What is radiography?
An X-ray (radiograph) is a quick and painless method used to diagnose many health conditions. The procedure involves exposing part of the body to a small dose of ionising radiation (X-Rays).
The X-Rays travel through the body where they are absorbed at different levels by different tissues such as bones, muscles and organs. When the X-Rays come out on the other side of the body they hit a photographic film, making a pattern of light and shade. The images produced are black and grey.
At Shaw Vets we have a state of the art Computerised Radiography (CR) Unit which produces digital images. This allows images to be magnified and adjusted to produce extremely high quality images.
The images are attached to your pets records, so we can access them at any time.
In most cases in animals a general anaesthetic or heavy sedation is required to perform an accurate x-ray. This is because most pets, however well behaved, will not stay completely still in the required position to obtain high quality diagnostic x-rays. Very rarely, if an anaesthetic might be dangerous, for example in a cat which has difficulty breathing, we may take a survey x-ray with the animal fully conscious to remove the additional risk associated with an anaesthetic. Under the guidelines set down by the Royal College of Veterinary Surgeons (RCVS), animals are not allowed to be manually restrained for x-rays for health and safety reasons.
What is an ECG?
An Electrocardiograph (ECG) records the electrical impulses associated with the heart beating.
What can we use ECG’s for?
- To diagnose and evaluate changes in heart rhythm (arrhythmias). These are generally associated with damage to the heart muscle or defects within the pacemaker that regulates the heartbeat rhythm. Once treatment has started a repeat ECG can give useful information on the progress of the disease
- To assess the shape and size of the heart. This is particularly useful when combined with radiography and ultrasonography
- An ECG can be used as an extra sensitive monitor for patients during high risk general anaesthesia
How we record an ECG
- For diagnostic ECGs we tend not to use sedation or general anaesthetic. Most dogs are compliant but keeping a cat still can sometimes be tricky!
- The animal is laid on his/her right hand side, and a small metal clip is attached to the top of each leg. The clips do not grip too tight and most animals do not notice them
- All four clips are then connected via leads to the ECG machine. A small amount of surgical spirit on a piece of tissue paper is applied to improve the connection
- The ECG machine then records the electrical impulses formed as the heart beats and the difference between the signals produced in each leg. this information is then printed out so it can be evaluated by the vet
Blood Pressure Monitoring
Just like humans, animals can suffer from high blood pressure or hypertension. Often it is not obvious that an animal has high blood pressure unless it is measured, but a thorough eye examination may sometimes reveal indicative signs.
High blood pressure is most commonly seen in cats, who may present when they suddenly become blind in one or both eyes. This is usually caused by a detached retina.
Another sign of high blood pressure could be nose bleeds.
In cats, most hypertension is secondary. i.e. it is a complication from another disease.
The most common causes of secondary hypertension are chronic renal failure & hyperthyroidism (over active thyroid).
How do we measure blood pressure in pets?
There is no need for sedation – in fact sedation lowers blood pressure so this would affect the results. A small patch of hair is clipped away from the back of the front foot and a Doppler probe is placed in this area in order to hear the animals’s pulse. Ultrasound gel is used to improve the connection.
A cuff is placed around the top of the leg, just like the ones used in people but smaller (for cats we use a cuff designed for premature babies). The cuff is inflated until we can no longer hear the pulse via the probe. The pressure is then slowly released and the reading is taken.
Blood pressure monitoring is a relatively simple, non-invasive procedure which usually takes 5-10 minutes.
The normal blood pressure for dogs and cats is a systolic blood pressure of 140-160mmHg.
Tonometry is the measurement of pressure within the eye (called intraocular pressure) to determine if glaucoma is present.
Intraocular pressure (IOP) is the pressure exerted against the outer layers of the eyeball.
Tonometery is performed using an instrument called a tonometer. We use the latest model from Reichert.
What does tonometry reveal?
- Tonometry measures intraocular pressure (IOP) to diagnose glaucoma. Glaucoma is caused by the build up of fluid within the eye. Abnormally high pressure can damage the optic nerve leading to loss of vision
- Tonometry is also useful for identifying low IOP which may occur with anterior uveitis (inflammation within the eye) or following intraocular surgery. Low IOP can also be associated with dehydration
- Normal values vary between different species of animals and sometimes between breeds and individuals. Normal values are also affected by the technique used to measure them, so values are usually give as a range
- Normal ranges are as follows: Dog: 11-22mm Hg
- Values that differ between eyes are considered significant if the difference is >8mm Hg
We have our own laboratory where we perform many diagnostic test including routine haematology and biochemistry, cytology and parasitology. This allows us to test sample and get results quickly, which means that any problems in your pets can be diagnosed and treated sooner.
We use an external laboratory for more specialised tests including checking hormone levels and isolating bacteria from samples such as diarrhoea or from infected ear canals. We use an overnight courier so we can get the result to you as quickly as possible