What Is Heartworm Disease in Dogs?

Dirofilaria immitis is the organism that causes heartworm disease not only in dogs, but also in cats, ferrets, and other mammals. It is a large worm, reaching up to a foot or more in length, and as it completes its life cycle, which takes about six to seven months, it ends up in the heart and pulmonary vessels, where it can live for several more years. As the heart becomes clogged with worms, there is less blood it can push out to the rest of the body, and heart failure can result.

Symptoms of Heartworm Disease in Dogs

The severity of the infection will be related to the symptoms present, and symptoms of heartworm disease are related to the organs affected: the heart and lungs. Symptoms often include:  

Cough  

Lethargy  

Exercise intolerance  

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Sudden death   

Some dogs may show weight loss, difficulty breathing, and even excessive panting. Left untreated, dogs may go on to experience right-sided heart failure and ascites (buildup of fluid in the abdomen).

Causes of Heartworm Disease in Dogs

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Mosquitoes serve as the primary vector (carrier) for transmission of heartworm disease; transmission cannot occur from one dog to another. As mosquitoes bite and take a blood meal from an infected host, they ingest circulating microfilariae, or young immature heartworms. Inside the mosquito, the microfilariae undergo three stages of larval development (called L1, L2, and L3).  

When the same mosquito bites a dog, the L3 is deposited onto the dog’s skin, and it then migrates into the dog’s body and develops into L4. Then as an L5, it migrates throughout the tissues and bloodstream, winding up in the heart, where it takes up residence as an adult. This entire process usually takes about four months to complete. 

A few months later, around 7 months of age, the adult females become sexually mature, mate, and produce microfilariae. The commercially prepared tests to diagnose heartworm disease in the veterinary hospital detect antigens (proteins uniquely found on the surface of an organism that are used to detect the presence of that organism in the sample) produced by the female adult heartworm; that’s why testing usually starts around 7 months of age.

How Veterinarians Diagnose Heartworm Disease in Dogs

Dogs 7 months and older should be tested for heartworm disease at least annually. If the dog misses a dose of prevention, then she should be tested more frequently. Testing is often done in the hospital at the bedside and requires a small amount of blood.  

The most widely used method for diagnosing heartworm disease is antigen-based testing. Antigens are proteins uniquely found on the surface of an organism that are used to detect the presence of that organism in the sample. In this case, the antigens being tested for are produced by the female adult heartworm, and if the test shows positive, then the dog is infected.  

Other tests that can be performed include a blood smear or a modified Knott’s test (often a test that is sent out for diagnosis), which are done to check for the presence of circulating microfilariae.  

Once diagnosis has been obtained, your veterinarian may recommend more testing, which is used to find out the severity of the infection as well as the amount of risk involved for treatment. Other testing often includes chest radiographs, EKG, blood pressure, cardiac enzyme evaluation (NT-proBNP), echocardiogram, blood work, and urine testing.  

Class I dogs are those with the lowest amount of risk for treatment, and Class IV dogs are those often diagnosed with caval syndrome and are at highest risk. This means the worm burden is so great that the worms are blocking blood from exiting the heart. These dogs are dying and require surgical removal of the worms (often done by a specialist) to survive.

Treatment of Heartworm Disease in Dogs

Once your dog is diagnosed, your veterinarian will most likely explain to you next steps including treatment options, more diagnostics, and time frame for follow-up visits.  

First, your dog should have his activities restricted as exercise can increase the potential for the heartworms to dislodge and cause clots elsewhere in the body. Additionally, if your dog has circulating microfilariae in his bloodstream, mosquitoes, after ingesting a blood meal from your dog, can then transmit the parasite to others, so limited exposure to the outside is recommended.  

Certain medications may be prescribed, such as: 

Steroids: to decrease inflammation created by the worm itself 

Antibiotics: doxycycline is used to kill Wolbachia, a symbiote organism that lives within the heartworm. Without the symbiote, the host heartworm becomes easier to kill and secondary inflammation is minimized. 

Specific kind of heartworm preventive: to prevent younger worms from developing into adults and to rid the bloodstream of any circulating microfilariae   

An injection containing the arsenic-based compound melarsomine will be given to your dog 60 days, 90 days, and 91 days after diagnosis by the veterinarian. This is a medication designed to kill the adult heartworms and is usually administered in the lower back deep into the muscle. As it is painful, pain medications will most likely be sent home at those visits as well.     

Prevention of Heartworm Disease in Dogs

The best way to treat your dog is to do your best to prevent the disease in the first place with year-round heartworm prevention. The good news is that there are multiple types and forms of heartworm prevention on the market, and they are all affordable.  

There are tablets, topicals, and even injectable versions that can provide anywhere from 1 month to 12 months of protection. There are even products that are combined with flea and tick control to give your dog a more comprehensive preventive profile.  

All products are designed to kill the L3 and/or L4 heartworm larvae, and some will clear the blood system from circulating microfilariae.  

If your dog tests positive for heartworm disease, it is important to discuss the specific type of preventative needed while treating it, as there are only a few that should be given to minimize secondary complications.  

You should speak with your veterinarian to decide the best type of prevention for your dog’s lifestyle and your budget. Limiting your dog’s exposure to mosquitoes will also help, but in some places, limiting exposure is nearly impossible. It only takes one infected mosquito to cause heartworm disease.  

Recovery and Management of Heartworm Disease in Dogs

Treatment for heartworm disease is not risk free. Dogs that undergo heartworm treatment as discussed above can suffer from anaphylaxis (shock), emboli (clots), and sudden death, not to mention the possibility of abscess (pocket of pus) formation at the site of melarsomine injection and the emotional distress from months of exercise restriction.  

Dogs can also suffer from long-term health risks from the damage caused by the worms to their heart and lungs. Scarring and inflammation (swelling) generated by the worms makes it difficult for blood to be pumped through the heart and lungs, and right-sided heart failure can develop, even with successful treatment. 

The degree of severity will affect the prognosis, and the sooner the disease is caught and treated, the greater likelihood there is for a good outcome. Unfortunately, dogs that suffer from heartworm disease do not get immunity and are at risk for becoming infected again in the future. That is why year-round prevention is critical for your dog’s health.

Heartworm Disease in Dogs FAQs

Can heartworms affect humans?

Heartworm disease has primarily been known to cause health-related issues in dogs, cats, and ferrets. Yet heartworm disease can affect multiple mammals, and according to the CDC, that includes humans. Fortunately, your dog is not contagious: the disease in humans is acquired from the mosquito itself and is not that common.

Can heartworms in dogs be cured?

Yes. If caught early and treated appropriately, your dog may go on to have a good quality life.  Unfortunately, some dogs may experience undesirable consequences either from treatment or from the disease itself and may end up with lifelong complications.

What are the first signs of heartworms in dogs?

Some dogs may not show any signs, especially if they live a more sedentary lifestyle. Others, however, may show exercise intolerance and coughing.

What is the survival rate for dogs with heartworms?

Dogs presenting with Class I heartworm disease, and even Class II, have a much better prognosis and survivability than those in Class III and IV. Class IV dogs require surgery for lifesaving treatment and will die without it.

Featured Image: iStock.com/valentinrussanov

WRITTEN BY

Michael Kearley, DVM

Veterinarian

Dr. Michael Kearley graduated from the University of Florida College of Veterinary Medicine in 2013. He graduated with a certificate in…

Ureterolithiasis in Dogs 

Ureterolithiasis is a condition involving the formation of stones that may lodge into and block a dog’s ureter, the muscular tube that connects the kidney to the bladder and carries urine from kidneys to the bladder. Typically, the stones originate in the kidneys and pass down into the ureter.

Depending on the size and shape of the stone, the stone may pass down to the bladder without any resistance or it may partially or completely obstruct the ureter, resulting in the dilatation of the upper portion of the ureter and subsequent kidney damage.

There are a number of different types of stones found in animals and type of stone may vary in according to breeds, age, and sex of the dog.

Symptoms and Types

Some dogs with ureterolithiasis display no symptoms, especially during the initial stages. Otherwise, be attentive to the following symptoms:

Pain Kidney failure Enlargement or shrinkage of the kidney Accumulation of waste products like urea Rupture of ureter, resulting in urine accumulation in the abdomen

Causes

The underlying cause may vary depending on the type of the stone. Typical causes include:

Genetic factors Urinary tract infections Adverse drug reaction Cancer Diet and/or supplements Surgery that has lead to the narrowing or scarring of the ureter

Diagnosis

Your veterinarian will conduct a complete medical history and perform a physical examination on your dog. He or she will then use routine laboratory tests including complete blood count, biochemistry profile, electrolyte panel, and urinalysis to assess the condition of your dog and severity of the disease. These tests also help in evaluating your pet for any other concurrent disease or condition.

Abdominal X-rays are extremely useful in visualizing the stones and their size; it will also confirm if the kidney has become enlarged as a result of the stones. Similarly, X-rays will depict if the ureter is intact or ruptured. In some cases, a special dye is injected intravenously and X-rays are taken afterward. This helps better visualize the stones by providing contrast. Ultrasound scans is another method for detecting ureter stones and kidney size.

Treatment

Removing the obstructing stones is the primary objective of treatment. Fortunately, advances in modern technology has enabled veterinarians to remove the stones without surgery. A new technique called extracorporeal shock wave lithotripsy removes stones located in kidney, ureter, or bladder by producing shockwaves that break apart the stones, which can then be passed through the urine. Extracorporeal shock wave lithotripsy technique does not work for all animals, so consult with your veterinarian if it is right for your dog.

For dogs in which surgery is necessary, intravenous fluids are administered to maintain them hydrated. Antibiotics are also prescribed for dogs with concurrent urinary tract infection.

Living and Management

As relapses are common, continuous monitoring of the dog’s condition is necessary. Typically, followup evaluations are done every 3-6 months. Depending on the type of stone, your veterinarian will suggest dietary changes to prevent future episodes of stone formation. If your dog is not tolerating the dietary changes well, contact him or her for necessary changes.

The overall prognosis is highly variable depending on the type of the stones.

Teratozoospermia in Dogs

Teratozoospermia is a morphological (referring to form and structure) reproductive disorder characterized by the presence of spermatozoal abnormalities. That is, 40 percent or more of the sperm are abnormally shaped. The sperm may have short or curled tails, double heads, or head that are too large, too small, or badly shaped.

The effect of specific abnormalities on fertility is largely unknown, but optimal fertility is expected in dogs that have at least 80 percent morphologically normal spermatozoa. Therefore, it is known that it is nearly impossible for sperm that are abnormally shaped to fertilize an egg.

This condition can affect dogs of any age, but older dogs are more likely to have other age-related diseases or conditions that affect overall sperm quality. There is no breed predilection, however, Irish wolfhounds have been reported to have significantly lower semen quality than dogs of other breeds.

Symptoms

Spermatozoal abnormalities are sometimes classified into primary and secondary defects. Primary defects occur during spermatogenesis, the development stage, and secondary defects occur during transport and storage within the epididymis (part of the spermatic duct system). Often there are no outward symptoms of this disorder. The most obvious symptom makes itself apparent in the breeding dog, when the male dog fails to impregnate a breeding partner.

Causes

Congenital

Dogs with fucosidosis (a metabolic disorder caused by a deficiency of the enzyme fucosidase, which breaks down the sugar fucose) have been found to have an associated abnormality in spermatogenesis (the process by which spermatogonial stem cells develop into mature sperm cells) and sperm maturation (retention of proximal droplets), with morphologically abnormal sperm and poor motility (movement); English springer spaniels have an autosomal recessive inheritance pattern, but only males have presented reproductive abnormalities as a result Primary ciliary (hair-like cells) dyskinesia (difficulty in performing voluntary movements) – an abnormality of the cilia which results in absent or abnormal motility of the ciliated cells; affected animals are infertile; reported in many breeds; probably autosomal recessive inheritance Idiopathic (cause unknown) inherent poor sperm morphology Testicular underdevelopment

Acquired

Conditions disrupting normal testicular thermoregulation (temperature regulation) – trauma; hematocele (swelling due to a flow of blood); hydrocele (collection of fluid in a sac); orchitis (inflammation of the testis); epididymitis (inflammation of the epididymus, the ducts through which the sperm are conveyed); prolonged fever secondary to systemic infections; obesity (increased scrotal fat); inability to adapted to high environmental temperatures; exercise-induced heat exhaustion; seasonal (summer months) Infections of the reproductive tract – prostatitis; brucellosis (infectious diseases caused by the bacteria Brucella melitensis); orchitis (inflammation of the testis); epididymitis (inflammation of the epididymus, the ducts through which the sperm are conveyed) Drugs Testicular cancer Prolonged sexual abstinence in a non-neutered male Excessive sexual activity Testicular degeneration

Diagnosis

You will need to give your veterinarian a thorough history of your dog’s health, along with any possible incidents that might have led to this condition, such as trauma, infection, or travel (as other climates, especially hot climates, may have played a role).

A history of your dog’s infertility will help your veterinarian to make a diagnosis. For example, has he been infertile after appropriately timed mating to several reproductively-proven bitches? Have spermatozoal abnormalities been found during routine breeding soundness evaluation? Your veterinarian will probably do a hormonal profile as well as an examination of the ejaculates (the sperm cells). Your doctor will also test for bacterial infections, and may use visual diagnostic tools to examine the reproductive tract. An ultrasound examination may show whether there is a blockage, orchitis (inflammation of the testis), hydrocele, hemorrhage into a cavity, cyst of the epididymus, or tumor in the testicular region that is affecting the sperm ducts and sperm morphology.

Treatment

There is no a specific treatment for spermatozoal abnormalities; if applicable, the underlying disease or condition will be treated. Antibiotics and anti-inflammatory agents will be prescribed for infectious diseases and swelling due to inflammation. Unilateral surgical removal may be recommended for unilateral testicular tumors or severe orchitis. Your veterinarian may recommend sexual rest for edema (swelling) or for a cyst associated with trauma. Frequent semen collection may temporarily improve sperm quality in dogs with idiopathic teratozoospermia, but the quality of the sperm will have to be tested before it is used for breeding purposes, to avoid genetic abnormalities resulting from poor sperm. If your dog is in an extremely hot environment, or it is the summer season, protect your dog from high ambient temperatures by moving him to a cooler space. In addition, alter your dog’s exercise program to reduce heat stress, unless your veterinarian has specifically ordered more exercise for treatment of obesity.

Prevention

It may help to provide a climate-controlled environment for your dog if it is not adapted to high environmental temperatures. Also, avoid heat exhaustion during exercise or grooming (e.g., drying cages).

Living and Management

If an underlying cause is identified and treated, your veterinarian will want to perform a sperm evaluation at 30 and 60 days after the condition is resolved. In cases due to reversible causes, a complete improvement in sperm morphology does not usually occur before 60 days — the approximate length of a complete spermatogenic cycle. 

What Is Spina Bifida in Dogs?

A dog’s backbone (spinal column) is made up of many smaller bones called vertebrae, which are connected by spongy intervertebral discs. Together, they allow movement and protect the spinal cord. 

Spina bifida is a congenital defect (present at birth) that occurs when the upper portions of these vertebrae fail to close. This leaves the membranes that cover the spinal cord, or the spinal cord itself, exposed. This defect can cause a wide range of neurological problems ranging in severity such as the inability to walk, urinate, or defecate.

Fortunately, this condition is relatively rare in dogs. When it occurs, it usually affects the lower lumbar spine. Spina bifida often occurs with other neurological conditions and most often is apparent in the first few weeks of life when puppies learn to walk. Sadly, because most of these puppies have a poor prognosis of a functional life, many of them are humanely euthanized. For the few that are not significantly impacted by the defect or have minor symptoms, they can go on to live a relatively normal life with minor inconveniences to the pet parent. 

Symptoms of Spina Bifida in Dogs

Symptoms of this condition include:

Weakness of the rear limbs

Urinary and/or fecal incontinence

Poor muscle tone

Poor use of the tail (lack of wagging or weakness in tail movements)

Abnormal reflexes

Lack of pain perception

Knuckling of the toes

Bunny hopping or abnormal gait

Hyperesthesia (increased sensation) and pain

Additionally, dogs may have a dimple (a small external visible depression) along the spine, which often is painful when touched.  Some dogs, depending on the severity of spina bifida, may have few symptoms or neurological deficits that aren’t detrimental to their long-term well-being.

Causes of Spina Bifida in Dogs

Spina bifida occurs when tissues do not form properly within the womb. The exact reason this happens is unknown, but it could be associated with several factors such as exposure to toxins or certain environmental conditions while the mother is pregnant. 

Other congenital defects often occur with spina bifida, such as:

Meningomyelocele (protrusion of the meninges and/or spinal cord with or without fluid pockets)

Hemi or block vertebrae (abnormally shaped vertebrae)

Hydrocephalus (excess fluid in the skull, causing brain swelling)

Dermoid sinus (tubular sac arising from the skin and extending to deeper tissues)

The English Bulldog is the breed most affected by this condition, but it has also been seen in Collies, English Cocker Spaniels, French Bulldogs, Boston Terriers, Miniature Poodles, Chihuahuas, and Dobermans. Males seem to be affected more than females.

How Veterinarians Diagnose Spina Bifida in Dogs

Your veterinarian may recommend basic blood work like a complete blood cell count (CBC), internal organ function screening, and a urinalysis. The results from these tests provide a baseline and can also help rule out other conditions. X-rays are often recommended as a next step and can help identify related conditions.

Pet parents most likely will be referred to a veterinary neurologist for an MRI, which is the standard test for this condition. A CT scan and a CSF (cerebrospinal fluid) tap may also be recommended and performed with this specialist.  

If unable to perform these tests due to no MRI available or the cost, your veterinarian may perform a myelogram, in which contrast dye is injected into the fluid surrounding the spinal cord. This test is not without risks for dogs with certain health conditions and requires anesthesia.

Treatment of Spina Bifida in Dogs

Unfortunately, this condition is lifelong and carries a heavy burden on the pet parent, with limited quality of life for the dog. Euthanasia is often chosen. Surgery cannot cure spina bifida in dogs, but it can alleviate some symptoms and make a dog more comfortable. Surgery will be pursued if symptoms are mild and the dog is in good health.

Dogs with less severe symptoms are often more prone to urinary tract infections, skin infections, and muscle atrophy, so frequent follow-up visits and rechecks are still necessary. Dogs often require medication to help with manual expression of the bladder.

The three goals of treatment for this condition are: improvement in neurologic deficits, enhanced bladder and bowel function, and better movement. Consistent grooming habits, bathing, and hygiene care are needed and even a doggy wheelchair or similar device may be required for improved mobility. 

Recovery and Management of Spina Bifida in Dogs

When surgery is an option for a dog, the recovery is often lengthy and requires rehabilitation and physical therapy. Several days of hospitalization are needed and physical therapy can last several weeks to months.

Partnering with your veterinarian, particularly if they are a member of the American Association of Rehabilitation Veterinarians, to get an individualized treatment plan is advised. Acupuncture, laser therapy, and massage could be additional post-surgical therapies. 

Long-term care depends on the symptoms, and many dogs require some form of nursing care.  Again, physical therapy coupled with pain medications or NSAIDs when needed will be vital to improve your dog’s strength and mobility while limiting or preventing muscle atrophy. Toe-grips for traction, rugs, a harness, or a wheelchair are all tools that can help your dog remain mobile and enjoy a better quality of life. 

Joint supplements such as Cosequin®, Dasuquin®, and Welactin®, among others, as well as feeding your dog a well-balanced high-quality food, can reduce inflammation and support joint health.  Maintaining proper grooming habits and the use of doggie diapers and pads can be helpful if they are changed frequently, and the skin should be inspected for signs of infection and urine scalding. 

Spina Bifida in Dogs FAQs

What is the life expectancy of a dog with spina bifida?

Depending on the severity of symptoms experienced, some dogs can have a relatively normal life.  However, many dogs with spina bifida have little to no control over their hind limbs or control of their urinary and fecal habits. In these cases, euthanasia is often chosen.  

Can spina bifida in dogs be cured?

There is no cure for this condition and dogs usually require some form of life-long extensive management. Depending on severity, however, some dogs can have a functional life and committed pet parents can ensure their lives are filled with joy and dignity.

Featured Image: Adobe Stock/zinkevych

References

Wilson JR, Kurtz HJ, Leipold HW, Lees GP. Spina Bifida in the Dog. Veterinary Pathology. 1979;16(2):165-179.

Arias M, Marcasso R, Margalho F, et al. Spina bifida in three dogs. Brazilian Journal of Veterinary Pathology. 2008;1(2):64-69.

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WRITTEN BY

Michael Kearley, DVM

Veterinarian

Dr. Michael Kearley graduated from the University of Florida College of Veterinary Medicine in 2013. He graduated with a certificate in…

Stertor and Stridor in Dogs

Unusually loud breathing sounds are often the result of air passing through abnormally narrowed passageways, meeting resistance to airflow because of partial blockage of these regions. The origin may be the back of the throat (nasopharynx), the throat (pharynx), the voice box (larynx), or the windpipe (trachea). Abnormal breathing sounds of this type can be heard without using a stethoscope.

Stertor is noisy breathing that occurs during inhalation. It is a low-pitched, snoring type of sound that usually arises from the vibration of fluid, or the vibration of tissue that is relaxed or flabby. It usually arises from airway blockage in the throat (pharynx).

Stridor is high-pitched, noisy breathing. The higher-pitched sounds result when relatively rigid tissues vibrate with the passage of air. It often occurs as the result of partial or complete blockage of the nasal passages or voice box (larynx), or collapse of the upper part of the windpipe (known as cervical tracheal collapse).

The upper respiratory tract or upper airways includes the nose, nasal passages, throat (pharynx), and windpipe (trachea).

Noisy breathing is common in short-nosed, flat-faced (brachycephalic) dog breeds. Inherited paralysis of the voice box, known as laryngeal paralysis, has been identified in Bouviers des Flandres, Siberian huskies, bulldogs, and Dalmatians.

Acquired paralysis of the voice box (laryngeal paralysis) is more common in certain giant-breed dogs, such as St. Bernards and Newfoundlands, and in large-breed dogs, such as Irish setters, Labrador retrievers, and golden retrievers, than other breeds.

Affected short-nosed, flat-faced dogs with inherited paralysis of the voice box typically are younger than one year of age when breathing problems are first detected. Acquired paralysis of the voice box typically occurs in older dogs. Inherited paralysis of the voice box has a 3:1 male-to-female ratio.

Symptoms and Types

Change or loss of voice – inability to barkPartial blockage of the upper airways produces an increase in airway sounds before producing an obvious change in breathing patternUnusually loud breathing sounds may have existed for as long as several yearsBreathing sounds can be heard from a distance without the use of a stethoscopeNature of the sounds range from abnormally loud to obvious fluttering to high-pitched squeaking, depending on the degree of airway narrowingMay note increased breathing effort; breathing often accompanied by obvious body changes (such as extended head and neck and open-mouth breathing)

Causes

Condition of abnormal breathing passages in short-nosed, flat-faced animals (a condition known as brachycephalic airway syndrome), characterized by any combination of the following conditions: narrowed nostrils (stenotic nares); overly long soft palate; turning inside-out of a portion of the voice box or larynx (everted laryngeal saccules), such that the space for air to pass through the larynx is decreased; and collapse of the voice box or larynx (laryngeal collapse), and fluid build up (edema) of the voice box or larynxNarrowing of the back of the nose and throat (nasopharyngeal stenosis)Paralysis of the voice box or larynx (laryngeal paralysis) – may be inherited or acquiredTumors of the voice box or larynx – may be benign or malignant (cancer)Nodular, inflammatory lesions of the voice box or larynx (granulomatous laryngitis)Reduction in the diameter of the lumen of the windpipe (trachea) during breathing (tracheal collapse)Narrowing of the windpipe (trachea; tracheal stenosis)Tumors of the windpipe (trachea)Foreign bodies in the windpipe (trachea) or other parts of the airwayInflammatory masses that develop from the middle ear or eustachian tube (nasopharyngeal polyps)Condition caused by excessive levels of growth hormone, leading to enlargement of bone and soft-tissues in the body (acromegaly)Nervous system and/or muscular dysfunctionAnesthesia or sedation – if certain anatomy exists (such as a long soft palate) that increases susceptibility to abnormal, loud breathing soundsAbnormalities or tumors of the soft palate (the soft portion of the roof of the mouth, located between the hard palate and the throat)Excessive tissue lining the throat (redundant pharyngeal mucosal fold)Tumor in the back of the throat (pharynx)Fluid build-up (edema) or inflammation of the palate, throat (pharynx), and voice box (larynx) – secondary to coughing, vomiting or regurgitation, turbulent airflow, upper respiratory infection, and bleedingDischarges (such as pus, mucus, and blood) in the airway lumen – may occur suddenly (acutely) after surgery; a normal conscious animal would cough out or swallow them

Risk Factors

High environmental temperatureFeverHigh metabolic rate – as occurs with increased levels of thyroid hormone (hyperthyroidism) or a generalized bacterial infection (sepsis)ExerciseAnxiety or excitementAny breathing or heart disease that increases movement of air into and out of the lungs (ventilation)Turbulence caused by the increased airflow may lead to swelling and worsen the airway obstructionEating or drinking

Diagnosis

You will need to provide a thorough history of your pet’s health leading up to the onset of symptoms. Your veterinarian will use a stethoscope to listen to the entire area from the pharynx to the trachea. If the sound persists when your pet opens its mouth, a nasal cause can virtually be ruled out. If the sound occurs only during expiration, it is likely that airway narrowing is the cause. If the abnormal sounds are loudest during inspiration, they are from disease other than in the chest. If you have noticed a change in your dog’s voice, the larynx is the likely abnormal site. Your veterinarian will systematically listen with the stethoscope over the nose, pharynx, larynx, and trachea to identify the point of maximal intensity of any abnormal sound and to identify the phase of respiration when it is most obvious. It is important to identify the location from which the abnormal sound arises and to seek aggravating causes.

Internal imaging techniques, such as radiography and fluoroscopy, are important for assessing the cardiorespiratory system and to rule out other or additional causes of respiratory difficulty. Such conditions may add to an underlying upper airway obstruction, causing a subclinical condition to become clinical. X-rays of the head and neck may help to identify abnormal soft tissues of the airway. A computed tomography (CT) scan may also be used to provide additional anatomic detail.

In some cases, your dog’s physiological inheritance can make the diagnosis more apparent, such as with dogs that are brachycephalic. In these situations, your veterinarian will determine the location that is being most affected by your dog’s conformation and decide where to go from there.

Treatment

Keep your dog cool, quiet, and calm. Anxiety, exertion, and pain can lead to increased movement of air into and out of the lungs, potentially worsening the airflow. Low levels of oxygen in the blood and tissues, and decreased movement of air into and out of the lungs occur with prolonged, severe blockage to airflow; supplemental oxygen is not always critical for sustaining patients with partial airway collapse. In addition closely monitor the effects of sedatives that have been prescribed, as sedatives are known for relaxing the upper airway muscles and worsening the blockage to airflow. Be prepared for emergency treatment if complete obstruction occurs.

Extreme airway blockage or obstruction may require an emergency intubation (that is, passage of an endotracheal tube through the mouth and into the windpipe [trachea] to allow oxygen to reach the lungs). If obstruction prevents intubation, an emergency tracheotomy (a surgical opening into the windpipe [trachea]) or passage of a tracheal catheter to administer oxygen) may be the only available means for sustaining life. However, a tracheal catheter can sustain oxygenation only briefly while a more permanent solution is sought. Surgery may be required if a biopsy has indicated a mass in the airways.

Prevention

Avoid strenuous exercise, high ambient temperatures, and extreme excitement. Your veterinarian will advise you on the correct level of exercise to encourage in your dog.

Living and Management

Your dog’s breathing rate and effort will need to be monitored closely. Complete blockage or obstruction could occur after an apparently stable patient is taken home or if continual observation is not feasible. Even with surgical treatment, some degree of obstruction may remain for 7 to 10 days due to postoperative swelling. Care will need to be taken during this time to protect your dog from complications due to labored breathing.

After surgery, your dog may feel sore and will need proper rest in a quiet place, away from other pets and active children. You might consider cage rest for a short time, until your dog can safely move about again without overexertion. Your veterinarian will also prescribe a short course of pain killers until your dog has fully recovered, along with a mild course of antibiotics, to prevent any opportunistic bacteria from attacking your dog. Medications will need to be given precisely as directed, at the proper dosage and frequency. Keep in mind that over dosage of pain medications is one of the most preventable causes for death in household animals.

Breeding Timing To Maximize Fertility in Dogs

Breeding timing refers to the purposeful timing of insemination during the estrus period—commonly refrred to as being “in heat”—in order to maximize fertility and the chances of conception. This technique may be utilized to ensure conception in dogs.

The condition or disease described in this medical article can affect both dogs and cats. If you would like to learn more about how this condition affects cats, please visit this page in the PetMD health library.

Symptoms and Types

In order to maximize the odds of conception with properly timed breeding in dogs, it is best to pin-point, as closely as possible, the day of ovulation for the female dog—more commonly referred to as a bitch, which is the correct terminology. Symptoms of estrus-onset in the bitch are evidenced by swelling in the vulva and the appearance of a clear to brownish vaginal discharge. The male animal, or stud, will show interest in the female, and she may exhibit “flagging,” by which she will respond to being stroked at the genital region by elevating the tail to one side. A vaginal exam, however, serves as a better indicator of a fertile period than the aforementioned physical and behavioral signs.

Causes

Breeding timing and related fertility-maximizing techniques may be utilized for a number of reasons. This may be deemed necessary if there is an apparent failure to achieve conception in the female dog.

Diagnosis

The most reliable method of determining the ovulation cycle is via vaginal exam and vaginoscopy in order to examine the vaginal lining and determine if the bitch is in estrus. Hormone levels, such as LH, and progesterone, will be tested to determine when fertility levels are peaking. Additionally, an ultrasound of the ovaries may help verify ovulation.

Treatment

To maximize fertility when breeding dogs, it is necessary to estimate the female’s day of ovulation. Because of this, a luteinizing hormone (LH) may be given to female dogs in order to control ovulation and regulate the bitch’s cycle, allowing breeding to be timed accordingly. The period of maximum fertility occurs approximately five to six days after the LH peaks. In this time, multiple breedings may be done by inseminating the bitch up to three times per week after progesterone levels rise. Frozen semen, though less likely to work than fresh chilled semen, may be used to inseminate the bitch – a single insemination five or six days after LH hormones peak is common. It is important to time insemination based on progesterone levels in order to improve chances of conception.

Living and Management

After initial fertility-maximizing measures have been taken, a follow up pregnancy examination can be done to determine the success of the procedure. This can be done via vaginal specimens. The gestation period for dogs lasts approximately 63 days from ovulation.

Prevention

Age related factors may make conception more difficult for older animals.

Just the word “flea” can make us itchy—and it’s no wonder why. One flea can rapidly turn into an infestation of parasites that lay innumerable little flea eggs on dogs and cats.

Catching fleas early is essential for controlling a flea outbreak. To get a flea infestation under control, it is important to fight fleas at every life stage, including targeting flea eggs.

Here are some tips for identifying flea eggs on pets and how to get rid of them so you can keep your pet (and home!) pest-free.

What Do Flea Eggs Look Like?

While adult fleas can be identified pretty easily, flea eggs can be a little trickier to detect.

Flea eggs are almost microscopic—typically about 0.5 millimeters in length and about half as wide. That’s about the size of a grain of salt. Flea eggs have a soft shell called a “chorion” that has an off-white color, similar to a grain of salt, though they are more oval in shape.

Because flea eggs are easy to mistake for dry skin or sand, it’s usually not the first thing pet parents notice if their pet has a flea problem. If you have a flea infestation, finding flea dirt or actual fleas on your pet or in the home are more obvious signs.

If you’d like to discern a flea egg from something else, place the speck on a dark piece of paper under a magnifying glass to identify the characteristically oval shape of a flea egg.

Flea Eggs vs. Flea Dirt

People often mistake “flea dirt,” or flea feces, for flea eggs—though both are signs of a flea infestation.

Unlike flea eggs, flea dirt is dark and crumbly. You can identify flea dirt by putting a few of the specks on a white piece of paper and adding a couple drops of water. If you see a red color—which signals the presence of digested blood—then you’re dealing with flea dirt.

Flea dirt itself isn’t actually harmful and it’s easy to wash away with a gentle bath. The bad news is that it absolutely indicates a flea problem, which means your pet will require more than just a bath for treatment.

What Do Flea Larvae Look Like?

Flea larvae hatch from flea eggs. They are an off-white color and look like tiny worms, ranging from 2–5 millimeters in length. But you may not see them during an infestation because they quickly burrow deep into carpets, cracks, and grass.

How To Get Rid of Flea Eggs

At any given time, flea eggs make up more than half of a flea population, so it makes sense that you’ll want to address them quickly and effectively. However, getting rid of flea eggs should be a part of a multi-pronged approach to eliminating a flea infestation.

Treating Pets to Kill Flea Eggs

Many modern flea treatments for pets contain ingredients that kill adult fleas and insect growth regulators (IGRs), which stop flea eggs from maturing into adults. Some IGRs also work to sterilize female fleas so they can’t lay viable eggs.

Talk with your vet to decide which treatment they recommend for killing flea eggs on cats or dogs. They can help you choose the best product for your pet.

Products for Eliminating Flea Eggs in the Home

Foggers provide a simple way to kill flea eggs (and many other pests). It’s recommended to use foggers in combination with sprays or other products that can be used under furniture, where foggers have trouble reaching.

Many pet parents choose to use an environmental insect growth regulator to stop fleas from developing. Sprays with IGR, such as Sentry Home household flea and tick spray for pets, are great for killing flea eggs in your home.

Vacuuming and Cleaning to Get Rid of Fleas

Another effective way to get rid of flea eggs at home is to vacuum thoroughly. Flea eggs aren’t sticky, so while adult fleas typically lay their eggs on their host, those eggs soon fall off into the environment.

Several years ago, people commonly believed that the fleas would continue to develop in the vacuum and make their way into the environment, but that’s simply not the case. Vacuuming kills adult and non-adult fleas (eggs, larvae, pupae), which means you don’t need to worry about what to do with the vacuum bag or canister.

You can remove 32–90% of flea eggs (depending on the type of carpet you have) by simply vacuuming every other day while treating your flea infestation. Vacuuming will also lift up carpet fibers so that other environmental treatments work more effectively.

Vacuuming is a great idea even if you don’t have carpet—on hard surfaces such as hardwoods or tile, vacuuming can lift flea eggs from hard-to-reach cracks. Mopping and steam cleaning can help to kill flea eggs, and washing linens, bedding, and pet beds in the washing machine on the hot cycle is also advisable.

If possible, declutter your home so it’s easier to clean and there are fewer places for flea eggs to hide.

It’s important that your flea-control program tackles fleas at all of their life stages, including flea eggs. Employing multiple types of flea protection will help to cover any gaps in your strategy.

Be sure you speak with your veterinarian about the safety of any products you choose to use in your home and on your pet.

Featured Image: iStock.com/Nevena1987

WRITTEN BY

Jennifer Coates, DVM

Veterinarian

Dr. Jennifer Coates is an accomplished veterinarian, writer, editor, and consultant with years of experience in the fields of veterinary…

Dominance, Fear, or Predatory Aggression in Dogs

While some consider aggression to be normal behavior in dogs, it can be impulsive, unpredictable, and even dangerous. Aggressive behavior includes growling, lip lifting, barking, snapping, lunging, and biting. With aggression directed towards family members or other people familiar to the dog, treatment is currently aimed at controlling the issue, as there is no known cure.

Symptoms and Types

It can be challenging to determine whether a dog is demonstrating abnormal aggression. Aggression is often exhibited near the dog’s food bowl, toys, and times when the dog is being handled. This type of aggression is shown to familiar people, most often their handlers or household members.

Aggression can be seen often and it may not even be towards the same person regularly. Aggression is often displayed as:

Ears tucked backSnarlingEye aversionBitingLunging

While most aggression towards familiar people is a sign of a serious problem, there are some instances where an animal will be aggressive following a painful medical procedure or if they are in pain regularly.

Causes

Some breeds are more aggressive than others. These breeds include Spaniels, Terriers, Lhasa Apsos, and Rottweilers, amongst others, but aggression can appear in any breed. Dogs will normally demonstrate signs of aggression between the ages of 12 and 36 months, and is seen more in male than female dogs. Medical conditions and the after-effects of medical procedures can also cause an animal to exhibit aggression towards familiar people. In addition, inconsistent or harsh punishment from the dog’s owner can contribute to the animal’s aggression.

Diagnosis

During a medical examination, your veterinarian will look for fear-based aggression, anxiety conditions, and pathological disease. Typically, however, a traditional blood test will not find any abnormalities.

Treatment

Animals exhibiting aggression towards familiar people require strict behavior modification therapy, and possibly medication. Behavior therapy involves eliminating or controlling situations that may trigger aggression. Veterinarians will help the owner identify the triggers and behaviors, so they can work to correct them. Some dogs will require a muzzle until the behavior is under control. Affection control (working to make the animal obey a command before they receive any treats) is also effective for behavior modification. In addition, desensitization can decrease the animal’s responsiveness to anxiety and fear.

In some cases, physical activity can help reduce feelings of aggression in dogs. A low-protein/high-tryptophan diet has had success in reducing aggression. There currently are no approved medications to treat canine aggression, but surgically neutering aggressive male dogs is a common recommendation.

Living and Management

The treatment recommendations given to reduce aggression are designed to be lifelong and should be strictly and consistently followed by the dog’s owner. There is currently no cure for aggression.

Prevention

One of the best preventative measures is to not breed aggressive animals, and to begin socialization and hierarchy training at an early age.

See Also

Tooth Luxation or Avulsion in Dogs

Tooth luxation is the clinical term for a dislocation of the tooth from its normal spot in the mouth. The mutation can be vertical (downward) or lateral (on either side).

In vertical luxation, the tooth may move up (intrusion) or down (extrusion) in its bony socket. In lateral lunation, the tooth tips to the side. Lateral luxation usually occurs due to an injury that has pushed the tip of the tooth to one side. Vertical luxation is related to the dislocation of the root of the tooth. A tooth is called avulsed, meaning that it has been torn suddenly from its spot, if it has been luxated completely from its bony socket.

Symptoms and Types

In cases of intrusion, the affected tooth appears shorter than normal. In extrusion, the tooth appears longer than normal and can be moved both vertically and horizontally when touched. In case of lateral luxation, the upper part of the tooth is found deviated on the either side. It may be overlapping a nearby tooth to some degree. In cases where there is avulsion of the tooth, the tooth is found to have become completely displaced from its bony socket. This is most often as the result of an injury to the mouth, or to an infection at or near the tooth.

Causes

Trauma or injury, such as road side accidents, falls, or fightsDogs with chronic tooth infections are at higher risk

Diagnosis

You will need to give a thorough history of your dog’s health, onset of symptoms, and possible incidents — such as recent injuries — that might have preceded this condition. Your veterinarian will conduct a complete physical examination and will closely look into your dog’s mouth to evaluate the complete set of teeth. The close physical examination will enable your veterinarian to see if the tooth is luxated or avulsed and whether it can be saved. The most important diagnostic test is radiographic imaging of the tooth arcade, i.e., mouth cavity. X-ray films will be placed into the oral cavity to take an X-ray of the affected teeth. Typical changes will enable your veterinarian to precisely diagnose and treat the condition.

Treatment

Surgery can usually be conducted to fix the tooth back to its normal position using various materials, including fine wires. Anesthesia will be required for conducting the surgery to prevent pain related to this procedure as well as movement by the dog. For this reason, your dog’s health and any other underlying conditions will be taken into consideration, since some animals are at an increased risk for anesthesia complications and the risk may not be worth saving the tooth.

If your dog is a good candidate for the oral surgery, time is a crucial factor for the successful outcome of the surgery. The sooner the avulsed tooth is placed back in its bony socket, the better the chances are for recovery. The best results are typically achieved when the avulsed tooth is placed back in its socket within 30 minutes of its avulsion.

If you have found yourself in a situation where your dog has had its tooth forced from its mouth, by trauma or other causes, you can place the avulsed tooth in a normal saline solution to protect it from damage and take it to your veterinarian along with your dog. If you don’t have saline at home, you can also place the tooth in a small amount of milk to keep it safe until it can be delivered to your veterinarian. You should not waste time getting the avulsed tooth to the veterinarian. Once the tooth has been fixed in place again, it usually takes 4-6 weeks for the tooth to properly reimplant in the socket.

Antibiotics are standard after the surgical procedure for the prevention of infection, and a mild pain reliever may be prescribed to keep your dog comfortable. After a period of 4-6 weeks, the fixation material will be removed and X-rays will be taken to confirm the reimplantation of the affected tooth. If the tooth has not properly fixed, it will need to be removed due to fixation failure.

Living and Management

For a few days after the surgery, your dog should not be fed hard foods. Your veterinarian will recommend a temporary soft diet that will be beneficial to healthy bone reformation, and that will not move the tooth out of its socket during this period in which the tooth is resetting. Also during this time, do not allow your dog to pick up solid objects with its mouth to prevent further trauma to the implanted tooth.

Maintenance and good oral hygiene after surgery is of paramount importance for the full recovery of your dog’s tooth. Daily rinsing with antiseptic solution is usually required in these animals. Your veterinarian will brief you on the correct method of cleaning your dog’s teeth, as well as the best procedures for removing debris, food particles and other material from the space in between the teeth, including the implanted tooth. Oral rinses are available for dogs, which can be used to maintain good oral hygiene. However, you should only use oral rinses under the recommendation of your veterinarian.

What Is Pyometra in Dogs?

A pyometra is a severe bacterial infection in the reproductive tract that causes the formation of purulent (pus or containing pus) material to develop in the uterus. This occurs secondary to hormonal changes in female dogs. 

Cystic endometrial hyperplasia is often used synonymously with the term pyometra, and while these terms are often associated with one another they are not the same. Cystic endometrial hyperplasia is a thickening of the uterine tissue which then makes for an ideal environment for a pyometra to occur. 

Bacteria and toxins from the infection can leak through the wall of the uterus and into a dog’s bloodstream, causing a body-wide infection (sepsis). The uterus becomes very fragile, and pus can start to leak into the abdomen. 

Without treatment, this can be a life-threatening condition. 

Symptoms of Pyometra in Dogs

The symptoms of a pyometra can be vague, and it may resemble other types of infectious diseases. Generally, a veterinarian would become suspicious of a pyometra in a dog that finished her heat cycle about 1-2 months earlier and has one or more of the following symptoms:  

Pustular to bloody vaginal discharge 

Poor appetite 

Vomiting/diarrhea 

Drinking a large amount of water 

Lethargy/depression 

Fever 

With an “open” pyometra, the cervix is open, and the infectious material inside the uterus leaks out through the vagina/vulva. You may see a small to moderate amount of this pustular material on your pet’s vulva or tail, but you may also notice it on your pet’s bed or where she has been sleeping. 

However, a pyometra can also occur with a closed cervix. In this case, no discharge will be able to escape the uterus, making diagnosis more difficult. Since the infection is trapped inside the body, these dogs present with more serious symptoms. 

While this is a disease of non-spayed females, there can be a very rare infection of the uterine tissue which remains after a pet is spayed. We call this a “stump” pyometra. Symptoms will be very similar to a standard pyometra, but the pet may have been spayed many weeks to several years before. 

Causes of Pyometra in Dogs

Starting at approximately 6 months of age, once a pet becomes hormonally mature, a dog will go through a heat cycle every 6 months or so. Each cycle brings the possibility of pregnancy. The uterine lining will thicken in preparation to potentially be the home of a growing embryo. 

In a rare occurrence, the lining continues to thicken abnormally, and cysts form from glands within the wall of the uterus. This abnormal tissue becomes excessive and persistent. It is called cystic endometrial hyperplasia (CEH). 

The exact cause of CEH is not known, but the hormones progesterone and estrogen during successive cycles are definitive factors. Successive cycles means that the likelihood of a dog developing a pyometra increases with each heat cycle that she goes through, as hormonal effects accumulate on the uterus. 

However, pyometras can occur in any reproductively active pet, including dogs that are only 4-6 months old. Once CEH occurs, the engorged uterine tissue is a great breeding ground for an infection. While the uterus is a sterile environment, the vagina is not. Bacteria from the vagina travel into the uterus and become the source of infection for the pyometra. 

The bacteria that most commonly cause pyometras are Escherichia coli (E. coli), staphylococcus, streptococcus, and pseudomonas.

How Veterinarians Diagnose Pyometra in Dogs

When a pyometra is open, the purulent/pustular vaginal discharge makes the diagnosis of a pyometra much easier. When there is no discharge, a diagnosis can be challenging. Your vet may do the following to confirm a diagnosis: 

Blood work: While there is no specific blood test to diagnose a pyometra, blood work tends to be consistent with widespread infection or inflammation. Typically, these pups will have very high levels of white blood cells; however, with dogs that have severe infections, normal or even low white blood cell counts can be possible, as white blood cells leave the blood system and head to the uterus to start fighting on the front lines.  

Elevation in a particular group of blood proteins called globulins can also be seen, as these blood proteins often increase when the immune system is active. Damage to the liver and kidneys may also be seen with severe infections. 

Radiographs or X-rays: Radiographs tend to show an enlarged uterus. The uterus may be grossly swollen, making pyometra easy to diagnose. Other times, it is not as obvious, and confirmation with an ultrasound may be required. 

Ultrasound: An enlarged uterus does not always mean a pyometra; this could also be explained by a pregnancy, hydrometra (fluid distension of the uterus), uterine torsion (twisting of the uterus), or cancer. An abdominal ultrasound can be very helpful to differentiate between a pyometra and other possible conditions. 

Physical exam: Your vet will evaluate your dog with a physical exam and weigh the results of the diagnostic tests to determine the best course of treatment. 

Treatment of Pyometra in Dogs

Surgical removal of the uterus and ovaries, the definitive treatment for a pyometra, removes the source of the hormones and infected uterine tissue. If the ovaries are not removed, they will continue to produce hormones which can affect even the small stump of uterus that is left behind. 

This surgery is much more complex than a routine spay, even though in both surgeries the ovaries and uterus are removed. Once the uterus is infected, it can be quite challenging to remove it safely. 

Many dogs will require intravenous (IV) fluid therapy to help with dehydration and electrolyte abnormalities before surgery can be performed. Antibiotics are generally given during the surgery and continued for 7-14 days after surgery. 

Pain medications are needed after any major surgery, and a pyometra surgery is no exception. Most dogs will most likely need to stay hospitalized for 24-48 hours after surgery for continued care.  

Treatment of a stump pyometra involves removing the infected uterine stump and finding and removing the source of hormones that caused the formation of the stump pyometra in the first place. This may be a small portion of ovary that was left behind after a spay, or, in rare occurrences, a piece of ectopic ovarian tissue, where hormone-producing cells are found outside of the normal ovary locations.  

For breeding animals, there is a medical approach to treating pyometras. However, it is not often recommended, as the success rate is variable. There is considerable risk, and often long-term breeding complications still occur. Please discuss this alternative thoroughly with your veterinary reproductive specialist. 

Recovery and Prevention of Pyometra in Dogs

Prevention is the key to success, as a spay procedure generally keeps a pyometra from ever becoming an issue. If your pet does have surgery for pyometra, surgical recovery at home is similar to that with a spay: 

Your pup will need a calm and safe space to stay during recovery. A large kennel or a small room is preferred. 

Limit activity to leash walks for elimination purposes only, as any increase in activity can put additional strain on the incision site. 

It is very important for your pet to not lick the incision. An e-collar or a surgical suit will help with these recovery efforts. 

Check the incision daily for redness, swelling, and/or discharge. 

Medications like anti-inflammatories, pain medication, and antibiotics should be given as directed by your vet. 

If your dog is not eating or is experiencing lethargy, pain, vomiting, or diarrhea, contact your vet immediately. 

Pyometra in Dogs FAQs

How does pyometra occur?

Hormonal effects in the uterus can cause a buildup of uterine tissue, which can then become infected by bacteria traveling up from the vagina. The uterus fills with an infection, causing the dog to become ill.

When does pyometra occur?

Pyometras can happen in dogs of any age, though it is statistically more likely in an older dog that has not been spayed. One to three months after a dog’s last heat cycle tends to be the time frame in which a pyometra is most likely to occur.

What happens if a pyometra goes untreated?

A closed pyometra can be a life-threatening condition if immediate medical attention is not taken. Even with an open pyometra, the toxic effects from the bacterial infection can be fatal if left untreated.

References

Veiga, Gisele Almeida Lima, et al. “Cystic Endometrial Hyperplasia-Pyometra Syndrome in Bitches: Identification of Hemodynamic, Inflammatory, and Cell Proliferation Changes.” Biology of Reproduction, vol. 96, no. 1, 1 Jan. 2017, pp. 58–69.  

Merck Veterinary Manual. Pyometra in Small Animals—Reproductive System.  

Featured Image: iStock.com/SbytovaMN

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WRITTEN BY

Stephanie Howe, DVM

Veterinarian

Dr. Stephanie Howe graduated from the University of Florida College of Veterinary Medicine in 2011, after receiving a Bachelor of Science…