Home Staff Services Contact Us Info Gallery Links News


emergencies greatdane

HomeStaff Services Contact Us Info Gallery Links News

© 2007 St Mary's Veterinary Clinic. All rights reserved.

Myxomatosis in rabbits

Cause

Myxomatosis is caused by the rabbit myxoma virus. The virus is spread by biting insects especially fleas and mosquitos. It does not infect other species and there is no risk to your dog or cat should they eat a wild infected rabbit. Your dog or cat may act as a carrier of infected fleas and hence transmit the disease.

Signs

Myxomatosis causes swelling of the eyelids, ears, nose and genitalia. There is usually a purulent conjunctivitis. Initially infected rabbits may continue to eat. As the disease progresses they become lethargic and anorexic. Death often occurs from pneumonia 2 weeks after the initial signs. The mortality is almost 100%

Treatment

There is no treatment and given the certain outcome euthenasia is advised once the diagnosis is confirmed.

Prevention

Vaccination is effective. Rabbits should be vaccinated at least yearly and twice yearly if disease is present in the local wild or domestic rabbit population. The use of topical insecticides to control fleas and housing rabbits at night in hutches with mosquito netting may also help.
Back

Dental disease in rabbits

Causes

Rabbits teeth grow continuously and are worn down by the fibre content in the food and by opposing teeth. The causes of overgrown teeth are multiple and include genetics, diet, trauma and infection. If teeth are misaligned due to the lower jaw being too narrow or too short then tooth overgrowth will occur at an early age. If teeth are damaged by infection or trauma then individual teeth may start to overgrow at a later age. Incorrect diet with low fibre or low calcium can also cause overgrowth due to insufficient wear or misalignment from teeth moving in soft jawbones respectively.

Signs

Overgrown incisors are easily seen. Overgrowth of the molar teeth is difficult to see due to the small mouth and limited opening of the jaw. Rabbits with molar overgrowth may be bright and alert but refuse or drop food from the mouth. Saliva dribbling and weight loss occur as the condition progresses. Soiling of the perineal area with feaces may also be present.

Treatment

If incisor teeth become overgrown they can be trimmed to a normal length. This often requires doing every 2-4 weeks. It is not advised to attempt trimming them yourself with nail cutters as this may fracture the tooth along its length resulting in painful root disease. The incisor teeth are best trimmed using a high speed rotary dental burr. A permanent alternative is to have the incisor teeth extracted under a general anaesthetic. Food will need to be chopped into short lengths but otherwise rabbits will do well after extraction.
Molar teeth, when overgrown, often produce sharp spurs that cut into the tongue and cheek. Removal of these spurs produces rapid relief to the rabbit. This requires to be done under a general anaesthetic. Due to the continued growth of the molar teeth this often needs to be repeated every 4-6 weeks.

Prevention

As some genetic component may be present affected rabbits should not be used for breeding. Individial rabbits should be feed a high fibre diet based on grass and hay.
Back

Flystrike (myiasis) in rabbits

Causes

Flystrike is common in the warmer months when fly activity is at its greatest. The area usually affected is around the anus and genitalia extending up over the rump. The rabbit often has a history of soiling and dermatitis around this area. Flies are attracted to the soiled area and lay their eggs on the skin. The larva hatch feeding on the tissue an tissue fluids. Enzymes secreted by the larva cause further injury.

Signs

Affected rabbits are usually depressed and often anorectic. The affected areas appear inflammed and skin may be denuded to expose underlying muscle. Maggots of varying sizes may be present. Early stage maggots or larvae are very small (1-2mm), translucent and difficult to see. More mature larvae are whitish and about 1cm long.

Treatment

The area is often very sensitive and sedation may be required to allow the area to be cleaned and the maggots removed. As early stage larvae are difficult to see and older maggots can hide in anal and genital openings antiparasitic treatment is normally given. the exposed tissue is likely to be infected so antibiotics are given in addition. Even large affected areas can heal by themselves if kept clean.

Prevention

Check your rabbits bottom daily! If regular soiling is present then have your rabbit examined to look for an underlying cause. Use an insecticidal product licensed for the prevention of flystrike.
Back

Sore hocks (ulcerative pododermatitis) in rabbits

Rabbits do not have foot pads like cats and dogs. The foot is cushioned by thick fur. This can make them prone to injury of the underside of the foot, especially the hind foot. "Sore hocks" is a misnomer as the hocks are nor usually affected.

Causes

Multiple causes contribute to the developement of ulcers. These include poor flooring (irregular, rough, wire mesh), soiled bedding, frequent thumping bruising the skin, obesity, inactivity and heriditary factors such as thinly haired skin on the foot.

Signs

Affected rabbits show signs of discomfort and reluctance to move. The underside of the hind foot is bald and ulcerated, may bleed or have thick scabs present.

Treatment

Antibiotics are given to treat secondary infections. The rabbit must be housed on clean, dry deep litter. Bandaging may be helpful if the rabbit will tolerate it. The condition is difficult to resolve and infections can extend to the underlying bone if left untreated

Prevention

Make sure your rabbit does not become overweight. House on deep clean litter. Do not use mesh floor caging. Allow plenty of exercise.
Back

'Conjunctivitis' in rabbits (dacryocystitis)

Discharges from the eyes of cats and dogs are usually associated with a conjunctivitis. With rabbits it is much more likely to involve the tear duct (dacryocystitis)

Causes

Infectious causes include Pasturella and Staphylococcal bacteria. The infection is often localised in the tear duct. Inflammation and pus can cause obstruction of the duct. Tears and discharge will then overflow down the side of the face. The tear duct courses from the eye to the front part of the nose. Along the way it passes close to the roots of the molar and incisor teeth. Dental disease resulting in movement of the teeth roots can cause obstruction of the duct. Nasal infections can extend into the tear duct. High ammonia levels due to infrequent cleaning of the hutch and poor ventilation result in chemical irritation to the eyes and nasal lining predisposing to infections.

Signs

Milky white discharges may be seen on the eyelid margins or running down the face. With complete tear duct obstruction watery tear overflow may be the main sign. Fur on the side of the face below the eye is often damp or matted. The skin under the eye may become inflammed due to the constant wetting.

Treatment

The infection is usually focused in the tear duct. Antibiotics placed on the eye depend on normal drainage to reach the tear duct. If partial or complete blockage of the tear duct is present then this will not occur and treatment will fail. Flushing the tear ducts under local anaesthetic will remove the obstruction and allow antibiotic penetration. Oral antibiotics may need to be combined with eye drops to deal with underlying nasal infections. If the primary problem relates to tooth roots impinging on the tear duct or scarring of the duct is present then the signs may never resolve completely. In these cases treatment revolves around minimising the effects, especially the tear overflow causing facial dermatitis. Clipping the fur to prevent matting and applying vasaline to the skin to prevent wetting will help keep the skin healthy.

Prevention

Provide a high fibre diet to reduce the chance of developing dental disease. Clean the hutch regularly. Do not obstruct the ventilation by covering the hutch front in an attempt to keep the rabbit warm in cold weather.
Back

Arthritis

By far the commonest form of arthritis is degenerative joint disease (DJD). This the classic arthritis of older dogs and people. It is less prevelant in cats. It is characterised by a degeneration and thinning of the cartilage and production of new bone around the edges of the joint. The cartilage is the cushioning on the ends of the bones that also lubricates movement between them.

Causes

DJD is not a single disease but an end state which may have multiple causes. Trauma (physical injury) to the joint, either a single severe event or low grade wear and tear is a common cause. Having abnormal joints such as in hip dysplasia, elbow dysplasia or angular deformities of the leg predispose. Aging, on its own, or coupled with obesity may result in DJD in the absence of other factors.

Signs

Often the initial sign is stiffness after resting. This is usually most noticeable in the morning on waking. Your pet may show reluctance to go up stairs, jump or play. The affected joint may become swollen due to new bone or increased fibrous tissue (grissle) around the joint. Your pet may show pain on manipulation of the joint

Treatment

Treatment involves a number of approaches.

Prevention

The use of breeding programs to reduce the level of hip and elbow dysplasia will help to reduce the level okf disease in those at risk breeds. In individual animals a good diet during the growing stages and keeping weight under control is sensible. High impact and exercise involving twisting and turning stresses on the joints can increase the risks. Such exercise should be built up gradually over time so the structures around the joints have time to strenghten and protect the joint. Back

Kennel cough

A common highly contagious disease of the dog.

Causes

The bacteria Bordetella bronchiseptica and a number of viruses the most significant of which is Canine parainfluenza virus. The more severe signs are caused by Bordetella infection or bacterial infections secondary to viral infections. Viral infections on thier own are thought to produce minor signs only. The infection is most likely to be contracted where there is a high concentration of dogs such as kennels or shows.

Signs

Signs vary from a mild cough to a severe persistent coughing, gagging and retching. The retch is often thought to be due to something stuck in the throat. Exercise, excitement or pressure on the throat exacerbate the signs.

Treatment

No treatment is needed if the symptoms are mild and thought to be due to a viral infection. Severe signs are treated with antibiotics effective against Bordetella and likely secondary bacterial infections. Rest and avoiding situations that trigger coughing are helpful. Avoid contact with other dogs while symptomatic. Some dogs may remain infective for weeks after apparent recovery.

Prevention

Vaccination against Bordetella is useful if your dog is to be kenneled or attending shows. Routine vaccination of pet dogs is optional.
Back

Abscesses, cats

Causes

Abscesses are one of the commonest bacterial infections seen in cats. They are almost always caused by cat bites. The rapid healing of puncture wounds results in the trapping of bacteria beneath the skin. Growth of these bacteria coupled with an influx of inflammatory cells results in the formation of a large pocket of fluid pus under the skin.

Signs

Abscesses present as a soft painful swelling. The limbs, tail head and head are common sites. If the limb is involved the cat is often lame. Poor appetite and depression often occur.

Treatment

Early abscesses may respond to antibiotics alone. Mature abscesses require drainage in addition. Often part of the overlying skin will be dead and can be punctured to allow drainage without the cat feeling anything. If this is not the case then heavy sedation or anaesthesia is needed to allow a skin incision and drainage. The hole made is left open to allow continued drainage.

Prevention

Neutering and keeping cats in at night will reduce fighting. If a bite wound is found prior to abscess formation antibiotic cover will prevent this happening. Cats that get bitten are also at risk of FIV infection.
Back

Feline immunodeficiency virus

Causes

Feline immunodeficiency virus (FIV) infection is common, the prevelance is 13-19% in sick cats and 2-3% in healthy cats. It is more common in middle age to older cats, especially males. The virus is found in various body fluids including saliva. Transmission is thought to be through bite wounds. After an initial illness the cat becomes asymptomatic and appears healthy for many years. The final period of illness is generally related to suppression of the immune system causing infections, wasting syndromes or neoplasia

Signs

A wide range of signs are possible reflecting the variety of opportunist infections or tumours. Signs may include weight loss, lethargy, inapppetence, mouth infections, eye discharge, nasal discharge, chronic diarrhoea and fevers. The commonest cancer associated with FIV is lymphoma. Diagnosis in ill cats or in healthy cats, say after a bite wound, is with a blood test. Testing after bite injuries needs to be delayed for 3 months or false negatives may be obtained.

Treatment

Antiviral drugs are available but they are expensive,and may be associated with severe side effects. Cats should be restricted to both prevent spread of the virus to other cats and to protect them from oppurtunist infections. Infections can be treated but the response is often slower than in an unaffected cat.

Prevention

There is no vaccine against this virus. Restricting cats indoors, at least at night, and neutering will reduce the risk of fights and hence contracting the infection.
Back

Feline leukamia virus

Causes

Feline leukaemia virus (FeLV) is an important infection in cats. The prevalence of infection in healthy cats is about 1-2% and 11-17% in sick cats. Young cats are more susceptible than older cats but there is no age at which the risk is zero. Persistently infected cats secrete the virus in their saliva. The main means of transmission is thought to be through mutual grooming. From the mouth it spreads to the lymph nodes and bone marrow. Most cats clear the virus but a proportion become persistently infected and will become ill with one or more of a variety of diseases.

Signs

The signs of FeLV infection may be delayed for several years after infection and depend on the type of disease that develops. The commonest disease is a cancer called lymphoma. This may affect the gut causing vomiting and diarrhoea, the kidneys causing increased drinking, urinating and weight loss, the chest causing breathing difficulties, or signs may be one of a vague illness and weight loss. Despite the name few cats get leukaemia. Effects on the bone marrow and blood cells may produce weakness due to anaemia or an increased rate and severity of infections due reduced numbers of white cells that fight disease. Diagnosis of FeLV infection is by a blood test.

Treatment

There is no treatment for the viral infection itself but some of the resulting diseases can be treated. Secondary infections may respond to extended courses of antibiotics. Certain types, but not all types of associated anaemias may be treatable. Lymphomas can be treated with chemotherapy. The overall outlook is poor with the majority of cats surviving less than 3 years after diagnosis.

Prevention

Vaccination will provide a measure of protection but is not 100%. Cats that are already infected but assymptomatic do not benifit from vaccination. Infected cats are a source of infection for other cats and should remain isolated. Transmission requires direct cat to cat contact and it is unlikely to be transmitted on clothing. Isolation also reduces the risk of secondary infections in the immune compromised affected cat.
Back

Anal sac(gland) disease

Causes

Anal glands or anal sacs are broad bean size and positioned at 4 o'clock and 8 o'clock to the anus. The ducts empty at the anal opening. They consist of small sacs lined with glandular tissue and full of liquid secretions. The secretions are normally emptied when the animal defecates. Disease of the glands is most common in the smaller breeds.Soft faeces, abnormal anatomy, abnormal secretions, scarring from previous disease episodes and anal skin bacteria can all contribute to disease. The glands may become impacted, infected or abscessated.

Signs

Signs are usually one of irritation such as 'scooting' (rubbing their bottom on the floor), low tail carraige or biting around the base of the tail and flanks. If abscessation has occured then discomfort on defecating, depression and loss of appetite may occur. If the abscess ruptures some of the signs of pain may diminish.

Treatment

Simple impaction requires manual expression of the glands by squeezing them together and upwards. Some glands are quite deep and need to be expressed by inserting the index finger into the rectum and squeezing between the thumb on the outside and index finger. If infection is present then antibiotics are instilled directly into the anal sacs. This often requires sedation. Abscessation may require lancing and flushing under sedation and oral antibiotics.

Prevention

If the stools are soft, the addition of fibre to the diet may help with emptying of the anal glands during defecation. Regular evacuation of the anal glands may reduce the risk of abscessation or impaction in those animals with a prior history of problems. Surgical removal of the glands will eliminate future problems.
Back

Flea allergy dermatitis

Causes

Flea allergy dermatitis (FAD) is the commonest skin condition seen in cats and dogs. The species of flea involved is usually the cat flea. The allergic reaction is to the flea saliva. Animals in multi-pet animals are often affected as more animals mean more chance to bring fleas into the home. Free ranging cats are the most likely culprit to bring in the fleas.

Signs

Only one animal in a home may be affected as the allergy is specific to that animal. Non-allergic animals may show very few signs with a low flea burden where as an allergic animal may react severely to just one flea. Dogs with FAD have severe itching, hair loss, scaling and crusting of the skin. The skin lesions predominantly affect the rump, tail head and thighs but may also affect the underside of the abdomen. Cats may show less itching but have similar skin signs. Some cats may only have hair thinning and loss or raised reddened plaques (eosinophilic granuloma complex).

Treatment

Flea control is paramount. All animals in a house must be treated with an effective insecticide. Using a pet shop or supermarket product may only suppress the level of fleas so they appear to have gone but still allow adequate numbers to continue the FAD. The same may happen if only apparently affected animals are treated. Contact us for advice on suitable products. Treatment of secondary skin infections with antibiotics and the use of steroids to reduce self inflicted damage may be needed. The additional use of enviromental flea growth inhibitors which prevent flea larva in the carpet from developing into adults may also help.

Prevention

To prevent further episodes flea treatment must be continued for the life of the animal.
Back

Hypertyroidism in cats

Causes

The signs of hyperthyroidism are caused by enlarged and overactive thyroid glands producing excess thyroid hormone levels in the blood. The enlargement is generally of a non-cancerous type. Thyroid glands are positioned in the neck either side of the trachea (wind pipe). The enlargement is not usually sufficient to be noticable by pet owners.

Signs

Hyperthyroidism is a common condition of the middle aged to older cat. A number of signs may be present. Not all signs are present in all affected individuals Diagnosis needs to be confirmed by measuring the levels of thyroid hormone in the blood

Treatment

There are three treatment options available for hyperthyroid cats
Surgery This is the surgical removal of the affected thyroid glands. As the patient may be in poor general health due to the effects of the disease, surgery is often preceded by a month of medical stabilisation using the drugs discussed below. One or both glands may need to be removed. Risks associated with surgery include general risks associated with anaesthesia and surgery and also damage to the parathyroid glands. These tiny glands are attached to the thyroid glands and their blood supply can be compromised during the surgery. They control the blood levels of calcium and if significantly damaged a life threatening drop in calcium levels can happen. This requires prompt and sometimes lifelong medical treatment. This is a rare complication and can only occur if both thyroid glands have been removed. More common (10%) is a return of hyperthyroidism due to growth of thyroid remnants or ectopic thyroid tissue which can occasionally be found outside the thyroid gland in normal animals.
Drug treatment Drugs to block the production of thyroid hormone can be used. This is life long treatment. Blood tests need to be done to establish the correct dose in each animal and to monitor for any adverse effects. Repeat testing on a regular basis throughout the cats life will be required. Dosing may be once, twice or three times daily depending on test results. the medication also comes in 2 strengths. Stomach upsets are quite common initially but will resolve with continued medication. Other rare side effects include bone marrow or liver damage. A major disadvantage over surgery is the need to give tablets on a regular basis.
Radioactive iodine Radioactive iodine is injected into the patient and is taken up by the overactive thyroid gland tissue. The affected tissue is then destroyed by the radiation. This would appear to be the best option but is only available in a few specialist facilities due to regulations on handling of radioactive substances. Post treatment hospitalisation, again due to safety regulations may be several weeks.

Prevention

No method of prevention is available
Back

Diarrhoea

Diarrhoea is a common presenting complaint in dogs and to a lesser degree, cats. Most cases of diarrhoea are of short duration (acute) and respond to symptomatic treatment. As a result the cause is often not discovered.

Causes

Acute diarrhoea is often caused by dietary indiscretion such as eating food not normally given or eating spoiled food. Changing diets may cause diarrhoea if done rapidly especially in puppies. Internal parasites such as roundworms may also cause diarrhoea in puppies. A number of viruses can be implicated such as parvovirus, coronavirus and rotavirus. Bacterial causes include Salmonella, Campylobacter, E.coli, and Clostridia.

Signs

Diarrhoea is the production of liquid or semi-liquid faeces. The consistency can vary from porridge like to almost pure water. Colour may be normal, bright yellow, or dark. Blood may be present, either fresh in appearance or black as a result of digestive enzymes. Irritation of the bowel may result in clear mucoid material. An affected animal may be otherwise normal or be lethargic and off its food. Vomiting often accompanies diarrhoea.

Treatment

Treatment depends on the severity. Mild diarrhoea often resolves with the feeding of a easily digestible diet of chicken or white fish with white rice or pasta. Withholding food for 24 hours may also be helpful. If parasites are suspected these are treated. If fluid loss has resulted in dehydration then the use of oral rehydration fluids will benefit the animal. If this is not possible due to vomiting then fluids will need to be given intravenously (into a blood vessel). As most acute diarrhoea is not the result of a bacterial infection then antibiotics are not usually needed. Those that are caused by bacteria often resolve themselves without antibiotics. The use of antibiotics is generally restricted to animals with an elevated temperature, marked depression, intestinal bleeding, abnormal blood results, confirmed or highly suspected bacterial involvement. Intestinal protectants such as kaolin appear to be beneficial. Probiotics (‘normal’ bacteria) can also be used to help normalise the bacterial flora.

Prevention

Regular worming especially of young animals and avoidance of sudden diet changes will help minimise episodes of diarrhoea. Many dogs are scavengers by nature and this can be very difficult to stop. Exercise your dog in an area you can have a clear view of its activities and spend plenty of time working on the command ‘leave’ followed by the recall and a reward! Do not be tempted into giving leftovers especially spicy or fatty foods.

Feline cystitis

Causes

Feline cystitis is part of a group of conditions grouped under the term Feline Lower Urinary Tract Disease (FLUTD). This section only discusses the non-obstructive forms. Overweight, sedentary, indoor cats seem most at risk. Causes include bladder stones, behavioural problems, anotomical defects and rarely bacterial infections. In the majority of cats no obvious cause is found and it is termed idiopathic cystitis.
It has been suggested that idiopathic cystitis may be stress related. Nerves from the brain can stimulate the bladder causing inflammation. It has also been suggested that a defect in the mucus lining of the bladder can allow noxious substances in the urine to irritate the bladder wall. It may be that both these factors are present or one may cause or exacerbate the other.

Signs

These include an increased frequency of urination of a reduced volume possibly stained with blood. Urination is often in abnormal places with the bath being a common location.

Treatment

If a specific cause is present then this needs to be treated. Bladder stones may require surgery or a special diet to dissolve them. On the rare occasions that a bacterial infection is present then antibiotics are required.
Without treatment cases of idiopathic cystitis often resolve over 5-10 days. Repeat episodes often occur. When treated the following may be helpful:

Prevention


Back

Feline stomatitis

Causes

The exact cause of stomatitis is unknown. It has been linked to feline calici virus, feline immunodeficiency virus, bacterial spirachaets, food sensitivities and abnormal immune responses. It is likely that more than one factor may be responsible in an individual.

Signs

Cats with stomatitis may show oral pain with a reluctance to eat and drool saliva. When the inside of mouth is examined a raw inflammed mucosa is visible especially around the teeth and the angle where the top and bottom jaws meet.

Treatment

The condition is painful and an anti-inflamatory such as metacam can help to control this. As bacteria can be a major factor the use of antibiotics such as antirobe is common. Some success has been seen with the use of "classic cat foods" which may be related to food or food additive sensitivities. If viruses are implicated injectable inteferon, although expensive, may help. Some success has been reported using slippery elm tablets crushed in honey and used topically. A combination of treatments may be suggested.
If medical treatment fails then removal of all teeth apart from the canines is often successful. As a last resort the use of long acting steroid injections can be tried although serious side effects can occur.

Prevention

Good oral hygeine may help prevent this disease.
Back

Diabetes

Causes

Diabetes is caused by a lack of insulin in the blood. Insulin is produced by the pancreas and is needed to move glucose (sugar) from the blood into the body's cells. Glucose is the major energy source of the body's cells. It is absorbed from the gut as a result of carbohydrate digestion or it can be produced by the liver from protein and fat stores. If insulin is absent or insufficient then the blood levels of glucose rise until they "spill out" through the kidneys into the urine.

Signs

As the glucose is lost from the kidneys it draws out body water as well resulting in an increase in urine production which results in an increase need to urinate. To prevent dehydration there is an compensatory increase in drinking. These two signs are the classic polyuria/polydipsia (PU/PD) of diabetes. The energy/calories lost into the urine results in a compensatory increase in appetite. This increase is often insufficient as without insulin most of the calories are again going to be lost as glucose in the urine. This results in weight loss. A common complication in dogs is the development of cataracts. Untreated diabetes leads to metabolic complications known as ketoacidosis which is difficult to treat and often results in death.

Treatment

Treatment consists of giving twice daily insulin injections to replace the bodies natural insulin. This will reverse all the signs of diabetes. The dose needs to be tailored to the individual animal. An initial dose will be calculated and a test dose given with the pet staying with us for the day to monitor its blood sugar levels. If all is well you will be shown how to inject and will continue your pets injections at home for a week. If you have any problems with the injections we can help until you are confident to go solo. After a week your pet will spend another day with us during which we will again monitor their blood sugar levels. As a result of this we will adjust the dose and you will then continue at home with the new dose. After a further week we repeat the blood tests and again adjust the dose. This continues until the right dose is reached.
The amount of insulin required would vary depending on the amount and type of food and the amount of exercise. To minimise problems it is best to try to keep both as consistent as possible. Diabetic control in dogs is best when they are fed a high fibre diet such as hills r/d. Diabetic control in cats is best when they are fed a high protein diet such as hills m/d.

Prevention

Although a number of factors are known to contribute to an increased risk of diabetes the only one directly under the control of the owner is obesity. In dogs with diabetes prevention of cataracts is dependent on good control of the diabetes. Once cataracts develop surgery is the only option to restore sight.
Back

Causes

Signs

Treatment

Prevention


Back

Heart failure in dogs

Causes

The commonest cause of heart failure in dogs is a degenerative valvular disease. The heart valves are needed to ensure that each time the heart contracts the blood moves in a forward direction. If the valves degenerate and become leaky then blood can also flow backwards causing congestion upstream of the normal flow. The heart is divided into left and right sides. The commonest valve to be affected is on the left side of the heart. This side takes blood from the lungs and pumps it around the body. A degenerative valve results in leaking back towards the lungs which causes congestion and 'water logging' of the lungs. The resulting effect in the lungs is a bit like a soggy sponge. Degenerative valvular disease is most common in middle aged or older small breed dogs especially Cavalier King Charles Spaniels.

Signs

Many animals will have degenerative valves with no evidence of heart failure. More than 50% of Cavalier King Charles Spaniels over 4 years of age have evidence of valvular disease. This is usually detected as a heart murmur on a routine examination. It may be many years before symptoms develop. The primary signs of heart failure relate to the accumulation of fluid in the lungs. The reduced lung efficiency causes a reduced ability to exercise and heavier breathing in any given situation. The fluid also results in coughing. Both signs become more and more severe as the valvular degeneration worsens. Eventually the fluid accumulation becomes so severe that the animal will drown in its own body fluids.

Treatment

Several drugs are used in the treatment of heart failure. The primary drugs are diuretics which remove fluid from the lungs by causing it to be lost through the kidneys. Drugs may be used to dilate blood vessels upstream of the leaky valve thereby reducing the resistance to forward flow. This has the effect of increasing forward flow and reducing backflow. Drugs may be used to increase the contractility of the heart. Drugs may also be used to block adverse hormonal effects induced by the heart failure. Several of the commonly used drugs used may have more than one category of effect. Treatment reverses the signs of heart failure and increases life expectancy.

Prevention

There is as yet no way of preventing the development of heart failure. Dogs with heart murmurs but no heart failure are generally not medicated until they show clinical signs.
Back

Kidney disease in cats

This section will deal with the commonest kidney disease in cats: chronic renal(kidney) failure. Chronic renal failure is a common condition in the older cat. Although it is often advanced before it is discovered treatment can often slow its progression and improve the cats quality of life.

Causes

The underlying cause is usually unknown in an individual case. Possible causes include damage due to infection, kidney stones, immune disease, polycystic disease, neoplasia, trauma, drugs and toxins. A number of causes may contribute to a decline in renal function. Once a certain amount of function is lost compensatory mechanisms can themselves lead to further damage. The kidney is composed of thousands of hollow tubes each starting with a cup like structure. Inside the cup is a little tuft of blood vessels out of which the blood is filtered through the cup and into the tube. As the fluid passes down the tube it is altered by substances being reabsorbed into the blood or secreted into the fluid eventually forming urine. As the diseased kidneys lose more of these tubules each of the remaining ones must filter more blood. To do this there is an increase in blood pressure in the tuft of blood vessels. This increase in pressure and filtration can damage the whole tube which is then lost putting even more pressure on those remaining. The diease becomes self perpetuating.

Signs

The kidneys have a reasonable functional reserve so 2/3 to 3/4 of the kidney function must be lost before any signs are visible. The earliest and most common sign is an increase in water intake and associated increase in urine production. This is due to a loss of the kidneys' ability to conserve body fluids. Other signs include weight loss, reduced appetite, vomiting, anaemia and depression. These are due to a build up of products in the blood that are normally excreted or controlled by the kidneys. An additional factor causing anaemia is the reduced production by the kidneys of the hormone erythropoeitin which stimulates the production of red blood cells by the bone marrow.

Treatment

If a specific cause such as infection, kidney stones or neoplasia is discovered then specific treatment to prevent further damage to the kidneys can be used. Unfortunately once a certain amount of damage has been done the condition will progress even if the initial cause has been eliminated.
Two specific treatments have been shown to slow the progression of the disease and increase life expectancy. These are a low phosphorous diet and the use of an ACE inhibitor. Low phosphorous diets are available from vets in both dried and wet formulations in a number of flavours. To benefit from these diets they need to be fed exclusively as normal comercial diets and treats such as fresh chicken and fish have a high phosphorous level. ACE inhibitors have a number of effects, the major one in renal disease is probably reducing blood pressure within the kidney at the point where the blood is filtered. This pressure is normally increased in kidney disease and appears to be a factor in further damaging the kidneys.
Many waste products of protein metabolism are filtered by the kidney and hence in kidney disease build up in the blood. These substances are toxic to the body. The low phosphorous diets mentioned above are also generally lower in protein than standard cat diets and result in lower levels of these toxins. Again the most benefit is obtained if the diet is fed to exclusion of other foods. Fresh fish and chicken are almost 100% protein.
Waste products that build up in the blood can cause a feeling of nausea and inappetance. Some of this is directed through an increase in acidity in the stomach and can be improved by the use of antacids. Drugs are also available to directly reduce the feeling of nausea and also to stimulate the appetite although their effects are not always as good as one hopes.
Anabolic steroids are often used to combat weight loss and anaemia. Their effect is not well established and is thought to be over the longer term following repeated monthly injections.
To treat anaemia due to a deficiency in the hormone erythropoeitin, normally produced by the kidney, a synthetic human form can be used. Correction of anaemia can have a dramatic effect on the quality of the cats life. This is expensive and the effect is often short lived with the induction of antibodies which destroy both the injected hormone and the cats naturally produced hormone. The anaemia then rapidly worsens and is then untreatable.
Cats are not naturally big drinkers and often fail to compensate for the increased fluid loss through the kidneys. This can result in dehydration which further worsens kidney function. Diarrhoea, vomiting or inappetance all increase the risk of dehydration. In hospital administration of fluids intravenously can often improve matters temporarily. Long term use of injectable fluids administered under the skin at home can help maintain hydration. One must weigh the improved well being against the discomfort of repeated large volume injections.

Prevention

No method of prevention has been established but the sooner it is identified as a problem the better the outlook.
Back

Causes

Signs

Treatment

Prevention


Back

HomeStaff Services Contact Us Info Gallery Links News

© 2007 St Mary's Veterinary Clinic. All rights reserved.