What is Congestive Heart Failure?
There are a wide range of different causes of heart disease in dogs and cats - in particular, we think of hypertrophic cardiomyopathy in cats, dilated cardiomyopathy in dogs, “leaky valves” (endocardiosis), valve stenosis, arrhythmias, and many more. However, whatever the underlying condition, they all lead to the same place in the end - congestive heart failure, or CHF.
Whatever the underlying cause, a failing heart results in a gradual reduction in systemic blood pressure. This reduction is detected by the kidneys, which respond by activating as system called RAAS (Renin, Angiotensin Aldosterone System).
The kidneys trigger it by releasing a chemical called renin. Renin acts on proteins in the blood to convert Angiotensinogen to Angiotensin I; which is then converted by an enzyme in the lungs (called Angiotensin Converting Enzyme, or ACE) into the active form, Angiotensin II.
Angiotensin II has a range of effects on the body; but primarily it drives the retention of fluid - more salt is retained by the kidney, so more water is retained in the blood vessels. In the short term, this increases blood pressure, which is the reason the system is activated.
The RAAS is very well adapted by evolution to help an animal survive serious injury - typically, severe blood loss. In this situation, the problem is that the blood volume is too low, so boosting it is exactly the right response, allowing the blood pressure to be maintained while the body heals itself. However, in heart failure, the blood volume is normal, the problem is that the heart is pumping too weakly. Retaining fluid when the pump isn’t working properly doesn’t help - in fact, it makes it worse because the pump then has to work even harder to move the extra blood volume.
The harder the heart has to work, the sooner it will fail, so this RAAS activation actually makes matters worse. In addition, it is responsible for most of the symptoms of heart failure.
The increased fluid volume means that the blood vessels, especially the veins, are over-full; ultimately, this leads to leakage of fluid into other parts of the body. We commonly see ascites, or fluid on the abdomen, as fluid builds up in the belly. This is why so many cats and dogs in heart failure have a pot- bellied appearance. The over full veins also explain the distended and pulsing jugular veins that are quite common. However, the worst effect is that fluid tends to leak out of the small vessels in the lungs, leading to pulmonary oedema (fluid on the lungs). The extra fluid here makes it harder and harder to breathe, resulting in coughing (although this is also partly due to pressure on the windpipe from an enlarged heart), increased breathing rate and difficulty catching breath. Ultimately, this is usually the cause of death for animals in heart failure - internal drowning as the fluid builds up to the point where they cannot get enough oxygen into their blood.
So, what can we do about this?
Well, in most cases the underlying heart disease cannot be repaired (although there are some very promising results from heart surgery to repair leaking valves in dogs at the RVC in London). However, since most of the symptoms are due to CHF, not the underlying disease, it makes sense that controlling this should help.
There are three main types of medication we use in heart failure:
● Diuretics, or “water tablets” - these are a class of drugs that make the kidneys lose more
water. In dogs and cats, we mainly rely on frusemide (aka furosemide); however, sometimes we use a drug called spironolactone as well. The effect of these is to increase urination, reducing the amount of fluid in the blood. This then draws water back out of the abdomen and, crucially, lungs, “drying them out”. The bottom line - diuretics keep animals alive for longer by preventing them from drowning in their own fluids.
● ACE Inhibitors (such as benazepril or enalapril). These drugs block the action of Angiotensin Converting Enzyme (ACE); without this, levels of Angiotensin I may build up, but they cannot activate the water retention system. Although not 100% effective, ACE inhibitors dramatically improve quality of life.
● Pimobendan - this is a drug that makes the heart beat more strongly (although, for this reason, it cannot be safely used in cats with hypertrophic cardiomyopathy). However, in other causes of heart disease, this acts to increase blood pressure (so the RAAS is never activated), and maintain heart function. Interestingly, we now know (thanks to the EPIC Trial, published in September 2016) that pimobendan not only means that dogs live longer once they’re in heart failure, but it also delays the onset of CHF in dogs with an early heart condition.
By controlling CHF, we can therefore not only give animals a better quality of life, but we can extend their lives - even if they haven’t yet developed any symptoms of heart failure.
If you think your pet may have a heart problem, make an appointment to see one of our vets to get them checked out!
Why do dogs throw up so much?
The most likely answer is because they eat nasty things! Compared to cats (who won’t eat something unless they’re sure it's good to eat), dogs are much more indiscriminate (they’ll eat something to find out whether it’s good!). Of course, often enough they’ll find out it isn’t good for them, and then they’ll vomit it back up.
What causes vomiting?
In the base of the brain is a region called the Chemoreceptor Trigger Zone (CTZ), which monitors the blood and the gastrointestinal system for early signs of poisoning or intestinal blockages. It can be triggered by unusual chemicals (which is why vomiting is a possible side effect of almost every medication!), distention of the gut, or even mental confusion (because that’s a possible symptom of poisoning too) such as stress or motion sickness. The important thing to remember is that vomiting is a protective reflex, to try and keep the dog safe from the consequences their own folly or depraved appetite...
If the CTZ thinks that something is amiss, it releases a chemical called Substance P, which triggers the vomiting reflex. The result is nausea (usually seen as drooling and a miserable expression), then reverse peristalsis, where the gut goes into reverse gear, pushing food back into the stomach. Finally, a series of strong abdominal contractions force their stomach contents out and onto your lawn or carpet!
And the commonest causes in dogs?
Vomiting in dogs may be described as acute (sudden onset) or chronic (ongoing).
The commonest causes of acute vomiting in dogs include:
● Dietary Indiscretion, also known as Garbage Gut. This is the most common cause and is
a temporary gastroenteritis caused by eating rotten food or nasty rubbish! It’s often associated with diarrhoea as well. In most cases, this will self resolve in 24 hours or so, but occasionally an affected dog becomes so dehydrated that they need to be hospitalised and put on a drip.
● Infections. A high fever will often trigger vomiting just by tricking the CTZ into overreacting. Gut infections such as Salmonella can also trigger it, as can life-threatening conditions such as Pyometra (a womb infection).
● Poisoning, with substances like chocolate; vomiting may also be seen with many drugs.
● Gut damage, such as stomach ulcers or a high worm burden.
● Intestinal obstructions where a swallowed object (like a stone, or a toy) cannot be digested and blocks the bowel. This is a surgical emergency and is usually fatal without treatment, typically surgical removal of the obstructing object.
Chronic vomiting, however, is caused by more ongoing disease processes, such as:
● Kidney failure - as the kidneys fail, their ability to filter waste products out of the blood
decreases. As these wastes increase, the CTZ responds by triggering vomiting.
● SIBO - Small Intestinal Bacterial Overgrowth, a complex condition where, for various reasons, bacteria colonise and grow in the small intestine.
● IBD - Inflammatory Bowel Disease, a condition where the immune system overreacts to the gut contents causing chronic intestinal irritation and often vomiting.
● Tumours in the abdomen or gut wall, which prevent the intestines from working properly.
What should I do?
Acute vomiting can often be managed at home, but if in any doubt, call us! The best home treatment for a vomiting dog is to starve them - no solid food for 24 hours. Make sure they have access to water, but it’s best to give them little and often, otherwise many dogs will drink a whole bowlful in one go, which can make even a healthy dog feel sick.
A dog with chronic vomiting needs to be seen by one of our vets, as we’ll need to try and work out what the underlying cause is.
What signs do I need to worry about?
We REALLY need to see your dog if they show any of these symptoms:
● Persistent vomiting, despite being starved.
● Being unable to keep even water down.
● Vomiting blood.
● Signs of dehydration, such as sticky or dry gums, sunken eyes, no urination, and accelerated heart rate.
● If they seem ill in themselves or show any other symptoms.
If your dog has any of these worrying symptoms, or you are at all concerned, call us for advice straight away.
Feline Leukaemia Virus, the risk to our pets
FeLV is a serious and important infectious disease of cats; in some ways, it is very similar to HIV, or its feline equivalent, FIV. However, it is a different virus, and unlike the Immunodeficiency Viruses, it is easily and efficiently transmitted in saliva - so it’s much easier for cats to become infected. Fortunately it is preventable by vaccination and all outdoor cats should be protected against this virus.
Our Barnhill surgery has already been certified as a ‘Cat Friendly Clinic’ and our Dundee surgery will soon also be awarded this coveted status by the International Society for Feline Medicine (ISFM). This ensures that we reduce the stress of visiting the clinic as much as possible, we have a cat waiting area at Dundee and cat specific consulting times at Barnhill (Wednesdays, 4-5pm), our cattery is designed to ensure cats don’t face each other, our vets and nurses are trained in ways to reduce stress for our feline patients who are hospitalised and we strive to ensure we make your visit as stress free as possible for both you and your cat! More info on this award is available here: http://icatcare.org/catfriendlyclinic
So, what is FeLV?
FeLV stands for Feline Leukaemia Virus, and it is technically termed an oncornavirus. This means that it is one of the very rare infectious agents that can cause cancers to develop in otherwise healthy animals. However, in cats it more commonly causes damage to, and eventual destruction of, the immune and blood systems. About 1-2% of all cats are thought to carry the virus, and over 80% of these will develop symptoms within four years.
How do cats catch it?
Primarily via saliva - typically by sharing food bowls, but also by grooming or contact with faeces or urine. Infected cats often continually shed the virus, and infect others around them. Cats contract the infection by ingestion of the viral particles - however, these do not (fortunately) survive long in the environment, so it is usually only close companions and friends of the infected cat that are at significant risk. Occasionally, it may also be transmitted via a bite, but this is thought to be less common.
What does the virus cause?
There are three common outcomes to an active FeLV infection -
- Immunosuppression, or weakness of the immune system, is the most common outcome, seen in 50% of active cases. Typical symptoms include recurrent minor infections, slow wound healing, mouth ulcers, skin disease and chronic fevers. Eventually, the cat will succumb to an otherwise innocuous secondary infection.
- Anaemia occurs because the bone marrow is damaged by the virus, so the cat does not manufacture enough red blood cells. Symptoms may include pale gums, shortness of breath, lethargy and eventually difficulty breathing and collapse. This occurs in about 25% of infected cats.
- Tumour development is actually quite rare, occurring in about 15% of FeLV patients. The virus integrates its DNA into the cat’s genetic code, deactivating those genes that prevent cancers from starting. Lymphoma (solid cancers of the white blood cells), Leukaemia (blood cancer) and Fibromas (tumours of the fibrous tissues) are most common.
How do you know if a cat is infected?
There is a very simple blood test that we can do in the surgery that will tell us if your cat has FeLV - we can also test for FIV at the same time.
Can FeLV be treated?
There is no cure for FeLV; treatment is based on supportive therapy to manage the symptoms. Some human anti-AIDS drugs may slow down the infection, but they will not clear it completely.
How can FeLV be prevented?
There is a very effective vaccine, and we recommend that all outdoor cats are vaccinated against FeLV as standard! If your cat has FeLV, they should be kept away from other cats (ideally, even other FeLV-infected cats, because there are different strains of the disease), and will have to live indoors, to minimise the risk of infecting others.
If you are concerned about FeLV, please give us a call and chat to one of our vets.
Party Poisons for Pets
Christmas is a great time of year for humans - special foods, festive treats, decorations and all the rest. However, for our pets it’s a different situation - and a much more dangerous one too.
So, what are the particularly hazardous substances at this time of year? We’ve made a series of information to give you a quick spin through some of the most common ones!
Raisins, currants, grapes
Mincemeat, puddings, mince pies etc.
Dogs and cats.
Increased thirst, reduced urination, dehydration, vomiting, metallic-smelling breath, seizures and collapse. Often fatal.
Festive nut assortments; also some varieties of nut butter.
Dogs, possibly cats.
Lethargy, weakness or wobbliness; vomiting and diarrhoea, bloated abdomen and pain; depression and arthritic symptoms.
Nut selections and party foods.
Dogs and (rarely) cats.
Gut irritation and salt toxicity.
Vomiting and diarrhoea from the nuts. If pets eat enough salt, it causes thirst, lethargy and depression, muscle tremors and abnormal heartbeats. In severe cases, wobbliness, seizures and death follow.
Onions, garlic, leeks and chives
Stuffing, stews, Greek salad and many other foods.
Dogs and cats.
Red blood cell damage, leading to anaemia.
Pale gums, shortness of breath, collapse and fainting.
Theobromine and Caffeine
Chocolate, tea coffee, energy drinks - dark chocolate and coffee grounds are the most dangerous, but any exposure is potentially harmful.
Mainly dogs, but occasionally cats too.
Hyperexcitation of the nervous system and heart.
Initially, vomiting, diarrhoea and abdominal pain. Higher doses cause drooling, muscle twitching, restlessness or excitement, wobbliness and heartbeat disturbances. Eventually, seizures and sometimes kidney failure occur.
Artificial sweetener, some low-calorie baking.
Trigger insulin release, resulting in profound hypoglycaemia.
Abnormal behaviour, collapse, seizures and death.
Cooked meats - while raw bones can be risky, cooked bones are prone to splinter.
Dogs, cats and any other animal that eats them!
Splintering, causing lacerations and perforation of the gums, tongue, throat or intestines.
Pain after eating, vomiting, bloody vomit or faeces, collapse, fever and potentially septicaemia.
Rich, fatty food
Pretty much everything we eat over Christmas!
Dogs and cats.
Stomach upsets and potentially pancreatitis.
Nausea, vomiting and diarrhoea. If acute pancreatitis occurs, vomiting, severe abdominal pain and dehydration.
Mainly dogs (cats are usually more sensible!).
Neurological impairment, dehydration/acidosis and liver damage (aka drunkenness, hangover and cirrhosis).
Initially, wobbliness, abnormal behaviour and excitement. Later, weakness, lethargy, nausea and vomiting, increased thirst and collapse.
Festive flower arrangements.
Cats and dogs.
Drooling, vomiting and diarrhoea.
Tree decorations, some cake decorations too.
Mainly cats, potentially dogs.
Although not actually poisonous, tinsel if swallowed forms a linear foreign body which acts as a cheesewire, damaging the intestinal walls.
Loss of appetite, drooling, vomiting (often bloody), lethargy and collapse.
Baubles and other ornaments
Cats and dogs.
Can shatter and injure the mouth or intestines; alternatively, if it doesn’t break it can block the bowel.
Loss of appetite, drooling, vomiting (often bloody), lethargy and collapse.
This Christmas, do your pets a favour - keep them away from anything dangerous, and allow only supervised contact with decorations or leftovers!
If your pet appears injured or ill at all, contact us at once for advice. Don’t worry, we’ll be open for emergencies throughout the holiday!
Holiday Dangers - read about them with this link.
My dog hates having his claws clipped – what can I do?
A lot of dogs don’t like having their feet looked at - which unfortunately means they tend to wriggle and squirm just when we’re trying to clip their toenails! However, there are some techniques you can use to make it a bit easier...
First, why don’t they like it?
There are two possible reasons - most often, it’s because they’ve had a bad experience some time before, that’s made them very protective of their feet and claws. Bad experiences usually means that at some point, when clipping the claws, someone has caught the quick (the living part inside the claw). Sadly, this does happen occasionally - it doesn’t mean the person doing it is incompetent, it’s an unfortunate but common complication. In dogs with pale claws, it’s easy to see the quick, but in dogs with dark nails, there’s no way to know how far down the quick extends.
The other reason is that they have tender or ticklish feet. This may just be them, but is often because of an underlying disease process - allergies, contact dermatitis, or pododermatitis, for example, all make the feet very tender. If your dog has red or sore-looking skin, especially between the pads or toes; or if there is staining of the fur (other than with mud, obviously), it’s always worth bringing them in for a check-up. A lot of skin diseases are first noticed when they affect the feet, and so this can be a chance to get on top of the problem before it spreads.
OK, so what do I do?
If they’ve had something nasty happen before, it’s important to try and “dilute” that memory with lots and lots of happier, or at least less painful, ones. A good way to start is by examining the feet every day for 3-4 weeks (at least) - sit your dog down, as if you were going to trim their claws, but don’t actually do anything but look at them. After each session, make a big fuss of them and possibly offer a treat. After a few weeks, you can start to feel their toes, and (gently!) squeeze their toes and nails, but again without clipping. Then, get the clippers out but don’t actually clip - just put them on the nails. Again, reward them for good behaviour, don’t try to punish them if they get nervous or frightened. Finally, you’ll be ready to really clip just a tiny bit off the end of each claw, and gradually build up to normal clipping.
If they have tender feet, get them checked out for any underlying disease, but if they’re healthy and just ticklish, then sadly there isn’t a lot you can do about it! Some people recommend standing in cold water to reduce the sensitivity of the skin before clipping, but that can risk damaging the skin if done too often. Probably the best answer is to bring them in for us to do -
we’re used to dealing with ticklish dogs and our nurses are experts at holding dogs still without upsetting them!
Is there anything I can do to reduce the chance that I’ll catch the quick?
Yes! If your dog has pale claws, look at each one before clipping, and check that the quick (which is visible as a dark or pink line inside the nail) isn’t going to be caught. If your dog has dark nails, aim to cut them off level with the pads if they were standing. Also, squeeze gently before closing the clippers - if you’re over the quick, he is likely to flinch, and then you can move down to take a bit less off. This isn’t 100% reliable, but it’s better than nothing.
If in any doubt about claw clipping, bring your dog down and we can show you the best way to do it. Our Veterinary Nurses can do this during clinics at a reduced price too – 50% off!
WHY DO RABBITS NEED TO BE NEUTERED?
Although there are people who keep entire rabbits fairly happily, this is, sadly, the exception rather than the rule. Most of the time, rabbits are happier, healthier and live longer if they are neutered.
What is neutering?
Neutering means removing the reproductive organs of the rabbit but leaving everything else as it should be. It is a routine operation and regularly carried out safely in the surgery. In bucks (males) it is called castration and involves removal of the testicles through the scrotum (sac) or the skin of the abdomen - it’s a very simple procedure. In does (females) it is called spaying and involves the removal of the ovaries and uterus; this is a bigger operation but there are excellent reasons for doing it (as we’ll see below).
In this blog, we’ll look at the reason why this operation is so important in more detail.
There’s a reason the saying is “reproducing like rabbits”. You may well be aware of the statistic in cats (one female cat after seven years in optimal conditions could produce 40,000 offspring), but do you know how many rabbits there would be if you left a pair alone in a perfect environment for 7 years? - Over 184 billion. (If you don’t believe me, check out the maths HERE!)
Of course, there wouldn’t be enough food for that many, let alone enough space, so they’d fight, kill each other, or starve to death. These are not nice ways to go; and there’s no way you’d manage to rehome that many of them! Neutering ensures that not only can the rabbits not breed, but that they don’t want to either. Although the same control could be achieved by keeping them isolated from each other, this is not fair to a social animal like a rabbit.
Happiness and Wellbeing
As discussed, entire bucks cannot be kept with does because they’ll breed and breed and breed. However, it’s not easy to keep two does together without them fighting (unless they were litter mates), and two bucks will usually fight (again, brothers might get along, but don’t count on it!) and may even kill each other. Both sexes are very territorial and can be really aggressive - in both bucks and does this is caused by the hormone testosterone, which is made in the testicles of the male (it is the main male hormone) but is also produced by the ovaries of the doe. Removal of these organs at neutering makes them much calmer, less aggressive, and more friendly (although you still have to be careful when introducing new friends).
Not only do entire rabbits fight each other, they may even try and fight you! Rabbits can scratch and even bite, and although unlikely to be actually dangerous to you, it is unpleasant.
The other nasty habit that entire rabbits have is urine spraying - as territorial animals, they like to mark their territory, but this doesn’t go down well with their owners! Neutering minimises this behaviour.
Prevention of disease and increasing lifespan
This really is the most important factor to many people. Entire bucks usually die earlier than neutered ones because they’ll often try and fight (or ravish) anything that moves - and if they try it on a cat or a dog it’s not going to end well, as few carnivores appreciate being mounted by a randy rabbit.
In does, however, we have a different range of problems, primarily the huge incidence of cancer of the reproductive tract. Approximately 80% of entire does will develop uterine cancer by the age of 5 years - and it doesn’t matter whether they’ve had a litter or not. They also have a fairly high incidence of mammary tumours (breast cancer) and ovarian tumours. Removal of the uterus and ovaries eliminates the risk of uterine and ovarian tumours (no uterus = no cancer!) and dramatically reduces the risk of mammary growths.
If you want to learn more about how to keep your rabbit healthy and happy, or about the neutering procedure, pop in and talk to one of our vets or read more on our web site HERE.
BLOAT IN DOGS
Is it that dangerous?
Bloat, also known as a torsion, is more properly referred to as a gastric dilation and volvulus, or GDV. It is indeed dangerous - without immediate emergency treatment it is rapidly fatal.
What actually is it?
In a GDV, a dog’s stomach twists on its axis (this is a “torsion” or “volvulus”) so that it cannot drain. The stomach then fills with gas (this is the “dilation” or “bloat” component). This twisting and dilating prevents blood from flowing from the abdomen back to the heart. In addition, it blocks the blood flow to the stomach wall and, sometimes, the spleen as well, which leads to these tissues becoming deprived of oxygen, and they may start to die.
This results in severe abnormalities of the blood’s salt and acid base, as well as massive dehydration and shock. Eventually, the heart will become erratic, leading to the dog’s death.
What causes it?
No-one actually knows; however, the risk is greatest if the dog exercises on a full stomach.
What dogs are at risk?
Any dog may develop a GDV; however, large- and giant breed dogs with a deep and narrow chest are at the greatest risk. This risk tends to increase with age, and is highest in dogs with a relative who has suffered a GDV. Particularly high-risk breeds include Great Danes, German Shepherds, Setters (Irish, English and Gordon), Weimaraners, Saint Bernards, Poodles, and Basset Hounds.
What are the symptoms?
A GDV may be initially subtle, but the signs will rapidly worsen. The typical symptoms include:
- Dry retching without producing any vomit, except possibly a little bit of froth.
- Restlessness and excessive salivation.
- Swelling of the abdomen, especially on the left hand side of the belly.
- Abdominal pain.
- Signs of shock, such as pale gums, rapid heart rate.
- Collapse and, eventually, death.
How do you diagnose the condition?
The symptoms are highly suspicious; however, to confirm the diagnosis we will X-ray the dog’s abdomen. A dog with a GDV usually has an enlarged gas-filled stomach, which appears black on X-ray. However, affected dogs are very sick, so emergency stabilisation is sometimes required before we can X-ray them.
How is it treated?
There are two phases to treatment - emergency stabilisation, and definitive treatment, which involves a surgical operation called a gastropexy.
Emergency stabilisation is needed to try and normalise the dog’s blood, heart and organ function before going to surgery. This involves intravenous fluids to correct the salt and acid imbalances in the blood and to treat the shock. It may also require the use of heart drugs to stabilise their heartbeat. Sometimes, the dog’s stomach is so distended that it stops them from breathing normally, or prevents the blood from flowing into the heart normally. In these cases, the stomach must be “decompressed” (emptied) either with a stomach tube passed down the throat, or occasionally with a needle through the skin.
Once they are medically stable enough, we will take them to surgery. The procedure is called a gastropexy, and involves rotating the stomach back into its normal position, and then fixing it to the body wall so it cannot rotate again. If the spleen or part of the stomach wall is too severely damaged to survive, we may have to remove them at this point. This is a complex operation, on a dog who is quite unstable and very ill, but it is the only way to save their life. Because the stomach is usually full off food with much gas causing it to be distended, the stomach often has to be opened up in order to be emptied, with further risk to the dog from contamination and infection.
How serious is it?
Very - overall, about one third of dogs with a GDV won’t make it. With immediate and effective treatment, perhaps as many as 80% will survive, but without it, almost all affected dogs will die.
Can it be prevented?
The best prevention in most cases is to minimise the risk factors - so:
- Never exercise within 2 hours of feeding.
- Feed wet food.
- Don’t allow dogs to bolt their food - use a slow-feeding tray if they tend to gobble their meals too fast.
- Feed dogs two or three times a day, not just once.
If your dog has a close relation (e.g. a sibling or parent) who has suffered a GDV, talk to us about a preventative gastropexy. For dogs at a very high risk, we can sometimes carry out a gastropexy to fix the stomach in place even before they have an episode.
If you are concerned your dog may be bloated or developing a torsion, call us IMMEDIATELY.
Big big balloon-like dark grey area is the distended stomach, stretched to 4 or 5 times its proper size by gas from fermenting food.
Do dogs get kidney problems?
Yes, they certainly can - although it isn’t as common as in cats, renal disease is seen in dogs.
What do the kidneys do?
A dog’s kidneys filter the blood and produce urine; overall, they have four basic functions:
- Controlling water and salt balance - by controlling how concentrated the urine is (more concentrated = less water is lost), and how much salt is reabsorbed from the urine into the blood before it is moved on down to the bladder.
- Getting rid of waste - the filtration means that wastes (like urea and creatinine) are removed from the blood, and other chemicals (like drugs or toxins) are excreted.
- Controlling blood pressure - firstly by controlling how much water there is in the body, but also by a complex cascade of chemical messengers called the renin-angiotensin-aldosterone system (RAAS) that controls both urine concentration and vasoconstriction (narrowing or widening of the blood vessels).
- Controlling red blood cell production - healthy kidneys produce a hormone called erythropoietin (or EPO for short) that tells the body to make red blood cells. If the kidney isn’t receiving enough oxygen in the blood, it makes more, to try and combat anaemia.
A dog can survive quite happily with only one kidney working - however, once there has been enough tissue damage that these functions are impaired, they are described as being in kidney failure.
What types of kidney failure do dogs get?
Dogs most commonly develop sudden onset kidney problems whereby large amounts of kidney tissue shut down - this is called acute renal failure (ARF). Sometimes it is relatively mild and they recover from it rapidly on their own. However, as damage mounts up, there is an increased risk that there will be permanent loss of function - this longer term condition is called chronic renal failure (CRF).
What causes kidney failure in dogs?
Cats develop CRF spontaneously, often without any obvious cause, but this is less common in dogs. In many cases, there will be a trigger incident that damages the kidneys (often causing ARF) and then they are left with permanent damage.
Typical causes include:
- Genetic defects (CRF is more common in certain breeds, such as the Samoyed, Bull Terrier and Cocker Spaniel).
- Dehydration, shock or abnormally low blood pressure for a prolonged time (after an injury, or occasionally in emergency surgeries such as for a GDV - Gastric Dilation & Volvulus or ‘bloat’).
- Urinary obstruction (a blocked bladder, generally caused by a bladder stone).
- Toxins (such as antifreeze, and some drugs).
- Infection of the kidneys (pyelonephritis).
- Cancer of the kidneys (usually lymphoma, a cancer of the immune system).
- Some immune diseases which attack the kidneys (such as in Nephrotic Syndrome).
What are the symptoms?
Typically, symptoms usually start relatively minor and then worsen as toxins build up in the body. They may include:
- Altered urination:
- Usually reduced in ARF - the less urine is produced, the more severe the damage and the worse the prognosis.
- Generally increased in CRF and very mild ARF.
- Increased thirst.
- Depression and lethargy.
- Weight loss (usually only seen in CRF).
- Loss of appetite.
- Vomiting and, sometimes, diarrhoea.
- Bad breath (often, the breath smells metallic due to the presence of the waste chemical urea).
- Collapse, seizures, coma and death.
Those are quite vague - how do you tell if it’s the kidneys that are the problem?
The most common way to diagnose kidney failure is with blood tests - increased levels of waste products such as urea and creatinine indicate that the kidneys aren’t working properly.
Urine tests are also useful - healthy urine shouldn’t contain much protein, and should be well concentrated; the presence of high protein in urine with low concentration is a massive red flag!
Can it be treated?
Some of the underlying cause can be treated (such as primary dehydration, kidney infections, many toxins, and cancers like lymphoma). However, once CRF has developed, the condition has to be managed, not treated - the kidney tissue that has completely failed won’t grow back.
In ARF the priority is to maintain hydration and to force the kidney to produce some urine (even if it’s not very good at it), so we will admit affected dogs into the hospital and put them on a drip, and may give them diuretics to chemically stimulate urine production.
In CRF a drip may also be needed, but most often these dogs are managed with special diets (that are properly formulated to minimise the amount of work the kidneys have to do), drugs (such as ACE inhibitors), regular blood pressure monitoring, and free access to water.
If your dog seems unwell and isn’t urinating as expected, get them seen by one of our vets as soon as possible.
Why does my puppy only have one testicle?
Retained testicles, or cryptorchidism, is sadly quite common in dogs - possibly as many as 1 in 30 in some breeds. This is a condition where one, or both, testicles do not descend into the scrotum, or “sack”, as they are supposed to.
Why do the testicles have to descend anyway?
While the puppy is developing in his mother’s womb, his testicles form up next to his kidneys. From there, they make a gradual descent through his body into the scrotum, pulled by a ligament called the gubernaculum. Sometimes, this process is less efficient than it should be, and a testicle gets left behind up in the abdomen somewhere. However, it is important for normal function in the adult dog that the testicles be outside of the body - they cannot work properly if they are kept at body temperature. Hanging outside in the scrotum, exposed to the air, they are cooled enough to produce viable sperm.
Does that mean there is a second one in there somewhere?
Almost certainly - it is very, very rare for a dog to be born with only one testicle (monorchidism). The other one has probably just “got lost” on the way!
Where does it end up?
Well, it could have stopped descending pretty much anywhere between the kidney and the scrotum! However, most retained testicles make it as far as the inguinal ring, a small gap in the body wall at the base of the scrotum.
Is it worth waiting to see if it comes down on its own?
It depends on how old the puppy is. The testicles in dogs normally reach the scrotum in the first couple of weeks after birth, but it isn’t unusual for them to take 6-8 weeks to be visible (remember, in a puppy before puberty, his testicles aren’t usually very big!).
If he’s reached 8-12 weeks old, it is fairly unlikely to make an appearance on its own.
If your dog is well into or beyond puberty, however, the testicle definitely won’t descend - by now it has grown too large to fit through the inguinal canal.
Can it just be left where it is?
Definitely not! Firstly, although a retained testicle cannot produce sperm, it will still produce testosterone, driving male behaviour (leg cocking, roaming, potentially aggression, and sexual behaviours such as humping and masturbation).
Secondly, a retained testicle is much more likely to become cancerous - they have nine times the risk of a testicle in the correct position. The most common tumour is a Sertoli Cell Tumour, which can be life-threatening, and can also cause Male Feminisation Syndrome (as it produces oestrogen).
Finally, cryptorchidism is an inherited condition - dogs carrying the genes for retained testicles should not be permitted to breed.
So what can be done about it?
Ultimately, all cryptorchid dogs should be castrated as soon as it becomes apparent that the rogue testicle isn’t going to descend on its own. In most cases, the testicle is in the inguinal canal, and as soon as he is anaesthetised for surgery, it becomes visible and can be removed in more or less the usual way. Occasionally, however, the testicle is in the abdomen, and so exploratory surgery is needed to go in, find it, and remove it.
If you are concerned about your dog’s development, make an appointment to see one of our vets!
Toxoplasmosis in cats - what are the risks?
Toxoplasmosis, or “Toxo”, is a very common feline (cat) parasite that can infect almost all mammals - including people. The infection's more common effects (such as abortion) are fairly well known. However, some of the more subtle signs of infection are less well recognised and there is widespread misunderstanding of the common routes of infection.
What is Toxo?
Toxoplasma gondii is single-celled parasite, rather like an amoeba. It lives inside the cells of its host (in fact, it cannot survive outside the cell for very long). The Toxo organism’s life-cycle is quite complicated, but the basic cycle is:
1. Adult parasites in the intestinal wall of a cat (and only a cat). Here, they reproduce, producing oocysts (eggs) which are passed out in the faeces. However, most cats are not shedding oocysts most of the time - their immune system prevents this except when they are stressed or ill.
2. These eggs are then eaten by passing animals of one type or another.
3. If the oocysts are consumed by a cat (unusual, but possible), they will develop
into adults in the gut and continue the life cycle.
4. If the oocysts are eaten by another mammal, they too will become infected. However, in these intermediate hosts - i.e. anything except a cat - they do not progress to adulthood. Instead, they start to multiply in the tissues. This can cause mild, or occasionally severe illness, but is usually short-lasting.
5. After a while, the intermediate host’s immune system attacks the parasites, and they stop multiplying and just form tissue cysts. Here they stay, causing very little trouble (but see below!).
6. Most intermediate hosts are dead-end hosts - the life cycle will never complete. However, if they are eaten by a cat (think mice and rats, mainly, but theoretically any host, including people!), the tissue cysts will infect the cat, starting the cycle again.
So, what are the symptoms in cats?
Very few - some cats may have diarrhoea, but in the vast majority of infections, there are no symptoms. Very occasionally, a cat may become much, much sicker (typically if their immune system hasn’t responded normally to the Toxo organisms), and may get a fever, eye, brain, liver or lung disease.
OK, so it’s not a problem in cats; what about dogs?
Dogs are intermediate hosts - and if a dog is infected it is, from the parasite’s point of view, a mistake (not many cats are going to eat a dog!). Most dogs will develop either no symptoms or fairly mild, localised signs (such as muscle pain and stiffness) until the immune system suppresses the infection. Very young dogs, and those with a less effective immune response, may develop tremors, convulsions, eye and digestive problems, but it’s quite rare. A pregnant bitch may abort her litter, but otherwise, symptoms aren't seen often.
What happens if humans are infected?
Just like dogs, humans are a dead-end intermediate host. In us, infection usually causes very mild cold or ‘flu-like symptoms, which may not even be recognised. Then the immune system suppresses the parasites and they hide away in tissue cysts (and usually never cause a problem again). Very rarely, people may develop more severe symptoms, such as encephalitis or blindness - but this is only usually people with a damaged or weakened immune system (e.g. with AIDS, or taking anti-rejection medication).
If a woman is infected when pregnant, she may miscarry, or the baby may suffer from birth defects. However, infection before pregnancy is not generally thought to be a risk for future miscarriages.
So most of the time it isn’t really that important?
Well, yes and no. In recent years, we have discovered that the parasites in rats and mice cause them to lose their fear of cats. There is now some evidence that Toxo infection in people may lead them to take more risks (such as speeding when driving); and may be associated with the development of clinical depression. This is not yet proven, and research continues, but there does seem to be a fairly strong association.
That’s worrying - do I have to get rid of my cat?
Unless you, or someone in your house, suffers from a severely weakened immune system, that probably isn’t necessary - remember, in the UK about 20-30% of the population contract Toxo at some stage in their lives, and suffer no ill effects!
Also, contact with cats does not seem to be a significant risk factor for contracting it - people with cats and people who work with cats (like vets and vet nurses) are not at a higher risk of infection. This is because, in humans, the most common route of infection is by eating undercooked lamb or pork containing the infective tissue cysts.
If you are pregnant, or have a weakened immune system, you are still very unlikely to contract infection if your cat is healthy. You should, of course, avoid handling cat faeces directly (but then that applies to everyone!), but the risk of contracting Toxo is very low from just stroking them or sharing a house with them.
Where can I find out more?
If you want to know more about Toxoplasmosis and cats, check out the International Cat Care website here: http://icatcare.org/advice/cat-health/toxoplasmosis-and-cats
If you want to know more about Toxoplasmosis in people, check out the NHS Choices page here: http://www.nhs.uk/Conditions/T oxoplasmosis/Pages/introduction.aspx - if you are concerned, talk to your GP.
If you are concerned about your cat’s health, or whether they may be carrying the parasites, make an appointment to see one of our vets!
My dog has a cruciate problem - what are the options?
A cruciate ligament rupture is a common injury in dogs, but there are a bafflingly wide range of treatment options available. Which is the most suitable will depend on a number of factors, including your dog’s body weight and other concurrent diseases. However, to understand the treatment, you’ll need to understand the underlying condition. Although the condition is common, to treat it can be expensive and pet insurance is always a good idea!
OK, so what is a cruciate ligament?
The cruciate ligaments are two strands of tissue in the stifle, or knee joint of a dog’s hind limb. They form a cross-shape (hence the name!) and act to maintain the relative positions of the bone below the joint (the tibia) to the bone above (the femur). If they are injured, the symptoms may range from mild, intermittent lameness to severe pain and inability to bear weight on the affected leg. Often there is also swelling of and around the joint (often referred to as a “medial buttress”, and there may be abnormal movement of the tibia (“cranial draw” or “tibial thrust”).
How can they become damaged?
In most dogs, the ligament breaks because of a long-standing, gradual degeneration of the tissue. We don’t yet know the exact cause, but it is probably genetic, and is more common in certain breeds, including Labradors, Boxers, and Westies. It is also exacerbated by certain types of exercise (sudden, rapid twisting or jinking), and by obesity. This degeneration often results in long-standing lameness that gradually deteriorates, and then a sudden worsening as the weakened ligament finally snaps.
Occasionally, a healthy ligament can spontaneously tear – this is usually due to massive over-exertion, typically a fall or violent twisting movement.
OK, so how can it be treated?
There are three types of management available…
Conservative (Non-Surgical) Management
As the name suggests, this approach does not involve any surgical intervention. It is therefore much safer for dogs with heart conditions or other illnesses that might make them unsuitable for a general anaesthetic. The key components are weight loss, physiotherapy, tight control of exercise, and painkilling medications.
This type of management works best for small dogs (under 8kg), but takes months and rarely results in a complete recovery. It is generally contraindicated in patients over 15kg, because in these larger dogs, the joint just doesn’t heal well. For dogs between 8 and 15kg, it may be attempted, but the success rate declines with increasing body weight.
Ligament Replacement Surgery
There are several different operations available (most commonly, fabellar suture procedures), but they all work in the same way. Essentially, the principle is to replace the damaged ligament with a wire or nylon graft.
The advantage is that these operations replace the damaged ligament that had degenerated with a stronger, synthetic replacement. Following surgery, there will be a fairly prolonged period of rehabilitation and physio- or hydrotherapy.
Joint Reconstruction Surgery
These are a series of different operations that rebuild the stifle joint in such a way that the cruciate ligaments are no longer required. Cutting and repositioning the bone transforms the joint into one that is inherently stable even in the absence of these structures.
The most common procedures are:
- Tibial Plateau Levelling Osteotomy (TPLO), where the top of the tibia (or shinbone) is cut off, then rotated and reattached. This involves specialised equipment, including arc saws.
- Tibial Tuberosity Advancement (TTA) techniques, such as the Modified Maquet Procedure (MMP). In these operations, the front of the tibia is cut off and moved forward, then reattached, often with an implant or wedge to hold it in place (in the MMP, a titanium foam wedge is used, for example).
The great advantage of joint reconstruction surgery (especially the TPLO) is that the dog can bear weight on the limb very rapidly – sometimes within a few hours of waking up! Although they still need exercise restriction and physio, this can start almost immediately. At Parkside we are very lucky to have Stuart Ashworth, who has a CERTIFICATE IN ORTHOPAEDICS and does TPLOs and extra capsular repairs along with some tightrope procedures.
Which operation is best?
It depends on the patient and the type of injury! Overall, all the surgical interventions have a similar success rate, but reconstruction procedures usually have a faster recovery time. That said, if the dog doesn’t have their exercise properly restricted and they over-exert themselves they can easily break their leg before the bone heals. Our vets will be able to advise you as to which is the most appropriate for your dog.
If your dog is limping or lame, make an appointment to get them seen by one of our vets as soon as possible!
Should I give my cat cow's milk?
The iconic image of a kitty with milk-stained whiskers, licking its lips with delight, has to be one of the most stereotypical animal-food relationships, among other joys such as a donkey with a carrot, a cow with a buttercup or a safe of ducks harassing the elderly for a loaf of bread. (Yes, we did have to check the term for “a group of ducks on land”…) However, is milk good for cats? Or, of even greater concern, is it bad for cats?
Why can’t some cats drink cow’s milk?
Kittens thrive off their mother’s milk. In the first few days post-birth, they drink the mother’s colostrum; this high-protein initial milk of lactation contains many “maternally-derived antibodies”, which help the young kittens’ immature immune systems. After this, the mother produces milk which is of lower protein content. At around four weeks of age, kittens typically begin the weaning process, and after that start to enjoy the delights of mice and tins of food which look better than the average student’s dinner. When a kitten stops drinking milk, it may stop producing the enzymes necessary to break down and digest milk, which is lactase, necessary to digest the lactose in cow's milk. When the cat no longer produces this, it means that milk cannot be digested, and can cause diarrhoea. The milk can remain in the gastrointestinal tract undigested; bacteria in the gut capitalise on this energy substrate, causing fermentation, gas and abdominal pain for the unsuspecting cat. The particles of undigested milk can also induce “osmotic diarrhoea”, which essentially draws water into the gastrointestinal tract which is then passed as a watery diarrhoea.
This can be a risk to a cat’s health due to potential damage to the gastrointestinal tract, a loss of fluids which can cause dehydration, and loss of appetite which can cause a negative energy balance. Of further concern is the loss of ions and electrolytes necessary to maintain your cat’s healthy cells and organs. In short, diarrhoea should be avoided where possible; one such way is in not giving them cow’s milk.
My cat has never had a problem; are all cats lactose intolerant?’
No, not all cats are lactose intolerant, however, the crude way to test whether a cat is lactose intolerant would be by giving it milk and seeing it produce diarrhoea; beyond the obvious welfare implications, this is not a pleasant task to clean, as any vet student having done their stint in a cattery will tell you!
For cats capable of digesting milk, we need to be careful about keeping them trim; one saucer of milk is a lot for a cat, and a high fat content can lead to our feline friends becoming a bit more ‘cuddly’ than may be healthy for them! This is a particular concern for less active cats, such as the elderly or house cats.
If your cat is a milk-fiend, there are alternatives. “Cat Milk” tends to have more calcium, less lactose and be high in protein and be well tolerated by cats. Whiskas, TopLife and others all do brands of special milk for cats. Replacing dairy milk for the feline-friendly formulations is not likely to be met with protest!
“Cats will amusingly tolerate humans only until someone comes up with a tin opener that can be operated with a paw”- Terry Pratchett