Dog | The Sleepless Veterinarian

There are other options to removing rodents if you have pets. I must admit, my cat does a fine job at killing the ones around our house and I’m not talking about the out of doors variety!

Rat bait, or rodenticide, poisonings are a relatively common occurrence in emergency practice.  The majority of cases present after the owner has noticed some baits moved about where their dogs may have access, or occasionally, they notice very green pooh which may indicate what pooch has been eating.  In the past weeks we have seen two clinical cases of rodenticide poisoning in our veterinary hospital, as well as the early non-clinical ones, which made me think, maybe it is time to write a blog about the dangers of rat baits.

Funnily enough, many people think if their dog eats the rat bait, they will get sick very quickly.  I’m not sure what signs they are expecting…vomiting? Diarrhoea? Seizures?  Rodenticides don’t cause any of these signs in the first day or two, and in fact not cause any abnormal signs initially apart, perhaps, from green pooh!  The vomiting, diarrhoea and seizures may develop several days later, but that depends on which organ system is first affected by the poison.

Rat baits cause a slow and probably very horrible death for rats.  They are designed so that the rat will eat the bait and go away to die in their nest, and hopefully the human in charge doesn’t have to see rotting mice bodies lying around their kitchen.  At least that is one way to put it I guess.  When dogs eat the bait (cats are a little smarter but are at risk if they eat the rat before it is killed by the bait) it will similarly take several days before the signs develop.  This can lead to a false sense of security for the pet owner who is expecting their dog to start seizuring or vomiting or show some other sign of poisoning, only to find them flat and pale several days later.

How do they work?  Well, there are a few different generations of rodenticides with the newer ones taking longer to kill and requiring a longer course of treatment.  Warfarin is the earliest type and is still used today.  It is much shorter acting than the newer poisons and only requires a week of therapy to reverse the signs.  The longer acting, newer generation rodenticides require up to 4 weeks of therapy.

Rodenticides act by causing a depletion of vitamin K1 in the liver.  In the healthy animal, vitamin K1 is utilized in the formation of clotting factors and then regenerated in the liver by another mechanism.  It is not a vitamin that is commonly obtained through food, like vitamin C for example.  The rodenticide blocks this recycling step so that there will no longer be any active vitamin K1 for inclusion in the production of clotting factors.  It takes time for all the clotting factors that have been produced to be utilized in the body but once they have passed their “use by date”, the body’s internal homeostatic mechanisms don’t function as well so normal tissue repair cannot occur and animals can bleed to death.

Often the cause of such severe internal bleeding is not obvious, however, without treatment it will not cease and death will occur.  Without fail.  Signs of rodenticide poisoning are not always clear.  In some cases blood loss is not obvious, particularly if the animal has bled into the brain cavity or the spinal cord.  Such bleeds may cause the animal to have seizures or become paralysed, respectively.  In many cases, the bleeding occurs into the abdomen or chest cavities though other sites are occasionally seen.  One of our patients bled into the bladder and was seen to pass urine that looked exactly like blood!

The treatment for rodenticide toxicity is so easy and simple to perform if implemented early, and so there is really no reason why it shouldn’t be sought early when owners are aware of their pet’s access. Treatment involves making the dog vomit if caught within hours of ingestion, possibly followed by administration of activated charcoal to mop up any toxins that may be wandering around the gastrointestinal tract.  Charcoal will not provide any benefit once the clinical signs have developed.

If the ingestion has been caught early, lots of the poison has been vomited up and there is a very strong assumption that the dose eaten may be less than that required to cause clinical poisoning, the dog may not require any treatment.  However, this is ideally a decision for your vet to make.  If the decision to NOT treat is made, it is extremely important that your dog has a blood test 48-72hrs later to determine for certain whether or not treatment is required (one very specific blood test may tell us if there is a problem developing with blood clotting).

Fortunately there is an antidote, vitamin K1 tablets (injection or liquid forms are also available).  That’s right, just a simple, twice daily vitamin tablet!  Yep, this simple vitamin will ensure that your dog, who may have eaten a whole packet of rat bait, will not bleed to death as a result.  Ok, maybe it is not as simple as that, I mean you can’t just go to the pharmacy and buy a multi-vitamin for your dog, and the wrong type of vitamin K won’t do an awful lot of good.  The medication is not cheap, however, much more cost effective and successful than treating with fresh frozen plasma and possibly blood transfusions if the dog reaches the point of severe internal haemorrhage.

It is not worth taking the risk with your pet if you think they may have, or know they have, eaten a rat bait.  Even if you make them vomit at home yourself, it is so important to have a vet check them than to just sit and wait until you see signs of poisoning.  Why gamble with your dog’s life?

Fortunately the two dogs we saw, despite coming into the hospital looking close to death, responded extremely well to therapy and within 24 hours were bright and happy with no further bleeding.  The last point I wish to make is to never assume that because the bait is placed in a position where you think your dog can’t reach it, that your dog won’t reach it.  They are ingenious at accessing the unaccessible, and more so if your rats have shifted the bait from one place to another!

Who would have thought a fun game of catch could have such a traumatic outcome?  A play in the park with a ball or a stick is usually par for the course for many large active dogs, yet even something as simple as throwing a stick can land in a trip to the emergency room.

 We had a patient in a little while ago, Jasper, an Australian Cattle dog, who simply loves a game of stick chasing with his owners.  At least that was until the night he came in to see us with the end of a stick emerging from his mouth.  Dad had been throwing quite a long narrow stick and Jasper had managed to land end-on on the stick, basically impaling the stick down his throat.  The stick had been longer, but for comfort sake, Jasper had managed to chew the long end off so he could actually close his mouth.  The question was how much more stick was in his mouth/throat, and where had it lodged?  Had it damaged any important structures?

Jasper’s owner was keen to get his boy fixed, so Jasper was anaesthetised to have some x-rays performed to assess the path of the stick prior to carefully removing it.  Sticks and wood are not easily identified on radiographs as they tend to blend in with the surrounding tissues.  So I considered injecting some contrast solution (Iohexol -> a benign sterile agent) around the stick to see if we could see where it was.  The pictures worked well and we could see importantly that it had not penetrated the chest cavity, and did not appear to have caused interference with the oesophagus or trachea.

For those unfamiliar with radiographs of the neck, this may not mean a lot. The normal structures are the vertebral column and the endotracheal tube maintaining gaseous anaesthesia can been seen as the straight lines down the airway. The hazily outlined structure between is the stick!

The stick was carefully removed and we explored the wound with endoscopy.  Unfortunately, Jasper had managed to have this accident with a stick covered in bark, and there were thousands of tiny pieces of bark along the track the stick had made.  There was no way I would be able to remove them all so we attampted to provide a drainage solution.

We see this often with stick injuries where tiny pieces of bark remain in the tissues and cause ongoing problems, developing abscesses intermittently and sometimes requiring repeated investigations.  This material will track around the body via tissue planes and can be exceedingly difficult to locate and remove.  His owner was warned of potential complications with foreign material inside his neck as is commonly seen.

Jasper and the stick we removed from his mouth & neck

So not surprisingly, Jasper had a couple of repeated occurrences of draining neck wounds which failed to respond to antibiotics.  He was eventually referred back to our hospital to see our surgeon.  By this point there was a lot of scar tissue and several pockets of pus found.  The surgeons explored these pockets and hoped to remove the source of his infection.  He recovered well and hopefully will be out of trouble now.  These wounds can be very difficult to get on top of at times though and there is still a chance that small amounts of material remain behind.

Interestingly, the Australian Veterinary Association has recently released a report encouraging a ban on throwing sticks for dogs given the number and extent of injuries seen.  A veterinarian from the RSPCA has stated that stick injuries are seen at least once a month at emergency facilities, and I expect our figures would support this.  Many are small wounds to the back of the oral cavity, however they can be far more sinister.  One recent patient seen at the hospital developed severe and critical complications secondarily to a stick injury, and succumbed to those complications despite our best efforts.

Moral of the story, if it is small enough to enter the mouth, and sharp, it is probably too small to play with…  And there is more than one way to impale a dog on a stick, as one of our other vets tells the story of a patient who managed to stop his down hill run on a large branch which went through his chest and abdomen.  He survived fortunately and amazingly!  Maybe a good solid rubber stick is the way to the future of stick play.

Charlie, the Staffordshire terrier pup, came in to see me one wet and wild Monday night with a very sore leg.  At 18 weeks of age, he was (I should say, is) full of energy and very bouncy, and not immune to accidents so it seems!  He had already had some dental problems from chewing on rocks, but this night he had been a little too excited to see his owner’s when they came home.  Jumping several feet into the air he had landed awkwardly on his right hind leg, tripping over a bar stool, and was suddenly very sore and lame.

Charlie getting some cuddles

My suspicion on examining Charlie was that he had injured his tibial crest.  The tibia is the main long bone in the leg below the knee.  The tibial crest is the top and front part of the bone.  In young animals, it is not well adhered to the bone as it is part of the growing apparatus.  Young bones have “growth plates” where new cells are constantly forming to help baby bones grow.  These areas are soft and prone to injury.  Damage to the growth plates can interfere with normal growth of the limb and potentially lead  to deformities if not repaired in a timely manner.

Charlie was sedated and x-rays were taken of both his back legs to compare the knee joints.  The changes were subtle but there were some slight changes that suggested he may have a tibial crest avulsion.  When traumatised, the ligament of the patella (the knee cap), which is attached to the tibial crest, can pull on the soft tissue attachments and separate if off the tibia where it normally sits.  Many puppies who suffer this injury can have significantly displaced tibial crests, Charlie was fortunate that his was only marginally injured.

The tibial crest is the “parrot beak” shaped fragment of bone in front of the long bone (the tibia). While it looks like a fracture, this is a relatively normal appearance with very slight displacement of the “beak” and a tiny possible fragment of bone in the space below. In many cases of avulsion the “beak” is wide open (squawking!) and the joint quite unstable.

When an avulsion occurs, the joint is very painful and may become quite swollen.  Charlie was holding the limb up to take weight off of it and relieve the discomfort.  He was very bright and happy otherwise.  He was given some pain relief for overnight and was scheduled to see a specialist the following morning.

The recommended treatment for a tibial crest avulsion, and other growth plate injuries, is generally surgery.  Surgery will often be performed in these cases to fix the crest back onto the tibia and help to stabilise the joint in growing dogs, so as to reduce the incidence of long term problems with the limb.  In very mild cases, rest and anti-inflammatories may be all that is required and each case needs to be judged on an individual basis.

Charlie saw the surgeon the following morning.  He was becoming more comfortable on the limb and the surgeon assessed his injury as being mild with a stable and comfortable tibial crest and knee joint.  Conservative treatment (rest and pain killers) was elected to see how he progressed over the first few days, so a plan for a re-examination was made and Charlie was sent home.  Interestingly, though this injury can occur in any breed, I tend to see it mostly in Staffy pups – running into retaining walls, jumping off beds, you name it!  Charlie was a great little puppy to have in hospital and hopefully his streak of bad luck has ended…if he can control the mischief!

One of the more common emergency conditions we deal with is seizures.  Seizures can occur for a number of reasons and at any age, from the young puppy or kitten to the elderly patient.  The reasons for seizures can be as diverse as the patients.  It can be a very traumatic event for both you and your pet when it first occurs, so being informed can help you to provide the best care for your mate and hopefully be a little less distressed if a seizure occurs.

I recently saw a young dog who had seizured so much that he was not able to respond to us.  He had been fine the previous day but found seizuring in the morning.  There was no known access to toxins and other tests did not reveal any specific causes, but unfortunately, his owner decided not to continue with his care before more investigation could be performed.

All seizures are essentially caused by abnormal signals in the brain, however, the origin of seizure disorders will be classified as intracranial (within the brain or central nervous system) or extracranial (outside of the brain).  Intracranial diseases include such disorders as brain tumours, meningitis or other inflammatory conditions and commonly, canine epilepsy.  Seizures can develop as a result of scarring of brain tissue from earlier head trauma, or migration of parasites into the brain tissues.  Infections of the central nervous system from bacteria, fungal infections and viruses can also result in seizures.

Extracranial causes of seizures can be just as diverse, often resulting from organ dysfunction, commonly of the liver.  The liver metabolises and clears all the nasty toxins from the body.  If it is not working properly, it is unable to do this job successfully resulting in a build up of toxins that can overload the brain and result in seizures.

A common cause of seizures, particularly in the very young patients, is low blood glucose levels.  Glucose levels drop quickly in puppies and kittens who are either unwell or not eating for various reasons.  Brain cells are unable to function properly in a low glucose environment, leading to abnormalities in nerve conduction.  Adult patients who have blood-borne bacterial infections or who receive an insulin overdose may also seizure due to low blood glucose levels.  There is a also a type of cancer in the pancreas, called an insulinoma, in which insulin is produced excessively, often resulting in severe drops in blood glucose levels.

Low blood calcium levels also commonly cause seizures as calcium is also very important for nerve conduction in the brain.  Eclampsia or “milk fever” is a common name for the condition where lactating bitches begin to tremor and seizure in the days or weeks after giving birth, especially to large litters.  This is due to loss of calcium in milk when their diet is lacking in nutritional balance.

Toxins can also be a cause of extra cranial seizures and there are many that should be considered before a diagnosis can be made.  Some of the more common toxins include lead, antifreeze, snail baits, organophosphates, strychnine, certain types of garbage ingestion, recreational drugs and toads.  Occasionally foul play can be involved, but in general, accidental access in the pet’s yard is the main cause.

Some seizures will be termed “partial” or focal seizures, where the seizure appears to be localized to a part of the animal’s body, such as a facial twitch.  Some random behaviours, including “fly-catching”, can be types of seizures.  These classifications are due to more localized intracranial causes but can still be forms of epilepsy.

These are just a few of the potential causes of seizures.  The most common diagnosis for seizures in our dogs (less so for cats) is epilepsy.  However, the underlying message is that if your pet has a seizure, epilepsy is not necessarily the cause, and many other conditions need to be ruled out before epilepsy can be assumed.  Even then, there is no diagnostic test that confirms epilepsy.

So, what does a seizure look like? Syncopal (pronounced “Sin-cop-all”) episodes may be confused for seizures.  A syncopal episode occurs as a result of heart disease.  The animal will generally collapse without significant tremoring or other stressed muscular actions.  However, I did recently see a cat who was having syncopal episodes due to a heart problem and kind of looked like she was seizuring.  Her actions included stretching and curling, she was unresponsive to us, but when she came to, she appeared normal.  Most animals will remain mentally inappropriate after their seizure for a short period, known as the “post-ictal” period.

A seizure can be a very violent action. It often involves a loss of awareness, possibly followed by twitching, drooling, sometimes jaw champing before falling and either showing rigid limbs or violent paddling.  Some will stretch open their jaw as though howling.  Loss of bowel and bladder control is common.  After what seems like an eternity the animal may relax, though it will be a little longer before they come to and then they may not be mentally appropriate.  The post-ictal period may see some animals become very excitable and some will pace or vocalise.

During a seizure, the best thing you can do as an owner is not to panic and make sure your pet is in a safe position, unable to hurt themselves by falling objects or falling from heights.  It is extremely rare for an animal to swallow their tongue and placing your hand in their mouth is more likely to get you bitten and injured than serving any benefit to your pet.  Most seizures will only last around 30-60 seconds, though seem like an eternity.  In some cases, the animal continues to seizure (what we term “status epilepticus”).  This scenario is a true emergency and you need to contact your vet immediately!  Continued seizures lead to overheating and potentially fatal injury to the blood and internal organs.

The diagnostic process for seizures can be lengthy and “unrewarding”.  I say this because of the perceived lack of value of performing tests which do not reveal any diagnosis.  In the opinion of the veterinarian though, a negative diagnostic test can be just as informative for what you are not finding, hence, ruling out potential conditions.  I have met many owners who felt that their vet has wasted their money on blood tests or x-rays that have come back normal.  But if those tests were not performed and an obvious cause was there….

A thorough history is the first important step in any diagnostic work up.  Further diagnosis may require a thorough blood work up, looking at organ functions and blood cells, examination of the urine, blood titres for certain microorganisms, spinal fluid analysis, and brain imaging with CT scans and/or MRIs where available.  Where finances are limiting, sometimes a treatment trial with anti-epileptic medication will be performed depending on what the vet thinks the underlying cause may be.  There is little point, for example, in trialling anti-seizure medications if the cause is a liver shunt or snail bait intoxication.  When commencing anti-epileptic medication, most animals will be lethargic and a little sedated for the first week or two as they learn to adapt to the medication.

This is a selection of medications your pet may be treated with to help control epileptic type seizures

Animals can live well with epilepsy for a reasonable length of time if their seizures are adequately controlled on medications.  If not, additional medications may be required, or further diagnostics where they were not performed initially.  Seizures can be quite harrowing for owners and their pets, so it is important to get to the bottom of the condition early and gain appropriate supportive care.

After discussing onion toxicity and while on the topic of barbecues, I thought I would discuss another problem that we sometimes see with BBQs.  Our dogs love the leftovers and nothing better than chewing the meat and fat off a cooked chop bone or the big eye bone from a large steak.  Yum!

But what happens when the bone is the wrong shape or is accidentally swallowed?  While my recent bone complication was not due to a tiny chop bone, it highlights how much care we need to take when selecting appropriate bones for our dogs to chew on.

Oscar’s Mum didn’t think anything of giving him a big chunky bone to chew on, which normally would probably not cause any problems.  However, this time he managed too get it caught over his lower canine teeth and became quite distressed as he struggled to remove it.  He was promptly brought in to see us and with a little sedation on board, I was able to manipulate the bone and gently remove it off off his lower jaw.  He recovered well without any serious injuries to his jaw, and went home a little groggier but I am sure much happier!

Oscar with a marrow bone stuck on his lower jaw

In some cases, dogs can get the whole ring wedged over the lower jaw, requiring some heavy duty bone cutters to remove the offending item.

Other issues we see with bones can be a little more life threatening.  When a whole bone is swallowed, it may get caught in the oesophagus, unable to pass through to the stomach.  Once wedged, there is a risk that the pressure of the bone will block the blood flow to the local area of oesophagus, damaging the tissue and causing it to perforate.  An injured oesophagus can be prone to other complications such as stricture where scarring causes a narrowing of the pipe.  More seriously though if the oesophagus does perforate, a nasty and life threatening infection of the chest cavity may develop requiring intensive hospital management with a guarded outcome.

If the bone makes it to the stomach, a cooked bone is unlikely to be digested as the cooking process changes the structure of bone making it less prone to the action of stomach acids.  The bone may then cause a blockage of the stomach outflow into the intestine, or travel down the intestinal tract until it can pass no further, causing an intestinal obstruction.  Again, pressure and loss of blood flow damage the intestinal wall and can perforate the bowel, leading to a septic abdomen.  The resulting complications of intestinal obstruction may be very difficult to treat successfully.

Treating animals with obstructions can be very successful if caught early.  In the oesophagus, removal of the bone may be achieved via endoscopy under anaesthetic.  If there has been no significant damage to the oesophagus, the patient often recovers uneventfully though may go home with some medications to help prevent further acid damage to already irritated tissue.  If the bone can not be safely withdrawn from the oesophagus, sometimes it can be pushed through into the stomach from where it can be retrieved through surgery.  Surgery in the abdomen is a lot less complicated then surgery in the chest (to retrieve the bone from the oesophagus), and recovery tends to be less painful.

If the bone is in the small intestine, it may be removed via surgery and may require only an incision into the intestine.  If the bone has been present for some time and there is evidence of damage to the blood flow, a section of the intestine may need to be removed with the bone.  Then healthy intestine can be attached to healthy intestine for a more optimal recovery.

Where your dog has had a good chew of the bone before devouring bone pieces, even if the bone can pass through, it may congeal into hard faecal balls in the colon.  This can happen with too much raw bone as well.  The result may be a painful constipation which then may require an anaesthetic for an enema to help break down and remove the bony chunks.

So is it worth giving our dogs bones then?  Bones can be very beneficial for canine dental management, but think of the dog in the wild.  They don’t eat cooked bones and they often spend more time gnawing on larger meatier bones.  Our domestic friends have lost the ability to be selective in their choice of bones, so it is up to us to be careful about what we offer them and to keep an eye on them while they eat.  If your dog is suspected to have swallowed a whole bone or a large section of bone, it is important to seek veterinary attention urgently, especially if your pet is distressed.  Bones can be bad news!

Now that Christmas is over, back to blogging!

I know I seem to be focusing a lot on poisonings in these pages, but there are so many that come our way. Some poisonings are quite unusual and unexpected and without a little guidance, many pet owners may be putting their pets at risk without realizing it. I mean who would have thought the average Australian backyard BBQ could be a dangerous place for the family dog and cat!

Not only can those fatty off cuts and cooked bones cause trouble for your dog (or the overindulgent cat), but the humble bit of barbecued onion could cause some serious disease in your best friends. Fried up on the barbie with all the fats and flavourings, it is not surprising that a dog might find onions a tasty treat. And while cats generally do not tend to eat the extraordinary, I recently saw a cat who found his mother’s chili con carne quite appetizing and had eaten a good chunk of onion mixed in with the rich chili flavouring.

Onions and their associated family, which includes garlic, are actually quite a toxic plant, not only to dogs and cats, but to humans as well. At least they would be if we ate enough of them but our red blood cells are fairly tough in comparison to those of our pets. Cats have the most fragile red blood cells of any animal and regularly burst them in response to illness and disease, so they very sensitive to the toxic effects of onions and garlic.

The toxic principal in onions and garlic is an alkaloid disulphide that acts on the red blood cells and interferes with their normal metabolism causing Heinz bodies to form (nothing to do with baked beans!). Red blood cells don’t cope well with Heinz body formation and will swell and burst, causing the animal to become anaemic. The following website has a great description for anyone who is scientifically minded: http://cal.vet.upenn.edu/projects/ poison/plants/pponion.htm. Garlic tends to be more potent than onion and the powdered form of both is even more potent than the fresh product. Powdered onion is often found in baby foods, and cats may be poisoned from eating your little one’s left overs.

How much is too much? This will vary from animal to animal as with any intoxication. Everyone has heard stories of friend’s animals, or even their own, who regularly eat cooked onions with no trouble, or who get garlic supplements as a preventative for fleas (not a treatment I would swear by!). The toxic dose recorded in the literature also varies but tends to be in the range of 5g/kg for dogs and less for cats (the average large onion weighs about 200g). Clinical signs will not become evident until sufficient red blood cells have been damaged. Cats may become sick after eating as little as a teaspoon of onion.

Signs that suggest your pet has eaten too much of the left over onion can take between 6-24 hours after exposure to develop and this generally depends on how much of a toxic dose they have eaten. Animals can generally deal with a low grade anaemia but once the red blood cell concentration drops to a critical point, the animal may start to pant more and tire more easily. They will be weak and have rapid pulses, pale gums and may start passing dark urine as a result of the breakdown pigments in red blood cells. The signs develop because the animal can no longer carry enough oxygen to the vital organs for normal functioning so the heart and lungs start working harder and energy levels drop.

What to do? Well, if your cat has eaten any onion or your dog has eaten a questionable amount, the first thing to do is to empty their stomach and clear out their system. Taking them straight to see your veterinarian or an emergency practice is the safest approach, especially with cats, who may require special drugs to make them vomit. Once the stomach is emptied, a good dose of activated charcoal will help to bind any onion toxins left behind in the gut. Other supportive measures may include intravenous fluids and monitoring in hospital depending on various findings that concern your vet. One important tool is to monitor the animals red blood cell volume (PCV – packed cell volume). If this is noted to drop over the following 24 hours, your pet may need a blood transfusion depending on how low it gets and how your pet copes with the drop.  Close monitoring will be required for the next few days while the body begins to rebuild its red blood cell stores.

It is important to really consider what we are giving our pets when feeding them from our table. And it is not just what we give them, but what they can access. I have recently seen a couple of dogs for onion ingestion after an owner came home to find one (or both) had jumped on the kitchen bench and nearly devoured a whole raw onion! Does not sound very tempting, but discretion is not a strong point for some animals!

Brunfelsia pauciflora in full bloom. Botanical gardens, Brisbane

Nature can be deadly, and colour in nature is often tied to how deadly or poisonous something is.  Of course that is not always the way.  Funnel web spiders, for example – not so colourful really but incredibly deadly!  So how do we tell which colours are safe and which are poisonous?  Colour may just surprise you, and what looks to be pleasant and pretty can be very deadly for our pets, who are often quite indiscriminate about what they put in their mouths.  Like small children.

There is a very pretty, fragrant shrub, or small tree, growing in many yards across Australia, particularly in northern NSW and Queensland, known as Brunfelsia pauciflora (or Yesterday, today, tomorrow).  The plant is so called because of the way the flowers change colour over a couple of days after blooming.  Brunfelsia species are native to South and Central America and the West Indies.  It is commonly seen in gardens in the southern states of the US also, where it flourishes in the warm weather.

The most common variety has purple or blue flowers which change to white, though there are variations with pink, yellow and red flowers.  All parts of this plant can be poisonous to dogs but it is often the seed pods falling off the tree that are particularly attractive and often eaten.

It is proposed that there are three different types of toxins in the Brunfelsia plant which cause the clinical signs seen.  These include:
– Brunfelsamidine which excites the nervous system and can cause seizures and death.
– Hopeanine, a nerve depressant that may contribute to paralysis or weakness, and
– Scopoletin or gelseminic acid (I guess they haven’t decided which), proposed to relax the arteries and drop the blood pressure and heart rate.

Sounds pretty sinister, and it certainly can be.  One of the problems with the toxicity is that it may take 15-18 hours for the signs to be revealed.  Pet owners may not realise that the signs are representative of behaviour performed that many hours prior.  So it can be tricky for us to work out that Brunfelsia is implicated in some of our patients.

The signs we see in dogs that have chewed on the plant generally include gastrointestinal and central nervous systems signs, such as depression, vomiting, diarrhoea, muscle tremors and seizures.  Some will drool profusely and may look like cane toad intoxications.  Occasionally sneezing will be the first sign seen, which I thought was odd but I recently saw two cases from the same household (same night) who were both reported to have been sneezing before other signs developed.  Apparently oro-nasal irritation can occur when the plant is eaten.

The signs then are not that different to a variety of other types of poisoning so it can be difficult to diagnose until certain revelations are made.  The main one is the detection of plant material in the gastrointestinal tract (either in vomitus or faeces).  More specifically, when a rectal examination is performed, finding large amounts of seed pods in the faeces is a sure way to gain a diagnosis.  The seed pods are often chewed and fragmented but very typical in appearance.

Poisoning with Brunfelsia can be mistaken for other types of toxicities such as strychnine and snail bait intoxications, or exposure to certain types of illicit drugs.  While it can look like toad intoxication initially, the dogs lack the red gums and ropey saliva that toad exposure tends to cause and diarrhoea is uncommon in toad toxicities.  Common culprits for exposure are young dogs who do seem to be a little less discriminating of what they chew on than older dogs.

There is no specific antidote and like many poisons, treatment consists of a few very straight forward steps.  Though I do need to add that recovery of your pet who has eaten the plant may not be very straight forward.  The steps to treat most toxicities, especially where the cause is unknown, includes the ABC’s -> ensuring airway is clear and open, the breathing is adequate to maintain normal oxygenation and the circulatory system is functioning appropriately (heart is pumping normally and blood pressure is good).

Supportive care is essential to ensure the ABC’s remain adequate, so intravenous fluids will be provided and possibly flow-by, nasal or in-cage oxygen if there is an indication for it.  Seizures will need to be controlled if they are occurring and if the patient is overheating from tremoring, cooling and medications to control the tremors may be required.  If seizures are difficult to control, general anaesthesia may need to be performed to completely relax the body and central nervous system.

One of the most important steps for any toxicity though, and not least for Brunfelsia toxicity is decontamination.  Decontamination is necessary to help eliminate the toxin from the body as quickly as possible and help control or halt any further progression of the intoxication.  Decontamination in a dog that is conscious and mentally appropriate may include the induction of vomiting to help remove sources in the stomach.  Making a dopey dog vomit can be dangerous because they may not be able to protect their airway and aspiration of vomitus could cause pneumonia to develop.

If the dog is quite dopey or seizuring, general anaesthesia is best performed, so that the stomach can be lavaged (essentially “pumping the stomach”).  An endotracheal tube will be placed to protect the airway from water being flushed the wrong way.  Plant fragments can then be “cleaned” out of the stomach and help reduce further absorption of the toxins.  While asleep, the other end can be flushed out as well to remove any material that has already made its way to the dog’s rectum.  Enemas can also be performed on conscious dogs where plant material is present.

Once the top and bottom ends have been cleared out, activated charcoal can be given to the patient.  This acts by binding any toxins still in the gastrointestinal tract, where flushing and lavage have not reached.  Caution needs to be used though because once again, if charcoal ends up in the lungs….  So we generally wait until the patient is conscious and able to eat the foul stuff on their own.  It is amazing how many young dogs will eat a bowl full of charcoal and dog food!

Recovery time really depends on how sick the dog was when they arrived at the clinic.  I have seen mildly affected dogs go home the next morning, while those who present seizuring may require a couple of days on intravenous fluids and anti-seizure medication until the toxin clears from their system.

The other issue that may cause a problem to the pet owner is removing the source of the poison.  Yes, that means removing the ENTIRE plant!  As all parts of the plant are toxic, every last bit needs to be removed.  One of my colleagues saw a patient who was ill after chewing on the roots left behind after shrub removal.

The best advice to anyone with pets – Don’t plant a “Yesterday, Today, Tomorrow” plant in your garden!  Part of responsible pet ownership is keeping them safe in your yard as well as outside of the yard.  Pretty plant versus loved family member?  The choice is simple.

One of the things I enjoy about emergency work is dealing with the more challenging cases that do not always have a straightforward answer.  The process of medicine sometimes requires a detailed diagnostic plan to define the problem and decide on the best treatment course.  Sometimes the answer is obvious and no or minimal investigation is required.

Charlie was one of those cases that needed just a little more work up than usual and had an interesting outcome.  He presented to me one night after being a bit off colour for a couple of days.  His appetite had dropped in the previous 2 days and on this particular day he was not interested in any food.  He’d had a couple of small vomits in the morning but did not bring up anything remarkable.  Charlie and his sister had apparently been destroying some bedding at home, but at the age of 6 years old, he was not known to eat the things he should not be eating.

Charlie after the event, a little sadder but I am sure relieved!

When I examined him, his belly was tense and a little tender toward to front of his abdomen, around the stomach area.  Nothing obvious stood out and I certainly did not appreciate any swelling of the stomach.  He appeared dehydrated so he was admitted into the hospital for treatment with intravenous fluids while further investigation was performed.

As I mentioned in the post on Simba, sometimes deciding on the most appropriate diagnostic test is not clear, and several may need to be performed to obtain an answer.  I ran a blood panel on him initially to determine if he had any inflammation of his liver or pancreas.  Blood tests are often very useful, sometimes for what they don’t reveal.  His organ function was normal, but the electrolyte component of his blood showed all the main ones to be very low (Sodium, Chloride and Potassium).  A low potassium and chloride level can suggest an obstruction around the stomach or top of the small intestine, but the low sodium level did not really fit the picture.

We decided the next step should be an abdominal ultrasound.  Now here we could have opted for an x-ray first, however, from the history obtained we figured if he had an obstruction, it was likely to be some sort of material.  Material does not show up so well on x-rays, so we felt that an ultrasound was more likely to tell us if there was an obstruction, where it was and what the best plan would be for removal.  The abdominal ultrasound was helpful but still left us with some questions.  Everything in the abdomen looked normal aside from the stomach which was distended with an unusual layering of material that moved back and forth with the stomach rather than separately to it.  So it was not certain that this was a foreign body, though highly likely.  And if so, what was it?

A single x-ray was taken and proved to us that surgery was indeed necessary to remove the obstruction in Charlie’s stomach:

The x-ray of Charlie’s stomach was a lot more dramatic than expected. For those not familiar with x-rays, the large odd-patterned mass in the centre of the view is the swollen stomach!

After speaking to Charlie’s family, permission was obtained to proceed with surgery.  Once under anaesthetic, it became quite obvious that Charlie had a distended stomach, and I was surprised that I could not palpate this earlier.  He was just too uncomfortable.  Surgery was performed and Charlie’s stomach was carefully emptied.  The photo below will help you understand why it took a while to empty Charlie’s stomach!  An attempt at reconstruction suggested that the contents of Charlie’s tiny stomach (keeping in mind he is about a 10kg dog) was two whole man-sized, leather gardening gloves!  They must have been tasty!  His stomach was closed and the rest of his intestinal tract was examined to ensure there were no other pockets of obstruction.

Not sure how he fit all of this in his belly!

Charlie recovered really well from surgery that night and I heard that he was brighter and eating the next morning and so went home to his family the following night.  I spoke to one of his owners a week later and was pleased to learn that he was doing well and back to his normal bouncy and boisterous self, news we always like to hear.  He was so bright that his Dad was having trouble keeping him settled so as to recover fully from his surgery!

The time is arriving when emergency practice, for us in eastern Australia at least, becomes dominated with the care of poor animals suffering from the effects of the toxin from the Australian paralysis tick, Ixodes holocyclus.

Tick paralysis caused by I. holocyclus is unique to Australia.  Different tick species exist all over the world and are well known to transmit diseases but only a few cause paralysis.  Two species in the USA (Dermacentor variabilis and andersoni) cause a paralysis that animals can apparently recover from without treatment once the tick has been removed.  These are vastly different to our ticks and pet owners seeking the wrong information on the internet can come away very poorly informed.  Australia is well known to have the nastiest of the nasties, and our ticks fall into that category as well.  Once paralysis develops from the I. holocyclus toxin, recovery is rare without the lifesaving anti-serum despite removal of the tick or ticks that caused the clinical signs.

The Australian paralysis tick is distributed along the eastern seaboard of Australia, mainly found in coastal and bushland areas.  Normal hosts for ticks are the wildlife who have lived in symbiosis with these creatures for longer than white man has existed in this country.  They are often resistant to the effects of the toxin due to daily exposure and innate immunity. Dogs, cats and other domestic introduced species are not normal hosts for ticks, hence they are more susceptible to the toxic effects of their venom.

Two ticks of the species ixodes holocyclus, picked off koalas in the Koala Hospital in Port Macquarie, New South Wales, Australia. The small tick had not yet started feeding, while the other had probably been at work for a couple of days.  (Photo credit: Wikipedia)

Ticks will often be attached for several days before their toxin causes clinical signs.  They feed in spurts rather than constantly and will inject venom during these feeding spurts, which increase in frequency after a couple of days.  Once the frequency of feeding steps up, ticks will inject more venom, which also helps to numb the feeding site.  When they have filled their bellies to feed their young, they will fall off and leave a dying host.

The toxin is not well defined and due to ethical reasons, good studies into the effects of  tick toxins on animals have been difficult to perform.  The tick toxin obviously is part neurotoxin, since the predominant effects are neurological.  It is also thought to have a cardiotoxin, exerting effects on the heart which may explain the unfortunate cases of sudden death in animals that appear to have recovered from the neurotoxin effects.

Removing a tick as soon as it is found is essential, ideally without squeezing the body, though I am not convinced that a rough removal causes more problems for the pet.  I do not think there is any evidence that salivary flow increases during tick removal.  Acute allergic reactions have occurred in humans upon removal of ticks, but I have never seen or heard this reported in other species.

Paralysis ticks do NOT have a head, which is a common misconception, so it is impossible to leave the “head” behind.  They have mouth parts which penetrate the skin and may be left behind when the tick is removed, but these no longer inject venom without the body that provides life, and a venom sack!  At worst, they may cause a local reaction as a splinter may do.  Tick removal may be painful and very difficult in some pets, especially when positioned around the face.

I hear lots of owners complaining about how diligent they are at applying the preventatives so how can their pet still develop paralysis?  There is no tick preventative that is 100% effective.  A combination of products may help but is still no guarantee.  Daily searching for ticks is very helpful, but they can find tricky hiding places.  Often they show up in places that have been previously checked and not found, however it would be unlikely that a fully engorged tick had only been present for 24 hours or less.  Sometimes they are found under fresh tick collars!  Clipping of long haired animals prior to the onset of Spring is a good idea to help tick searching and we always recommend clipping the coat on any animal coming into the hospital for treatment of tick envenomation.

Resistance to tick toxin can develop in animals that are exposed to ticks everyday, as our wildlife are.  There are certainly dogs and cats I hear of who have ticks removed on nearly a daily basis and never suffer the ill effects of the toxin.  The only way to guarantee that your pet will never get tick paralysis if you live in a tick prone area, is to lock them indoors 24 hours a day, although even then humans may carry them indoors allowing them exposure to indoor pets.  It seems the only way to avoid tick paralysis in your pets is to avoid living in a tick prone area – way out west or Western Australia are good locations for this!

This is such a huge topic with so much important information that I feel pet owners need to know, so I am going to continue the discussion in my next post.  Then I will delve into the clinical signs and treatment.  In the meantime, start checking your pets daily for ticks.

There has been a recent spate of dogs being diagnosed with hemorrhagic gastroenteritis at our practice. While bloody diarrhoea may be a sign of parvovirus, a highly contagious and potentially fatal disease, this is not always the case.   Haemorrhagic Gastroenteritis (HGE) is a distinct clinical condition which generally has a far better outcome than parvovirus, especially when treated appropriately. But there are many causes of bloody diarrhoea and all must be investigated to ensure your pet gets appropriate care in a timely manner

HGE is a disease that tends to occur unexpectedly in healthy dogs. The cause is often unknown, though stress may play a role as may dietary allergens and bacterial toxins. Signs may be vague initially and your dog may be off its food, lethargic, potentially nauseous and/or vomiting, and may be passing bloody diarrhoea. Sometimes they are sick enough to warrant veterinary attention before the diarrhoea has shown itself.

Examination of your pet may alert the vet to the possibility of HGE. Your dog’s gums may be dry, the heart rate may be elevated and there may be blood on the thermometer. Lot’s of “may”s I know, but the main diagnostic indicator is found through a simple blood test. Your vet will take a small amount of blood to assess the dog’s PCV (packed cell volume) and TP (total protein or total solids). The PCV is the percentage of red blood cells in the peripheral blood as compared to total blood volume. It is measured by spinning blood in a centrifuge. The TP is measured with an instrument called a refractometer, which assesses the protein content of the serum separated from the red blood cells when the blood is spun.

The haematocrit tube can be seen with the red blood cells separated at the bottom, the top component consisting of the serum the red cells are carried in.

How is this diagnostic for haemorrhagic gastroenteritis I hear you ask? The majority of dogs with HGE will have a very high PCV, often >60%, with a low or low normal protein level. This may be surprising given that when owners see the diarrhoea, a first concern may be the potential for the dog to become anaemic. HGE dogs rarely become anaemic, even with aggressive intravenous fluid therapy. The reason for the high PCV in the face of bloody diarrhoea is that there is a comparatively small number of red blood cells being lost in the diarrhoea compared to the amount of fluid that is exuded. The extent of dehydration may not be obvious on examination because the fluid loss is rapid. I could insert a whole lecture in here on fluid dynamics but this would be a big distraction from the topic at hand. Maybe this could be reserved for a future post if anyone is interested!

Diarrhoea occurs because the intestine becomes leaky. The leaks are thought to occur due to a type of allergic reaction affecting the intestinal lining. You may have seen your dog’s face swell as a result of a bee sting? Well this same type of swelling would be occurring if the intestine was a closed organ. Being a tube, the fluid pours into the centre (the lumen) and is high in water and small molecules like protein. Hence the low TP. The red blood cells may be too large to pass through the leaks, but enough are lost to give the diarrhoea its classic appearance.

Sometimes the PCV is not that high, especially in the early stages. Other tests may be performed to rule out other potential causes of bloody diarrhoea. These may include a parvovirus test, especially if vaccination history is questionable, a faecal smear or float to rule out intestinal parasitism, and other blood tests to assess for certain diseases and blood clotting disorders.

In the majority of cases, treatment is straightforward and the outcome is generally good. Without treatment, death may occur if dehydration is rapidly progressing, which it can. Bloody diarrhoea is not something that should be left unseen – a “wait and see” approach is definitely not recommended. Treatment involves administering large volumes of a balanced electrolyte solution intravenously to restore tissue hydration and vascular volume. Intravenous antibiotics are often administered to help prevent infections caused by the presence of bacteria in the compromised bowel. Pain relief may be provided if your dog has abdominal pain and possibly drugs for gut protection and nausea if present.

The course of disease is fairly short lived in the milder cases, and many dogs are home within 24-48hrs of commencing intravenous fluids. Discharge will occur when the vets are happy that fluid loss is easing and the dog is eating and drinking happily. More complicated cases may require several days in hospital. They may need additional fluids such as plasma or artificial colloids, which are a manufactured fluid that aims to replace lost protein temporarily until the body can make more of its own. Other times, there may be a secondary (or sometimes another primary) disease process which also needs to be addressed.

So while HGE is often simple and straightforward to treat, complications can occur. Unfortunately, there is not a lot that you can do at home for your dog once the disease takes hold. We can never force our dogs to drink enough water to replace the intestinal losses that occur, and it is not worth risking more serious disease issues by holding off to see if they will get better on their own.