The resonating clink-clink of the Swiss made bell was audible from the distant covert. Familiar October sights and smells flooded my senses while the heavily white tri-colored setter explored for grouse perfume to surrender her forward progress. My mind wanders to the memory of picking out my first setter pup with grand grouse dog ancestry. I’d love to propagate this setter’s lineage, but I’m a grouse hunter stuck in the Wild West! The airline-cargo nightmares of shipping Canis familiaris to her prospective mate makes my blood pressure soar! Family and career commitments make traveling by car to a far-off northern state impossible. What if I could have the stud dog’s genetic blueprints shipped to me without all the travel hassles?

A basic knowledge of the canine estrous or reproductive cycle and understanding what specific diagnostic tests and exams are looking for will aid in your quest for the perfect litter. Domestic dogs are monestrus which means they complete one full cycle to the completion of ovulation per estrus (heat) cycle. Their cycle is not dependent on what time of year or season it is and they can cycle one to four times per year depending on the breed or individual bitch. The estrus cycle is divided into the four stages of proestrus, estrus, diestrus, and finally anestrus. Having a general knowledge of the canine estrus cycle can assist in timing the day of ovulation.

Proestrus which is the beginning of the heat cycle (duration of about 7 to 9 days on average) where the bitch attracts the male, but she is not receptive to mating just yet. During proestrus, her vulva will start to swell and a serosanguineous (reddish-blood and serum) discharge will develop. Estrogen is the main hormone that is regulating the behavioral and clinic signs of the bitch. Progesterone levels are low (< 1 ng/ml) and the cells seen under the microscope will consist of red blood cell, white blood cells, and normal vaginal epithelial cells.

Estrus is the next stage of the heat cycle and can range from 1 to 3 weeks in duration on average. This is the time when the bitch is receptive to the male. Hormonally, estrogen levels will begin to drop and subsequently progesterone levels will begin to rise. Later it will become apparent why we monitor progesterone levels when we artificially inseminate dogs. The vulva is still swollen and has a lighter pink discharge instead of the red discharge seen in proestrus. Estrus is complete when the eggs from the ovaries are ovulated and become mature for fertilization to occur. Vaginal epithelial cells seen under the microscope are mostly cornified and there is not a lot of “background” cells such as red blood and white blood cells.

Diestrus is the next stage to follow in the estrus cycle and can range up to 4 months in length. During this stage the bitch is no longer receptive to the male, and her vulva returns to normal with no visible discharge. Progesterone levels are at their highest concentration during this phase. Mammary development occurs at the end of this period prior to parturition or whelping of the puppies.

Finally, anestrus is the last phase of the heat cycle and this is the longest period lasting up to 4 months or more. During anestrus, the bitch is not receptive to mating and the estrogen and progesterone levels are at their lowest levels. This is considered a dormant or inactive stage of the canine estrus cycle.

Why is it important to understand the diagnostic test available and what their respective results mean to determine the day of ovulation? This is a great question to consider when managing the breeding in a bitch that is to be artificially inseminated or in one that has been difficult to get pregnant. When considering whether or not to artificially inseminate your bitch, several terms will be used by your veterinarian. Vaginal cytology, LH surge, progesterone levels, transcervical insemination versus surgical insemination, fresh chilled semen versus frozen semen, the list goes on. 

Timing of ovulation is of critical importance when considering artificial insemination in the bitch because optimal fertility can be expected between 2 and 4 days after she has ovulated. The best way to determine the time of ovulation is to monitor her blood progesterone concentrations. During proestrus, the progesterone levels are very low (usually less than 1 ng/ml) until the very late stages. LH is a hormone from the pituitary gland that aids in control of the estrus cycle. There is an increase of LH at the very end of proestrus which is referred to as the LH surge.  This surge causes the follicles on the ovaries to rapidly mature and get ready to be ovulated. The progesterone levels at the time of the LH surge climb from less than 1 to about 1.3 ng/ml. Dogs will typically ovulate 2 to 4 days after this LH surge. Progesterone levels will reach 5 ng/ml once ovulation has occurred (Remember—optimum conception is 2 days post ovulation or 2 days post progesterone levels of 5 ng/ml).

Canine ova (eggs) are ovulated and must go through a maturation phase that can take 48 to 72 hours. So again the optimal time to artificially inseminate the bitch is 2 to 3 days after their progesterone levels have reached 5 ng/ml (which is the progesterone concentration at ovulation). In the average bitch this is about 12 to 14 days from the onset of proestrus or when she first went into heat.

Once determination of ovulation is complete, now it’s time to deposit the semen into the uterus.mThis can be done surgically or transcervically (across the cervix) via the usage of a rigid endoscope and fiber optics. Surgical AI is when the bitch is placed under general anesthesia and the uterus is gently exteriorized from the abdominal cavity and the semen is injected directly into the uterus. This is a fairly reliable method, but has the risks of anesthesia associated with it, and canine conception rates that vary. 

A recently popular method of transcervical AI is now being used in many veterinary clinics around the US. This is a procedure that does not require general anesthesia and dogs seem to tolerate it fairly well with mild physical restraint. Transcervical insemination involves the usage a ridged fiber optic scope to aid in visualizing the cervix and gentling inserting a polypropylene catheter through the cervix to insert the semen. This is a very effect and safe way to inseminate your bitch without the risk of general anesthesia with relatively decent canine conception rates.

 

The other half of the equation is, of course, the collection, quality, handling and delivery of the selected sire’s semen. ”Canine Reproduction, Part II” will cover that topic.

As we approach the Dog Days of Summer, remember to be judicious about training your bird dogs during the intense heat of the day. Exercise and muscular activity can rapidly drive our bird dog’s body temperature to a life threatening level. Heat stroke can develop and lead to the death of your athletic partner. 

What is heat stroke? Heat stroke is a form of hyperthermia (extremely elevated body temp) that occurs when a dog’s heat-dissipating mechanisms of their body cannot accommodate extreme temperatures. The mechanisms to dissipate heat include panting and sweating; heat is removed from the body by the evaporation of sweat and dilation of blood vessels. Dogs do not sweat the way horses or people do, so they rely mainly on panting and dilation of the peripheral blood vessels to remove excess heat. Body temperatures in the dog that exceed 106° F without evidence of an infection suggest hyperthermia (a normal dog temperature can vary from 100 to 102.6° F, and a fever is when their temperature is greater than 103° F). The critical temperature for our bird dogs when they are hyperthermic is 109° F—as this is the temperature that is associated with heat stroke and organ failure!

When a dog reaches the 109° F core body temperature, thermal cellular damage begins. Excessive heat causes cellular death leading to multiple organ (liver, brain, kidney, gastrointestinal, muscles) failure and ultimately death may result.

Signs to look for while in the field include excessive panting, high rectal body temperature, excessive salivation, brick-red gums, higher than normal heart rates (it’s a good idea to know what your bird dog’s normal body temp and heart rate is), difficulty breathing, bloody diarrhea or bloody vomit, dizziness, disorientation, muscle tremors or weakness, changes in behavior—just to list a few.

Factors that can influence the severity of heat stroke include age, obesity, long hair coat, poor acclimation, poor conditioning, underlying heart or lung disease, dehydration, and most importantly, a previous history of heat stroke or other heat-related disease such as heat exhaustion. Dogs that have had a previous heat-related injury are much more prone to having a second episode because their heat regulatory center in the brain is most likely already damaged.

What can you do to immediately begin treatment in the field while on your way to the nearest hospital? Spray your dog with water or immerse their entire body prior to traveling to the nearest hospital. Use a cooling fan if at all possible or place them in a well ventilated area to aid in evaporation. You can soak the dog’s feet and groin/armpit area with rubbing (isopropyl) alcohol to aid in convection or removal of heat. Monitor the dog’s temperature constantly; once they return to 103° F, stop all cooling procedures because they can become hypothermic very suddenly. DO NOT use ice on the dogs because it causes the blood vessels to constrict which will impede heat removal. Be very careful in giving them both food and water once they are in heat stroke as it may cause severe gastrointestinal distress. Move your dog promptly to the nearest hospital for further treatments—which may include IV fluids and other emergency protocols deemed necessary by your veterinarian. Blood work can assist your veterinarian in assessing the degree of organ distress or damage such as the liver, kidneys, and pancreas. 

Some things that I do with my own dogs are to condition them early in the morning when the sun is not directly over head. I offer them cool water before and after exercise. I work them in an area with lots of available ground water for dunking and drinking. Make sure you force regular breaks or periods of rest on your dogs! Make them rest and rehydrate them often! When you are finished training, place your bird dogs in an air conditioned car with you. Finally, condition, condition, and condition them! Heat stroke is a condition that can be avoided by using an ounce of prevention! 

What it is:  Canine Influenza Virus (CIV) is a very contagious virus in the Influenza A family that is closely related to the Equine Influenza A strain. It has been proposed that the equine virus adapted or evolved and emerged as a new canine-specific variety. The H and N nomenclature is important because these are the glycoproteins in the outer layer of the virus that the host (dog, human, horse, etc) cells produce antibodies against (natural infection with the virus &/or response to vaccinations).

     The very first reported or recognized outbreak with the canine version of the H3N8 virus was in January 2004 in racing greyhounds from a Florida racetrack. Subsequently, the virus has been confirmed and documented in 30 states. CIV is very prevalent in the states of Florida, Colorado, New York and Pennsylvania.

Transmission: CIV is extremely contagious from dog to dog and can be transmitted through aerosolized secretions from the dog’s respiratory tract, contaminated objects (i.e. food and water bowls, tack and kennel surfaces, etc), and from our own hands and clothing. The CIV has been shown to be able to infect dogs from contaminated surfaces and human clothing for up to 24 hours. CIV is extremely contagious to dogs because it is a new emerging virus and there is very little natural immunity in our (naive) canine population from vaccinations or natural infections.

     The incubation period is between 2 and 5 days from the time the dog is exposed to the CIV before they begin showing any clinical signs of influenza. It is very important to understand that dogs are the most contagious to other dogs during this incubation period before they’re even displaying any outward signs of disease. Infected dogs can shed or spread the virus for 7 to 10 days from the onset of clinical signs.
     Because our canine population is naïve to CIV, virtually all dogs exposed to the virus will become infected; however, only about 80% will develop clinical signs. This means that roughly 20% will become infected and not display any outward evidence that they have CIV. Clinical signs include productive coughing, high fevers of 104 to 106 degrees F (normal dog temp. is 101 to 102.8 F), severe green nasal discharge, and clinical signs of pneumonia. The cough in some dogs is very similar to kennel cough caused by the bacterial infection from Bordetella bronchiseptica, but the cough tends to persist for 10 to 21 days even when the dog is being treated with antibiotics. It’s very important to note here that CIV is highly contagious but has a very low mortality rate 1 to 5% (and it appears to this author that mortality is over represented in racing greyhounds).

Diagnosis: CIV is most reliably diagnosed today by detecting antibodies to the H3N8 glycoproteins. These can be detected in an infected dog’s blood as early as 7 days after the onset of clinical signs. Veterinarians typically look at blood samples for antibodies at the onset of clinical disease and a second sample a few weeks later to watch for a rise in the antibody titer to the CIV virus. A single sample only confirms exposure to the virus or vaccination for that virus. Serological testing is currently being performed at Cornell University’s Veterinary Diagnostic Laboratory. Nasal or pharyngeal swabs and tissues samples can also be submitted to labs to aid in the diagnosis by PCR (detects viral RNA) testing and viral culture, which is less effective than the antibody serology.

Treatment: Is limited to supportive care as with most viral infections. Supportive care includes good nutrition, good housing conditions, antibiotics to prevent secondary bacterial infections, and maintaining good hydration (possibly via IV fluids). 

Prevention: In kennels, boarding facilities and shelters the virus is easily killed with the commonly used disinfectants such as bleach and benzalkonium chloride solutions. Good hygienic protocols should be established by thoroughly cleaning all surfaces, bowls, and cages between usages. Remember that the virus can remain viable for 24 hours on clothing and surfaces. Wash hands, change your clothing, and disinfect all surfaces if there is any chance you have come in contact with an infected dog. Isolate sick or exposed dogs from others for a minimum of 14 days.

Vaccination: In May of 2009, the USDA approved a conditional license to Intervet/Schering Plough Animal Health Corporation for their H3N8 Canine Influenza Vaccine. The vaccine contains inactivated wholes portions of CIV subtype H3N8. The Canine Influenza Vaccine is consider a “life style” vaccine and is not recommended for every dog. Many states do not include it as one of their “Core” recommended vaccinations. The vaccine is intended as an aid in the control of the disease associated with CIV infections. Like many vaccinations, it may not prevent the CIV infection altogether but may significantly reduce the clinic signs of the disease, reduce shedding of the virus, and decrease the duration of the disease. Researchers also found that the incidence and severity of the lung disease was significantly reduced when dogs were vaccinated.
    Dogs can be vaccinated (subcutaneously) as early as 6 weeks of age and need a booster in 2 to 4 weeks after the initial vaccine and then can be given annually as determined by you and your veterinarian. Due to the conditional licensing status with the USDA, the manufacturer of the H3N8 Influenza vaccine must continue to submit data obtained to support the products performance, safety, and efficacy.
     We, as sporting dog owners, should always consult with our veterinarian to see if any vaccination is appropriate for our bird dog’s lifestyle. It’s very important to understand a few things about vaccines. First of all, there is no guarantee that being vaccinated with any vaccine will insure immunity towards that disease…H3N8 included. Furthermore, vaccinations for our bird dogs do not have to be FDA approved but rather USDA approved which does not have the stringent rules (FDA’s) applied to getting them to the pet industry. Manufacturers have to demonstrate that the vaccine they are marketing must be first and foremost safe for the animal and secondly they have to provide some evidence that the vaccine is effective towards that disease.

A brisk northwesterly wind swept across the yucca and cholla-choked plains of Southeastern Colorado as my hunting partner’s cherished pointer searched for aromatic affirmation that there were birds in the neighboring environs. The pointer gracefully hurdled and bounded over the greasewood and sand-sage common in Colorado scaled quail country in search of any evidence of birds. Suddenly, a jackrabbit shot up and loped across the plains sending the pointer on a dead run after the impish creature. Frantically, my friend cussed and bawled for his pointer to “Whoa Dimmitt Whoa!” Shamefully, the pointer broke chase and returned to us 3-legged lame on the right pelvic limb.

The above paragraph is a very common scenario of how athletic dogs rupture or damage their cranial cruciate ligament (This is a common injury in people and is referred to as a torn or ruptured ACL). ACL rupture is a relatively common injury in athletic dogs and is the most common cause of degenerative joint disease or osteoarthritis in the stifle (knee joint). The role or function of the cranial cruciate ligament in the stifle joint is to limit internal rotation and forward or cranial displacement of the tibia in relationship to the lower femur bone. The ligament also plays a role in preventing the stifle from hyperextension during strenuous exercise.   

Injury to the ACL occurs when excessive internal rotation and hyperextension are added to forces greater than the ligament’s inherent strength, ultimately leading to damage of the fibers of the ligament. Diagnosis of the injury is made based on history of the injury, clinical signs associated with the dog, and radiographs of the stifle joint. 

Most dogs with an ACL strain or tear will be non-weight bearing for the first couple of weeks due to the amount of swelling and intense pain associated with the injury. The most common clinical sign veterinarians look for is the failure of the dog to sit normally. They fail the sit test when they swing the affected leg away from the body as the patient tries to move into the sit position. Radiographs of the stifle are also an effective tool to aid in the diagnosis because they help highlight the swelling in the joint that is commonly associated with a strain or tear of the ACL. Finally, palpation of the joint for pain and swelling and a forward motion of the femur relative to the tibia or Drawer’s Motion can aid in the proper non-invasive diagnosis of an ACL rupture. Partial or incomplete ruptures can be diagnosed by arthroscopic examination of the joint prior to surgical repair on dogs where ACL damage is strongly suspected.

There are numerous other environmental and genetic factors that can lead to damage of the ACL in dogs that generally do not apply to our well-conditioned and athletic bird dogs, so I will not address them in much detail.  These conditions can include such things as inadequate conditioning, obesity, hypothyroidism, and poor conformation, luxating or slipping kneecaps and chronic inflammation or arthritis in the stifle joint.

Once your dog has been properly diagnosed with pathology of the ACL, treatment options should be considered and initiated to get your bird dog back to top hunting performance. The goal of treatment should be to return your bird dog to the level of performance it was at prior to injury. The sooner surgical repair and stabilization are initiated, the better the outcome that can be expected. If left untreated, the unstable joint leads to damage of the articular cartilage and eventually osteoarthritis that can be performance limiting or stopping.

The two most common surgical techniques offered for ACL repair are Tibial Plateau Leveling Osteotomy (TPLO) and the new Tightrope CCL Technique. I will briefly describe both procedures in the following paragraphs.

The tibial plateau (the top of the tibia which is the bottom bone beneath the femur—both bones articulate to form the stifle joint) of the canine stifle is sloped and when the ACL is torn the femur slides down the tibia.  Some people have used the analogy of a car on a hillside tied to a rope. When the rope breaks, the car starts to roll down hill. However, when the car is placed on a level surface, it stays in the same spot and does not need to be tied in place. This is the simplified concept of the TPLO surgery.

Rupture of the ACL, and the sloping of the canine tibial plateau create what is termed as tibial thrust along with the forces exerted by the muscles of the calf and quadriceps. This tibial thrust creates excessive wear and tear on the joint causing damage to the cartilage and swelling which ultimately causes severe pain. A TPLO essentially levels the playing field and eliminates the tibial thrust, thus creating a dynamically stable and pain free gait.

TPLO surgery involves arthroscopic examination of the stifle joint to clean up the damaged ends of the ligament and to inspect the medial and lateral meniscus to see if they were damaged as well. Then the tibial plateau of the tibia is cut and the plateau is rotated to level the slope to about 2 to 14 degrees. The tibia is then secured back into place with a surgical plate and multiple screws.

The healing process after TPLO surgery requires 8 to 12 weeks of serious commitment. In my experience, patients are usually touching their toes on the ground a few days post-op. Patients need to be confined to leash walking and cage rest for a minimum of 8 weeks. Follow-up radiographs are recommended at 6 weeks, 8 weeks and 12 weeks to insure that the bone is healing properly without any complication of infection or broken hardware. At 8 weeks, patients are allowed to go on longer leash walks and after about 4 months post-op, most exercise restrictions have been lifted. Patients can usually be hunting or performing by 6 months post-op.

With TPLO surgery, it is estimated that 90% of the patients will return to the level of performance they were pre-injury while about 10% develop osteoarthritis that may limit or even stop their athletic ability. Many surgeons recommend that the patient be radiographed annually to determine the amount of degeneration in the joint. All bird dogs that have suffered an ACL injury that required surgery should be on glucosamine/chondroitin sulfate, omega-3 Fatty Acids (fish oils), niacinamide or Vitamin B-6, and joint supportive diets (Please see other Strideaway articles on Canine Osteoarthritis).

Radiograph showing severe swelling or joint effusion due to rupture of the ACL.

Radiograph of the same dog after TPLO surgery.  Note the cut in the tibial plateau and the plate/screws.

Dr. James Cook, a veterinarian from the University of Missouri, recently developed the Tightrope CCL Technique to address some of the shortcomings of other ACL repair techniques including the aforementioned TPLO surgery. Dr. Cook fashioned this technique on a procedure used in humans with ankle surgery because human ankle injuries are very similar to canine ACL disease. The Tightrope  (TR) procedure was developed to stabilize the stifle without the invasive process of cutting the tibial plateau as takes place with the TPLO surgery.

The TR technique also includes arthroscopic visualization of the structures within the stifle to remove the damaged ligament and inspect the medial and lateral meniscus. Then small tunneling holes are drilled through the femur and tibia bones so that the TR (which is made of Kevlar) can be passed through and anchored to stabilize the stifle joint.

Tightrope Procedure/Technique showing anchor points (drawing courtesy of James L. Cook, DVM, PhD, Diplomate ACVS, Director, Comparative Orthopaedic Laboratory, University of Missouri)

Opening of the stifle joint to clean out the torn ligament and remove the damaged medial meniscus prior to Tightrope Procedure.

Drilled holes in the tibia and femur for the Tightrope to be placed.

Tightrope being placed.

There is still a required 10 to 12 week recovery period to insure that there is adequate healing time with this surgical procedure. One of the most common complications that I have heard from surgeons in the Denver area is infection associated with the Tightrope. TR surgical technique appears to have similar return to function rates as the TPLO surgery.

ACL damage is by far the most common orthopedic disease that we see as veterinarians. Dogs that rupture one ligament are very likely to rupture the other at some point in time. On a positive note, I see it more commonly with obese patients and that rarely includes our hunting and field trialing dogs. Traumatic rupture of the cranial cruciate ligament accounts for only about 20% of all the ACL disease in the canine population. Having a basic knowledge of what occurs with ACL disease will help us as bird dog owners to get our 3-legged lame partners to the veterinarian sooner to aid in a healthier recovery. One final note, it’s never a bad idea to get more than one opinion before you commit to any surgical procedure for your hunting partner.

Shawn will be happy to answer questions. We will be adding a logo link to his site shortly. You can find Shawn at Bird Dog Doc’s Chronicles

My very best quail dog suddenly became labored in her breathing not long after the close of a great upland bird season. After examining her and osculating her chest, I had determined that the appropriate course of action was to get a chest radiograph (x-ray) and a diagnostic lab work up. The radiograph demonstrated a classic pattern within the lung tissue of an infiltrative type disease such as cancer or mycotic (fungal which includes Blastomycosis, Histoplasmosis, and Coccidioidomycosis) disease. I had hunted her in the Southwestern desert on quail and was concerned about Valley Fever which is a fungal disease known as Coccidioidomycosis. Serological blood tests for all the mycotic diseases were negative.  She ended up having an incurable type of cancer of the endothelium of the blood vessels called Hemangiosarcoma. Jibber’s clinical signs and chest radiographs were very similar to those of a bird dog with Blastomycosis.

Blastomycosis is a systemic fungal (mycotic) infection caused by a soil borne organism called Blastomyces dermatitidis. The small mold (fungal) spores are inhaled from moist soil, and enter into the dog’s respiratory tract and drift their way to the terminal airways in the lungs. Once these spores reach body temperature in the host (dog, cat, human), they transform into a yeast which is the active or infectious form of the organism. When the organism has successfully converted into the yeast form within the lungs it causes a pyogranulomatous pneumonia. The yeast can then circulate via the blood stream throughout the body.

The tri-colored setter is poised at the breakaway of the first brace of Grand National Grouse Championship. The frosty morning foretells weather conditions perfect for the hour-long stake and the excitement is electrifying! With muscles taut, she awaits that first moment of freedom. Six months ago she was diagnosed at her veterinarian’s office with osteoarthritis affecting multiple joints, but over time, through proper conditioning and medical management, it is possible for her to give a strong ground performance and be pain free!

As was mentioned in Part 1 of Osteoarthritis in the Sporting Dog, osteoarthritis (OA) is a progressive, wear-and-tear joint disease that involves the synovial (freely movable) joints within the canine body. Progressive implies that over time the condition is going to become worse with use and it can become more painful, leading to a decrease in the dog’s performance. There are management as well as medical treatments that can slow down the progression of the disease, and make our bird dogs more comfortable.

The lean white and lemon pointer soared across the Canadian prairie searching for that mesmerizing fragrance of chicken. Her gait was elegance-in-motion as she rolled across the wheat stubble with her massive muscles quivering and bulging…the shadows lengthening across the cold prairie and orange hues slowly fading to grays across the September horizon. As she rounds the corner on the last quarter section, I notice a very subtle change in her gait… “Danged burrs” was my very first thought! Or, is it possible that my 3 ½ year old, well conditioned, raw-boned, bird dog is developing osteoarthritis?

How is it possible that my pointer bitch is developing osteoarthritis at such a young age? Excellent question! Recent accounts in the literature suggest that approximately twenty percent of all dogs over the age of one already have some minor degeneration of their joints. Twenty percent of all dogs over the age of one…this makes osteoarthritis a significant sporting dog disorder. Having said that, what is canine osteoarthritis? Having a general knowledge of canine joint anatomy and the pathophysiology of osteoarthritis can be a benefit in the prevention and treatment of the disease in our canine partners.