Sunday, February 15, 2009
A pyometra is an infection which affects the uterus causing the build up of pus. It is normally a progression of a condition called cystic endometrial hyperplasia.
I have actually seen quite a few cases of pyometra in some of the practices I've worked, since owners were reluctant to spay their pets.
Basically, cystic endometrial hyperplasia (fluid filled and swollen uterus) is common in older entire females. Progesterone (hormone) normally from the ovaries causes the uterus (womb) wall to thicken and the lumen (cavity of the uterus) to retain/fill with fluid (secretions). Therefore, in older bitches, they often have fluid in their uterus.
This makes the uterus a breeding ground for bacteria which can invade. If this happens, the womb fills up with pus making the dog ill (pyometra). Sometimes the cervix is open allowing the pus/discharge to drain from the vagina (open pyometra).If the cervix is closed and the pus can't drain,this is quite serious and can make the pet very ill (closed pyometra).
Normally, pyometras are diagnosed by ultrasonography, examination, bloods and clinical presentation. I normally treat them by dealing with the bacteria/toxins in the body first and then removing the source. I firstly stabilise the patients by putting them on a drip (intravenous fluids) and giving antibiotics. Once stable, I usually spay the animal and then send home when eating ok.
I have occasionally treated some pyometras just medically with varying degrees of success (normally very old patients, other disease present or owner wants to breed from). This involves giving an injectable prostaglandin drug for about 4-5 days to stimulate the uterus to contract and expel the pus via the vagina. You can only use this method with open pyometras and there is a risk of causing the wall of the uterus to rupture (burst uterus releasing pus into abdomen - very serious). Also prostaglandins generally make animals feel ill - vomit, inappetant, fever etc.
To be honest, in most cases, it is better to spay the animal than use medical therapy because the animal will still have cystic endometrial hyperplasia (fluid filled uterus) despite treating the pyometra meaning a recurrence of the pyometra is very likely.
The statistics show that 1 in every 4 entire female dogs develop pyometra by the age of 10 years.
Friday, February 13, 2009
Hydromyelia (HM) is a condition where there is a widening of the central canal (channel) of the spinal cord. Fluid can accumulate in this region, causing increased pressure on the spinal cord (known as syringohydromyelia).
Syringomyelia (SM) is a condition that involves fluid collecting in the area of the spinal cord that is outside the central canal. The result of hydromyelia and syringomyelia is essentially the same: an abnormal cyst or cavity (collection of fluid) in the spinal cord that is associated with a wide range of neurological disorders and destruction of the cord. To simplify, the term syringomyelia is used to refer to a fluid-filled cyst in the spinal cord that is inside or outside of the central canal.
The disease affects both Cavalier King Charles Spaniels (CKCS), in the cervical (top part) spinal cord and the brainstem, as well as, Weimeraners, in the lumbar spinal cord (back part towards the tail). Causes include genetic (as in the case of the above breeds), trauma, infection and tumours. In the case of the CKCS, sometimes the skull is too small to accommodate the brain and so the end portion of the brain squeezes out of the hole at the back of the skull (the foramen magnum) blocking the flow of spinal (CSF) fluid down the canal. This abnormal flow of fluid lead to the formation of a cyst.
Common symptoms as the dogs grow and the condition develops include pain (can be very severe) and scratching of the shoulder and neck. As it gets worse and the spinal cord deteriorates, it can cause weakness of the limbs and paralysis. In Weimeraners, it tends to affect only the back legs and cause hopping (like a rabbit).
Diagnosis is normally confirmed by an MRI. If not genetic (e.g. a tumour), the underlying cause should be treated. Otherwise, drugs used include steroids and anticonvulsants (to stop seizures if very serious). One anticonvulsant sometimes used is gabapentin, which controls fits, helps with nerve pain and acts as a pain killer.
Sometimes other drugs used include: diuretics (e.g. frusemide), carbonic anhydrase inhibitors (e.g. acetazolamide) or proton pump inhibitors (e.g. omeprazole), to decrease the fluid build up in the brain (if showing brain signs e.g. fitting) and painkillers (like tramadol).
Surgery to promote drainage may be performed although complicated and expensive. The aim of surgery is to allow the spinal fluid to flow. This will reduce pain and deterioration. Recovery rates are better when the surgery is performed before the condition has developed to an advanced stage.
One alternative treatment option is periodic acupuncture. There are some reports that this can help to make the animals more comfortable.
If surgery is not an option and all else fails, sometimes euthanasia may be the kindest option to minimise the suffering.
Thursday, February 12, 2009
This is a controversial topic amongst vets. There are so many conflicting opinions and vested interests involved. One of the biggest problems is that we live in a commercial world, where profit and greed, dictate a lot of the advice given to both ourselves and our pets.
The industry of giving vaccinations to our pets is a multi-million pound business. If the sole argument is to make money, then the pharmaceutical companies and veterinary clinics should be giving as many vaccines and as frequently as possible.
The pharmaceutical companies have a lot to answer for - a lot of new drug trials and university lectures/studies are sponsored by drug companies. They regularly wine and dine vets and doctors, in addition to giving free gifts to promote selling their products (which pretty much tantamounts to a form of bribery). In addition to this, a lot of new drug trials aren't always so reliable and the papers published have to be read and interpreted carefully. Since, the drug companies are paying for the trials and to publish them in popular journals - they always try and manipulate the drugs to look as favourable as possible.
A lot of new drugs aren't much different from an older version of the drug. The main reason for introducing a new drug, is often because the patent (licence) giving the company sole rights to produce the drug is expiring. When a company has a patent, it can sell the drug at high prices as there is no competition. Once the patent expires, any company can manufacture the drug and so it becomes cheap to buy (as companies compete for business). Pharmaceutical companies therefore try to sell as many vaccines as possible by recommending regular injections although over the recent years, a lot of pressure has forced us to rethink our advice of giving vaccines.
First and foremost - I think that vaccines are very important for preventing disease. Before the use of vaccines, certain diseases such as parvovirus (causing severe gastroenteritis) and distemper virus (affecting multiple body systems) were fairly commonly seen and unfortunately, claimed the lives of many pets.
So vaccines are important and we are lucky that they have played an important part in preventing disease. So where has the controversy arisen? Well, the important questions need to be addressed?
What are vaccines?
"Any preparation used as a preventive inoculation to confer immunity against a specific disease, usually employing an innocuous form of the disease agent, as killed or weakened bacteria or viruses, to stimulate antibody production".
Which vaccines should we use for which pets?
The most commonly used vaccines for dogs are against parvovirus, distemper virus, parainfluenza virus, adenovirus 2 (against hepatitis), leptospirosis (bacteria) and kennel cough (Bordetella). Other vaccines are also used in other countries such as prevention for rabies, heartworm or Lyme disease.
In cats, the most commonly used vaccinations are against herpes virus, calicivirus, panleucopaenia virus, chlamydia (bacteria) and feline leukaemia virus (FeLV). There are other vaccines such as FIV virus vaccines and coronavirus vaccines (against FIP virus) but benefits of these are debatable.
Which vaccines to use should be based on the individual animal. For example, if it is an solitary indoor cat, a FeLV vaccine is un-necessary. Likewise, if the dog rarely comes into contact with other dogs, Bordetella is probably not needed.
What are the risks involved in using vaccines?
Vaccines are relatively safe. One of the risks involved is an allergic reaction (like itchy skin or swollen face) or more seriously anaphylaxis (severe reaction which may be fatal). The reaction of the pet's immune system can be directed to any component of the vaccination (such as the infectious organism, stabiliser or preservative). Fortunately, reactions are relatively uncommon with studies showing the occurrence at 13 doses out of every 10000 given.
Other possible problems are auto-immune disorders (like haemolytic anaemia when the body destroys its own red blood cells), transient infections and a possible risk of cancer where a vaccine has been injected (mainly cats - but link still unclear as variety of injections may cause a tumour called a sarcoma).
How regularly should we vaccinate our pets?
Everyone seems to vary on their advice! The following intervals for vaccinating are commonly used guidelines:
Bordetella: Intranasally one dose (at 16 weeks of age) and then repeated every year (depends on dog's lifestyle - if in contact with many other dogs)
Distemper, Parvovirus, Parainfluenza and adenovirus: 3 initial vaccines (at 9,12 and 16 weeks) and then one annual booster every 3 years although initial immunity may last for 7-8 years and possibly longer (need further research).
Leptospirosis: 2 vaccines 2-4 weeks apart (at 12 and 16 weeks) and then annually (depends on whether high risk area).
Rabies: 1 dose at at around (16 weeks or more) and then every 3 years depending on vaccine type (mainly for exporting pets).
Feline Herpes, calicivirus and panleucopaenia viruses: 3 initial vaccines at 9,12 and 16 weeks and then one annual booster then every 3 years in low risk environments (although immunity may last longer).
Rabies: As for dogs
Feline leukaemia virus: 2 doses given at 12 and 16 weeks and then booster every year (only use if high risk e.g. outdoor cat).
Bordetella vaccine: As for dogs in high risk environments.
FIV,FIP and other vaccines: Not recommended as benefit in preventing disease controversial.
Should blood samples be taken to measure antibody levels?
This is debatable. Low levels of antibodies do not necessarily indicate a lack of protection (although initially they could be used for assessing a response to a vaccine - mainly for research purposes). Since, the level of antibodies doesn't reliably indicate protection, I do not routinely recommend blood sampling titres.
Cat flu is one of the most common diseases in cats and can be extremely frustrating for both owners and vets. It is normally caused by several pathogens which include both viruses and bacteria.
The common pathogens that cause cat flu are:
Herpes Virus (FHV): this causes recurrent eye and airway problems (rhinitis). Once a cat has caught the disease, it can return during stressful periods such as boarding in a cattery. It is similar to cold sores recurring in infected people.
Calicivirus (FCV): This can also affect the nasal passage but less seriously than FHV. It can cause mouth ulceration and sometimes chronic mouth inflammation (gingivostomatitis) throught a cat's life .
Bordetella Bronchiseptica: This is a bacteria which both dogs and cats can catch. It normally causes respiratory signs (tracheobronchitis) and is very infectious spreading from one animal to another. It is related to the bacteria that causes whooping cough in humans.
Other bacteria include Chlamydophila felis, Mycoplasma felis and Bartonella henselae.
Often, infected cats that recover aren't able to completely eliminate the pathogens/organisms from the body and so remain as "carriers" spreading the disease to other cats in the future.
Cat flu pathogens can survive in the environment for several days. The disease is spread by being in contact with infected cats, carrier cats and a contaminated environment.
Common symptoms of cat flu include sneezing, nasal discharge, conjunctivitis (irritated and weepy eyes), inappetance and a fever.
Treatment is frustrating and often symptomatic. Often an oral antibiotic, like doxycycline, is used for the bacterial component of the disease. Eye drops can help with the conjunctivitis e.g. chloramphenicol. Other commonly used drugs may include appetite stimulants (e.g. cyproheptadine) and mucolytics (e.g. bromhexine) to decrease the nasal secretions.
Antiviral drugs, such as interferon and acyclovir, given in a variety of ways (e.g. eye drops, injectable and oral) are used to varying degrees of success but are quite expensive to use.
Lysine can be used long term to stop the replication of the herpes virus which is useful for stopping recurrences.
There are effective vaccines against Bordetella, FHV and FCV. Cats still may develop disease though if they caught a pathogen before vaccination and/or there are many pathogens involved.
How can you get a healthy dog to eat if they are refusing the food. The first thing to do is to check there is no illness present by a vet. If he/she is very active and normal in every other way, tips that may help to get her eating are:
1) Make sure the food you are giving her isn't stale. For example, in the case of dry dog food - make sure it is being stored in air tight container or the bag is sealed well. Stale biscuits lose both their smell and flavour.
2) Don't leave food out for her - bad training more than anything else. Put the food down and give her 5-10 minutes to eat it. If she rejects the food, take it away and offer it again at the next mealtime. You need to decide when she eats not vice versa.
3) Don't feed her snacks all the time; this will obviously make her not want to eat her regular meal. For training purposes, it is perfectly acceptable to use her regular food (biscuits) as a reward (which makes her less fussy).
4) Make sure she's exercised enough - doing work and exercise will increase her appetite.
5) To stimulate her to eat, heating food with strong smells like fish or liver, may stimulate the appetite.
6) Trying cat food for a while can be useful for the short term (try wet cat tinned food like tuna flavoured whiskas). Don't feed a dog this long term however.
7) Appetite stimulants like cyproheptadine and mirtazipine can be used as a last resort to varying degrees of success.
Hope the above helps, if all else fails, let her eat cat faeces - every dog can't get enough of it (only kidding).
The average lifespan for female hamsters tend to be around 18 months and 24 months for males. The difference is life spans with females tends to be because of common occurence of atrial thrombosis (blood clots blocking the main artery/blood vessel) in entire females.
Female Syrian hamsters normally have a 4 to 5 day oestrus cycle, which ends with white smelly discharge (which can look like pus - even under a microscope as can contain white blood cells and bacteria).
If your hamster has a vaginal discharge but is eating and drinking well, in addition to being as active as normal, it may simply be a normal post-ovulatory discharge, which may go away after a few days and then keep coming back as she cycles during the breeding season (around 6 months).
Occasionally, a vaginal discharge may be indicative of a more serious problem like a pyometra (uterine infection) which may require surgery. Fortunately, cases of pyometras in hamsters are pretty rare. To diagnose a uterine problem, she may need an abdominal ultrasound (difficult to get small enough probe) or an exploratory surgery.
Masticatory myositis is quite an unusual disease. I normally see only about one or two cases a year! It is basically an autoimmune disease, where the body's defence system starts attacking itself. The immune system starts to react and produce antibodies against the fibres in the muscles that control chewing (masticatory muscles) and occasionally, the muscles around the eyes (extraocular). The cause of the immune assault is not completely understood.
It tends to be found in larger dogs like GSD, golden retrievers, weimeraners and rottweilers.
Normally, the dog ends up with painful and swollen muscles making the animal reluctant to open the mouth (leading to less eating). After some time, once the inflammation subsides, the damaged muscle fibres are replaced with fibrous tissue (stiff and rigid tissue). This leads to severe jaw muscle wasting (atrophy) and an inability to open the mouth.
There are some tests to check for antibodies against the muscle fibres. Most of the time though, a muscle biopsy of the jaw muscles may be performed to confirm the diagnosis. Beware though, these dogs can be sometimes impossible to intubate (put airway tube in for anaesthetic) if the jaw doesn't open!
Treatment normally involves immunosuppressive drugs long term to minimise pain, fibrosis (fibrous tissue build up) and decreased range of jaw motion. Drugs used include steroids, azathioprine and/or cyclosporin. Liquid/soft food may need to be given. The jaw can sometimes be gently opened manually on a daily basis although this can sometimes cause a joint dislocation or jaw bone fracture.
If the disease is caught early before severe muscle wasting/destruction and fibrosis, the prognosis to normal muscle movement is good. But once severe damage is caused, the likelihood of reversing it is very low.