Kangaroos are susceptible to a highly contagious respiratory illness which can often be fatal in small animals especially less than four kg. The first symptoms are sneezing and a runny nose. If untreated the joeys can develop copious, thick, nasal secretions and mucosal oedema which can prevent the animal from breathing through its nostrils. Wheezing and breathing difficulty can also develop. Despite intravenous antibiotics animals often die . At post mortem there appears to be gastrointestinal tract ulceration and consolidation in both lungs. Several joeys have developed ulcers on the cornea , nostrils and cloaca.
Herpes viruses are known to affect kangaroos. We have used an antiviral called Valaciclovir successfully to treat this respiratory illness in small eastern Grey Kangaroos. This medication is used to treat herpes virus infections in humans.
It is important to use this medication early ie. as soon as it is noticed that an animal has sneezed several times – not just got something up its nose! Valaciclovir acts to prevent the virus from replicating. Hence the need to commence it early in the infection as soon as the joey starts to sneeze.
Each Valaciclovir tablet is 500mg. The human dose is 1g of Valaciclovir (ie.2 tablets ) three times a day for one week. We have been using the following dose rate for joeys . Crush one tablet finely and suspend in 15 ml of cooled boiled water. Use at a rate of 0.5 ml per kg of the shaken suspension three times a day for seven days.This can be given before or with formula in a syringe to make it more palatable. Keep unused medication in the fridge for use the same day.
For those joeys which already have severe symptoms we have used the following medications to treat them symptomatically: (a)Paracetamol at 10 mg per kg twice daily if the joey has a fever; (b) FESS nasal saline and simple suction instrument (available at a Chemist) to soften and remove nasal secretions; (c) Bromhexine (Bisolvon) to reduce the viscosity of the mucous.Crush one tablet finely and suspend in 15 ml of boiled water and use 0.5 ml per kg of the shaken suspension three times daily.This can be given before their formula or mixed with a small amount of formula in a syringe to make it more palatable. Keep unused medication in the fridge for use the same day ; (d)Salbutamol (Ventolin) nebuliser or inhaler with spacer and mask if the joey is wheezing and having breathing difficulty; (e) Amoxycillin(BetamoxLA) at 0.1 ml per kg SCI second daily to prevent secondary infection and (f) Sucralfate(Carafate) for gastrointestinal ulceration. Disperse half a tablet in 15 ml of boiled water and use 0.5 ml per kg four times daily for 7 days. Use if joey appears unwell despite the Valaciuclovir and is refusing formula.
In the most recent outbreak of this respiratory illness which appears to have been brought into Possumwood by a 3 kg joey, Cherry Blossom, from Captains Flat 13 0f the 15 of our joeys less than 6 kg have been affected . Spencer and Darby were immune despite having mild symptoms only during the previous outbreak.Most of the joeys stopped sneezing after 3-5 days of Valaciclovir.One joey,Hogan- 1.9 kg, became unwell despite the use of Valaciclovir .He was given Bisolvon, Carafate and Betamox and now appears to be doing well. Our newest arrival,Rafke-900g-has been given a prophylactic dose of Valaciclovir and as yet has not developed symptoms .Tthe prophylactic dose of Valaciclovir is 0.5 ml of the suspension once daily for 7 days.Prophylaxis is advisable for the smaller joeys (less than 3 kg).
Following infection the joeys will have developed immunity to this virus .The identity of the virus causing this illness will hopefully soon be available.
This fact sheet is dedicated to our pecious little Sophie -the last of our joeys to succumb to this virus. Valaciclovir saved her friends Spencer and Darby- the first time we used this medication. Since that outbreak it has been effective in treating a number of our joeys whenever this virus has been brought into our sanctuary by a new arrival. The incubation period appears to be about a week.