Dermatophytosis is a medical term for a fungal infection that mostcommonly affects the hair, nails (claws) and skin of felines. The most commonparasite for this infection is known as ‘microsporumcanis’, trichiphyton mentagrophytes and microsporum gypseum (this is whatis commonly known as ringworm).
This fungal infection is more common in cats,and other mammals, but more likely affect long haired breeds than short haired.Ringworm (microsporum gypseum) isdiagnosed largely in populations with kittens than those with older cats. Many different species of fungifound around the globe have the potential – or already do – to cause ringworm,however most cases in felines are caused by the fungi microsporum canis, microsporum gypseum or of trichophyton (aspecific genus of fungi) species.
Spores can be found on infected animals oraround the area of living quarters of infected animals, and any spores that areshed from infected animals can live for up to 24 months. The optimalenvironment for these spores are humid, and warm. It is because of this thatthey can inhabit anywhere; i.e. bedding, furniture, walls, or any fomite. Felines are known to beasymptomatic carriers of the fungal infection and can harbour or shed theorganism without showing any clinical signs, it is known that chronic carriersof this fungal infection can be routinely cultured to determine if they carrythe fungal infection. Like most fungi, ringworm can betransmitted by direct contact with the fungal spores; these fungal spores canbe found almost anywhere (as mentioned previously). Because the spores cansurvive for a long period of time, it is common for felines to contractringworm from anywhere else that other felines (or even dogs) have been.
Fortunately,adult felines usually have a resistance to the fungus and never develop anyvisible clinical signs. But any felines under a year old and senior,free-roaming cats, and those that are malnourished, under stress or have anyimmunosuppressant diseases such as parasites or viral infections may also havean increased risk of developing symptoms and contracting the fungal infection.It is also thought that genetic factors can play a role, as Persian felinesappear more susceptible to ringworm than other breeds. Felines with ringworm may presentwith different symptoms, such as skin lesions (which can appear in differentshapes and sizes depending on where they occur and how long they have beenpresent) – one of the most classic symptoms is a small round lesion that isdevoid of any hair (even in long-haired felines). It is common for skin lesionsto have ‘scaly’ skin around the centre, and small pustules are often found inthe lesion. Like most skin lesions, it will start as a small spot and continueto grow. The lesion may or not be irritated or itchy, it entirely depends onwhat type it falls under.
Skin Lesions are commonly found on the ears, tail andhead. It is also common, if the infection occurs over the entire body, that itcreates a generalised scaly or greasy skin condition – it is also common forfelines to suffer hair loss if affected with this fungal virus. Alopecia isalso known as the first clinical sign, and can also cause hairballs orscratching at the ears. In some cases of this fungal infection, ringworm cancause the claws to grow malformed. Like most fungal infections, itcannot be diagnosed by observing the lesion, as several tests are normallycarried out to properly diagnose. A common method for treatment is by aspecialised black light called a ‘Wood’s lamp’. Several species of the ringwormfungus will glow a fluorescent colour when exposed to a Wood’s lamp.
The mostreliable way to identify a ringworm infection is by collecting scales and crustfrom the skin and coat and performing a fungal culture. It’s common for theVeterinarian will use a toothbrush to collect this sample of hair and scales,and to do this in-house; meaning that results are much more rapid than if sentto a laboratory to be cultured.As mentioned before, lesions arecommon as a clinical sign of fungal infections, but can be treated.
In healthyshorthaired felines, with minimal lesions, they can be treated with a topicalcream that contains and antifungal such as miconazole, or thiabendazole. Tofurther treat any underlying conditions, a good diet and good hygiene is key. If the condition if more severe,then a combination of topical and oral treatment can be used. If the feline islonghaired then the veterinarian may advise to clip all the fur to achieve anyringworm treatment, this ensures that the topical treatment reaches the skinproperly and diffuses into the dermis. It’s also important to note that anyequipment used to clip any fur must be properly sterilised before being used onany other animal as they would then pose a risk of infection. Again, if thecase is more severe, then a recommended topical treatment; is a lime sulphurdip.
These do pose a bad odour and could even turn the coat a yellowish colour,but they are extremely effective and should be used if recommended.Alternatives to this include miconazole shampoos and rinses. If your feline has severe lesionsof the skin, oral anti-fungal agents are recommended. Especially where thefeline is longhaired and in cases where the claws are infected also. These canalso be recommended if the patient does not respond to any topical treatmentwithin two to four weeks. Bacterial disease in dogs – Nocardiosis Nocardiosis is an infectious disease that affects different bodysystems, including the respiratory, nervous system and musculoskeletal in Canines.
This highly infectious bacterium is found in soil and can enter the dog’s bodythrough any open wounds or through the respiratory tract when it inhales. Themost common strain of this bacterium is Nocardiaasteroides. Though this is rare, dogs are also susceptible to proactinomyces spp. It is also importantto note that any dogs suffering from an immunosuppressant disease, theirlikelihood of contracting Nocardiosis increases. Nocardia is a pleomorphic (canalter their size), facultative (able to live under different environmentalconditions), intracellular bacterium, and non-spore forming.
When a Gram smearis performed, it appears as cocci or coccobacilli forms with long branchingfilaments – it also tends to fragment into rods and cocci. The symptoms of Nocardiosis spp are hugely dependant onthe site of the initial infection. For example, if the bacterium infects theplural body cavity (this includes the lungs and all surrounding mucousmembranes) then the symptoms can include pyrexia, dyspnoea and emaciation. Ifthe infection is located on the skin, then different symptoms will be present,e.
g. chronic non-healing wounds and draining lymph nodes. If the initialinfection is not localised in one specific area of the canine, then thesymptoms could include: weight loss, lethargy, and pyrexia. Diagnosis of this bacterialinfection is based on the epidemiologic findings, the clinical signs and amicrobiologic examination. The Veterinarian will most likely take samples fromthe tracheobronchial fluid or the abdomen to identify the site of theinfection. Other diagnostic procedures can be carried out, e.
g. x-rays, andurine analysis. There are usually one or more diagnostic procedures carried outto rule out other potential causes (this could include tumours or even fungalinfections). The treatment for Nocardiosis isdependent upon the initial site of the infection (where the bacterium has infected)and the symptoms that coincide.
If infection occurs in the pleural cavity, thenit is most likely that the canine will be hospitalised to prevent any furtherdehydration caused by the infection. It is also likely that drainage of anyfluid will occur (this may be performed on a regular occurrence on direction ofa Veterinarian). Alongside other forms of treatment, a long-term antibiotictherapy is imperative to fight off the infection.
But like all infections,tender, loving care is also key in ensuring a full recovery from the infection!Because of the nature of Nocardiosis,and its frequency to affect the musculoskeletal and central nervous system(CNS); it is imperative that the dog is closely monitored for up to a year aftertherapy. The signs to look out for are as followed: anorexia, pyrexia,seizures, dyspnoea. Any of these clinical signs could indicate reinfection.Prevention of this infectious disease is difficult, but can be managed. Generalcleanliness and frequent disinfection of any wounds your dog may harbour is a keyway to help prevent this infection, especially if your dog isimmunosuppressed. Viral diseases in rabbits – Rabbit haemorrhagic disease (RHD) Rabbit Viral Haemorrhagic disease (VHD or RHD) is a highlyinfectious disease that is caused by the calicivirus, and only affects lagomorphsof the Oryctolagus cuniculus species i.e.
domesticated European rabbits. The calicivirusin rabbits is known to shut down major organs, such as the liver and gut, but isalso known to cause haemorrhages or bleeding.Rabbit Viral Haemorrhagic disease,is a very swift killer. Some rabbits infected with this disease may passwithout showing any clinical signs at all. But it has been reported that somebleed around the mouth, nose and rectal passage. The reason that this diseaseis such a swift killer, is because the incubation period of the disease fromthe date of contracting the virus is minimal – with most rabbits dying within48 hours from initial exposure. The mortality rate, according to rabbit.
org, isbetween 50 and 100%, with the latter of the two being the closest figure. Therabbit calicivirus is a hard one to beat (according to peteducation, the viruswas able to kill over ten million rabbits within eight weeks), as it can remainviable in the environment for 105 days at 20°C – 68F – and for even longer at3.8°C (39F). This strong virus, can even withstand freezing. VHD has no knowncure in the UK, but a vaccine is available (and strongly advised of) to all Lagomorphsby administration from a Veterinarian.Treatment of VHD is almost non-existent due to the quick mortalityof rabbits infected with the calicivirus, as mentioned previously, it isimportant that rabbits are vaccinated annually, as the vaccination onlyprovides cover of a year. The clinical signs that may be present (ifapplicable) can include: anorexia, lethargy, dyspnoea, pyrexia, spasms andsudden death.
A Veterinarian may offer Intravenous fluid therapy (IVFT) as anoption to help with the clinical signs, but in cases where VHD is present, thenit is normally kinder for euthanasia to take place. If a case of VHD is suspectedi.e. if large numbers of populations of rabbits are dying, then it should bereported to a veterinarian, whom will then be able to advise on proper handlingof an infectious rabbit. Transmission of VHD in rabbits cannormally occur by direct contact with an infected rabbit or any fomites thatmay harbour the virus. Other ways of infection are: oral, conjunctival pathwaysand intranasally; it is also possible that the urine and faeces of an infected rabbitmay shed the virus. This virus is also known to be airborne, and can travel by thewind.
Though the virus cannot reproduce in other mammals, predators such a fox,some birds and ferrets can excrete the virus through their faeces afterinjected an infected rabbit. Flies, mosquitoes and rabbit fleas also have the potentialto harbour and spread the disease throughout the lagomorph population. Diagnoses of VHD can be indicated inan infected rabbit usually by post-mortem, as the clinical signs of VHD can be likemyxomatosis, pasteurellosis and E. coli.
Lagomorphs that pass from VHD arenormally in a good outward state, however post-mortems usually reveal necrosisof the liver & splenomegaly. The liver of a rabbit that has died from VHDusually shows it as being friable and swollen, the spleen being dark/black incolour. It is also possible that haemorrhages be seen in other organs and tissues.Enteritis of the small intestine and swollen meninges may also occur.
Another method of diagnosis includeslaboratory tests, such as revere transcription polymerase chain reaction (RT-PCR)which is a method used in molecular biology to detect the RNA expression of a virus,negative staining and western blotting (used to detect different proteinswithin a tissue).