Heart Disease
What does the heart do?
The heart is a large muscle located in the chest. The right side of the heart pumps blood to the lungs to pick up oxygen. The left side of the heart receives blood from the lungs and pumps it around the body. The left and right sides of the heart each consist of 2 chambers; these are separated by valves which ensure that body flows only in one direction.
What can go wrong with the heart?
Rarely dogs are born with heart defects such as ‘hole in the heart’. These conditions may be noticed when puppies are examined for vaccinations. Sometimes these ‘congenital heart conditions’ may only become evident as animals age. More commonly heart diseases develop as animals’ age and the heart muscle starts to wear out. As pets now live longer, heart disease is becoming more common.
You may have heard of angina and heart attacks. These occur when the supply of blood to the heart muscle is reduced or totally blocked. Whilst heart attacks are common in humans they rarely occur in other animals. Indeed dogs develop different heart conditions from cats, and within species heart conditions can occur more frequently in certain breeds.
Heart disease in dogs is usually caused by damage to the valves or stretching of the muscle. ‘Valvular heart disease’ most commonly occurs in Cavalier King Charles Spaniels. The valves become leaky allowing blood to flow back into the heart and reducing blood supply to the body. In ‘dilated cardiomyopathy’ the heart swells and the contractions become weak, reducing blood supply to the body. Dilated cardiomyopathy most commonly occurs in large and giant breeds particularly Doberman’s, Great Danes and Irish Wolfhounds.
The heart muscle may also stretch in a manner similar, this stretching has been linked to low dietary levels of taurine. The condition is now rare as most pet foods are now supplemented with extra taurine.
How do you know if your dog heart disease?
Dogs tend to show similar signs of heart disease regardless of the actual condition. They may have reduced energy levels and be reluctant to exercise, this can be mistaken for general aging changes. In more severe cases weight loss, poor appetite and water retention may occur. Build - up of fluid in the lungs can cause panting and coughing. Rarely, heart conditions can lead to seizures.
How does a vet diagnose heart disease?
The most useful tool for the vet is a stethoscope. A change in normal sounds can indicate heart disease. In disease the heart rate may be increased (or occasionally decreased). An irregular or unusual (murmur) noise may be heard. X–rays can show that the heart is enlarged or that fluid is present in the lungs. In some cases a vet may require ultrasound to image the heart or an ECG to look at the heart’s electrical activity.
It is good advice to ask your vet to examine a new puppy. You may want to return to the breeder a puppy born with a heart defect. Alternatively it may be possible to correct a condition surgically before any symptoms develop.
How is heart disease treated?
There is no need to treat dogs in early heart disease when no symptoms are present. Unfortunately however the disease does get worse. Treatment can slow the rate of progression.
Treatment includes:
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Lifestyle changes increasing controlled exercise
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Drugs to increase the strength of the heart beat or change the rate of heart beat
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Drugs to remove retained fluid
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Dietary changes may also be of benefit.
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Drugs to increase the strength of the heart beat or change the rate of heart beat
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Drugs to remove retained fluid
Heart disease is not the same as heart failure. Many animals with heart disease lead relatively normal lives without medication. However, heart disease is progressive and once symptoms develop, treatment will probably be needed for the rest of an animal’s life.
What is the prognosis for dogs with heart disease?
This is an impossible question to answer. Whilst some animals can live normal lives with no symptoms, others may die quickly despite treatment. A vet may be able discuss prognosis on a case by case basis. The most important factor is obviously the quality of life which your pet enjoys. If you have concerns that medication is not helping or that your pet seems unwell, you should contact your vet.
Complications of heart disease include increased blood pressure which can lead to blindness or clot formation which can lead to hind limb paralysis in dog. The latter is often misinterpreted as the result of a road traffic accident.
Hyperthyroidism
Hypothyroidism is a condition in dogs which results from an underproduction of thyroid hormones from the thyroid gland. This lack of thyroid hormone in the blood stream results in several changes in the body as thyroid hormones are responsible for maintaining a normal calorie burning level, normal tissue repair levels and a healthy immune system.
Hypothyroidism is more common in medium to large-sized dogs. There are some breeds affected more commonly that include: Golden retriever, Doberman, Poodle, Boxer, Great Dane, Airedale terrier and Old English sheepdog. It is more common in middle-aged dogs from four years and older.
The most common signs are increased tiredness, weight gain,patchy hair loss or excessive shedding, recurrent skin infections and dullness (often noted as a decrease in interactions with people and other dogs particularly a reduction in play behaviours). Sometimes you might notice your dog appears colder than it used, trying to seek out warmth more regularly. Occasionally, hypothyroidism can contribute to the development of aggression problems. These clinical signs often develop slowly over a number of months.
There are a number of causes of hypothyroidism, but the most common is thought to be an immune mediated condition where the body’s own immune system creates antibodies that attack the normal thyroid hormones. A small proportion of cases can be caused by a cancerous destruction of the thyroid gland.
The vet will examine your dog to look for signs that suggest hypothyroidism. It is a common finding to see bilateral symmetric baldness (alopecia) on the trunk of the body and the tail, rarely on the head. This hairloss is usually not itchy and the bare skin can feel thickened and be darker than other normal areas of skin. Skin infections are common in dogs with hypothyroidism due to the weakened immune system, and this infection can lead to red areas and spots which are often itchy. Your dog may show signs of generalised weakness and a stiff stilted gait sometimes alongside the development of a puffy face. Occasionally they may also show signs of in-coordination and imbalance. Your dog should be weighed to assess for any abnormal weight gain.
To confirm the diagnosis of hypothyroidism your vet will need to perform some blood tests. This will often start with a test to measure the level of thyroid hormones. It may also be appropriate to perform a generalised blood test at the same time to ensure there are no additional internal diseases that might have triggered the low levels of thyroid hormone and also to check there no additional problems that might affect the successful treatment of hypothyroidism. There are times when the routine blood screens do not confirm a case which is highly suspicious of hypothyroidism. In these cases we will recommend that we perform further tests include a blood test after an injection which should stimulate the thyroid gland to assess if it is able to react normally and produce thyroid hormones.
Dogs with hypothyroidism normally respond well to treatment with synthetic thyroid hormones given to them daily in the form of a tablet. The appropriate dosage varies between individual dogs so it may be necessary for us to repeat the blood tests to assess if the correct dose has been found. We recommend that once this correct dose is found, your dog should have regular blood tests to monitor that the thyroid levels remain within normal limits as the damage to the thyroid gland can be ongoing and overtime we may have to increase the amount of synthetic hormone your dog receives in order to keep your dog healthy. Treatment will be lifelong but most symptoms resolve over a few weeks or months. Dogs with well managed hypothyroidism have an excellent prognosis and life expectancy is normal.
Whelping and Dystocia
A lot of bitches will whelp on their own without any difficulties. You should keep a close eye on your bitch throughout her late pregnancy and labour. Having a good idea of what is normal will allow you to spot signs of trouble (dystocia) early.
What will I see?
In the last week of pregnancy, your bitch may start to look around for a suitable place to have her puppies and show signs of nesting. It is a good idea to get the bitch used to the place where you want her to have her puppies well in advance of whelping. However if she does start whelping in an area other than the one you planned, it may be less stressful for all concerned to allow her to continue in her chosen place. Make sure you spread lots of old newspaper and if possible cover the carpet with a polythene sheet. Some bitches like their owner to be with them the whole time they are in labour. Others prefer to get on with it in seclusion. You will have to judge this at the time.
Some bitches stop eating during the last 24 hours before labour and she may appear restless and start nest making. In most bitches, the rectal temperature will drop below 37.8°C (100°F) but this may only occur an hour or two before she starts in labour.
These signs may last for up to 24 hours and are part of first stage labour.
During second stage labour your bitch will start to strain and hopefully puppies will start to arrive.
What can I prepare in advance?
- You will need lots of clean newspaper and towels.
- Prepare a whelping box – the size will depend on the size of your dog, but should be large enough for her to move around freely and have low enough sides so that she can move in and out easily.
- Bedding, e.g. Vetbed, which is easily washed
- Hot water bottles
How long will whelping take?
This can vary. Dogs with fairly slim heads such as Collies and Dobermans may deliver all of their puppies within 2-3 hours. Brachycephalic breeds, i.e. those with large, round heads such as Bulldogs and Pekingese, tend to have more difficult deliveries and sometimes will produce one or two relatively quickly and then rest for a while before labour starts again.
Puppies are usually born head first with the forelegs extended. They can also be born with tail and hind legs coming first which is normal. An abnormal or breech presentation is one in which the hind legs are forward and the tail and bottom are presented.
When should I be concerned?
If:
- Your dog goes into labour and you notice that more than two hours has passed without any puppies being born.
- She has a green discharge from the vagina without puppies having been born.
- It is more than two hours between puppies
- If she is continually straining for a few minutes with a puppy or fluid filled bubble stuck in the birth canal.
- Your dog has intense contractions/straining for more than 20 minutes without a puppy being delivered
- If your dog is depressed, lethargic or her body temperature is more than 39.4°C (103°F).
- If she is bleeding from the vagina for more than ten minutes.
- If a puppy’s tail is seen hanging from the vulva or alternatively there is a lump just behind the vulval lips and your bitch is straining, it is probably a breech delivery. Some breech presentation can be delivered without assistance, but often complications occur.
If you can see a puppy at the vulva and it is not being delivered, take a piece of clean tissue or towel and gently take hold of the puppy. Gently pull the puppy at approximately 45° angle to the ground. Keep a constant pull even when your bitch is not straining, as gentle traction will stimulate her to keep straining. If the puppy does not move or if it appears to be painful to your bitch, contact your vet urgently.
If you have any concerns, contact your vet for further advice. If you need to take your bitch to the vets, take any puppies she has already delivered with you in a separate secure box with a hot water bottle or heat pad to keep them warm. Ensure the hot water bottle is well wrapped in a towel or similar to prevent overheating or burning the puppies.
What causes dystocia?
There are many possible causes of dystocia. Your vet will examine your bitch and may need to perform blood tests, x-rays or an ultrasound scan to advise you on the best course of treatment.
Predisposing Factors to Dystocia:
- Age
- Brachycephalic and toy breeds, especially Pugs, Bulldogs, Chihuahuas, Boston Terriers, Pekingese
- Obesity
- Abrupt changes in environment before your bitch goes into labour
- Previous history of dystocia
Treatment
Your dog is likely to be admitted to the hospital for treatment and monitoring if suffering from dystocia.
If there are no contractions of the uterus and no sign of an obstruction, your bitch may be treated medically. She may receive intravenous fluids (a drip), glucose, calcium, oxytocin or a combination of these.
If there is a puppy stuck in the pelvic canal, it may be possible for your vet to assist your bitch to deliver this puppy.
In other cases, a caesarian section may be recommended as the safest course of treatment for both bitch and puppies.
Aftercare
Each puppy is enclosed in a sac that is part of the placenta or afterbirth. This sac is usually broken at birth and passed after each puppy is born. You may not see all the placentas as it is normal for the bitch to eat them. The bitch normally chews at the umbilical cord and breaks it about an inch from the puppy. Keep a close eye on your bitch as sometimes that can be over enthusiastic and injure the puppy.
If a puppy is born within the sac and the bitch does not break the sac within a few seconds, carefully break the sac yourself and then clean the puppy’s face and nostrils to allow it to breath. Ideally give the puppy straight back to the bitch, however in some cases you may find that the bitch is more interested in delivering the next puppy in which case gently rub the puppy dry with a clean towel and place it in a box with a warm water bottle covered by a towel. Cover the puppies to keep them warm.
Ensure your bitch has lots of TLC and lots of food and water. Producing milk for her puppies takes up a lot of energy and is thirsty work.
Eclampsia (milk fever, puerperal tetany or hypocalcaemia) is a condition that most commonly affects nursing mothers but can also occur during late pregnancy. Signs are seen when the calcium levels in the blood drop too low. Signs can be vague to start with but they include restlessness, panting, increased salivation and stiffness when moving. This can progress quickly to muscle twitching, fever and death, so contact your vet immediately if you notice any of these signs.
Some discharge after whelping is normal, if your bitch has a blood stained or smelly discharge, 24-48 hours after delivery, contact your vet.
Even if your bitch appears to have no problems delivering her puppies, it is worth getting mum and puppies checked over by a vet, to ensure they are all healthy and everything is healing normally.
Please note:
This advice is not a substitute for a proper consultation with a vet and is only intended as a guide.
For any further information or advice, please do not hesistate to contact the practice and speak to one of our friendly staff.