AS the popularity of small furries as pets continues to grow, so do cases of infestation by the parasites which attack them. This article provides a guide to the major groups of parasites affecting rabbits, guinea pigs and ferrets and explains how to protect pets against them.
Rabbits
Rabbits are the third most popular pet in the UK and are most frequently affected by the following parasites:
- Encephalitozoon or E. cuniculi is an obligate intracellular protozoal parasite of rabbits which, when ingested, can cause partial or complete paralysis, uveitis and kidney disease. Recent studies suggest that up to 52% of domestic rabbits have been exposed to the parasite, which can also affect humans.
Some animals are asymptomatic and show no signs of illness but others can suffer from increased thirst and urination, weight loss or kidney failure. Infected rabbits can also suffer from partial or complete rear limb paralysis, head tilts and tremors or convulsions.
Treat infected rabbits with an antiparasite drug based on fenbendazole (Panacur Rabbit, Intervet/Schering Plough; or Lapizole, Genitrix) for up to 28 days and provide supportive care in terms of high-quality nutrition with medication to support those suffering head tilts, eye drops for those with eye inflammation and a comfortable environment for those with rear limb weakness.
Measures which may reduce the likelihood of infection are prophylactic use of fenbendazole, regular disinfection of the environment and using water bottles rather than bowls to avoid urine contamination.
- Myiasis or flystrike is an infestation with maggots from the eggs of green bottle flies and very common in the summer months. The flies are attracted to warm, damp places such as wet fur around the inguinal area of rabbits. The eggs hatch and the maggots eat into the host’s flesh. As they develop they eat further into the host and, unless caught and treated quickly, the rabbit is unlikely to survive.
Flies can strike any animal but it is generally those with a wet or dirty groin which are most at risk – potentially older animals with reduced mobility, obese rabbits, rabbits with teeth problems or long-haired breeds. Rabbits react in different ways: some try to escape pain by digging themselves into a tight corner while others dart about and pull at their genital area.
An effective preventive health regime involving thorough hygiene and husbandry procedures and regular monitoring will help to prevent flystrike. Further insurance can be provided by discouraging flies with the use of suitable repellent insecticides such as permethrinbased products (Xenex Ultra, Genitrix) or inhibiting larval development with an Insect Growth Regulator (Rearguard, Novartis).
- While there is a species of flea specific to rabbits, Spilopsyllus cuniculi, domestic rabbits are more commonly infested with Ctenocephalides canis and C. felis, the dog and cat fleas, which cause discomfort and itching. Prevent and treat flea infestations with a suitable approved insecticide (Advantage, Bayer; or XenexUltra, Genitrix).
- Mites. Surface-dwelling mites Cheyletiella and Leporacus are the most common mites affecting rabbits. They can cause skin lesions resulting in discomfort and pain to the rabbit. Rabbits are also affected by the Psoroptes cuniculi ear mite. Affected animals may shake their heads frequently to relieve itching. Finally, they may be affected by either the Sarcoptes scabiei or Notoedres cati mange mites which burrow into the skin causing hair loss, scratching, seizures and even death.
Prevent and treat mite infestations with an approved invermectin-based product (Xeno, Genitrix).
Guinea pigs
Guinea pigs can occasionally fall victim to flystrike but the main parasite groups affecting them are lice and mites:
- Guinea pigs are prone to attack by two types of biting louse: Gliricola porcelli and Gyropus ovalis. They bite into the host’s skin until the blood flows, then feed. A serious infestation can result in so much blood being consumed that the host suffers anaemia and lice are also the means by which certain fatal bloodborne diseases such as Rickettsia are transmitted. They are passed between individuals and via bedding.
- Mites. The surface dwelling mites Chirodiscoides and Mycoptes are the most common mites found on guinea pigs but they can also be affected by Trixacarus caviae, a mange mite which burrows into the skin. As with rabbits, these infestations can cause hair loss and, in more serious cases, seizures and death.
Prevent and treat mites and lice with an ivermectin-based product.
Ferrets
Ferrets are most commonly affected by lice and mites but heartworm also represents an increasing threat.
- The ear mite Otodectes cynanotis is the most common parasite in ferrets. It may be acquired at birth or from other ferrets or from dogs and cats which share the same parasite. Ferrets with ear mites often shake their heads or scratch at their ears. A dark brown, waxy, odorous discharge is also produced. Ferrets can also be affected by Sarcoptic mange mites, particularly if they are in regular contact with wild rabbits.
- The most dangerous parasite for ferrets is heartworm (Dirofilaria immitis) which also infects dogs and cats. It is spread through the bites of mosquitoes and blocks major arteries to the lungs, causing heart failure and death. Because ferrets’ hearts are so small, it takes only a few worms to cause death.
A ferret with heartworm will seem lethargic, may have a chronic cough and may become short of breath if active even for just a few minutes. Fluid builds up in the abdomen because of the failing heart and blocked blood vessels and the disease is rapidly progressive and fatal.
Prevention and treatment of mites and heartworm in ferrets can be achieved with the use of a suitably approved ivermectin-based product.
Other species
Mice, rats, gerbils and hamsters are all susceptible to mites and lice. The common parasites are listed in the Table and are responsive to treatment with topical ivermectin.
