If you believe your fox is unwell, please seek veterinary advice.
Flea, Mite and Tick Infestations
Fleas
Archaeopsylla erinacei (Hedgehog flea)
Ctenocephalides canis (Dog flea)
Ctenocephalides felis (Cat flea)
Nosopsyllus fasciatus (Rat flea)
Malaraeus penicilliger mustelae (Vole flea)
Monopsyllus sciurorum (Red squirrel flea)
Orchopeas howardi (Grey squirrel flea)
Paraceras melis (Badger flea)
Pulex irritans (Human/Pig flea)
Spilopsyllus cuniculi (Rabbit flea)
Introduction and Background:
Fleas are small, six-legged ectoparasites (Siphonaptera), that live on the exterior of the host. They are bloodsucking insects that vary from 0.1 to 0.32 cm in length and are notable carriers of zoonotic disease and are a common pest.
Clinical Signs:
Visible fleas or flea dirt
Excessive itching and biting of skin
Dull coat and mild skin irritation
Alopecia (hair loss)
Hot Spots - an area of localized infection around a bite
Flea allergy dermatitis - a hypersensitive response to flea bites
Anaemia (pale gums), due to excessive blood loss
Lethargy, due to blood loss or infection
Other symptoms may appear if the flea was carrying any infections
Death in extreme cases, due to blood loss or infection
Diagnosis:
Flea infestation is diagnosed with the detection of either adult fleas or flea faeces in the fur. The latter is generally tested with the wet blotting paper technique. However, microscope examination of the material is sometimes suggested for a more accurate, specific species diagnosis. Bloodwork will also be required to rule out any infections.
Treatment:
Fleas can survive for a long time in the environment without a host and they breed quickly. It is essential to treat both your pet and your home as soon as you are aware of a problem. See your vet for advice on the best flea products that will work for your pet and environment.
Prevention:
Regular use of flea prevention medication, such as fipronil, permethrin or selamectin based products, as directed by your vet or the product packaging.
A veterinary licensed edible tablet, (such as Bravecto or NexGard), is available for animals difficult to handle, which is given with food on a 3-month basis
Deep clean enclosures and wash pet bedding and soft furnishing at 60oC regularly
Vacuum floors, skirting and furniture regularly - and empty your vacuum cleaner after use
Use a flea spray/powder for bedding and furniture
Groom your pet regularly so you can spot any early signs of parasitic infestation
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures.
Plant pet-safe insect repelling and self-medicating plants
Mites
Otodectes cynotis (Ear mites)
Sarcoptes scabiei (Sarcoptic mange)
Introduction and Background:
Sarcoptic mange is the most common infection in foxes in the UK. Mange mites are microscopic, eight-legged arachnids that need a host in order to feed and breed. As with ticks and fleas, they may survive in the environment without a host for long periods of time. The female mite burrows under the skin and lays her eggs which hatch in 3-10 days producing larvae which, in turn, move to the skin's surface where they develop into adults to breed and the cycle begins again.
Clinical Signs:
Skin irritation, leading to constant scratching
Head cocking (in the case of ear mites)
Greasy skin and smelly odour
Open sores
Thickening of the skin
Dull coat and alopecia (hair loss)
Infection and septicemia
Mange mites can often be fatal if not treated in the early stages
Diagnosis:
Diagnosis can often be made on physical observation of the animal, however, to confirm a diagnosis of mites, a skin scraping or hair sample needs to be examined under the microscope. Bloodwork will also be required to rule out any infections.
Treatment:
While you may be tempted to use a home remedy or over-the-counter product to relieve an animals itching, it won’t help in the long run. Getting rid of the mites is a must in order to treat the problem. For severe cases in captive foxes, vets can prescribe a fast-acting medication to relieve discomfort, like oclacitinib (Apoquel).
Mange treatment recommended by the Fox Project, includes;
"Mange treatment given to captive foxes is usually successful, involving doses of Stronghold 5 -10kg (or generic ‘spot-on’) or two injections of Ivomec or Panomec (.125ml) given over a two week period. Both treatments are best applied in conjunction with a broad spectrum antibiotic such as Baytril or Synulox to combat skin infection.
In most cases, captive foxes will have been cage trapped, but... Ivomec or Panomec may be applied orally, in food. However, these treatments may be dangerous to pets and other species (and to suckling fox cubs, so this is risky to provide during the fox breeding season – between mid-February and early April) and a veterinary surgeon will require your assurance of a predictable feeding pattern."
Prevention:
Treatment with Isoxazoline is suggested for prevention of mite infestations. It is a group of drugs that can be found in many veterinary licensed flea and tick control products, such as Stronghold and Bravecto
Deep clean enclosures and wash pet bedding and soft furnishing at 60oC at least once a week
Vacuum floors, skirting and furniture regularly - and empty your vacuum cleaner after use
Use an insecticidal spray/powder for bedding and furniture
Groom your pet regularly so you can spot any early signs of parasitic infestation
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures.
Plant pet-safe insect repelling and self-medicating plants
Ticks
Dermacentor reticulatus (Ornate cow tick)*
Ixodes canisuga (Dog tick)
Ixodes hexagonus (Hedgehog tick)
Ixodes ricinus (Sheep tick)
Ixodes ventalloi (Rabbit tick)
Rhipicephalus sanguineus (Brown dog tick)**
*The Ornate Cow Tick carries canine babesiosis which is a risk to dogs, and it is implicated in transmission of Tick-borne Encephalitis (TBE). This tick has ornate markings on its back and is often pictured in UK newspapers, despite its rarity.
**The Brown Dog Tick has been brought into the UK from Europe on dogs and can survive and reproduce inside a home, unlike the native UK ticks.
Introduction and Background:
Ticks are eight-legged arachnids related to spiders, mites and scorpions. They range from 0.5mm-2.5mm in size and are a notable source of disease transmission. There are around 20 different species of tick living in the UK, each preferring to feed on the blood of a preferred wildlife host, however, they occasionally find their way onto pets and humans instead.
Clinical Signs:
Ticks may be visible around the head, eyes, ears and inside of the limbs and may appear like a small lump or possible skin tag. In heavy infestations, many ticks can be seen clustering around these points.
Bite symptoms can vary depending on the type of tick involved, symptoms may include;
Irritation of the skin
A rash
Anaemia
Lethargy
Fever
Joint pain
Other symptoms may appear if the tick was carrying any infections
Death in extreme cases, due to blood loss or infection
Diagnosis:
Tick infestation is diagnosed with the detection of either adult or nymph ticks, when inspecting the animals coat thoroughly. Microscope examination of the tick is sometimes suggested for a more accurate, specific species diagnosis. Bloodwork will also be required to rule out any infections.
Treatment:
Ticks are present in the environment all year and can survive for a long time without a host. It is essential to treat your pet on a regular basis to ensure they remain protected. See your vet for advice on the best tick products that will work for your pet and environment.
Prevention:
Regular use of tick prevention medication, such as fipronil, permethrin or selamectin based products, as directed by your vet or the product packaging.
A veterinary licensed edible tablet (such as Bravecto or NexGard), is available for animals difficult to handle, which is given with food on a 3-month basis
Deep clean enclosures and wash pet bedding and soft furnishing at 60oC at least once a week
Vacuum floors, skirting and furniture regularly - and empty your vacuum cleaner after use
Use an insecticidal spray/powder for bedding and furniture
Groom your pet regularly so you can spot any early signs of parasitic infestation
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures.
Plant pet-safe insect repelling and self-medicating plants
Infections Transmitted by Biting Insects
Anaplasmosis
Introduction and Background:
Anaplasma phagocytophilum is an emerging intracellular gram-negative bacteria that primarily infects neutrophils of both humans and animals. It is transmitted by Ixodes ricinus ticks and a recent survey demonstrated that 0.74% of ticks in the UK were infected with this bacteria.
Clinical Signs:
Infection is often mild and self-limiting, but occasionally more severe signs are seen. Symptoms generally occur around two weeks after the tick bite. Associated with acute fever in canids. Other clinical signs can include lethargy, anorexia, polyarthritis, stiffness, pale gums, swollen lymph nodes and enlarged spleen.
Severe anaemia (thrombocytopenia) presents in around 90% of cases.
Diagnosis:
Anaplasma can be diagnosed with blood smears, PCR and serology. A negative antibody titre can be useful to rule out A. phagocytophilum infection as long as the animal has not been sampled too early in infection (within a week).
Treatment:
Two weeks of doxycycline (10 mg/kg orally once daily) is the treatment of choice for A. phagocytophilum associated disease, (optimum treatment duration is not known). Most animals improve within 24-48 hours of starting treatment. Supportive care e.g. intravenous fluid therapy, may be required for some animals.
Prevention:
Regular use of tick prevention medication, such as fipronil, permethrin or selamectin based products, as directed by your vet or the product packaging.
A veterinary licensed edible tablet (such as Bravecto or NexGard), is available for animals difficult to handle, which is given with food on a 3-month basis
Deep clean enclosures and wash pet bedding and soft furnishing at 60oC at least once a week
Vacuum floors, skirting and furniture regularly - and empty your vacuum cleaner after use
Use an insecticidal spray/powder for bedding and furniture
Groom your pet regularly so you can spot any early signs of parasitic infestation
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures.
Plant pet-safe insect repelling and self-medicating plants
Babesia (Red Water Fever)
Introduction and Background:
Babesia is a protozoan blood parasite transmitted by ticks to both humans and animals. There are many species of babesia, but in the UK, B. canis, B. microti and B. annae are of most concern. Babesia destroys the red blood cells, leading to the observable symptoms listed below.
Clinical Signs:
The signs can vary in severity but most animals will become acutely ill. They will develop very pale gums, dark/red urine, can suffer from dyspnea (air hunger) and jaundice and even collapse from severe anaemia (thrombocytopenia), due to direct haemolysis of red blood cells by the parasite (sometimes associated with erythrocyte antibodies).
Diagnosis:
The parasite may be visible in red blood cells under the microscope or your vet may have to send blood samples to the lab to look for the parasite (PCR testing).
Treatment:
Treatment will vary depending on the species of Babesia. In the case of Babesia canis (the most common species in Europe) your fox will receive two Imidocarb diproprionate injections given two weeks apart or Ataquavone plus azithromycin for 10 days for B. microti and B. annae spp. It is likely that they will also need additional supportive treatment such as intravenous fluids and blood transfusions. Unfortunately, some animals with severe clinical signs may not recover, despite treatment.
Prevention:
Adequate tick prevention is the best form of protection
Deep clean enclosures at least once a week
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures
Groom your fox, checking for parasites regularly and maintain regular health checks with your vet
Plant pet-safe insect repelling and self-medicating plants
Bartonella (Cat Scratch Disease)
Introduction and Background:
Bartonella spp. are a group of emerging infectious diseases caused by gram-negative bacteria belonging to the Bartonella genus, which are mainly transmitted by vectors, such as fleas, ticks and lice. Bartonella henselae is of main concern in the UK. Humans, domestic animals and wildlife at risk of infection, typically through a bite or scratch from an infected carrier.
Clinical Signs:
The symptoms that develop tend to be of mild disease (stiffness, fatigue, swollen lymph nodes or papules/red spots) that ends without treatment within 2-4 months (self-limiting), however symptoms may not appear for several days or weeks after the exposure. Bartonella can cause severe infection in some cases. Immunocompromised animals are more likely to develop severe, life-threatening disease with cardiac, neurological or renal complications reported.
Diagnosis:
Bartonella does not grow readily in the laboratory, is not easily recovered from wounds. Bartonella infections in symptomatic animals should be confirmed by blood or tissue culture, with samples taken from lymph nodes or the heart valve (in cases of endocarditis) or by amplifying Bartonella-specific DNA sequences from tissues using PCR. Serology using immunofluorescence antibodies (IFA) is the most sensitive tool for diagnosing exposure, but it is not useful in predicting animals that require treatment.
Treatment:
Doxycycline, amoxicillin, enrofloxacin, and rifampin may be given for 4-6 weeks to reduce the level of bacteremia in infected animals. The ability of antibiotics and their combinations to completely clear B. henselae from the blood stream has not been established. Given the concern for development of antimicrobial resistance and length of time antibiotics are required, treatment is only recommended in pets with clinical symptoms.
Prevention:
Adequate tick prevention is the best form of protection
Deep clean enclosures at least once a week
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures
Groom your fox, checking for parasites regularly and maintain regular health checks with your vet
Plant pet-safe insect repelling and self-medicating plants
Borrelia (Lyme Disease)
Introduction and Background:
Borrelia burgdorferi sensu lato comprises a group of genospecies of spirochaete bacteria that causes Lyme disease in humans and animals. Borrelia is found worldwide and is transmitted by Ixodes ricinus ticks in the UK. Recent surveys have found that 2.3% of ticks in the UK were infected with borrelia.
Clinical Signs:
Most infected animals show no clinical signs. However, a rash may occur where the tick attached. In animals that show clinical signs, these usually develop around 2-5 months after the initial tick bite and can include lethargy, fever, intermittent or migrating lameness and swollen lymph nodes. Signs may be worse in young or immunocompromised animals. Occasionally more severe cardiac, neurological or renal signs are reported.
Diagnosis:
Diagnosis of Lyme disease is challenging and supportive laboratory testing is essential, including IgG and IgM serology, PCR or even Dark Field Microscopy. Haematological and biochemical changes are not characteristic of borreliosis, although it may support the presence of an inflammatory response. A low white blood cell or platelet count may suggest concurrent infection, as coinfection is relatively common. Joint taps will have a high number of non-degenerate neutrophils, with increased protein content, with joint fluid having a reduced viscosity.
Treatment:
Early antibiotic therapy has been shown to be very effective in reducing spirochaete numbers, leading to rapid improvement in arthritis signs over a 24 to 48-hour period. Doxycycline is the drug of choice for treating borrelia. Doxycycline is lipid-soluble, and thus has good tissue and cellular penetration and is generally used for a minimum of four weeks. If proteinuria is documented (and other causes excluded), early treatment for glomerular nephritis should be instigated alongside antibiotic therapy. Angiotensin-converting enzyme (ACE) inhibitors will reduce renal protein loss through altered glomerular filtration pressure. Ultra-low aspirin therapy (0.5mg/kg/bid) is suggested to prevent thromboembolism as a result of antithrombin loss and platelet dysfunction.
Prevention:
Adequate tick prevention is the best form of protection
Deep clean enclosures at least once a week
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures
Groom your fox, checking for parasites regularly and maintain regular health checks with your vet
Plant pet-safe insect repelling and self-medicating plants
Ehrlichiosis
Introduction and Background:
Ehrlichia canis is a rickettsial bacteria transmitted by ticks. The tick that transmits the bacteria is not indigenous to the UK, although it is able to survive in warm and damp environments (e.g. kennels) here in the UK.
Clinical Signs:
The acute symptoms may be mild and not specific: fever, reduced appetite, enlargement of the lymph nodes and lethargy. Sometimes, these symptoms will go away without treatment and the animal may remain asymptomatic for months or even years. Then the symptoms will present again and be more severe: e.g. fever, weight loss, bleeding tendencies and other signs that may resemble autoimmune disease.
Diagnosis:
The organism may be visible in samples taken from the lymph nodes, spleen, bone marrow or even blood in some cases. If not visible, more sensitive tests can be done to look for the DNA of the organism in the samples (these tests are called PCR). Your vet may also look for antibodies against the pathogen in blood samples (false negatives are common in the first two weeks after exposure).
Treatment:
A two-week course of doxycycline is given in the acute stages of the disease and, in most cases, it will clear the organism from the body. In the chronic stage of the disease it is more difficult to eliminate the organism completely. However, your vet can give treatment to deal with the infection and control the symptoms.
Prevention:
Adequate tick prevention is the best form of protection
Deep clean enclosures at least once a week
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures
Groom your fox, checking for parasites regularly and maintain regular health checks with your vet
Plant pet-safe insect repelling and self-medicating plants
Leishmaniasis
Introduction and Background:
Leishmania Infantum is a protozoan parasite which causes a disease called Leishmaniasis, Leishmaniasis is a severe disease that can affect humans and animals. The parasite is transmitted through the bite of the sandfly, the species most commonly known for transmission is not present in the UK and the risk is extremely low. However, it is present in many countries in Southern and Eastern Europe, and imported foxes that have lived in these areas are at risk of becoming infected prior to travel and can pass it onto mates and offspring.
Clinical Signs:
Most infected animals show no clinical signs and may not develop symptoms for moths or years after exposure. When symptoms arise, they often present as skin lesions, depression, weight loss, excessive thirst. Some animals may develop kidney failure. It is possible for infected animals to become unwell without having any skin lesions.
Diagnosis:
Diagnosis depends on the presenting signs, but it is likely to be through a combination of blood tests and tissue sampling (e.g. from the skin, lymph nodes or internal organs).
Treatment:
Treatment can vary depending on the clinical presentation. Asymptomatic and do not always require treatment. However, most animals will require medication and this is likely to be a combination of two drugs (allopurinol and miltefosine or allopurinol and meglumine antimoniate). Allopurinol in most cases will be continued for a few months until the signs have resolved and blood tests have all returned to normal. Unfortunately, treatment is not curative and the animal will remain persistently infected. Relapses are common after stopping medication.
Prevention: There are vaccines against this parasite which are licensed to be used in the UK. They reduce the likelihood of your animal developing symptoms if they becomes infected but it does not prevent infection itself. The only way to prevent infection is to avoid contact with the sandfly.
Rickettsia (Tick Bite Fever)
Introduction and Background:
Rickettsiae and related (rickettsia-like) bacteria (such as Ehrlichia and Anaplasma) are an unusual type of bacteria that infect the cells lining small blood vessels, causing the blood vessels to become inflamed or blocked or to bleed into the surrounding tissue. Many species of these bacteria live in small animals (such as rats and mice) and are transmitted to humans and animals through the bites of infected ticks, fleas and mites. Rickettsia felis and Rickettsia rickettsii are two such species that may present a minor risk to foxes in the UK.
Clinical Signs:
Infection is usually asymptomatic, but illness can develop in a small percentage of cases. Symptoms result from immune-mediated thrombocytopenia (low platelet count) or neurological complications, and include:
Capillary bleeds in the eyes and in the mouth
Slow blood clotting and bruising due to low platelet count
Edema from low blood protein
Immunodeficiency due to decrease in white blood cells
Reduced urine production, thirst, fatigue, abdominal pain due to increase in nitrogen compounds (ureas and creatinine) in blood (Azotemia) associated with renal failure
Nausea, vomiting from increased liver enzymes
Lethargy due to low sodium in blood or other blood chemistry abnormalities
Muscle spasms from low calcium levels
Altered mental states
Vertigo, dizziness
Hypersensitivity to stimuli
Diagnosis:
Diagnosis of rickettsial infection is difficult as the infecting organism occurs at a low ratio in the bloodstream and its population fluctuates in the host animal. Usually, multiple diagnostic methods are required to reach a diagnosis of rickettsial infection. Diagnostic methods used, often in combination, include stained blood films or tissues examined under a microscope to locate infecting organism, serological tests, and molecular detection assays. Diagnosis is further complicated by the fact that multiple infectious organisms are often present with Rickettsia infections.
Treatment:
If rickettsial infection is suspected, treatment with antibiotics should be started immediately before test results confirming diagnosis are received, animals that display symptoms have a life-threatening condition and early treatment will result in a more favorable outcome. Antibiotics such as doxycycline and tetracycline are commonly used to treat rickettsial infections. Supportive care such as intravenous treatment and possibly blood transfusion for symptoms will be administered by your veterinarian with caution, due to the vascular disorder that often results from rickettsial infection. Removal of fleas or ticks that transmitted the disease will also be necessary.
Prevention:
Adequate tick prevention is the best form of protection
Deep clean enclosures at least once a week
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures
Groom your fox, checking for parasites regularly and maintain regular health checks with your vet
Plant pet-safe insect repelling and self-medicating plants
Tick-borne Encephalitis Virus (TBEV)
Introduction and Background:
Tick-borne encephalitis virus is a pathogenic tick-borne virus affecting humans and animals in Europe, and a potentially fatal zoonosis. Its rapid spread across Europe and establishment in the UK is therefore of concern but the risk it poses to pets and owners low.
Clinical Signs:
Signs of encephalitis usually appear suddenly and get rapidly worse. They are a sign of a medical emergency so if you suspect your dog has encephalitis, you should take them to your vet or veterinary hospital right away. Symptoms to watch out for include; fever, seizures, blindness, loss of coordination or circling (ataxia), pain, head tilt, paralysis, behaviour changes such as depression or lack of responsiveness.
Diagnosis:
Diagnosis of TBE is difficult. A definitive diagnosis relies on isolation of the causative virus from blood or cerebrospinal fluid but carries a poor sensitivity. Negative results, therefore, do not rule out infection. IgG serology can be used with a fourfold increase in titres indicative of acute infection.
Treatment:
There is no specific treatment which can target the virus itself and treatment therefore is supportive and symptomatic. Pain relief and intravenous fluid therapy may be required alongside anticonvulsives, sedatives and muscle relaxants. Non-steroidal anti-inflammatory drugs (NSAIDs) can be used in animals with pyrexia, and antibiotics used for secondary bacterial infections on the basis of culture. Dexamethasone in the convalescence phase has been shown to hasten recovery but given too early can be detrimental, increasing viral proliferation. The overall prognosis for animals with TBE is poor and those that survive often require 6 to 12 months to make a full recovery.
Prevention:
Adequate tick prevention is the best form of protection
Deep clean enclosures at least once a week
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures
Groom your fox, checking for parasites regularly and maintain regular health checks with your vet
Plant pet-safe insect repelling and self-medicating plants
Tuleremia (Rabbit Fever)
Introduction and Background:
Tularemia is caused by the Francisella tularensis bacteria. It is transmitted directly from contact with infected ticks and wild rabbits and thrives in wet, humid and damp environments. It infects both humans and animals and is most likely to peak during the warmer spring and summer months of the year, and if exposed to the condition, can take anything between one day and a fortnight to cause symptoms in animals.
Clinical Signs:
Tularemia or rabbit fever can take anything from a day to a fortnight to show symptoms, but once it does become symptomatic, it develops quickly and soon gets worse. The first and most obvious symptom of tularemia is a sudden high fever that appears to happen almost at once rather than taking hours or days to develop. The animals limbs will appear both weak and stiff to the touch, and they will become lethargic, showing no interest in food, drinking or exercise. As the condition advances, you may also notice swelling in the lymph nodes, and jaundice of the eyes. The stomach and abdominal area may swell and become tender as the spleen and liver become enlarged, and there may be a visible discharge from the eyes and nose. All of these symptoms will develop relatively fast, often within the span of just a few hours, and so you should seek veterinary treatment promptly and not simply wait and see how the condition will develop.
Diagnosis:
Tularemia can prove fatal within just a few hours, and the sooner that you seek treatment, the better the chances of survival and recovery. Your vet will need to take a sample of blood to test for an elevated white cell count, which may indicate that tularemia is present in the blood and give your vet enough information to begin treatment. However, in order to definitively confirm diagnosis, your vet will likely need to send some blood samples away for specialist analysis while treating under the assumption of tularemia in the meantime.
Treatment:
Tularemia is treated by means of the administration of fast-acting antibiotics, and supportive care and monitoring to keep the animal hydrated and deal with the potential effects of the disease infecting the spleen and liver. This will almost certainly mean that the animal will need an inpatient stay in the clinic for at least a couple of days.
Prevention:
Adequate tick prevention is the best form of protection
Deep clean enclosures at least once a week
Clean up leaf litter regularly and keep plants trimmed back in gardens and enclosures
Groom your fox, checking for parasites regularly and maintain regular health checks with your vet
Plant pet-safe insect repelling and self-medicating plants
Sources
www.todaysveterinarypractice.com
