If your pet has been diagnosed with a condition we know this can be a worrying time. That’s why we’ve produced fact sheets on some of the most common conditions we see, to help explain the causes and treatment options available.
Chronic Diarrhoea (chronic enteropathy)
What is chronic enteropathy?
Chronic enteropathy is often characterised by diarrhoea that has occurred for a period of three weeks or more. Diarrhoea occurs when the small or large intestine does not function normally, so fluid is either secreted excessively or not re-absorbed properly. This causes faeces to appear soft or runny and sometimes they can contain fresh blood, black digested blood, or mucus.
Signs and symptoms
There are many different causes of diarrhoea such as foreign bodies, dietary indiscretion, chronic enteropathy, systemic diseases such as liver disease or kidney failure and others. These diseases need to be ruled out before chronic enteropathy can diagnosed.
Other potential symptoms of chronic enteropathy include weight loss, inappetence, vomiting, regurgitation, and reflux. Chronic enteropathy can have different causes including dietary intolerance, immune system dysregulation or gut bacteria imbalance.
How is chronic enteropathy diagnosed?
As there are many causes of diarrhoea, initially bloods to assess organ function (including pancreatic function), vitamin levels specific to the intestine, faecal analysis (assessing for infectious diseases such as worms or bacterial infections like salmonella) and imaging are necessary. Your local vet may have done some of these tests before referral. Ultrasound imaging can be useful to assess the intestine and organ structure as well as being able to identify blockages such as foreign bodies or tumours.
If chronic enteropathy is suspected, endoscopy (video imaging of inside the gut) may be discussed. Endoscopy of the stomach and guts allows for visualisation of the wall and for small ‘grab’ biopsies to be obtained with forceps passed inside the endoscope. This can be of the upper gastro-intestinal tract (stomach and first part of the small intestine) and/or lower gastro-intestinal tract (large intestine). Your pet will need to be fasted overnight for endoscopy and will require to take gut cleansing solutions and enema for lower gut endoscopy. Grab biopsies carry a small risk of bleeding but are non-invasive and only obtain the inner layer of the intestine. It may be that surgical abdominal exploration to access areas that cannot be reached via the scope and/or full thickness gut biopsies are recommended. A rare complication of this is wound breakdown which could cause leakage of gut content from the intestine into the abdomen and cause peritonitis. However, this is rare if certain safety measures are respected.
Biopsies will characterise the type of inflammation but may not confirm which treatment will work best and treatment trials may be recommended.
Chronic enteropathy is often treated with or a combination of dietary management, antibiotics or drugs which ‘dampen’ the immune response such as steroids. Exclusion diets where a novel (never fed before) protein and carbohydrate source or hydrolysed protein diet may be recommended to be fed for a minimum of four weeks (although improvement is usually seen within two weeks) while no other treats or other foods are given.
What is the prognosis for chronic enteropathy?
Chronic enteropathy is an ongoing disease that usually cannot be cured but we aim to control. In most cases clinical signs can be managed with treatment (which may be lifelong) providing a good quality of life. It may take weeks to months for treatments trials to be completed so that a final treatment plan can be decided on and adjustments might need to be made over time. Some severe cases may not respond to treatment and may carry a poor prognosis.
Immune Mediated Haemolytic Anaemia (IMHA)
What is IMHA?
IMHA is a condition where the body’s immune system attacks and destroys its own red blood cells causing anaemia. Red blood cells deliver oxygen around the body and severe anaemia can mean poor oxygen delivery to organs such as the kidneys, brain, liver and others, causing damage. It affects both cats and dogs with some breeds being predisposed such as the Springer Spaniel.
Secondary IMHA can be caused by an underlying trigger e.g. some infectious agents like tick borne diseases, tumours, some medications, toxin ingestion and other conditions. If there is no underlying cause (which is the most common form) detected it is called ‘primary’ IMHA.
What are the clinical symptoms?
Symptoms will vary on how severe the disease is. In mild cases or early stages, you may notice that your pet is just more lethargic than usual or inappetent. In severe cases, the patient can collapse and have difficulty breathing due to anaemia or the formation of blood clots (stroke). This is usually accompanied by pale gums, and you may see a yellow (jaundiced) tinge to the skin, whites of the eyes and gums caused by bilirubin. This may also cause the urine to be a more orangy yellow than usual, or if a severe attack is happening then red urine can also be seen. Sometimes a fever may be present.
IMHA is diagnosed using a combination of blood tests and diagnostic imaging which may be radiographs and abdominal ultrasound or a computed tomography (CT) scan to search for any underlying triggers. Primary IMHA is diagnosed only when other causes are ruled. In some cases, a bone marrow biopsy may be obtained.
If there is an underlying cause identified, then treatment for this is started. Cases of primary IMHA are treated by suppressing the immune system, initially using steroids. Additional immunosuppressive medication may be added to get an additional immunouppressive effect or to help dogs that do not tolerate high doses of steroids very well. Dogs with primary IMHA are at risk of developing blood clots so medication is often started to try and lower this risk. In severely anaemic animals blood transfusions are often necessary to help improve oxygen delivery to the body in the short term. Sometimes blood transfusions can be rejected by the patient (known as a transfusion reaction), or the red bloods cells broken down quickly due to the IMHA. Normally, these reactions are mild and can be managed with supportive care but very rarely a severe reaction can be seen.
The prognosis when there is an underlying cause will depend on what the cause is. Infectious causes are very treatable, but some cancers do unfortunately carry a poor outlook. The prognosis for primary IMHA is variable. Unfortunately, either due to severity of disease or its complications, IMHA can be life threatening and despite treatment some animals will not survive; usually we will know this within the first 7- 1 4days after diagnosis as animals that do not do well often do not survive to hospital discharge. Dogs and cats that respond to immunosuppressive medication can do well and often can be weaned off treatment gradually although there is a risk they may relapse later in life (this could be weeks, months or years later or sometimes never). Only about 15% of dogs/ cats are thought to relapse after an initial promising response and disease control.
Anal Sac Adenocarcinoma
What is anal sac adenocarcinoma?
Anal glands sit just inside the anus and produce a (often strong smelling) secretion which is emptied onto the faeces as the dog or cat defecates.
Anal sac adenocarcinoma is a tumour which develops from the lining cells of these glands. They account for approximately 2% of canine skin tumours. This tumour can be metastatic, which means it can spread to other locations (malignancy).
It most commonly spreads to the local lymph nodes (glands) which sit in the abdomen, just below the spine and in front of the pelvic bone. Anal sac adenocarcinoma can also spread into other tissues, most commonly the spleen, liver, and lungs.
It can also be associated with high blood calcium levels (hypercalcaemia) as the tumour cells can produce a hormone which causes release of calcium from the bones. This occurs in in 16% to 53% of cases.
Signs and symptoms of anal sac adenocarcinoma
Some of the signs and symptoms of anal sac tumours in animals include:
- A lump or mass close to the anus that may bleed or cause irritation.
- Straining to defecate with altered faeces shape e.g. flattened faeces rather than rounded.
- Increase thirst, drinking and urination due to hypercalcaemia, and possibly reduction in appetite.
When a mass is found, your vet might suggest that a fine needle aspirate (where a needle is inserted into the mass and cells taken out) or surgical biopsy is performed to define the origin of the mass better.
Testing may include blood samples for haematology (to look at red and white blood cells) and biochemistry (looking at organ function, blood calcium and other parameters).
Further diagnostic imaging may be performed to assess the tumour and search for any spread, which could include computed tomography (CT) or x-rays of the chest, x-rays or ultrasound of the abdomen.
What are the treatment options?
Treatment options for anal sac adenocarcinoma are tailored to the individual patient and centred around maintaining a good quality of life. This could include a combination of treatment options such as surgery alone, surgery and chemotherapy, palliative radiotherapy, chemotherapy alone or palliative care.
The aims of treatment include:
- Controlling the level of blood calcium if high (medically). This may be achieved through fluid therapy or medication and can be done prior to surgery, although ultimately removal of the tumour will often normalise the calcium levels.
- Controlling the primary (original) tumour. This involves surgery to remove the affected anal gland and the tumour. This will reduce the tumour burden and reduce side effects of the original tumour such as irritation of the area and difficulty defecating. This may need to be followed up by chemotherapy and/or radiotherapy. Chemotherapy can sometimes also be used to reduce the tumour size prior to surgery and to reduce the risk of post-operative complications.
- Controlling local spread to the lymph nodes (by surgically removing them). If the disease has been shown to spread only to the local lymph nodes (glands) then these can be removed surgically through an abdominal approach. Radiotherapy or chemotherapy might be advised after surgery.
- Preventing or delaying disease progression if surgery is not performed or after surgery. Chemotherapy can be continued after surgery (once the surgical site is healed) to delay any remaining cancer cells from forming tumours. If surgery is not possible or the cancer has spread to multiple sites, then chemotherapy can be useful in controlling/stabilising the disease and trying to reduce tumour size.
We may recommend repeating imaging such as a CT or abdominal ultrasound after surgery or finishing chemotherapy to detect disease reoccurrence as early as possible.
What is the prognosis?
As anal sac adenocarcinoma tumours can spread, many animals are unable to be cured but their quality of life can be improved for long periods of time. The average life expectancy following appropriate therapy (such as surgery, chemotherapy, radiation therapy) is highly variable (between 12-30 months) and is affected by size of the tumour, if it has spread, the growth rate and other concurrent factors like high blood calcium levels.
What is atlanto-axial instability?
The atlanto-axial (AA) joint is the joint between the first (atlas) and second (axis) vertebrae (bones) in the neck. It is different from other joints in the vertebral column (spine) as there is no intervertebral disc present. Instead the AA joint is stabilised by ligaments – this allows the head to move from side to side.
This condition is typically the result of a congenial malformation of bones or ligament at the AA joint and that leads to this joint being unstable. This instability may lead to excessive movement (subluxation) resulting in a trauma and compression of the spinal cord.
We typically see AA instability in miniature and toy breeds, often less than 2 years of age. However any breed can be affected. It is also possible to develop AA instability following trauma to the neck.
What signs are associated with AA instability?
Onset of signs can be acute (sudden) or chronic (long) and intermittent depending on the specific abnormality. Clinical signs can vary from neck pain only, to dogs with tetraplegia (no movement in all four limbs) with respiratory difficulty.
How do we diagnose AA instability?
Diagnosis of AA is usually based on a combination of signalment (age, breed), history, corresponding neurological examination that identifies neck pain with or without neurological deficits, and diagnostic imaging.
X-rays of the neck can be useful for diagnosing AA subluxation however they only provide limited information about the abnormalities and will not provide information about the spinal cord. Therefore, in many cases further imaging such as MRI or CT (or both) may be required. An MRI scan will give information about spinal cord injury whilst the CT scan enables better visualisation of the bones and is needed for planning surgery.
What is the treatment for AA?
There are two main treatment options for AA instability: medical management or surgery.
Medical management involves strict cage rest and pain-relief. Sometimes we will discuss using a short-term bandage or splint. This may be beneficial in dogs with mild clinical signs however surgery is indicated in most patients.
The aim of surgery is to stabilise the AA joint in a normal position. This would hopefully alleviate any neck pain, stop the spinal cord from sustaining any further injury and allow the spinal cord to recover from injury. Commonly the surgery performed involves placing bone screws into the first and second cervical vertebral and connecting the screws together with a specialist bone cement. This surgery is complex due to both the location of the problem and the size of the patients and therefore should only be performed by a surgeon with advanced training. The prognosis tends to be better in dogs that show clinical signs when young and are walking at the time of surgery.
Cruciate ligament rupture and Tibial Plateau Levelling Osteotomy (TPLO)
My pet has a ruptured cruciate ligament. What does this mean?
There are two cruciate ligaments in the knee (stifle joint) of dogs, the cranial cruciate ligament (CCL) and the caudal cruciate ligament, and their job is to prevent forward/backward movement and rotation of the joint. The cranial ligament is usually the ligament that ruptures, and this causes over extension and internal rotation of the knee joint.
What causes the ligament to rupture?
The most common cause is progressive degeneration of the ligament, the reason for which is still elusive despite years of research. Abnormal conformation and gait, shape of the tibia (shin bone), obesity, and lack of fitness have been suggested as a cause but not proven.
Signs and symptoms
Lameness is the main symptom of cruciate rupture, and this can be sudden in onset or more gradual. The severity of lameness can also vary from mild to almost non-weight-bearing. This is often related to the type of cruciate ligament disease:
1 – Partial rupture:
Typically seen in young, large breed dogs. Lameness can be mild initially but becomes worse with progressive ligament degeneration. Usually, the ligament will go on to rupture completely.
2 – Complete rupture:
This is usually seen in middle-aged dogs, and the ligament may rupture during normal exercise. Lameness is usually marked, and this can improve initially but typically dogs remain with a limp.
3 – Traumatic rupture:
Sometimes there is a history of trauma such as a road traffic accident or getting a leg stuck when jumping over a fence. Lameness is usually sudden in onset and severe.
Diagnosis is not often made on clinical examination alone; knee joints in dogs with long-standing CCL rupture often are not markedly painful on manipulation, and it can be difficult or impossible to assess the integrity of the ligament in conscious dogs, especially those who are tense. Suspicion is usually raised when a firm swelling on the inside of the knee is felt, and there may be muscle wastage around the thigh.
Diagnosis is confirmed when the dog is sedated or anaesthetised for further palpation of the knee and radiographs. Two tests to check for ligament rupture are ‘cranial draw´ and ‘tibial compression test’, which are positive when the ligament is ruptured. Sometimes the tests are falsely negative if the rupture is only partial, and in these cases a presumptive diagnosis is often made on the radiographic findings. Signs on radiographs include arthritic changes and joint effusion (an increase in the normal volume of joint fluid).
What is the treatment for cruciate rupture?
Surgery is usually recommended, though some small dogs e.g. those <10-15kg will improve with conservative treatment (a 4-6 week period of rest, anti-inflammatories, and weight control followed by a controlled return to exercise).
There are numerous different surgical techniques for the treatment of cruciate rupture, though the most common, and the type we usually perform at Cave Veterinary Specialists, is the tibial plateau levelling osteotomy (TPLO).
What does TPLO involve?
Unlike humans, dogs and cats walk on their tiptoes with their knees bent forward. Normally, when forces are applied down through the thigh bone (femur) across the knee joint to the tibial plateau (the weight-bearing surface of the tibia), the CCL prevents forward-backward movement of the joint by preventing the femur from moving backwards. When the CCL is ruptured, this movement is no longer controlled and during weight-bearing the femur ‘slips’ because the tibial plateau slopes backwards.
During tibial plateau levelling osteotomy, a curved cut is made in the top of the tibia, allowing rotation of the tibial plateau. The bone is secured in its new position with a metal plate and screws. The aim of rotation is to alter the angle of the tibial plateau to eliminate the need for the cranial cruciate ligament; the femur is less prone to slipping down the tibial plateau when the dog/cat bears weight, therefore joint stability is improved.
During surgery, the joint itself will be examined by an ‘arthrotomy’ (incision into the joint) to assess the cruciate ligament and the menisci. The menisci are cartilage cushions that act as shock-absorbers in the knee, and there is one on each side. Sometimes, in association with cruciate ligament rupture, there is a meniscal injury due to the instability of the joint. Usually, it is the inside (medial) meniscus that is torn, and this is painful. Treatment involves surgical removal of the torn portion.
Are there any possible complications?
TPLO is a major surgery that is technically difficult, therefore complications are possible.
Minor complications include swelling around the surgical site, wound discharge, patellar ligament strain and superficial wound infection.
Major complications include deeper infection (which will require antibiotics and sometimes removal of the plate and screws), fracture of the tibia, and breakage of the plate or screws. Occasionally a meniscal injury can develop after TPLO surgery, and this unfortunately requires another surgery to remove the injured portion. The proportion of dogs that develop a complication and require further surgery is reported to be between 2 and 10%.
Most pets make a very good recovery from surgery and will be using the leg within a few days. Use of the leg should continue to gradually improve, with over 90% of dogs making a full recovery by around six months. Long-term, it is inevitable that some arthritis will develop in the joint despite surgery. The severity and consequence of this depends on the individual i.e. it may never cause a problem, but some dogs will develop lameness.
How shall I look after my dog following surgery?
You will be provided with a separate sheet detailing post-operative care. Briefly, this involves an initial period of strict rest for between 6-8 weeks. Use of a cage is usually required to limit exercise, with controlled short lead walks only. Exercise limitation must be continued until there is good radiographic evidence of bone healing. Pain killers are given for around 7-14 days to ensure comfort. Usually, we will ask you to bring your dog back to us for radiographs between 6-8 weeks after the operation. If we are happy with your dog’s progress, we will then advise a gradual return to exercise over a further 6-8 weeks.