The disease is complex one and thereby characterized by a group of symptoms manifested by lacrimation, conjunctivitis, rhinitis, salivation and oral ulceration. It is a problematic disease in catteries.
Distribution
The disease is widely prevalent throughout the world. Vaccination programme has curbed down its occurence in some countries.
Aetiology
It is caused by a group of viruses comprised of Feline herpese virus-1 also known as Feline viral rhinotracheitis and feline calci virus of late, FCV has been found to be involved in greater proportion.
The upper respiratory signs in cats may be associated with agents like Chlamydia psittaci, Mycoplasma spp. Other respiratory organism like Reovirus, Cow pox virus, feline coronavirus and Bordetella bronchoseptica may play some role to induce respiratory complex. Staphylococcus, Streptococci, Pasteurella spp. may appear as secondary invaders.
Susceptible Hosts
Feline spp are only susceptible. This is a species specific infectious disease. The disease is not zoonotic in nature.
Mode of Transmission
Young kittens or cats contract the infection through infected oral, nasal and ocular discharges. Fomites like food, water, plates, table, cages, human hands may act as agents for viral transmission. Virus may be spread to the extent of 2 to 4 feet by sneezing and coughing through air movement – aerosol transmission.
Pathogenesis
The viruses have got affinity for the epithelium of upper air ways as well as conjunctiva and nose, thus causing sneezing, coughing and salivation. They have got predilection to oropharyngeal mucosa and lung parenchyma setting up buccal ulceration, mild rhinitis and pneumonia.
Clinical Findings
The signs include high rise of temperature, sneezing, rhinitis, conjunctivitis and salivation. Nasal and ocular discharge are serous in nature but gradually turn into mucopurulent to purulent type. There is anorexia followed by extreme debility, ulceration of buccal mucous membrane and ulcerative keratitis.
C. psittaci may produce persistent conjunctivitis with mild respiratory signs. Reovirus may produce mild conjunctivitis along with respiratory signs. A limping syndrome has been reported with feline calcivirus. Cow pox virus may produce skin lesions in cats. Mycoplasmal infection may produce abortion besides respiratory problem. They may also produce chemosis. The mortality rate is low and may respond to therapy. But, in young kitten the rate may be high.
Diagnosis
Diagnosis can be made based on:
- Typical clinical signs characterized by conjunctivitis, sneezing, rhinitis, lacrymation, salivation and oral lesions.
- Blood count – leucopenia
- Cytological examination – causative organisms can be identified by geimsa stained conjunctival scrapings. The inclusion bodies are intracytoplasmic in Feline pneumonia. In case of mycoplasma they appear as extracellular coccoid bodies. Samples may be obtained from oropharyngeal mucosa and nares.
- Isolation of the viral agent ideal for FCV.
- Immunofluorescent test – ideal for FHV.
Differential Diagnosis
- FVR – affects mucosae conjunctivae and nasal passage.
- FCV – affects oral mucosa and lower respiratory tract.
- Chlamydia – produces chronic mild conjunctivitis.
Treatment
Treatment is symptomatic in nature. A course of broad spectrum antibiotic is to be given to combat secondary bacterial invaders. For this, amoxycillin, enrofloxacin and cephalexin are preferred. All the nasal discharges are to be cleaned carefully. Fluid and nutritional therapy is to be extended. Force feeding may be resorted with syringe. Potassium and vitamin B complex may be supplemented. All care should be taken to clear air passages. Vaporizing inhaler may be used. Nasal decongestant may be administered. For chlamydial infection tetracycline will be the drug of choice. Ocular antibiotic preparations may be instilled in eyes. A course of antihistaminic preparations may be of value to prevent nasal and respiratory damage.
Control
Strict hygienic measures are to be adopted in cat colony. Affected should be isolated from rest of the colony for treatment. Virucidal agents may be used in the catteries to reduce viral load. Preventive dose of antimycoplasmal drug may be extended to susceptible population. Similarly tetracycline may be administered against chlamydia prone population.
Modified live or attenuated vaccine may be given as routine protocol.
