. When I process proteins, I end up with urea, a byproduct that is toxic to the body and should be discarded. So I send this urea to the kidneys, where it’s filtered from the blood and expelled next time your dog urinates.
And what do I do with the remnants of food after all the goodies have been removed? I simply send them off back into the intestine and out of your dog’s body next time he poops.
I Am a Storage Unit
While your dog may not take as many vitamins as you do, I play a role in the metabolism and storage of vitamins.
I am responsible for storing several fat soluble vitamins such as vitamins A, D, E, and K. This is why when a dog goes into liver failure their diet is often supplemented with several vitamins, further explains veterinarian Race Foster. Without these, dogs wouldn’t live much longer.
Along with vitamins, I also store metals such as iron, copper, and zinc in the right quantities so they’re ready when Rover needs them. My storage unit also houses a nice amount of blood. Consider that I store about 15 percent of the total blood in the body.
Should your dog ever lose a large quantity of blood, all sorts of alarm bells go off and within seconds I will send off my reserved supply to try to help as much as I can.
I also store glycogen in case your dog needs it when his blood glucose gets too low. All I need to do is convert the the stored glycogen into glucose to give your dog a quick energy boost.
I Can Regenerate Myself
Perhaps this is my most amazing feature. You might have heard about lizards being able to grow back their tails after losing them, well I am proud to say that us livers are also equipped with similar powers.
When we’re on the surgery table and the vet finds us injured or affected by disease, we can afford to have even up to three-fourths of us removed, and by the end of the year, we can regenerate and grow back to our original sizes.
Also, I am capable of still performing my duties despite 70 to 80 percent of me being damaged. Pretty amazing, huh? This doesn’t mean though that us livers should be taken for granted and neglected! It’s important to take good care of us!
Take Good Care of Me!
As the Canine Liver Disease Foundation explains, my ability to continue to perform my duties despite being damaged by some infection or a massive tumor, is a double edged sword considering that symptoms may show up only once a disease is well advanced, and possibly, non treatable.
So prevention is worth a pound of cure. To keep me healthy and happy make sure to feed your dog a healthy diet, provide access to fresh water, reduce the amount of toxins he’s exposed to and keep up with health checks as suggested by your veterinarian.
According to Merck Veterinary Manual possible signs denoting liver problems in dogs include loss of appetite, vomiting, stomach ulcers, diarrhea, seizures, fever, blood clotting problems, jaundice, ascites, increased drinking and urination and weight loss. If your dog is not doing well, play it safe and don’t hesitate to have your dog see the vet!
I hope this article has helped you understand me better. You know, I think I am sometimes underestimated and feel a bit in the dark hidden how I am under your dog’s rib cage. Take good care of me and I’ll likely effectively perform my duties so you can enjoy your four-legged companion for many years to come. Yours dearly,
Rover’s Liver
Disclaimer: The article is not intended to be a substitute for professional veterinarian advice, diagnosis, or treatment. If your dog is sick, please see your vet.
References:
Merck/Merial Manual for Pet Health, Merck & Co, INC. Whitehouse Station, NJ USA, 2007
Clinical Anatomy & Physiology for Veterinary Technicians, Thomas Colville DVM, Joanna M. Bassert VMD, Mosby Inc. St Louis, MO, 2002
Digestive Disease in the Dog and Cat, James W. Simpson & Roderick W. Else, Blackwell Scientific Publications, Oxford, London, 1991
Pet Education, Race Foster DVM, Anatomy & Function of the Liver in Dogs, retrieved from the World Wide Web on January 4th, 2016
Canine Liver Foundation, Canine Liver and Anatomy, retrieved from the World Wide Web on January 4th, 2016
Tufts University, Feeding the Dog with Liver Disease, September 2014 Issue, retrieved from the World Wide Web on January 4th, 2016
How can puppies be born and get to survive and thrive despite being born in such a helpless state? When it comes to animals coming into existence, there are two ways that the mission can be accomplished: the mother may endure a long pregnancy or incubation period which produces fully developed offspring, or the mother may undergo a short pregnancy which produces immature offspring. These two strategies draw the line between precocial and altricial species. Let’s take a closer look into the differences among the two, shall we?
Precocial Species
Let’s start with a lesson in etymology, the origin of words.
The word precocial derives from the Latin word praecox which means “maturing early,” which is also why we tend to refer to children or adolescents as “precocious” when we notice them developing certain abilities or physical traits at an earlier age than usual.
From a biological standpoint, generally precocial species refers to animals who are semi-independent and mobile from the day they are born or hatched.
Precocial species are motor and sensory mature and attempt standing/walking after birth. What animals are considered precocial? Several birds are considered precocial such as chicken, ducks, geese, but so are several mammals including herbivores such as horses, cows, goats and sheep.
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Altricial Species
If we look at the etymology of the word altricial we will see that it derives from the Latin root “alere” which means to “nurse, rear or nourish.”
From a biological standpoint, generally altricial species refers to animals who unlike the precocial species, are born incapable of moving around, are sensory underdevoloped and are dependent to a great extent on their mothers.
Altricial species are born deaf and blind, cannot regulate their temperature and often require to be nursed and must be licked by their mothers in the anogenital region in order to eliminate. Their initial lives are usually centered around a nest, pouch (in kangaroos) or den for protection.
What animals are considered altricial? Several birds are considered altricial such as sparrows, owls and many song birds, but so are many mammals such as cats and dogs, many rodents, marsupials and humans too!
Advantages of Being Altricial
What are some advantages of dogs being altricial? Here are some:
Because they are born helpless, altricial species are protected by their mother and provided with food and extra care. Being in a nest, den or pouch as seen in marsupials, also helps protect against predators.
One selective advantage for mother dogs is that they’re capable of absorbing puppy’s embryos in their early stage of development, an economical solution that allows a dead fetus to be broken down at an early stage when the fetus is only made of soft tissue and cartilage, explains veterinarian Steve Dean.
While altricial species are born with smaller brains at birth compared to precocial species, the trade off is that their brains continue to grow and attain larger sizes. (Ehrlich et al. 1988) This allows them time to gain more survival skills as they mature.
Did you know? Dogs are much tamer than wolves because of a longer period of development during which dogs have the opportunity to develop attachments, explain Raymond Coppinger and Lorna Coppinger in the book Dogs: A New Understanding of Canine Origin, Behavior and Evolution.
References
Eisenberg, John (1981). The Mammalian Radiations. London: Athlone Press
Ehrlich, Paul (1988). The Birder’s Handbook. New York: Simon & Schuster.
Can dogs lose their sense of smell? Many dog owners may find it surprising that dogs can become “scent blind” and lose their sense of smell. Perhaps this fact is quite surprising because we mostly hear about dogs who become blind or deaf, but rarely about dogs who lose their sense of smell. Because we think of dogs (especially scent hounds) as “noses on four legs” we would imagine the negative impact losing such an important sense would have on dog lives! In most cases though, it appears that dogs lose their sense of smell only partially, making it sometimes difficult for dog owners to take note of such changes. A decline in a dog’s sense of smell most likely would show up as alterations in appetite and food preferences, according to The Ohio State University College of Veterinary Medicine.
A for Anosmia
The medical term for a dog, other animal or human losing his sense of smell is “anosmia.” The term may be used to depict an animal or human who is unable to perceive odor or whose sense of olfaction is no longer functioning. The loss or decrease in sense of smell may be either temporary or permanent. Fortunately, in dogs, in most cases, the loss of smell is only temporary, it’s rare for it to be permanent, explains Dr. Pete a veterinarian with a Bachelor of Veterinary Science from the University of Melbourne, Australia.
Part of Aging
Just like people, dogs undergo several changes as they reach their golden years. Along with reduced activity levels, loss of muscle mass, hearing loss and decreased visual acuity, dogs may also undergo changes in the way they smell and taste food, explains veterinarian Melody Foess Raasch. These latter changes can reduce an older dog’s interest in food which can lead to weight loss. Let’s remember that “a dog’s ability to “taste” food resides in her nose” explains veterinarian Randy Kidd in an article for the Whole Dog Journal. Increasing the palatability of foods for older pets might be something to consider, consult with your vet or veterinary nutritionist for advice.
Respiratory Tract Problems
Just as people temporary lose a bit their ability to smell when they get a cold, dogs can also be susceptible to a decreased ability to smell due to upper respiratory problems. The most common causes for loss of smell in dogs include, infections of the nasal passages, blockages of the nasal passages either due to an irritation or presence of mucus, and less likely, polyps or tumors of the dog’s nasal passages that reduce airflow, explains Critical Care Vet, a Board Certified Specialist in Emergency and Critical Care.
Injuries to the Head
When dogs sustain some form of head trauma, their ability to smell may deteriorate because a specific part of the brain controls their sense of smell. According to the Merck Veterinary Manual an injury to the dog’s cerebrum can cause an impairment to the dog’s ability to see and smell along with other neurological complications such as seizures, coma, circling behaviors, and their inability to recognize their owners. Any injuries to a dog’s olfactory nerve, one of the dog’s 12 cranial nerves traveling from the nasal cavity to the brain, can also lead to loss of smell, according to Wikivet. The good news though it that this nerve, has shown the remarkable ability to regenerate when damaged.
Other Possible Causes
Dogs affected by distemper, a serious viral disease, may develop alterations in their sense of smell. In a study conducted by Myers LJ, Hanrahan LA, Swango LJ et al, a loss of smell was found in 5 or 6 dogs who recovered from a case of acute distemper 10 to 26 weeks earlier. If a dog inhales something toxic or caustic, this could scar the mucous membranes of the nose and lead to a loss of smell, adds Critical Care Vet. Brain cancer can also trigger a loss of the sense of smell according to Vet Arena.
Did you know? The sense of smell is one of the first senses puppies are equipped with at birth, along with the sense of touch and taste, the latter though requires still a few weeks to sharpen and completely mature, explains Stanley Coren, Professor Emeritus in the Department of Psychology at the University of British Columbia, in article for Psychology Today.
Disclaimer: this article and any other articles on this website are not intended to be a substitute for professional veterinarian advice, diagnosis, or treatment. If your dog appears sick, in pain or is not acting as his usual self, contact your veterinarian immediately. By reading this article you automatically accept this disclaimer.
For Monday’s Marvels we would like to introduce the dog’s thymus. We don’t hear much about this organ of the lymphatic system, other than perhaps when there are problems associated with it. Simply because it’s an organ that’s not that popular, we thought that it would be interesting learning more about it and how it affects our dog’s bodies. Our references point to some intriguing tasks carried out by this organ that make our dog’s bodies so interesting to learn about. So here’s what our dog’s thymus has to say.
Meet My Troops
Did you know? Dogs are much tamer than wolves because of a longer period of development during which dogs have the opportunity to develop attachments, explain 