Author: vetstream
Leptospirosis
Leptospirosis is a serious bacterial infection affecting the gastrointestinal tract or liver and kidneys of young dogs. Until recently the disease was uncommon as a result of an effective vaccination programme in the UK. However, we have recently seen development of infections caused by new types of leptospira not covered by the old vaccine.
Leptospirosis (like Weils disease in humans) is caused by a spiral shaped bacterium (leptospira). Leptospira organisms are carried by rats and shed in their urine they do not usually last long outside the rat but can persist in wet environments. The likelihood of infection is increased in dogs that spend a lot of time in water.
The signs of disease are often dramatic and come on suddenly. In some forms of the disease there is vomiting and bloody diarrhoea. In others liver damage is severe and jaundice develops. Sometimes the kidneys are affected with acute renal failure developing. Animals may die quickly before signs of disease have had time to develop.
Your vet will probably suspect that your dog might have leptospirosis from the symptoms that you describe, your dog’s vaccination history and the findings on physical examination. A blood test may show a severe decrease in the white blood cell number and/or damage to the liver and kidneys. The bacteria can be seen in special samples prepared form a urine sample.
Therapy is “supportive” and consists mainly of injecting the dog with fluids and electrolytes via a vein in order to compensate for dehydration and correct for on-going losses of fluid by vomiting. In addition, dogs are treated with drugs to stop vomiting, and with antibiotics to control the bacterium.
Early detection of the disease before your dog deteriorates severely and the institution of good medical therapy, will give your dog a good chance of survival. However, some dogs do not survive despite proper medical care and early diagnosis. The disease appears to be more severe in young pups and in those that have had no vaccination against leptospirosis or have only just begun their vaccination course.
It is essential to vaccinate your dog according to your vet’s recommendations. Pups that are born to vaccinated dams usually have antibodies from their mothers (maternal antibodies) that protect them against infection during the first few weeks of their lives. The pup is in danger after the level of maternal antibodies declines in his blood and that is when he should be vaccinated.
Maternal antibodies prevent active vaccination, therefore a vaccine should be injected when the maternal antibodies are no longer protective and that time differs between pups. The vaccination is repeated in order to make sure that the dog has had an effective vaccine dose and to boost this effect. Additionally, dams can be vaccinated before they become pregnant.
Dogs that have recovered from infection may continue to spread the bacterium for many months and pose a risk for other animals and humans.
To prevent the spread of infection, sick dogs should be isolated from other dogs and cages and pens should be properly disinfected and cleaned. Pups who have not completed their vaccination schedule should be prevented from any exposure to potentially infected animals or their environment.
Leptospirosis is zoonotic (can be passed to humans). If your vet diagnoses leptospirosis in your dog, you should seek advice from your GP.
Leishmaniosis
Leishmaniosis is a potentially fatal disease of dogs that can also affect other animals including humans. It is spread between animals by sand flies. Unfortunately domesticated dogs harbour the infection and your dog may catch it especially in countries around the Mediterranean, e.g. southern France, Italy, Greece, Spain, Portugal, Turkey, and the Middle East. Leishmaniosis is not uncommon in the UK because of the number of infected dogs travelling here. However, the sandfly that spreads the parasite between individual dogs, has not been identified in the UK yet.
Canine Leishmaniosis is caused by a small parasite that lives inside cells. The disease is spread by infected sand flies which pass the parasite from one animal to another when they bite and feed. The disease occurs in warm climates, e.g. Central and South America, the Middle East and Mediterranean regions. In these areas as many as 4 out of 10 dogs are infected. Dogs travelling into or through these areas can be infected.
Sand flies often live in woodland areas but recently they have adapted to survive in areas close to human habitation especially in South America. Sand flies are more common during the warmer months of the year although, with climate change, the seasonal period for transmission is increasing. Most sand flies that spread leishmaniosis are most active (and will bite) between evening and dawn. They are small flies and may not be easily seen.
Most affected dogs have swollen glands (swellings in the armpits, groin, around the throat) although these may not be obvious in long-haired breeds. Dogs may have poor appetite, listlessness, unwillingness to exercise and weight loss.
Skin problems are often seen. These may include loss of hair especially around the head and ears, scaly skin, swellings and ulcers on legs, foot pads and other areas including the mouth and tongue. Ulcers and inflamed areas can appear around the lips, nose, eyes and, especially, the tips of the ears. The nails may become very long and brittle.
Other signs may be seen depending on the area of the body affected and include lameness, eye problems, bleeding from the nose, drinking or urinating too much, vomiting and/or diarrhoea.
Joints may also be damaged by the disease and this causes lameness, stiff gait and swollen limbs.
Signs of disease may develop a long time after infection (up to several years) or within a few months of being exposed to an infected sand fly. It all depends on how susceptible your dog is and the number of sand fly bites.
You should be concerned and consult your vet if your pet starts to show any of the signs of ill health mentioned above, after travelling abroad (or if it was born abroad). Always mention that your pet has spent time in a Leishmania area, whether they were adopted and then came in the UK, or if they have travelled to an area where leishmania occurs commonly – even if only for a few days.
As leishmaniosis is becomly increasingly common in the UK, more diagnostic techniques are being developed for vets. However, more than one test may be necessary to confirm if your dog has active infection or has just been exposed to an infected sand fly bite. Leishmaniosis can be confirmed with one or more of the following tests:
- Looking for the whole Leishmania organism or looking for the Leishmania DNA (PCR testing) in samples from blood, glands, smears from the eyelid, bone marrow or skin biopsies.
- Looking for very high antibody levels in blood.
In dogs that have been imported from endemic regions to countries where Leishmaniosis is not common, diagnosis may be delayed as the disease may not always be considered initially.
Treatment in dogs is much more difficult than in people and the disease in untreated dogs is commonly fatal. Even with current treatments it is still not possible to completely eliminate the parasite. However, treatment can often dramatically reduce the clinical signs of disease and improve a dog’s quality of life. However, continued treatment may be needed life long in an infected animal to keep the parasite under control.
Treatment is not straightforward. There are licensed drugs in continental Europe for the treatment of leishmaniosis but these are not yet available in the UK. Your vet will have to do two things to obtain the right drugs:
- Contact a drug company which will import the drug into the UK for your pet
- Obtain a special certificate from the UK Veterinary Medicines Directorate that shows that all details about the drug comply with UK standards
Treatment can be expensive and rarely results in a cure. Dogs that look very well can still harbour small numbers of parasites deep in some organs such as the bone marrow. Before treatment your vet will want to check your dog’s kidney function, liver function and immune system. The drugs used are very powerful and may produce significant side effects if the disease has already caused kidney or liver damage. If your dog has serious kidney problems. unfortunately the outlook is likely to be poor.
The most successful methods of treatment involve using a combination of different drugs. The most commonly used drugs are meglumine antimonate and allopurinol, but the combination of the new drug miltofisine with allopurinol may be a good alternative.
At present dogs that have never travelled outside the UK are at very low risk of developing leishmaniosis. However, if the sand fly manages to establish within the UK, this will change.
If you are taking your dog abroad to a country where leishmaniosis is common then it is important to protect them against biting sand flies. Dogs should be kept in during the evenings (when the flies are most active) and certain insecticides (synthetic pyrethroids) in spot-on and collar formulation with fly repellent activity should be used. None of these products provides 100% protection.
A vaccine for leishmaniosis in dogs has now been developed (CaniLeish® – registered by the European Medicines Agency in 2011).
Bites from infected sand flies are the major route of transmission of leishmaniosis. Just like dogs, people are usually infected by being bitten by sand flies. If you are visiting an area where leishmania is known to be common it is vital that you apply repellant insecticides on yourself (as well as your dog).
There are no published reports of direct infection from an infected dog to a human without a sand fly vector being involved. However, there are reports of transmission of infection from human to human by blood transfusions and contaminated needles. There are also rare reports of transmission from dog to dog without the sand fly vector. Considering this, general advice would be to limit contact between infected dogs and children or adults with a poorly functioning immune system.
Kennel cough (acute tracheobronchitis)
Kennel cough is not a serious disease in most otherwise healthy dogs. However, it is very contagious and will spread rapidly around the dog population. As its name suggests, it causes coughing that can go on for a month in some cases.
Kennel cough is caused by a combination of viruses and bacteria including: Canine parainfluenzavirus, Canine adenovirus and Bordetella bronchiseptica. These agents get into the body and cause irritation to the windpipe resulting in coughing. It is called kennel cough because it is so infectious that if one dog in a kennel gets it the cough will spread rapidly through the rest of the dogs there.
Good kennels will insist that your dog is vaccinated against this disease before agreeing to take them for boarding. This is to prevent the spread of the disease through other dogs in the kennel. Even if your dog is fit and healthy and would not suffer as a result of catching kennel cough, there may be older or more vulnerable dogs staying in the kennels at the same time.
The protection given by the specific kennel cough vaccinations when they are administered into the nose (intranasal) lasts 12 months. It may therefore be wise to separate this vaccination from your dog’s routine boosters. Most dogs only receive intranasal kennel cough vaccinations at times of potential high risk, i.e. before going into kennels.
Many kennels prefer that the vaccination is given around 14 days before the animal is admitted to kennels so make sure you arrange this in plenty of time. Ask your vet for details of how to protect your dog against kennel cough before putting it in kennels.
As its name suggests, this condition causes a cough. Most dogs are not really unwell when they have the disease although occasionally they have a high temperature and are a bit ‘out of sorts’ for a day or two. The cough is dry and hacking and it often sounds as if your dog is choking on something stuck in his throat. The cough gets worse for a few days and then gradually goes away after about 3 weeks.
Your vet will probably know what is wrong with you dog from your description of the symptoms. It is very rare for further tests to be required.
There are treatments that will make your dog get better more quickly – basically they have to fight off the infection themselves. Very rarely, if the infection spreads to the chest or if your dog is unwell in himself, your vet may prescribe some antibiotic tablets. However, these will not stop the coughing more quickly, nor will they make it safe for your dog to mix with other dogs.
Your vet may prescribe some cough linctus to make the coughing less severe and this is normally given if your dog is having a particularly severe coughing fit. There are some tablets that can help to reduce coughing but these would only be given if there were a medical reason why it was dangerous for your dog to cough.
Just as in people with a cold, coughing is brought on by exercise, excitement and exposure to cold air. If your dog has kennel cough you should keep them in a warm environment (where possible) and try not to exercise them too much. Avoid situations where your dog is likely to bark, as this is highly likely to cause coughing. If your dog normally wears a collar, take this off, to stop it irritating his throat, and exercise him outside with a harness or halter and lead.
Above all be responsible – remember that other dogs are at risk of catching the cough from your dog. Do not take him to places where he is likely to meet other dogs (particularly in closed spaces like dog training classes) while he is still coughing and for a few days after.
Most dogs recover quickly from kennel cough. A young, otherwise healthy dog, should not be unwell with the disease and the cough should get better within 2-3 weeks. Very young or old dogs and dogs with other diseases may be much more severely affected by kennel cough. It would be very unusual indeed for a dog to die as a direct result of catching kennel cough.
There are several vaccines available which can protect your dog against the different viruses and bacteria that can cause kennel cough. Many of these vaccines are traditionally given as drops into the nose, although some are available as injections too. Ask your vet for details if you are not sure which diseases your dog is protected against.
Infectious hepatitis
Infectious hepatitis is a serious viral infection, most often seen in dogs less than one year old. It primarily causes damage to the liver. Although dogs with mild disease usually recover, the disease is often fatal in severely affected animals. Recovered animals can shed infection for many months and may be a risk to other dogs. An effective vaccine is available that can protect your dog from the disease.
Infectious hepatitis is caused by an adenovirus, related to the virus causing the cold in man. The disease is also known as canine adenovirus type 1 (CAV1). Animals become infected by breathing in the virus following contact with an infected dog or contaminated environment.
The virus multiplies in the tonsils and then is rapidly spread through the body via the blood. Infection first localises to the liver and kidney and causes damage to the cells here. Virus can be shed in the urine for up to a year after the infection and this poses a risk to susceptible dogs who come into contact with the urine.
The infection can also affect the immune system and the immune system may start to react against the dogs own tissues (an auto-immune reaction).
Dogs that are infected usually develop the signs of disease within a week of being exposed to the infecting virus. The initial signs of infection are listlessness, reduced appetite and fever. Some dogs recover within 1 or 2 days and become immune to further infection.
Even if the liver is affected dogs may get better in 3-5 days with appropriate care. Clinical signs are very variable; liver disease can cause jaundice, abdominal pain and depression. In severe cases spontaneous bleeding may develop.
Immune damage to the eyes can cause the development of a white colour to the front of the eye.
Your vet will probably suspect that your dog might have infectious hepatitis from the symptoms that you describe, your dog’s vaccination history and the findings on physical examination. A blood test which shows a severe decrease in the white blood cell numbers (and possibly the presence of virus bodies in the cells) as well as tests to detect damage to the liver will help to confirm the diagnosis. If your pet recovers, an increase in antibodies against infectious hepatitis in the blood will be seen.
Currently, there is no direct treatment against the virus. Therapy is “supportive” and consists mainly of giving fluids by a vein in order to compensate for dehydration and correct for on-going losses of fluid by vomiting, diarrhoea and the refusal to drink during the disease.
In addition, dogs are treated with drugs to stop vomiting, and with antibiotics, to prevent secondary infection with bacteria. If seizures are present then drugs may be used to control these but euthanasia may be the best option in very severely affected animals.
Mild cases usually recover whilst severe cases usually succumb despite therapy. Remember that recovered dogs may be shedding virus for a long time after and therefore are a risk to other puppies and unvaccinated dogs.
It is essential to vaccinate your dog according to your vet’s recommendations. Pups that are born to vaccinated dams usually have antibodies from their mothers (maternal antibodies) that protect them against infection during the first few weeks of their lives. The pup is in danger after the level of maternal antibodies declines in his blood and that is when he should be vaccinated.
Maternal antibodies can interfere with vaccination so vaccination must be timed so that it is given as soon maternal antibody levels start to drop and that time differs between pups. The vaccination is repeated in order to make sure that the dog has had an effective vaccine dose and to boost this effect.
To prevent the spread of infection, sick dogs should be isolated from other dogs and cages and pens should be properly disinfected and cleaned. Pups who have not completed their vaccination schedule should be prevented from any exposure to potentially infected animals or their environment.
Heartworm disease
This potentially serious parasitic disease can cause heart failure and other complications. In most countries where the disease occurs, preventative treatment is given to pet dogs to ensure they do not become infected.
The disease, as the name suggests, is caused by a parasitic worm called Dirofilaria immitis which lives in the heart. The life-cycle of this parasite involves both dogs (where it can cause serious disease) and mosquitos, which act as a vector, transmitting worm larvae between dogs and spreading infection. Cats and ferrets can also be infected.
Heartworm is an important disease in several parts of the world, including:
- Parts of Europe (not the UK, except in imported dogs)
- South-eastern and mid-western America and the Atlantic coasts
- Australia
- Japan
The tiny immature forms of the worm (larvae) enter a dog via a mosquito bite. They are carried in the blood and settle in the right side of the heart. Here the larvae develop and grow into adult worms. The presence of the worms in this location can lead to serious symptoms, depending on how many there are.
Mild signs may show as tiring and an inability to cope with strenuous exercise; there may be a cough. More advanced or heavier infections can result in heart failure:
- Fatigue
- Breathing difficulties and cough, sometimes with blood
- Abdominal swelling due to fluid accumulation
- Weight loss and poor overall condition.
The disease may be strongly suspected from clinical history and tests such as X-ray and ultrasound. Infection can be confirmed by finding tiny worm larvae known as microfilaria in a blood sample. Another blood test, to detect antigens (foreign proteins associated with the parasitic worms), may be used when microfilaria are not present.
Infected dogs can be treated with drugs to kill adult worms and microfilaria. These drugs are usually given by injection or by mouth. Side-effects and toxicity may occasionally occur during treatment, either due to the drugs or in response to effect of the drugs on the worms. As the worms are killed an allergic shock reaction develops in some dogs. If side-effects occur, additional treatment may be needed to support the dog and further treatment may need to be delayed to allow the dog time to recover.
If the animal has already developed heart failure when the disease is diagnosed additional treatment may be needed.
Normally, drugs to kill larvae are given 3-4 weeks after the adult worms have been eliminated. Medication to prevent further infection (monthly) is then started 2-3 weeks after larvae have been killed and a blood test has come back negative to prove that the dog is clear.
In areas where infection is high, preventative medication (milbemycin and avermectins), usually given monthly under veterinary prescription, is used to guard against heartworm infection. This prevention can be started in puppies at around 6-10 weeks of age. If your dog does not live in, or travel to, an area where heartworm is present they cannot catch the disease. Dogs in the UK are not at risk and preventative treatment is not routinely required.
Ehrlichiosis
Ehrlichiosis is a serious parasitic infection of dogs, transmitted by ticks in warm or tropical regions and occasionally elsewhere. The most serious form of the disease has a long course of many months to years and usually proves fatal. Ehrlichiosis may be seen in dogs in non-tropical countries if the animals have travelled from areas where the parasite is common.
Ehrlichiosis is a serious disease of dogs most often caused by a microscopic parasite called Ehrlichia canis which is transmitted by ticks. The tiny parasites, belong to a group of organisms known as Rickettsiae. The disease is seen mainly in the Americas, Asia, Africa and southern Europe, i.e. warm temperate and tropical climates (but not Australia), and also Finland. Some other species of Ehrlichia can also cause related conditions, with reports of these diseases in northern Europe, including Sweden and Scotland.
The disease is known by a number of different names, e.g. canine rickettsiosis, canine haemorrhagic fever, Lahore canine fever and Nairobi bleeding disease. When the disease becomes chronic and severe it is called tropical canine pancytopenia (pancytopenia means abnormally low numbers of all blood cells).
The juvenile parasite is found in ticks. When a tick attaches to a dog to feed, the parasite can enter the dog in the tick’s saliva. Once in the body the parasites enter the blood cells where they can hide from attack by the immune system.
Often, dogs may be simultaneously infected with Ehrlichia and two other parasites: Babesia and Leishmania. Although closely related to a species of Ehrlichia which infects people, Ehrlichia canis is not considered a threat to human health itself.
Common signs are:
- Lack of energy
- High temperature
- Poor appetite
- Prolonged bleeding after injuries
- Nosebleeds
- Tendency to develop infections
Other signs include vomiting, discharges from the nose and eyes, lameness, breathing problems and problems with coordination.
Dogs imported into areas where infection is common from parts of the world normally free of ehrlichiosis, are more likely to show signs than those born in areas where disease is common (although these may still be infected). German Shepherd dogs may be particularly prone to the disease.
After infection there is a period of 1-3 weeks when the dog appears normal. Signs of illness then develop. If untreated the signs of illness may last for several weeks after which the dog sometimes makes a complete recovery on its own. However, even after recovering from illness, a dog can be a carrier and may succumb to the condition again when stressed, e.g. by another disease or pregnancy.
Some animals develop a more chronic and serious form of the condition (tropical canine pancytopenia) which can eventually prove fatal after a variably long period (months to years).
In parts of the world where this disease is common, characteristic signs often lead to a suspicion of ehrlichiosis. If ticks have been found on the dog, then the suspicion is further increased.
Infection can be confirmed by examining the blood of the dog to look for the parasites inside blood cells. Often the number of blood cells is also reduced. Measurement of protein levels within the blood is helpful. Detection of antibodies to the parasite (made by the dog’s immune system) confirms that an infection has occurred.
The parasite can be killed by some antibiotics. Usually the drugs tetracycline or doxycycline are used. Treatment must be given for several weeks. Additionally, injection of a drug called imidocarb dipriopionate may be given to help prevent development of the severe chronic form of the disease.
Other treatments may be needed to support the affected animal, e.g. blood transfusions for severely anaemic dogs, vitamin supplementation etc. whilst they recover from the infection.
With proper treatment in the early stages, the outlook for the dog is good. If ehrlichiosis becomes chronic, however, the outlook is poor. The chronic form of the disease, tropical canine pancytopenia, cannot be cured.
Controlling ticks will prevent transmission of the disease. Various veterinary preparations are available to kill ticks or prevent their attachment to the dog. As the disease can be passed in infected blood, blood donors should be screened for ehrlichiosis before donating.
Dogs travelling in regions where ehrlichiosis is common need careful monitoring as they are very susceptible to contracting the disease.
Distemper disease
Distemper is a serious viral infection, most often seen in dogs less than one year old. Highly effective vaccines have ensured that distemper is rarely seen in vaccinated pet dogs. It is still a problem in the UK in unvaccinated pets, particularly in urban areas. In other countries the disease is still a big killer of dogs.
Distemper is a large virus related to the virus causing measles in humans. Animals become infected by breathing in the virus following contact with an infected dog or contaminated environment.
Dogs that are infected usually develop the signs of disease 1-2 weeks after they are exposed to the infecting virus. The initial signs of infection are listlessness, reduced appetite and fever. Some dogs recover at this stage and become immune to further infection. In other animals the immune system becomes affected and secondary infections are common.
Respiratory signs such as breathing problems, coughing and snotty nasal discharge are common, and diarrhoea and vomiting may also develop. In severe cases the virus may enter the brain and seizures (fits) may develop. About half of all severely affected dogs will develop neurological signs ranging from blindness to inco-ordination to persistent tics.
Your vet will probably suspect that your dog might have distemper from the symptoms that you describe, the dog’s vaccination history and the findings on physical examination. A blood test that shows a severe decrease in the white blood cell numbers and possibly the presence of virus bodies in the cells will help to confirm the diagnosis.
It is possible to grow the virus outside the dog and your vet could send samples to a laboratory to identify the virus. However this is rarely done in practice. Results of the test can take a long time and the diagnosis will often be obvious without this test. If your pet recovers an increase in antibodies against distemper in the blood will be seen.
Currently, there is no direct treatment against the virus. Therapy is “supportive” and consists mainly of giving fluids by a vein in order to compensate for dehydration and correct for on-going losses of fluid by vomiting, diarrhoea and the refusal to drink during the disease.
In addition, dogs are treated with drugs to stop vomiting, and with antibiotics, to prevent secondary infection with bacteria. If seizures are present then drugs may be used to control these but euthanasia may be the best option in very severely affected animals.
Around 1 in 5 of all dogs infected with distemper will die from the disease (despite veterinary care). One of the biggest killers is the development of pneumonia due to a compromised immune system. The outlook is much worse in those where the brain is affected.
The disease is more severe in young pups and in those that have had no vaccination against distemper or have only just begun their vaccination regimen. Even in dogs that do appear to recover the prognosis must be cautious. Some go on to develop brain problems months or years after the episode.
It is essential to vaccinate your dog according to your vet’s recommendations. Pups that are born to vaccinated dams usually have antibodies from their mothers (maternal antibodies) that protect them against infection during the first few weeks of their lives. The pup is in danger after the level of maternal antibodies declines in his blood and that is when he should be vaccinated.
Maternal antibodies can interfere with vaccination so vaccination must be timed so that it is given as soon as maternal antibody levels start to drop and that time differs between pups. The vaccination is repeated in order to make sure that the dog has had an effective vaccine dose and to boost this effect.
To prevent the spread of infection, sick dogs should be isolated from other dogs and cages and pens should be properly disinfected and cleaned. Pups who have not completed their vaccination schedule should be prevented from any exposure to potentially infected animals or their environment.
Ventricular septal defect (VSD)
Ventricular septal defect (VSD) is one of the more common congenital heart defects in dogs. It is sometimes referred to as a hole in the heart. The condition is often discovered in apparently healthy dogs by a vet during a routine examination (such as before vaccination).
Ventricular septal defect (VSD) is a congenital heart defect, i.e. it is caused by abnormal development of the puppy before birth. The dog’s heart, like that of humans, is a muscular pump with four separate chambers. The right side of the heart sends blood to the lungs where it picks up oxygen. The left side of the heart pumps the blood around the body. The heart is divided into left and right halves by a muscular wall (the septum). The ventricular septum separates the right and left ventricle.
In a VSD the septum doesnt develop properly resulting in a small hole in the septum allowing some blood to divert from the left side of the heart to the right side. The effects of this on the dog depend on the size and location of the defect. Most dogs have small defects that are well tolerated. In some cases, very small VSD holes may close spontaneously. Larger defects can lead to congestive heart failure.
Although the condition is present from birth, signs of a Ventricular septal defect (VSD) are usually not noticed until later in life. Many dogs with VSD have no outward signs of illness. The murmur caused by a VSD is often detected by a vet (often during a routine health check). When you bring home a new puppy it is always advisable to ask your vet to check for any heart murmurs. VSDs are seen most commonly in certain breeds of dog (English Bulldog, English Springer Spaniel and West Highland White Terrier and the Keeshond).
If the defect is large, clinical signs may be seen when the dog is less than two years of age. Severely affected animals may have stunted growth, although this can be difficult to recognise without direct comparison to their littermates. If the condition goes unrecognised and heart failure develops the affected animal may be reluctant to exercise, cough, or have difficulty breathing.
If your vet hears a murmur when listening to your dogs heart they will want to do some other tests. Heart murmurs are caused by the sound of abnormal and high-speed blood flow and are very common findings in dogs with VSD. Very quiet heart murmurs can be present in an otherwise healthy pet so a diagnosis of VSD or other congenital heart disease is not necessarily inevitable.
Ultrasound is the method of choice for finding the cause of a heart murmur. If a heart murmur is heard, an ultrasound examination is recommended. Ultrasound examination of the heart requires considerable knowledge and experience and should be performed by someone with experience in examining young dogs.
X-rays are important in the diagnosis and monitoring of heart disease. In dogs with severe VSD, evidence of heart enlargement on the left side is often evident. X-rays are also used to see if signs of heart failure are present, if there any signs of further heart failure treatment is usually started immediately.
If the VSD is very small, then your dog may lead a normal life with no treatment being necessary. However, if the defect is large, the outlook is worse and your dog may have a significantly reduced life expectancy. Your vet will discuss the outlook and long term management of your dog with you.
If the ventricular septal defect is small, then no treatment is needed and the hole may spontaneously close. Large VSDs may need medical management to treat heart failure if it develops. Some surgical options are available to help reduce the flow of blood across the hole but definitive repair to actually close the hole is typically not possible.
Many animals with ventricular septal defect live a normal life with no signs of heart disease but this depends on the size and location of the defect. Affected dogs and their parents (who could be genetic carriers of the condition) should be not be allowed to have puppies.
Dogs with more severe defects are likely to develop heart failure at a relatively early age and the long term outlook is poor. Life-expectancy may be reduced and long term medication will be required.
Pulmonic stenosis
Pulmonic stenosis is one of the more common congenital heart defects in dogs. The condition is often discovered in apparently healthy dogs by a vet during a routine examination (such as before vaccination).
Pulmonic stenosis is a congenital heart disease, i.e. it is caused by abnormal development of the puppy before birth. The dog’s heart, like that of humans, is a muscular pump. The right side of the heart sends blood to the lungs where it picks up oxygen. The left side of the heart pumps the blood around the body.
Pulmonic stenosis occurs when there is an obstruction to blood flowing out of the heart on the right side. In most cases, the obstruction is caused by a narrowed valve (pulmonic valve) that separates the right side of the heart and the pulmonary artery. This narrowing forces the heart to work harder to pump blood to the lungs. The signs shown by the dog depend upon the amount of narrowing (stenosis).
Although the condition is present from birth, signs may not be noticed until later in life. Many dogs with pulmonic stenosis have no outward signs of illness – although their growth may be stunted this may not be obvious without direct comparison to a littermate. If your dog is severely affected they may suddenly faint during/after exercise or show signs of heart failure.
It is most commonly seen in small breeds of dog (Bulldog, Scottish Terrier, Wire-haired Fox Terrier, miniature Schnauzer, West Highland White Terrier, Beagle, Boxer, Chihuahua, Samoyed and German Shepherd Dog).
If your vet hears a murmur when listening to your dogs heart they will want to do some other tests. Heart murmurs are caused by the sound of abnormal and high-speed blood flow and are very common findings in dogs with pulmonic stenosis. Very quiet heart murmurs can be present in an otherwise healthy pet so a diagnosis of pulmonic stenosis or other congenital heart disease is not necessarily inevitable.
Ultrasound is the method of choice for finding the cause of a heart murmur. If a heart murmur is heard, an ultrasound examination is recommended. Ultrasound examination of the heart requires considerable knowledge and experience and should be performed by someone with experience in examining young dogs.
X-rays are important in the diagnosis and monitoring of heart disease. In dogs with severe pulmonic stenosis, evidence of heart enlargement on the right side is often evident. X-rays are also used to see if signs of heart failure are present, if there any signs of further heart failure treatment is usually started immediately.
If the pulmonic stenosis is mild then your pet may live a normal life without any treatment. In some cases your vet may advise exercise restriction. In more severe cases (with clinical signs from an early age) the outlook is poor. Your vet will discuss the outlook and long term management of your dog with you.
In mild cases, treatment may not be necessary. If signs heart failure or intolerance to activity are present, your vet may prescribe medical management to assist heart function and reduce water retention.
In severe cases your vet may advise surgery. A catheter with a balloon tip can be passed into the narrowed artery and when the balloon is inflated it opens the vessel to allow more blood to flow. This is called balloon valvuloplasty, and typically helps relieve the severity of severe disease.
Many animals with pulmonic stenosis have a normal life span with no signs of heart disease. In affected animals annual monitoring of ECG and echocardiogram is advisable for early detection of signs of heart failure. Lifespan in severely affected animals may be significantly reduced.
Affected dogs and their parents (who could be genetic carriers of the condition) should be not be allowed to breed.