Black Fox UK

Silver Fox Routine Health Care

Routine health care is an important part of pet ownership. Animals are adept a hiding signs of injury or illness and foxes are no different. Less is known on the health and behaviour of captive foxes compared to other pets, so it is extra important they are checked daily for signs of ill-health.

Before bringing a fox home you should ensure there is an Exotic Pet Vet willing to register you and your specialist pet. Book an appointment for an initial health check as soon as you get home, and make arrangements for any vaccinations and treatments the vet may recommend.

Training your fox to tolerate handling from a young age will not only help to secure the bond between you and your fox, but it will also aid you in conducting thorough daily health checks, which will help you build an understanding of what is "normal" for your particular fox. 

It is important to remember that a fox's environment and emotional well-being are interconnected with their health and behaviour. A suitable diet, enclosure and plenty of species specific enrichment go a long way to ensuring your pet remains healthy! 


Vaccination safeguards you, your fox and any other pets in the household from nasty diseases that can cause pain and suffering and in some cases, even death. It is important to note that there are not always treatments available, where treatments are available, they can be expensive and in some circumstances even prove unsuccessful. It is for this reason that preventing disease through vaccination is strongly advised.

Vaccines contain a modified form of the virus or bacterium that causes a particular disease. They work by stimulating the body's immune system in a safe way. Should your fox come into contact with a disease, the immune system 'remembers the vaccine' and is stimulated into fighting off the disease before it can take hold. 

In order for vaccines to provide protection, it is advised that they are given before the animal is allowed to socialise with animals from outside of the home.  The ability to socialise with other animals from a young age is essential for the normal social development of a young fox, so for this reason it is vital they are vaccinated as soon as possible.  

Vaccinations are given at intervals over specific time-frames, which vary depending on the vaccine in question. Vaccinations recommended for captive foxes in the UK include;

  • Canine Distemper
  • Canine Infectious Hepatitis
  • Canine Parvovirus
  • Leptospirosis

Note: Lyme Disease and Canine Influenza Virus vaccines are now available for dogs in the UK.  It is not yet clear if these are suitable (or recommended) for use in pet foxes. 

Legacy of the Silver fox - How foxes have helped to reduce disease:

The canine distemper vaccine still used in pets today was originally developed by a U.S. fox farm in the 1930's and has been helping to protect pets from this disease since;

"Research on the once-world’s-largest fox farm, completed by Dr. R. G. Green in 1938 while employed under the Fromm Bros. in the Fromm Laboratory, is the reason dog and ferret owners have access to the distemper vaccine today"

US Fox Shippers Council - The Invention of the Fromm-D Distemper Vaccine

Parasite Treatments:

Captive foxes, like other pets, require regular treatments to help prevent them from suffering parasite problems. Your exotics vet will be able to provide advice about what products to use, how effective they are, and how often to use them.

Parasites such as worms, ticks, fleas and mites present a disease risk to both humans and animals, so it is important not to look over this aspect of health care. Ticks and fleas are known to carry many different pathogens and can easily transmit disease between wild animals, domestic pets and humans, if these pests are not kept  not kept in check.

To keep parasite burdens down ensure enclosures and bedding are kept clean. Remove and unwanted leaf litter and keep weeds and plants trimmed back. "Deep Clean" your home and animal enclosure once a week and check you pet daily for ticks, fleas and other parasites.

If you find your fox is suffering either internal or external parasites, it is important to seek veterinary advice. Remember to treat not only the animal, but other pets in the home, the animals enclosure and bedding, and your home (should your fox have access). Your vet will be able to recommend products that are safe and effective to use. 

Signs of Ill-health in  Silver Foxes:

  •  Sickness or diarrhoea
  • Abnormal weight gain or  loss
  • Loss of appetite
  • Drinking abnormal amounts
  • Lethargy or increase in sleeping
  • Unusual sores or swellings
  • Increase or decrease in toileting
  • Limping or weakness on limbs
  • Coughing, wheezing or sneezing
  • Bleeding
  • Scratching or chewing
  • Signs of pain (sensitivity)
  • Runny eyes or nose
  • Changes in behaviour 

If you notice any of the symptoms above in your fox do not hesitate to contact your vet

Grooming & Nail Trimming:

Grooming is not only important for maintaining health, but the process of allogrooming is an important social behaviour for foxes,  contributing to both their physical and mental well-being. Pet foxes will engage in allogrooming their human carers and other pets in the home if a strong enough bond develops. By grooming your fox you are displaying social behaviour that allows your fox to develop trust, which creates a foundation for a strong social relationship to develop between you in return.

Note: Ensure you begin training your fox to tolerate regular handling and grooming sessions from the first week you bring them home, the aim is to start desensitizing them the human behaviours they will need to learn ro tolerate in their life with you. Keep sessions short and sweet, stop if your fox appears fearful or uncomfortable, you need the sessions to be rewarding. Ensure training is consistent and regular, and remember to praise and treat your fox for allowing you to groom and handle them. 

Like wild foxes, silver foxes go through a moulting season each year. Silver foxes were originally bred for the fur trade and have developed much thicker and fluffier coats as a result of the selective breeding, which can be a handful when it comes out in a moult, I recommend investing in a good brush, both for the fox and your floor! Alternatively, hand-plucking the moulting clumps of fur can be just as effective. The Russian domesticated foxes however, through the process of domestication for desirable pet traits, have lost their thick seasonal coats and have an easier time when moulting season arrives, compared to their wild and farmed cousins.

Seasonal Moulting Behaviour;

Bathing is not a natural process for foxes, who use grooming to keep clean in the wild. Like cats and dogs, some tolerate it, some do not. It is important for your fox to learn to tolerate bathing, but this learning process must begin at very early age. While it is not necessary for a fox to be bathed, the occasional need will arise and the early training will be beneficial for both you and your fox.

As with other pets, nail care should also be an important part of your fox's health care routine. Foxes have long, sharp, curved nails that sit higher on the toe than in dogs, this allow them to grip and capture their small mammal prey. Overgrown nails can be uncomfortable and can lead to breaks and splits that are not only painful, but also present the risk of infection. Severe cases can cause pain and inflammation as a result of poor posture.

A fox that has adequate opportunity to dig, climb and exercise will get enough wear on the nails to keep them in check without much bother, but don't slack off, as ensuring your fox's nails remain the correct length is vital. Leaving nails to grow allows the quick to increase in size as it supplies the increasing length of the nail. A cut quick can bleed, can be painful and itself then represents a risk of infection. 

You can easily assess whether the length of your foxes nails are correct by walking them across a hard floor. If you can hear their nails on the floor when they walk, they are too long. If you are concerned about trimming your fox's nails you can book them into your vet's or a willing grooming parlour.

Microchipping & Neutering:

Microhipping is now a legal requirement for dogs in the UK. While foxes are canines, they are not covered by this legislation. However, it is advised that you get your fox micro-chipped at their first health check. This means that should your fox get lost or stolen, it can be identified and you can be notified.

While microchipping is helpful in reuniting lost pets with their owners, details must be kept updated for it to be effective, so remember to keep your details up to date. 

"It's Nicer to Neuter!" 

Dogs Trust Campaign Slogan

Here at Black Foxes UK, we agree.

Twice a year, during breeding season and again when young cubs leave their home territory to claim their own, foxes undergo seasonal behavioural changes and become much more challenging. During these times the dynamics of their social alliances changes, they become much more confrontational and are much more likely to attempt to escape. 

Young foxes can be neutered from around 4-8 months and should preferably be done before sexual maturity begins at about 10 months. Neutering may help to reduce unwanted behaviours and can also help to reduce not only how strong your fox smells, but the strength and frequency of territorial marking.

Neutering also prevents unwanted and unplanned pregnancies and reduces the burden on exotic pet rescues. Most importantly of all, it ensures your pet fox's genes don't end up in the wild fox gene-pool. 

The Five Freedoms

All pet owners and animal keepers, regardless of the species they keep, must comply with the Animal Welfare Act 2006. The act states five needs that owners must ensure they meet. Breech of the Act can result in a fine, imprisonment and/or a ban from keeping animals. 

The five needs include;

The need for a suitable environment - Make sure you fox has somewhere suitable to live. Foxes require a secure enclosure with a minimum of a 100 square foot per fox. While there is no regulation on the size of enclosure anything less than this would not be considered suitable in meeting their needs. The enclosure must include several warm safe places to hide from view and bad weather, it must be escape-proof and it must be safe. 

The need for a suitable diet - While they are carnivores, foxes are opportunistic omnivores. The diet of a captive fox should include whole small prey items daily where possible (Mice, chicks, insects). Other food items such as; chicken, liver, eggs, fresh fruits, vegetables, berries, seeds, honey and yoghurt, as well as complete commercial diets  (cat food, dog food or specialist wildlife diets), can be added to this to provide a balanced and nutritious diet. Foxes require a higher amount of taurine than dogs but less than cats. A balanced diet, complete with raw meat and whole prey items, will supply your fox's needs.

The need to exhibit normal behaviour patterns - Foxes have several natural behaviours that owners can easily accommodate. They are avid diggers, they also bury excess food in a behaviour known as "caching". Providing an area where your fox can dig safely will allow it to display these natural behaviours. Foxes are also great climbers and they enjoy taking in a view from a height, ensure your fox has platforms and climbing branches in their enclosure to allow them to behave as foxes need to behave. In the wild, foxes have to work hard for their food, so make sure you add food enrichment devices to your daily routine. 

The need to be housed with, or apart from, other animals - Foxes are social animals, but they have a socially select nature which they manage and maintain through agonistic displays. The social life of foxes adapts and changes over time and while some prefer the company of others, some do not. It is important to monitor the social behaviour of foxes that are group housed for this reason, especially during breeding and weaning season. As with the case with cats, there is no welfare concern housing foxes singularly.

The need to be protected from pain, suffering, injury and disease -  It is your duty as an owner to ensure your fox remains healthy. Ensure you are familiar with the signs of normal health and behaviour, if you notice anything out of the ordinary, do not hesitate to take action and contact your vet. Veterinary fee's can be expensive and there is little option for pet insurance for foxes, so ensure you are able to afford any costs that may occur over the course of your foxes life. If you cannot afford vets fees, you cannot afford a fox. 

Ailments of Silver Foxes

Captive foxes are just as susceptible to illness and injury as their wild counterparts and keepers need to be aware of the prevalence, transmission and zoonotic potential of diseases in both wild foxes and domestic pets in order to keep their foxes protected. 

Important diseases to note among domestic pets and wild foxes in the UK and across Europe (from both an animal welfare and public safety perspective) include;

  • Canine Infectious Hepatitis 
  • Dog Roundworm
  • Fox Tapeworm
  • Heartworm
  • Hookworm
  • Lyme Disease
  • Lungworm
  • Ringworm
  • Roundworm
  • Rickettsia
  • Sarcoptic Mange 
  • Toxoplasmosis
  • Anaplasmosis
  • Canine Distemper
  • Canine Parvovirus
  • Cat Scratch Disease
  • Canine Herpesvirus 
  • Ehrlichia Canis
  • Giardia
  • Leishmania
  • Leptospirosis
  • Liver Flukes
  • Salmonella
  • Tularemia

More information on the relevant parasites in UK pets, visit Jungle for Pets

Known diseases specific to silver foxes include;

  • Fox Encephalitis
  • Hereditary Hyperplastic Gingivitis 
  • Chaztek Paralysis

Note: Should you notice any sign of ill health or abnormal behaviour in your fox do not hesitate to take action and contact your vet. Animals such as foxes hide illness well and can "go down quickly". Your vet will be able to advise you on the best course of action. 

Fox Encephalitis (Canine Infectious Hepatitis):

Historically, fox encephalitis been considered "a common disease of the silver or red fox in captivity" and is readily transmissible between foxes, dogs and other similar animals. Although the agent of the disease was unknown at the time of it's discovery, there was an understanding of a link between fox encephalitis and both distemper and the hepatitis virus'.

The fox encephalitis virus (or canine infectious hepatitis in dogs), is a highly contagious adenovirus, of which there are two strains; canine adenovirus type 1 or adenovirus type 2 (CAV-1 or CAV2). CAV-1 is the strain of most concern in the UK. 

The virus invades the endothelial tissues, particularly the smaller blood vessels which results in local haemorrhaging and tissue damage at the affected site. This in turn, leads to inflammation of the brain and other organs. 

"ICH was first identified in North America in silver foxes in 1925 (Green 1925), but the disease was only described in domestic dogs in 1947 (Rubarth 1947). Beside red and grey foxes, and other Canidae, such as coyotes, jackals and wolves, CAdV-1 can also infect members of the families... Mustelidae (skunks and otters) and Procyonidae (raccoons) (Spencer et al. 1999)."

Fatal canine adenovirus type 1 acute infection in a Yorkshire Terrier puppy in Portugal: a case report (pg 210) - M.D. Duarte, 2014

As stated by the Merck Veterinary Manual;

"Infectious canine hepatitis (ICH) is a worldwide, contagious disease of dogs with signs that vary from a slight fever and congestion of the mucous membranes to severe depression, marked leukopenia, and coagulation disorders. It also is seen in foxes"

Overview of Canine Infectious Hepatitis - Revised June 2013 by Kate E. Creevy, DVM, MS, DACVIM

A case study of three wild foxes from the UK found that;

"Canine adenovirus type 1 (CAV-1) was isolated from all three foxes. In a serological study, antibodies to CAV-1 were detected in tissue fluid extracts taken from 11 of 58 (19 per cent) frozen red fox carcases from England and Scotland."

Infectious canine hepatitis in red foxes (vulpes vulpes)) in the United Kingdom - Thompson. H, et. al., 2010


Animals become infected though contact with contaminated body fluids, urine or faeces, or by breathing in the virus following contact with an infected animal . The virus can be shed in urine for up to a year after the initial infection, posing a risk to susceptible animals who come into contact with it. Contaminated enclosures, toys and bedding etc., can also serve as a source of transmission.

"The virus can be found in the brain, blood, spleen, upper respiratory tract and spinal cord. The reason the virus becomes pathogenic when large groups of foxes are put together is not positively known. Direct contact from quarrelling and the cannibalistic tendency of a fox, are thought to be causes as well as eating and drinking from the same containers.

The portals of entry are the respiratory tract, digestive tract. and skin wounds. Adult foxes (over one year old) are twice as resistant as are the younger foxes. When the disease occurs in a large group of mixed-aged foxes. the mortality rate is about 15-20 percent. Experimental inoculation shows about 80 percent mortality in foxes below the age of 6 months and approximately 15-20 percent mortality in adult foxes." 

Encephalitis of the Silver Fox - Harold A. Kjar, 1943

Unusual Symptoms:

Blue Eye: A condition caused by canine infectious hepatitis - Corneal clouding (“blue eye”) is the result of immune-complex reactions after recovery from acute or sub-clinical disease. This reaction is also observed in some animals vaccinated with the live attenuated vaccine.  

Note: The example below is of a sick fox from a fur farm in Qubec, that has thankfully since been closed down and the owner prosecuted. It is unknown what conditions this fox was suffering. 

Clinical signs;

Hepatitis (CAV-1)

  • Partial anorexia
  • Hyper-excitability
  • Fever
  • Vomiting and/or diarrhoea
  • Convulsions
  • Ataxia
  • Weakness of limbs and/or paralysis
  • Hallucination

Respiratory Disease (CAV-2)

  • Dry, hacking cough
  • Retching Coughing up white foamy discharge
  • Conjunctivitis


There is no specific treatment for canine infectious hepatitis, treatment is symptomatic and supportive. The goal of treatment to limit secondary infections, to support fluid balance and to control any haemorrhaging. In mild cases foxes can recover, but severely sick foxes may require a blood transfusion. It is though up to 20% of those infected succumb to the disease, it is for this reason vaccination is recommended.  

Hereditary Hyperplastic Gingivitis

Hereditary hyperlastic ginivitis is an autosomal recessive disease that occurs mainly in male foxes, but can also occur in females. It has been noted that it is a condition related to superior coat quality, specifically; the length and density of guard hairs. 

"Hereditary hyperplastic gingivitis is a progressive growth of gingival tissues in foxes resulting in dental encapsulation. It is an autosomal recessive condition displaying a gender-biased penetrance, with an association with superior fur quality. This disease has been primarily described in European farmed foxes... Until 2008, HHG had only been described in the farmed fox population, at which time a case in a wild red fox was reported in Germany." 

Hereditary hyperplastic gingivitis in North American farmed silver fox (Vulpes vulpes) - Jo-Anna B.J. Clark, 2015 


The disease is hereditary, passed on from parents to offspring.  The defect is present at birth. It is thought that viral infection gives rise to this phenotype expression. 

Clinical Signs;

Hereditary hyperplastic gingivitis is the slow-growing, non-tender growth of the ginigivial tissue. Clinical signs appear at around 2-3 years of age and continue throughout the fox's lifespan.  

The example below, by the Canadian Veterinary Medical Association, demonstrates how teeth may become covered by such growth. 


There is no specific treatment for hereditary hyperplastic gingivitis, treatment is symptomatic and supportive. The goal of treatment to limit secondary infections and to make life as comfortable for the fox as possible. Due to the nature of the disease, repeated surgical removal of excess tissue may be necessary to avoid impaction and displacement of teeth.

Chaztek Paralysis

Chaztek Paralysis is a disease first recognised in the Silver fox. It refers to the presence of neurological symptoms, as a result of lesions in the central nervous system, which are secondary manifestation of a thiamine (vitamin B1) deficiency from feeding too much of certain types of uncooked whole fish. Cases are typically limited to fur farms that feed whole fish diets, but in 2007, Chaztek paralysis was recorded in 2 wild foxes (vulpes vulpes japonica).

"Chastek paralysis, an acute dietary disease of foxes, is caused by including 10% or more of certain species of uncooked fish in the diet and may be prevented or cured by giving adequate amounts of thiamine"

Physiological Availability of the Vitamins - Daniel Melnick, 1945

Clinical signs;

  • Weakness and/or paralysis
  • Ataxia
  • Confusion
  • Death within 48-72 hours of neurological presentations without treatment


Chaztek paralysis is treated with thiamine supplementation and the reduction or removal of fish from the diet, which can lead to improvement of the symptoms and often, complete resolution. Other nutrients may also need to be replaced, depending on the severity of the condition.

Further Reading

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