Teresa Minniti, President of Give a Kitty a Home Rescue Inc
Give a Kitty a Home Rescue Inc. understands the serious nature of infectious diseases among Community Cats. Vaccination of cats is crucial !
The following information relating to Feline Infectious Diseases is credited entirely to:
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Feline Infectious Enteritis (Parvovirus, Panleukopenia Virus)
Feline infectious enteritis (FIE) is a disease caused by infection with feline parvovirus (FPV), also known as feline panleukopenia virus.
It is sometimes referred to as panleukopenia virus because one of the results of infection is the development of a low white blood cell count (which is what panleucopenia means).
Feline parvovirus infection is probably the greatest major disease threat to any rescue facility and infection carries a very high mortality rate, particularly in unvaccinated kittens.
This was the first disease of cats to be shown to be caused by a virus, and parvoviruses are particularly dangerous as they are able to survive for long periods (up to several years) in the environment, and are resistant to many disinfectants.
Feline parvovirus is spread by direct faecal-oral contact, and indirectly following contamination of the environment or objects (eg, on food dishes, grooming equipment, bedding, floors, clothing or hands). Cats infected with FPV can continue to excrete the virus for at least six weeks following infection, and the virus can also be transmitted by dogs.
In kittens over three or four weeks of age and in adult cats the virus causes a very severe gastroenteritis, following an incubation period of five to nine days. Affected cats develop acute onset haemorrhagic vomiting and diarrhoea and some cats die rapidly. The virus causes severe damage to the lining of the intestine and also travels via the blood to the bone marrow and lymph glands. Viral replication at these sites leads to a marked depletion of white blood cells. Infected cats and kittens usually have a fever, are obviously depressed and will not eat. Some cats may die before even showing signs of gastroenteritis.
Pregnant queens infected with parvovirus, the virus can spread to the unborn kittens where it can interfere with the developing brain. Kittens may then be born with a condition known as cerebellar hypoplasia (lack of development of the cerebellum, a part of the brain needed for fine coordination of movement). Kittens may initially seem fine, but as they start to move and walk it becomes obvious that they are highly uncoordinated. This may also happen in very young kittens (less than 4 weeks of age) infected with FPV as the cerebellum is still developing at that age.
No specific treatment is available for FPV infection and it is vital that any suspected cases are nursed in isolation as this is a highly contagious disease. Protective clothing must be worn and hands washed thoroughly after handling any cat or kitten suspected of having the disease. Where possible, one or two people who do not handle any other cats should be assigned as nurses.
Affected cats often die from dehydration and massive secondary infection, so aggressive support with intravenous fluids and broad spectrum antibiotics are crucial, but even with this, a high proportion of affected cats may die. Anti-emetic drugs may be useful to help stop vomiting, and feeding the cat small meals as soon as the vomiting has resolved is also important. Good veterinary and nursing care is vital to help cats, especially young kittens, recover from the disease.
Interferons are chemicals made in the body that can exert an antiviral effect. Recombinant feline interferon omega (or human interferon products) might be of some help in the treatment of severe cases. Feline interferon has been shown to be useful in managing dogs with parvovirus infection.
Feline parvovirus is much better prevented than treated. Highly effective vaccines are available and all cats and kittens should be vaccinated (including indoor-only cats). Modified live vaccines should not be used in pregnant queens or cats that are immunosuppressed and, in such cases, inactivated (killed) vaccines are recommended.
Control of the spread of FPV relies on both vaccination and good management practice, including disinfection (with appropriate disinfectants) and use of isolation procedures. When faced with an outbreak of FPV in a colony of cats, vaccinating all the cats will help, and in some countries anti-FPV serum is available that may be given to susceptible cats and kittens to help protect them by providing antibodies against the virus.
Feline calicivirus (FCV) is a highly contagious virus that is one of the major causes of upper respiratory infections (URIs) or cat flu in cats.
This virus is ubiquitous and causes disease in cats all over the world.
Feline calicivirus (FCV) is a small virus that mainly causes acute upper respiratory infections (URIs) in cats, although it has been associated with some other diseases also (see below). The virus is readily transmitted between cats through:
A characteristic of FCV is that the virus mutates readily during replication and this means that many different strains of the virus exist in nature, some of which are more pathogenic than others (ie, are a cause of more severe disease).
In most cases, a specific diagnosis of FCV infection will not be required. The presence of typical signs of URI is enough for a presumptive diagnosis of FCV (and/or feline herpesvirus – FHV) infection. If a specific diagnosis is required, ocular or oral swabs can be submitted to a veterinary laboratory where the virus can be grown in culture or, more commonly, detected by PCR (a molecular technique for detecting the genetic material of the virus).
FCV infections are frequently complicated by secondary bacterial infections, so supportive treatment with antibiotics is usually required. Good nursing care is critical and cats may need to be hospitalised for intravenous fluid therapy and nutritional support in severe cases. Steam inhalation or nebulisation may help in cases of severe nasal congestion and as the cat will not be able to smell food well, using tinned or sachet foods that are gently warmed will help.
In colonies of cats, any cat showing clinical signs should be isolated if at all possible, and strict hygiene should be ensured with disinfection, and use of separate feeding bowls, litter trays, implements etc, careful washing of hands, use of separate (or disposable) apron etc.
Vaccination for FCV is important for all cats. Two or three injections are recommended in kittens, starting at around 8 weeks of age. Cats should receive a booster at a year of age, and after that should receive further booster vaccines every 1-3 years.
Vaccination does not necessarily prevent infection with FCV but will greatly reduce the severity of clinical disease. Additionally, as there are many different strains of the virus, it is difficult to design a vaccine that will protect against all of them. Some newer vaccines incorporate more than one strain of FCV to provide a broader range of protection.
Feline calicivirus (FCV) is one of the major causes of feline infectious upper respiratory tract disease (cat flu).
Classical cat ‘flu’ follows a short incubation period of 3–5 days and consists predominantly of upper respiratory tract disease (sneezing, rhinitis, nasal discharge, conjunctivitis, ocular discharge and oral ulceration). These signs may be accompanied by pyrexia (raised temperature) and occasionally other manifestations, such as coughing and pneumonia.
From an early stage, transient lameness has also been observed as a clinical feature in some cats infected with FCV and it now seems clear that this is, in fact, a relatively common clinical manifestation of FCV infection. The transient lameness associated with FCV has acquired the name ‘limping syndrome’.
FCV was confirmed as a cause of lameness during early observations that showed kittens infected with FCV from other cats with limping syndrome developed pyrexia, depression and inappetence within 2-3 days. Within hours of developing pyrexia, the kittens also developed generalised or localised stiffness, manifesting as shifting lameness in some, and an almost complete reluctance to move in others. None of the cats developed sneezing or ocular discharge, but about one third developed oral ulcers (one of the classic signs of FCV upper respiratory infection). Clinical signs were reported to resolve within 48 to 72 hours with no residual effects. The joints were painful on touch/manipulation, and generalised hyperaesthesia (pain or hypersensitivity to touch) was present.
Further studies of FCV infection showed that FCV viral proteins could be identified in the synovial membrane (the membrane surrounding the joint space) in several cats either vaccinated with a live FCV vaccines and/or infected with FCV. Evidence suggests that the viral proteins are present in association with antibodies, and thus may be present as ‘immune complexes’ (a combination of the viral protein and a specific antibody produced against it) which can provoke an inflammatory response. In some cases, the entire FCV virus can be isolated from joints of cats exposed to FCV showing signs of disease including lameness, with evidence that the virus was provoking an acute inflammatory reaction.
It is therefore evident that after natural exposure to FCV, systemic infection arises which can, at least in some circumstances, involve localisation of the virus to joint tissues where it may cause an inflammatory reaction, possibly through local replication there or possibly through stimulation of immune-mediated inflammation. This is a form of viral-induced polyarthritis (joint inflammation affecting more than one joint).
It seems that certain strains of FCV have a greater propensity to cause lameness than others.
Limping syndrome associated with FCV infection is most commonly seen in kittens, and may occur after their first vaccination. Some vaccines may be more likely than others to induce limping syndrome but as manufacturers change and refine their vaccines this appears to be less common now. Additionally, even when occurring after vaccination, some cases of limping syndrome may still be associated with acquired FCV infection rather than the vaccine itself.
In summary, FCV clearly has the ability to cause a transient polyarthritis (inflammation affecting more than one joint) in cats, and most commonly in young kittens. This is a fairly common manifestation of FCV infection and may occasionally also be associated with FCV vaccination (especially live vaccines).
The severity varies widely from inapparent inflammation and mild limping, through to severe polyarthritis where the cats are reluctant to move, inappetent and the joints appear painful when touched.
Affected cats spontaneously recover, but if clinical signs are severe, anti-inflammatory medication may be required and your kitten or cat should be checked by your vet. Although FCV is obviously a common cause of limping syndrome in young cats, there are numerous other potential causes of lameness, and if clinical signs are severe, or persist for longer than a few days, veterinary attention should always be sought.
Cat flu, or upper respiratory infection (URI) is a very common disease that can vary considerably in severity, and on occasions can even be life-threatening.
In the vast majority of cases, disease results from infection with feline calicivirus (FCV) or feline herpes virus (FHV, or FHV-1). Clinical signs include sneezing, nasal discharge, conjunctivitis (inflammation of the lining of the eyes), ocular discharge, loss of appetite, fever and depression. Mouth ulcers, coughing, excessive drooling of saliva and eye ulcers may also be seen. Very young, very old and immunosuppressed cats are more likely to develop severe disease and possibly die as a result of their URI, usually due to secondary infections (such as pneumonia), lack of nutrition and dehydration.
Typical ocular and nasal discharges of cat flu.
Infection with feline herpes virus can cause serious eye damage.
URIs are common, as the causative viruses are widespread in cat populations. Typical risk factors include:
Most cat URIs are caused by infection with one or both of the cat flu viruses:
These two viruses are thought to be responsible for more than 90% of URIs in cats. Other important organisms that may be involved in some cases include:
The incubation period following infection with FCV or FHV is usually just a few days (2-10 days). After this, typical clinical signs develop which include:
The severity of these signs varies considerably – in some cats the signs are very mild and transient, in others they may be very marked and severe. There are some differences in clinical presentation between the two viruses, but these are not sufficient to be able to distinguish them simply from clinical signs:
Although FCV and FHV are viral infections, secondary infection with bacteria is common and can contribute to rhinitis (infection in the nose) conjunctivitis, and even lung infections. While most cats will recover from URIs, on occasions they can be life-threatening, and with severe infections the recovery may take several weeks. Some cats may also be left with permanent damage within the nose and may have persistent or recurrent nasal discharge (so-called ‘chronic rhinitis’).
In rare cases, a much more severe and often fatal form of FCV infection may occur. This is associated with particular strains of the virus that are highly virulent and termed ‘virulent systemic FCV’ (vsFCV) infection. Fortunately such infections are very rare (see: Feline calicivirus (FCV) infection).
Diagnosis by your vet is usually based on the typical signs associated with URIs, and exclusion of other causes. It is possible to confirm a diagnosis and to investigate which virus(es) are involved, but this is often not necessary.
Testing for FCV or FHV involves collecting a mouth or eye swab which is then sent to a specialised veterinary laboratory. Here the virus can be identified through culturing or by a PCR test (a molecular test to show the presence of the viral genes).
Treatment of URIs is largely symptomatic and supportive. Your vet may want to do some additional tests if they are concerned about the extent of disease (e.g., the possibility of pneumonia) or if they are worried about complications (such as infection with FIV or FeLV).
Antibiotics are indicated to treat secondary bacterial infections and to try to reduce the damage the infection causes. If nasal congestion is severe and breathing is difficult your vet may also suggest steam inhalation or nebulisation make discharges more liquid and more easily relieved by sneezing.
Affected cats are often reluctant to eat – they will have a poor sense of smell and eating may also be uncomfortable. Using soft, highly aromatic foods (for example kitten foods, fish in oil) that are gently warmed will help to tempt an inappetent cat. However, if anorexia is severe your cat may require hospitalisation for your vet to provide food via a feeding tube. This can be important, as poor nutrition will significantly contribute to disease and slow down healing. Intravenous fluids may also be needed if your cat is not drinking properly, to avoid dehydration. Analgesics may also be required.
Interferons are proteins that are produced in the body, in part to help fight viral infections. Injectable interferons may be used as a supportive treatment (either high doses of recombinant human interferons or recombinant feline interferon) – there is some evidence that this may be of benefit, but it probably needs to be given early in the course of disease for best effect.
There are a number of topical antiviral agents that can help to manage FHV-associated ocular disease (such as trifluoridine, idoxuridine and cidofovir). More recently a drug used to treat human herpes virus infections – famciclovir – has been shown to be safe and effective in cats when given orally. This is a major step forward in managing severe FHV infection in cats.
General nursing is also essential – discharges from the eyes and nose should be gently wiped away using damp cotton wool, and the cat should be kept warm and comfortable.
Most cats that recover from infection with URI viruses will become ‘carriers’. Carrier cats usually show no sign of illness but, may shed virus in saliva, tears and nasal secretions, and can be a source of infection to other cats.
Although almost all cats infected with FHV will remain long-term carriers, many of these will never shed significant amounts of virus. Others may shed virus intermittently, especially during times of stress. Some cats may show mild signs of URI again when they shed the virus, but most do not. Carrier cats in a breeding colony are a source of risk to their kittens, as the stress of kittening may induce shedding of FHV.
Most cats infected with FCV remain carriers of the virus, and continue to shed the virus for a period of weeks or months after infection, but the majority (although not all) will eventually eliminate the virus within a few months.
The viruses associated with URIs are spread in three ways:
What is Ringworm ?
Ringworm or dermatophytosis is an infection caused by a particular type of fungus that has the ability to grow on the skin and use the superficial layers of the skin, hair or nails as a source of nutrition. Collectively the fungi able to do this are termed ‘dermatophytes’.
Although ringworm is a common term used to describe dermatophyte infections, this has nothing to do with worms.
There are approximately 40 different species of dermatophyte fungi, each tending to cause infection in a particular host animal. In the cat, the vast majority of cases of dermatophytosis are caused by infection with Microsporum canis (M canis). This organism can also cause infection in many other species, including dogs and humans.
How do cats become infected with ringworm (M canis)?
Dermatophytosis is a contagious infection. During infection, thousands or millions of microscopic spores are produced around infected hairs and these are the main source of infection for other animals. Infected hairs and spores are shed into the cat’s environment so other cats may become infected either by direct contact with an infected animal or by exposure to a contaminated environment or object such as grooming tools, clippers or bedding. Spores in the environment can remain infectious for up to two years and are difficult to kill.
Spores will adhere to the skin and this can be the start of a new infection. Although intact skin is quite resistant to infection, any abrasion or damage to the skin will allow infection to develop more readily. Infection is more common in young cats (less than one year old), and in longhaired cats. Younger cats may have poorer natural skin defences and a less well developed immune response and it is possible that long-haired cats groom less efficiently so trapping of spores may be easier and removing of them more difficult.
The appearance of dermatophyte infections in cats is very variable. Some cats have severe skin disease, while other cats have only very minor lesions or no obvious lesions at all and may look completely normal.
Typical skin lesions are discrete, roughly circular areas of hair loss, particularly on the head, ears or legs. The hairs surrounding affected areas may be broken. The affected skin is often scaly and may look inflamed. However, ringworm can look very similar to many other feline skin diseases, including some of the clinical manifestations of flea allergy dermatitis, and may present as symmetrical alopecia or even feline acne. Some loss of hair is usually involved, but the amount of inflammation, scaling and itchiness is variable.
The clinical signs may suggest the possibility of dermatophytosis, but further investigations are needed to confirm the diagnosis and to rule out other diseases. Three diagnostic tests are commonly used:
If one cat in a household is diagnosed as having ringworm then all the other animals will need to be examined, even if they seem to be completely unaffected. In most cases all cats in a household will be culture-positive and require treatment. Please note that the absence of dermatophytes on microscopic examination of a skin biopsy does not rule out dermatophytosis.
Treatment is always advised because although most cases eventually resolve, infected cats are a risk to other cats and also to humans – M canis is an important zoonotic disease as it can be quite easily spread from cats to humans. In addition to treating the dermatophyte infection with anti-fungal drugs, any predisposing causes (such as other skin conditions) should also be managed.
Treatment can be either systemic (anti-fungal tablets or liquids given by mouth) or topical (applied to the skin). In most cases, it is best to use a combination of both systemic and topical therapy as this has the best effect. Topical treatment alone is rarely very effective, and should only be used in very young kittens if there is concern over using systemic drugs. In all other cases, systemic treatment is more important than topical treatment, although the latter can still be very helpful.
Several anti-fungal drugs are available that are usually very effective against dermatophytes although some may be better than others. Systemic therapy usually has to be given for a minimum of 6 weeks. Example include:
Topical therapy can play a very important role in reducing environmental contamination and helping to speed resolution of disease. A variety of preparations are available:
Careful clipping of the hair around infected areas will also be of benefit in helping to make treatment more effective and in reducing environmental contamination with spores.
Helping to prevent infection of other animals and humans by decontaminating the environment is important. This is much easier if infected cats can be restricted to one easily cleaned room. All areas of the house to which infected animals have had access will require decontamination, but efforts can then be concentrated on the room in which the cat(s) are confined.
Any objects such as collars, baskets, bedding, toys and grooming tools should also be regarded as contaminated and either disinfected or disposed of. Cardboard boxes can be used as temporary disposable beds and these should be disposed of at least once a week.
Decontamination is achieved by a combination of two approaches:
Where dermatophyte infections occur in multicat households, it is probably best and easiest to assume that all the cats are infected and treat them all appropriately. If cats are not already infected, the treatment they are receiving will help prevent infection developing and it is usually an easier way to ensure the infection is eliminated as quickly as possible.
Prevention of infection is a particular concern among cat breeders, and while it is impossible to ever completely prevent the risk, certain precautions may be warranted. In this situation, if a new cat is to be introduced into a household, it is possible to isolate the new cat and perform a fungal culture from a coat brushing (taking a brushing from all over the cat’s hair coat). If the culture result is negative this is the best assurance that it is safe to introduce the new cat.