Frequently Asked Questions

HSR is a referral only hospital. In order to book an appointment with us, you first need to take your pet for a consultation at your local veterinary practice, who will assess your pet’s condition and consider if referral is deemed necessary. In many cases, your local practice will have the expertise and equipment to treat your pet’s condition effectively. However, in more complex cases, they will suggest referral to us if they consider this to be in your pet’s best interests. As is the case in human medicine, you may also request a referral, and in such instances your local practice will usually be more than happy to arrange this for you. Ahead of your initial consultation at HSR, your referring vet will send us all the medical history we need; we will then contact you directly to book your appointment and begin your referral journey.

Before bringing your dog for an appointment, please speak to one of our Client Care Assistants to let them know of any concerns, we will then be able to discuss a plan of action after conferring with the hospital team. In certain cases, we may be able to assess your dog in the car park; this can help ease the stress of being in an unfamiliar environment.

Once you have had an in-person consultation with one of our specialists or physiotherapists, they will then be more than happy to give follow-up advice over the phone if required; you may also send us photos and video footage to assist with any future advice. Please note that, not all advice can be given remotely and may require further physical examination.

We are open 24 hours a day, 7 days a week, 365 days a year. Our Client Care Team are available from 08:00 – 20:00 on weekdays and 08:00 - 16:30 on weekends.

In emergency cases, surgery will often be performed the same day. For routine cases, we will book in necessary surgery at the earliest availability, after the consultation.

Yes, you are very welcome to have check-up appointments and follow-up x-rays performed at your local veterinary practice. We are always happy to review these x-rays for free if your vet would like our input. We do advise owners to bring their pets back at HSR around the six-week mark where possible, so that the surgeon can physically examine their patient to see how they are getting on.

We usually keep our patients in for one night following routine surgeries. This is so that we can monitor their condition and comfort and administer any necessary pain relief. Length of stay in the hospital is dependent on the procedure performed and the pet’s recovery; more complex surgeries, such as total hip replacements and spinal surgeries, often require additional hospitalisation.

Staying at the vets is rarely easy for pets, which is why we have paid great attention to the design of our kennels and dedicated cat ward. Each kennel has a glass door, enabling pets to stay in a bar-free atmosphere, including our extra-large walk-in kennels. The lighting and ventilation systems provide as much natural light and fresh air as possible to keep the environment fresh and relaxing. We have set aside quiet kennels for more nervous patients and have installed a Sonos™ sound system for those pets who prefer to have the radio on for background noise. We have a modern, glass fronted lift for dogs who are unable to climb stairs, to allow easy access to other areas of the hospital.

For orthopaedic cases, we generally look to obtain our own radiographs as we can then calibrate them to our specialist equipment here at the hospital, which is an important factor in surgery success. Our radiographs are taken with surgical correction in mind, this requires very specific angles and image quality that is not always achieved by the images taken at referring veterinary practices.

Recovery rates vary for each patient and depend on a variety of factors such as, the type of surgery performed, and the standard of aftercare provided. We have our own rehabilitation team at HSR who can tailor a recovery plan for your pet alongside the clinical team. This plan will provide you with the assistance you may need once your pet returns home and is beginning their recovery process. We will also provide personalised discharge instructions to each patient once they are discharged from our care, aiming to guide you through the initial recovery process.

Whilst you will have already had a consultation with you referring vet, our specialists require a physical consultation to assess your pet with a specialist’s perspective; they will need to acquire information that has likely not been provided by your referring practice. This is vital in determining a plan for investigations and treatment for your pet. It also allows time for you to have any queries answered that your referring vet was unable to advise on.

Fully qualified, recognised veterinary specialists are analogous to Consultants in human medicine.

To become a specialist, which is recognised as the highest level of qualification available within the veterinary profession, candidates must undergo several years of extensive training under the direct supervision of other recognised specialists and pass an exam which is extremely demanding and takes place over three days.

Prior to your consultation with one of our specialists, they will study your pet’s history that your referring vet has provided us with.  During the consultation, the specialist will have a thorough discussion with yourself regarding your pet’s condition, prognosis, treatment options, and make a plan that suits you and your pet going forward, should you elect to have treatment here at HSR. This discussion can often take up to an hour and provides an ample amount of time for you to relay any concerns or queries you may have in regard to your pet’s condition. Following the consultation, your pet may then be admitted for further investigations and or treatment. Alternatively, you can go away and think about your given options before proceeding further.

When booking in appointments, we recommend that your pet is brought to us on an empty stomach, therefore having no food past midnight the night before the appointment (water is fine to be given). This is to give you the option of conducting further investigations (such as imaging) on the day on the appointment, should they be deemed necessary, and if we have the availability to do so. This is discretionary and up to you as to whether you would like any investigations to proceed. Should you wish to go away and think about it before admitting your pet to the hospital, that is also absolutely fine; we will not proceed with any plan without your full understanding and consent. Should you have any concerns regarding this, please speak to our friendly Client Care Team.

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Depending on the nature of investigations or procedures required, your pet may need to be anaesthetised or sedated. This involves administering drugs that make the animal “sleepy”, provide differing degrees of pain relief and muscle relaxation to allow the procedure to be performed safely for both staff and animals.

Whether sedation or anaesthesia is more suitable for your pet, depends on the type of procedure, the temperament of your pet, concurrent diseases your pet has, how painful a procedure could be and how immobilised and relaxed your pet must be. Each sedation or anaesthetic is specifically prepared for each individual patient.

Your pet will monitored by one of our anaesthetists and theatre nurses the entire time, until they are fully recovered. After this, they will receive a lot of TLC from our ward nurses, who will continue to monitor them until they leave the hospital to ensure they are comfortable and progressing as expected.

Your pet will generally be starved for around 12 hours before receiving sedative or anaesthetic medication (specific correspondence is sent to you before your appointment). The reasons for this are outlined below. After their assessment by the anaesthetist, your pet will receive a first dose of calming drugs once in the theatre preparation area of the hospital. Depending on how calm your pet is, he or she will either have a cannula placed in order to administer this dose, or receive an intramuscular injection to allow venous cannula placement. To reduce the risk of infection, a fur must be shaved, and the skin prepared aseptically before this cannula is placed. In some cases, where your pet may be very anxious during vet visits, we may prescribe calming medication for your pet to take the night before and the morning of the appointment.

How sleepy he or she becomes following the first injection of calming drugs, depends on the type of drug and the dose given (see below for the difference between sedation and anaesthesia). If your pet is being sedated, drugs are administered until the desired level of immobilisation and relaxation is achieved. If your pet is being anaesthetised, additional drugs are administered until a tube can be placed in their airway (trachea) to protect the airway and deliver oxygen and, depending on the anaesthetic protocol, anaesthetic gases. During the anaesthetic the animal is not consciously aware of its surroundings, and preparation for the investigation or surgery can commence.

Your pet will be kept as warm as possible during the procedure or investigation. Once the procedure or investigation is concluded, drug delivery is stopped, to allow the animal to recover from the effects. Depending on the drugs administered, a reversal agent may be given to speed up the recovery process. If your pet was anaesthetised, we wait until it regains “control” over its airway before removing the breathing tube. Once he or she is awake enough to eat and drink, we will offer food based on their dietary needs we will have discussed with you during their admission to hospital.

Almost inevitably, your pet will remain slightly “sleepy” after it receives a sedation or anaesthetic, even if reversal drugs have been given. You may notice he or she is a bit quieter, and perhaps less interested in food if being discharged on the same day as having a sedation or anaesthetic (for outpatients only).

If your pet is deemed to be “too sleepy” to return home the same day, we will keep them under observation for the night. If your pet has undergone a complex procedure, or is sick, requires additional observation or pain relief, the hospital stay will be longer, and this will be discussed with your consultant during the admission process and subsequent phone calls.

Sedation and anaesthesia can be considered part a continuum, during which the animal is increasingly unaware of its surroundings and what procedure it is undergoing. Sedated animals can still move their limbs, turn their head, blink, and protect their own airway (maintain a patent airway and swallow). Anaesthetised animals do not blink when their eyelids are gently stroked, they cannot swallow, and their muscles are totally relaxed: they require a tube in their airway to protect it from aspiration (regurgitated stomach contents) and to keep the airway unobstructed. This emphasises why it is important your pet does not eat before its anaesthetic or sedation: you will receive specific instructions before you attend for your pet’s appointment.

The deeper sedation becomes, the closer the animal is to being anaesthetised. The same drugs could theoretically be used to sedate or anaesthetise an animal: the difference lies in the drug dose and administration technique used. Anaesthesia and sedation therefore share many possible risks, which your consultant will go through with you while obtaining informed consent for the animal to undergo sedation or anaesthesia.

Whilst sedated or anaesthetised, patients at HSR are monitored closely using state-of-the-art multi-parameter monitors. These give an indication of the blood haemoglobin saturation of oxygen, the carbon dioxide and inhalational anaesthetic gas an animal breathes out each breath, its blood pressure, electrical heart activity and rhythm and body temperature.

At HSR, we use specialist anaesthesia equipment to deliver inhalational anaesthetic gases and oxygen, while syringe drivers and fluid pumps are used to precisely administer injectable drugs. Dedicated anaesthesia workstations with integrated ventilators allow carefully controlled mechanical ventilation of anaesthetised animals while monitoring pressure in delicate airways where required.

Records are taken and interpreted under the supervision of our Anaesthesia team. The team works closely alongside our other specialties within the hospital to develops tailor-made anaesthesia and pain relief plans for patients under the care of all clinical disciplines in the hospital, ensuring first class care for all our patients.

Each anaesthetic plan is based on a detailed review of patient medical histories, a pre-anaesthetic examination of the patient and liaison with the specialist requesting a procedure. Based on this, the anaesthetist in charge of your pet creates a protocol, considering his or her needs as well as any challenges potentially arising during an investigation or surgery: ensuring patient safety and comfort are paramount throughout the stay at HSR.

Anaesthetists have significant input into the care of critical care patients requiring intensive care and play an ongoing role in adjusting your pet’s pain relief or advising on how to keep your pet calm in the postoperative period, both as an inpatient or an outpatient at HSR. Your pet will only be allowed to come home, once we and you are confident any remaining pain can be adequately managed at home with you.

A CT scan, also known as computed tomography scan or a computerised axial tomography (CAT) scan, is a computerised x-ray imaging procedure that generates cross-sectional images, or “slices” of the body. Once a number of successive slices are collected by the machine’s computer, they can be digitally “stacked” together to form a three-dimensional image of the patient. This allows for easier identification of body structures and for accurate surgical planning.

Unlike x-ray, a CT scan can differentiate between different types of soft tissue and thus can be used in the investigation of a wide range of non-orthopaedic diseases. CT scans are also particularly useful in oncology cases, both in delineating the extent of a primary tumour and in assessing for metastatic disease. With the administration of an intravenous contrast agent, a ‘contrast’ CT can detect subtle regions of pathology within a wide range of body tissues.

A CT scanner uses a motorised x-ray source that shoots x-rays as it rotates around the body. Special detectors are located directly opposite the x-ray source and each time the x-ray source completes one full rotation, a computer then produces a 2D image or a ‘slice’ of the patient. In a 16-slice scanner there are 16 detectors and thus each revolution acquires 16 slices simultaneously.

When a full slice is completed, the image is stored, the motorised bed moved forward incrementally and then the process is repeated to produce another image slice. This process continues until the desired number of slices is collected. A full body CT can be acquired in less than one minute in most patients.

Image slices can be displayed individually, which allows the region of interest to be viewed without with any superimposition of other structures. This is invaluable in orthopaedics and at HSR we routinely use CT scanning in the assessment of elbow dysplasia, specifically with regard to the diagnosis fragmentation of the coronoid process (FCP). CT is also the gold standard for the diagnosis of humeral intercondylar fissures, a problem commonly seen in Spaniels and Labradors.

Individual images can also be ‘stacked’ together by the computer to generate a 3D image of the patient. These reconstructed 3D images can then be rotated and be viewed from any angle. They, in turn, can be used to make custom implants and cutting guides using sophisticated computer software and 3D printing technology.

• For assessment of complex anatomic areas such as the skull or spine
• Planning of complex fracture repair
• For soft tissue and oncological cases
• Investigation of diseases of the thorax and abdomen, as the rapid acquisition of the images negates the movement artefact that would occur during an MRI scan.

Using ionising radiation, X-rays or radiographs are two-dimensional high-resolution images used to assess bone and joint diseases and malformations. A beam in the form of an X-ray is directed over the area of the body under investigation. The soft tissues are unable to absorb the radiation, whereas dense tissues such as bones absorb the radiation and thus produce an image.

Radiographs are very advantageous and accurate in orthopaedic workups and are generally the first diagnostic imaging tool used before other modalities like CT or MRI scans. Radiographs also provide a fast and cost-effective method in diagnosis.

• Orthopaedic problems: limb deformities, lameness and fractures
• Diagnosis of bone tumours
• Assessing the abdomen
• Checking organs
• Viewing changes in tumours or tissues such as tumours, cysts or stones

We tailor each session specifically for your pets’ requirements, as our treadmill has adjustable water height, speed, incline, and decline options. Prior to your pet’s session, we will do a full assessment, including a walk-up to assess movement and review gait analysis. We then shower your pet and apply a suitable harness before entering the treadmill. Our team provide a hands-on approach throughout the session, which enables us to assess patients and put them at ease. We are also able to assist in limb placement and use resistance bands to aid gait re-training and strengthening. Post-session aftercare includes a warm shower using natural shampoo followed by a towel dry, or optional blow dry, and lots of cuddles!

Patients can leave sessions feeling mentally stimulated; alternatively, they may feel an increase of energy and excitement. Please keep your pet calm and make sure they are kept gently mobile throughout the rest of the day to prevent possible re-injury or any muscular stiffness.

A session will last for 45 minutes, which includes assessment, showering pre and post session and drying, plus our handover with you.

Our water is heated to 30°C.

We use chlorine as a disinfectant to keep the water clean and test the water multiple times per day to protect both your pet and the hydrotherapists from any risk of infection.

We advise no feeding within TWO hours prior to a hydrotherapy session. If medication is required with food, we do allow for a small amount to then be given, but it should be avoided where possible. No feeding until half an hour after your pet is home and settled. 

The hydrotherapy session will take the place of ONE of your pet’s walks for the day. Please do allow for a short toilet walk before arrival.

• Conservative and post orthopaedic and neurology surgery.
• Hip and elbow dysplasia.
• Cruciate ligament rupture/repair.
• Patella luxation.
• Degenerative myelopathy.
• Spondylosis.
• Arthritis and mobility issues.
• Fitness and weight loss.

• Skin/eye infections.
• Open wounds.
• Urine infections.
• Tumours (unless for palliative care).
• Patient is non-weight bearing.
• Contagious diseases.
• External skeletal fixators.
• Sickness and/or diarrhoea.

Hydrotherapy is a form of therapeutic exercise which is carried out in warm water. Hydrotherapy relies on the many properties of water, which all have effects on the tissues of your pet and how they move. The warmth of the water will help to relax your pet’s soft tissues, reduce pain and allow for a greater range of movement of joints.

The buoyancy of the water allows your pet to exercise in a partially weight bearing environment, which reduces the concussive forces through their limbs, allowing them to move through greater ranges of motion with reduced pain.

The hydrostatic pressure of the water provides enhanced proprioception to pet’s paws and limbs and assists in blood circulation and helps to reduce swelling and pain.

The resistance of the water will help to strengthen muscles, and the turbulence of the water caused by movement will also aid in proprioception, stability, and strength.

Hydrotherapy initial consultation is £76.49, and a hydrotherapy follow-up is £63.69.

This will depend on the terms of your insurance policy and how the insurance company defines hydrotherapy. Check with your insurer to clarify your policy and check if you need to get pre-authorisation for hydrotherapy.

This is dependent on your vet and their referral. If your pet is a postoperative patient, hydrotherapy can usually start a few days after stitches or staples have been removed.

It is a common thought that most cats are averse to water. However, through applying appropriate hydrotherapy techniques and modifying handling to feline behaviour, many cats have adapted successfully to hydrotherapy. We have had many positive results when rehabilitating cats using the underwater treadmill. 

We will allow time for your pet to relax and become accustomed to the environment during their sessions. Some pets who appear to dislike water, can take to hydrotherapy very well; especially with our hands-on approach, lots of praise, reassurance, toys and treats for motivation.

Magnetic resonance imaging (MRI) is a type of scan that uses strong, static magnetic fields and radio waves to produce detailed images of the inside of the body. This is achieved through aligning the usually randomly orientated atomic nuclei of hydrogen atoms in the patient’s body.

A radio frequency (RF) pulse is then applied, forcing the spinning hydrogen protons to wobble. Once the RF pulse is turned off, the wobbling of the hydrogen protons generates a small electrical signal. The signal is detected by RF coils, which need to be positioned as close to the anatomical area of interest as possible. The rate at which the protons return to their equilibrium state distinguishes different bodily tissues.

MRI is able to distinguish subtle differences in the physical make up of body tissues and so provides detailed, high-resolution images of internal structures.

MRI is able to image through bony structures and so is the treatment of choice for image of the spine, spinal cord and brain disorders.

With the use of various ‘sequences’ MRI can be used to detect many different disease processes such as inflammation, haemorrhage and with the addition of appropriate contrast agents is invaluable in the investigation of neoplastic processes anywhere in the body.

MRI can be more cost-effective than combining various alternative diagnostics, is safe and non-invasive.

Diagnosis of spinal cord compression and spinal cord injury

Brain tumours

Tendon and ligament injuries

Investigation of seizures

Vestibular problems

Neck and back pain

Nasal discharge

Mast cells are normal defensive immune system cells which help to get rid of parasites but are also the cell behind allergies, and they can become mutated and develop into tumours. A mast cell tumour is the most common skin-based tumour in dogs. Some breeds are especially prone such as breeds with a short nose, retrievers, Weimaraners, and Shar Pei. Most predisposed breeds tend to have more frequent but less aggressive mast cell tumours. Most dogs are older when they develop a mast cell tumour.

All mast cell tumours cause a problem in the local area. Reassuringly, the vast majority of dogs with a mast cell tumour in the skin or the fatty tissue underneath will have long term control or a cure achieved through surgery, and will not need any further therapy. A minority of mast cell tumours will try to spread/metastasise and will not be cured by surgery alone. To try to identify those which will benefit from further therapy, we look at several features.

Grade is an assessment of aggressiveness of the tumour cells made by microscopic examination. There are two methods of grading which separate the less aggressive from the more aggressive tumours which require more treatments.

Stage is an assessment of how extensive the disease is in your dog. We can use needle samples of the liver and spleen taken with ultrasound guidance to see if there is spread of the cancerous mast cells within. This is a very safe and minimally invasive procedure. However, a common place for cancerous mast cells to spread is the nearest lymph nodes. Needle samples are a good start in assessing the lymph nodes, but the best information comes from microscopic assessment of the whole node after its removal. Other tests can be offered for complete staging. Dr Elders will discuss with you how much staging is advisable, sometimes no staging tests are pursued.

After surgical removal, the tumour tissue is examined microscopically. This gives us the grade, and also an assessment of how much of a cushion of normal tissue has been removed around the tumour (the margin). If the margin is narrow, a second surgery or possibly radiation therapy might be offered to minimise the risk of recurrence. If the margin is adequate, the risk of recurrence is already minimised. Combining all of the above information, will determine if further treatment is likely to be beneficial.

If further therapy after surgery is advised, then you will be offered options including chemotherapy, medication to turn off growth signals (receptor tyrosine kinase inhibitors), and/or supportive medications. This might sound scary, but side effects are actually very unusual - please see our chemotherapy overview section for more details.

Finally, veterinary research is ongoing, and Dr Elders will be able to discuss any novel developments which might have occurred since this document was written, including new treatments such as immunotherapy.

Chemotherapy is thankfully a very different experience in dogs and cats compared with chemotherapy in people. The medications used are often the same, but we use much lower doses. We use previous research to choose a dose which is effective against their tumour and should be easily tolerated by your pet.

Tumour cells usually reproduce more rapidly than most other normal tissues in the body. Most forms of chemotherapy medications work by damaging the DNA within reproducing cells, or other structures involved in reproduction. Rapid reproduction leads to chemotherapy causing greater damage in tumour cells than in normal tissue cells in which reproduction is typically slower. As the tumour cells try to reproduce, the chemotherapy induced damage can cause them to die off. This difference in sensitivity between tumour cells and normal tissue cells allows us to effectively treat tumours with minimal side effects in the rest of the body. Furthermore, normal tissue cells tend to repair themselves better than tumour cells.

Sometimes chemotherapy is used as the only therapy, such as with lymphoma. Sometimes we use surgery first to get rid of the bulk of a tumour, followed by chemotherapy to fight against any cells let behind locally or around the body (called “adjuvant” chemotherapy, such as with mast cell tumours, or osteosarcoma). Very occasionally we use chemotherapy before surgery (called “neo-adjunctive” chemotherapy such as with some mast cell tumours and injection site sarcomas).

There is no one size fits all approach, however, so depending largely on the tumour type diagnosed, Dr Elders will suggest which chemotherapy medications are most likely to be successful, based on previous research.

The vast majority of pets have treatment on an out-patient basis with an overnight stay being very rarely needed. The risk of side effects in your pet from chemotherapy medication is small but cannot be guaranteed to be zero. The majority of treated pets tolerate their treatment without any problem, due to the low doses used, validated by previous research. In the unlikely event of significant side effects, you pet would be welcome back here for further care on a 24 hour basis, and we can be contacted for advice at any time too. We will also discuss the risks of your exposure to chemotherapy residues before treatment starts and at each treatment visit.

Lymphocytes are normal defensive immune system cells which travel around the body, with each one devoted to combatting a different virus, bacterium or parasite, together comprehensively protecting the whole body. If one of these cells mutates and becomes cancerous, then lymphoma is the most common resulting disease. Some breeds are predisposed, such as any breeds with a short nose, retrievers and Siamese cats. Most cats and dogs are older when they develop lymphoma.

The best treatment for each individual pet depends on a number of features.

Stage, is an assessment of how extensive the disease is. The location of the lymphoma is significant in terms of predicting spread, the symptoms that will arise, the overall outlook including lifespan, and therefore the treatment which is best in response. Sometimes all the mutated lymphoma cells are present in one location, such as in most cases of nasal lymphoma, meaning that radiation therapy of just the nose is a comprehensive therapy for them. However, just as healthy normal lymphocytes can travel around the body, lymphoma cells often are able to travel too, and some nasal lymphoma patients will be found to have lymphoma cells outside the nose, which results in chemotherapy being a more comprehensive treatment for them than radiation therapy. This might sound scary, but side effects are actually very unusual in cats- please see our chemotherapy overview section for more details.

Testing can be offered to look for the spread of lymphoma such as x-rays, ultrasound, needle samples of organs, maybe bone marrow sampling. Dr Elders will discuss with you how much testing is advisable, and sometimes no such tests are needed. Blood and urine samples can be useful both for assessing spread and to see the impact of the lymphoma on your pets, sometimes revealing features that need to be addressed promptly such as a high calcium level.

Grade is an assessment of aggressiveness of the tumour cells made by microscopic assessment. The size of the individual tumour cells can be seen on a needle sample, and size and the grade of the lymphoma are often aligned with large cells being associated with a high grade, aggressive lymphoma. However, grade is a more comprehensive assessment of the lymphoma cells than merely their size, and often requires a surgical biopsy of the lymphoma, perhaps with removal of a mass or a lymph node. Depending on where a tumour is, a biopsy through a scope might be another option.

Phenotype is a term which mainly describes the origin of the lymphocyte which has been mutated, such as B (for those originating in the bone marrow) or T (for those originating in the thymus). This information can be determined from any needle or biopsy sample of lymph node tissue. Flow cytometry is an antibody-based method of assessing needle samples, and provides the T or B status of a lymphoma as well as several other features of the phenotype which can impact the anticipated outlook for a dog or cat, and the best treatment choices.

If there is any confusion as to whether the problems in your pets might not be lymphoma but might actually be caused by a beneficial but excessive immune response, we can offer a PARR test. This test assesses the how related the cells are at the genetic level.

The aim of treatment in most cats and dogs is to significantly extend lifespan with a normal quality of life, through the least frequent visits.

Some clients prefer not to have chemotherapy and we can offer supportive medication to improve quality of life and lifespan without chemotherapy too. Finally, veterinary research is ongoing, and Dr Elders will be able to discuss any novel developments which might have occurred since this document was written, including new treatments and vaccines.

Sarcomas are tumours which arise from mutation in any tissue which is not lining the insides or outside of the body and is also not a gland. They can arise from fat (lipoma), blood vessels (haemangiosarcoma), muscle (myosarcoma), etc. However, some mutated cells do not maintain the features of their origins, even after looking for them with sophisticated tests such as immunohistochemistry, in which case they are simply labelled soft tissue sarcomas. Although this might seem imprecise, soft tissue sarcomas are frequently diagnosed and well researched, so we know what to expect in terms of their threats and behaviour.

All soft tissue sarcomas have at least some potential to be malignant and spread around the body, none of them are truly benign. While all soft tissue sarcomas will have an effect in the local area, reassuringly, the vast majority of dogs with a soft tissue sarcoma will have long term control or a cure achieved through surgery, and will not need any further therapy. This is because only a small minority of soft tissue sarcomas will try to spread/metastasise. To try to identify those which will benefit from further therapy, we look at several features.

Grade is an assessment of aggressiveness of the tumour cells made by microscopic examination. This can be done through needle samples and biopsies.

Surgical removal of these is the most common treatment. After surgical removal, the tumour tissue is examined microscopically. This gives us the grade, and also an assessment of how much of a cushion of normal tissue has been removed around the tumour (the margin). If the margin is narrow, a second surgery or possibly radiation therapy might be offered to minimise the risk of recurrence. If the margin is adequate, the risk of recurrence is already minimised.

If further therapy after surgery is advised, then you will be offered options including standard chemotherapy, metronomic chemotherapy, and/or supportive medications, followed by a monitoring programme. For dogs who have surgery that does not remove all of the sarcoma cells with a good margin, we can recommend metronomic chemotherapy to combat the risk of recurrence. This is a very well-tolerated, home-administered form of low dose chemotherapy in pill form, and can also be used to retard the progression of sarcomas which are not removed through surgery. This might sound scary, but side effects are actually quite unusual- please see our chemotherapy overview section for more details.

Combining all of the above information, will determine if further treatment is likely to be beneficial. If further therapy is unnecessary your dog will be offered a monitoring programme.

Finally, veterinary research is ongoing, and Dr Elders will be able to discuss any novel developments which might have occurred since this document was written, including new treatments such as immunotherapy.

Apocrine gland of the anal sac adenocarcinomas (abbreviated to AGASACas) are tumours which arise from mutation of the paired glands just inside the anus of dogs. Some breeds are especially prone such as Spaniels, typically in their later years.

Some AGASACa masses are small and found on relief of blockages in the rest of the anal gland, whereas, others become large and interfere with defaecation, sometimes narrowing or flattening the stool and causing discomfort. All AGASACa have some potential to be malignant and spread/metastasise around the body, and none of them are truly benign. Although many dogs will not have overt spread/metastasis at the time of diagnosis, this is present microscopically in the vast majority of dogs, and will emerge over time.

The best treatment for an individual dog with AGASACa depends on whether there is any evidence of spreading and how extensive the spread is, therefore we recommend a CT scan for the most detail to make these decisions. Spread/metastasis from an AGASACa can be to any organ, but classically will be to the local lymph nodes initially, making its way over time from the lymph nodes at the back of the abdomen to the front. The anal area mass and the local lymph nodes can be removed at the same time, but how best to approach this operation depends on the location, size and mobility of the lymph node, especially those in the pelvis. The results of a CT can suggest whether a surgical approach from behind, from in front of, or though the pelvis is best. Most large lymph nodes revealed on CT can be sampled using ultrasound guided needle samples which is a minimally invasive procedure. Some large lymph nodes will be inflamed or infected rather than having tumour cells within. If the lymph nodes are particularly large with tumour cells within, sometimes we substitute radiation therapy for surgery as the best first treatment option, and if there is unusually widespread disease we might suggest medical management over surgery. There is a limit to how small a mass can be detected by any type of scan, which means that some dogs with a clear set of results initially might have overt spread detected months or years later.

Surgery is the best treatment for most dogs with AGASACa. The majority of dogs will have the local lymph nodes removed. After surgical removal, the tumour tissue is examined microscopically to assess how much of a cushion of normal tissue has been removed around the tumour cells (the margin). If the margin is narrow, a second surgery or possibly radiation therapy might be offered to minimise the risk of recurrence. If the margin is adequate, the risk of recurrence is already minimised.

If further therapy after surgery is advised, then you will be offered options including chemotherapy, medication to turn off growth signals, and/or supportive medications, followed by a monitoring programme.

It might seem unusual that for a mass which is almost guaranteed to spread/metastasise that chemotherapy is not being emphasised. This is in part because the tumour cells are not usually reproducing rapidly and therefore do not take much of a hit from chemotherapy. In many past surveys traditional chemotherapy choices resulted in no benefit or only a small benefit in overall survival of groups of dogs with AGASACas.

Finally, veterinary research is ongoing, and Dr Elders will be able to discuss any novel developments which might have occurred since this document was written, including new treatments such as immunotherapy.

Feline injection site sarcomas are tumours which arise from mutations in tissue which have been injected in the past, often with a vaccine but other drugs and implants have been associated with sarcomas too. They seem to arise from an excessive immune system reaction to injections, which mutates over time into a very aggressive tumour which persists even after the injected material has been absorbed. Tumour development was more common with historical vaccines, but still happens today including occasionally with non-vaccine injections, so some of the risk seems to be likely genetic, as most cats tolerate multiple injections without tumour formation.

Although feline injection site sarcomas have at least some potential to be malignant and spread around the body, few of them actually do spread/metastasise. Therefore, the major threat is from the local damage that the sarcoma causes. Injection site sarcomas are the most invasive type of sarcomas seen in cats, easily invading through local tissues including bone. While we treat most types of sarcomas by removing all tissue within 2-3 cm of the overtly abnormal mass, for injection site sarcomas, research has shown we need to remove 5 cm of tissue to achieve similar control. Having to remove such a large amount of tissue is quite routine for us, and will typically be followed by re-stretching of the skin over time, with comfort maintained throughout. Some injection site sarcomas are in challenging locations which can result in a compromise between removing the necessary amount of tissue for tumour control and the preservation of vital structures (e.g. nerve tissue).

To make as sure as possible that a surgery will have the desired effect, most cats have an initial CT scan to define in the best detail the most appropriate surgical approach.

Where we can predict that an injection site sarcoma is likely to recur even after extensive surgery, or where the microscopic analysis of a removed tumour confirms recurrence is likely, we can offer radiation therapy as well as surgery.

Where spread/metastasis is detected on a CT scan, or when other options are declined, we can offer either standard or metronomic chemotherapy, medication to turn off growth signals (receptor tyrosine kinase inhibitors), or palliative care. This might sound scary, but side effects are actually unusual - please see our chemotherapy overview section for more details.

Metronomic chemotherapy is a very well tolerated home-administered form of low dose chemotherapy in pill form and can also be used to try to retard the progression of sarcomas. Receptor tyrosine kinase inhibitors are growth factor inhibiting drugs which seek to oppose tumour cells dependant on these growth factors, given in a pill form at home every 2 or 3 days. At this point the evidence base for each of these medical options is quite weak when groups of cats are analysed, but individual cats can do well.

Osteosarcoma is a malignant tumour which has developed from mutation of normal bone cells, often with a mixture of uncontrolled production and uncontrolled destruction of bone tissue. Osteosarcoma is the most common diagnosis for a mass in a bone, but other tumours and non-tumour conditions can be present too. Some breeds are predisposed, such as any tall and/or heavy breeds, especially Rottweilers, but also heavily physically-trained dogs and dogs who have had a previous fracture or implant in the bone. Many dogs are older when they develop an osteosarcoma, but there are also many cases around the time of skeletal maturity/achieving adult height.

There are a number of different diagnostic tools that we can use to get an accurate diagnosis, these include; radiographs, biopsies, blood sampling, urine sampling and CT scans.

Quality of life is our main focus at Hamilton Veterinary Specialists. Without doing any surgery, we can improve comfort and lameness through external supports, medications, and radiation therapy. There are several medications which relive pain and also reduce further weakening of the bone which can be used in combination for patients not having surgery or prior to surgery. Radiation therapy is primarily offered as a further option for pain relief too. These would be considered palliative care as they do not tackle the tumour directly.

Surgical treatment options include lump removal, amputation and limb sparing surgery. Sometimes chemotherapy will then be used post surgery. Chemotherapy might sound scary, but side effects are actually very unusual- please see our chemotherapy overview section for more details. There are a quite a few variations to the above treatment options. Dr Elders will guide you through all these options. After completion of your choice of treatments, your dog will be offered a monitoring programme.

Urothelial carcinoma (previously called transitional cell carcinoma) is a tumour which arises from mutation of the normal cells lining the urinary tract (called urothelial or transitional epithelial cells). This is the most common bladder-based tumour in dogs, but can also effect the kidneys and the tubes that carry the urine (ureters and urethra). Some breeds are especially prone such as Spaniels and many Scottish breeds, most often in their later years.

The symptoms of a urothelial carcinoma are often the same as those for other bladder conditions like stones and infections. Some tumours are poorly structured and are prone to repeated infections making the underlying tumour more difficult to diagnose. There is a urine test based on a genetic change called a BRAF mutation which seems to be present only in cancerous urothelial cells. This allows the majority of urothelial carcinomas to be separated from other bladder conditions.

Other methods of making a diagnosis are mainly biopsy-based. There are several ways in which we can try to take a biopsy from the inside the urinary tract without crossing the skin (e.g. catheter-based, scope-based), which avoids the risk of spread. Very rarely is a surgical biopsy needed to reach a diagnosis.

Tumours arising at the front of the bladder can have a very good initial response to surgery. The majority of urothelial carcinoma arise at the back/trigone of the bladder, a more specialised area with a lot of vital anatomy nearby meaning beneficial surgery is typically impossible.

There are several treatments on offer, and Dr Elders will discuss the best approach with you. For a typical urothelial carcinoma at the back of the bladder, the most commonly chosen option is a medical combination consisting of chemotherapy and non-steroidal anti-inflammatory medications. Both medications are effective, and we can offer sole non-steroidal anti-inflammatory to clients wishing to avoid chemotherapy, however combination therapy is superior. If chemotherapy sounds scary, be reassured that side effects are actually quite rare- please see our chemotherapy overview section for more details.