Foxes and dogs are remotely related but the wild animal carries a number of diseases harmful to our gundogs, says David Tomlinson
Disease from foxes
All dogs, including gundogs can get the following disease from foxes:
- Sarcoptic mange
Dogs and foxes do suffer from the same diseases, though, of which the most worrying is rabies. We have been rabies-free in Britain for 98 years — since quarantine for dogs was introduced in 1922. However, there remains a reservoir of rabies in the European fox population.
Rabies can be found in many different wild animals, but the fox is the only European mammal that is able to both maintain and spread the virus.
A major killer of foxes
Sarcoptic mange is a major killer of foxes. The mange is caused by a tiny mite, Sarcoptes scabei, that buries itself beneath the skin. It’s clearly exceedingly irritating for dogs who catch it from foxes. Fortunately, most of the flea and tick prevention treatments available for dogs also kill these unpleasant mites.
Sarcoptic mange is probably the biggest controller of foxes there is in this country, at least in urban situations. The most mangy fox I’ve ever seen I caught in my back-garden Larsen trap: presumably it fancied my decoy magpie. The unfortunate animal had little fur left and its hairless tail bore no resemblance to a healthy fox’s brush. It posed a question as to how to put it out of its misery. I despatched it instantly with a shot to the brain, at close range.
Foxes can also transmit lungworm
Another disease from foxes which dogs can suffer from is lungworm, which is a relatively new problem. Lungworm, Angiostrongylus vasorum, is a parasite found in slugs and snails. Foxes pick up the parasite by eating these creatures. The first record of lungworm in the UK was in 1975 and it is now widespread. If left untreated, lungworm is a killer, as it leads to breathing problems and internal bleeding. Foxes eat both slugs and snails and spread the worm larvae in their droppings. Dogs become infected by eating or rolling in fox scats.
A dog suffering from a lungworm infection is likely to cough due to the presence of the worms in its lungs, while blood in the urine or vomiting blood are also indications. Other signs include depression, weight loss, poor appetite and lethargy. Early diagnosis by a vet is essential for a complete recovery.
A study made in 2015 found that 18.3% of foxes were infected. Dogs of all ages and breeds are susceptible to the parasite, though spaniels are reported to be one of the most commonly affected breeds.
A fox lifespan
In view of the number of diseases to which foxes are susceptible, it seems remarkable that they are such a widespread and successful animal. Their average lifespan is short — only around a year for a London fox — while few live longer than four years. The secret of their success is breeding prolifically, plus the ability of young animals to disperse widely.
Dogs and foxes are only remotely related, and though I’ve seen some foxy looking dogs, you can disregard dog-fox hybrids as the biology of the two species is very different. Dogs have a gestation period of 63 days, while that of a fox is 52 or 53 days. Most dogs I’ve known would rather kill a fox than mate with it, so the chances of a dog actually coupling with a fox seem extremely remote.
Some questions about dogs catching disease from foxes
Q: We have noticed a fox is starting to use our garden. As we have two dogs, I was wondering if this presents any particular health risk to our pets?
A: There are certainly a variety of diseases that can affect both dogs and foxes; most common are worms. mange, fleas and ticks. Foxes can also be infected with leptospirosis (Weil’s disease) and a dog could become infected if it were to drink water contaminated by urine from a fox infected with Weil’s. Similarly, foxes can be infected with parvovirus and canine distemper and, though the risk is low, it is again well worth ensuring your dogs are fully vaccinated. Foxes can carry other bacterial pathogens such as Pasteurella, listeria, mycoplasma, staphylococcus, salmonella and Escherichia and it is possible for your dog to catch these from eating fox poo.
Lungworm is surprisingly common in the UK and dogs will pick up lungworm/heartworm from eating infected slugs and snails harbouring the larvae. There can be an indirect link through foxes carrying lungworm, passing worm eggs in their faeces, where slugs and snails can become infected and thus pass the infection on to dogs. It is important to understand, however, that despite the threat, the risk of disease actually being passed from wild foxes to domestic dogs under normal circumstances is low, particularly where foxes are relatively healthy and don’t pose a huge health risk. Though rabies is currently absent from the UK, were it ever to be reintroduced and become endemic, the fox is likely to represent the greatest risk of carrying rabies and passing the infection on to dogs. It is reasonable to assume that, while foxes can spread disease to dogs in the UK, the chances of them actually doing so are slim. Nevertheless, the risk exists and therefore it is worthwhile taking sensible precautions to minimise contact and keep your animals safe from cross infection
Q: We have foxes in our garden and one has a lot of bald, sore-looking patches, especially over its head. A friend suggested that the foxes have mange, which could be passed onto our dogs. What do you suggest we do?
A: Foxes can suffer various types of mange and what you describe sounds like sarcoptic mange which is common, especially in the urban fox population. It is caused by a tiny mite called Sarcoptes scabiei that burrows into the skin. Different species have their own specific sarcoptic mite; in people it causes scabies. Though dogs have their own sarcoptic mite, they can still contract the fox mite – particularly if they are in close contact with foxes or their dens. The fox mite causes a less severe form of the disease mange in dogs, but will cause skin irritation and affected dogs will scratch and bite themselves.
Worried about mange
Q: We took our Jack Russell puppy to the vet because she was losing hair in patches, especially over the muzzle and around her eyes. The vet diagnosed demodectic mange and she is now on treatment, but I am concerned about our children, having read that mange can be transferred to people. What is your advice?
A: Mange is a collective term used to describe a skin disease caused by mites. Dogs suffer from two types of mange: sarcoptic and demodectic mange. Sarcoptic mange is caused by a mite called Sarcoptes scabiei, a round, eight-legged mite. The females burrow into the skin and lay their eggs. These eggs hatch and the young mites emerge to live and feed on the skin. It is highly contagious and can pass fairly easily from dog to dog and from dogs to people.
Demodectic mange is less common and is caused by a cigar-shaped mite known as Demodex canis. Demodectic mites live in hair follicles. They can cause the hair to fall out, but there is less irritation than with sarcoptic mites unless the dog becomes sensitised. If that happens, the presence of the mites leads to a more overt response and the resulting dermatitis can become more itchy. Demodectic mites are passed from the dam to her pups soon after birth and many such infestations cause no problems whatsoever. Demodectic mites are not passed from dogs to people, so you should not be at risk of developing mange. However, you would be advised to wash your hands after playing with the pup and, ideally, wear gloves when administering medicine or bathing her.
Itchiness and skin infection
Sarcoptic mange usually starts on the ears then spreads to affect the elbows and chest until eventually, unless treated, it will affect the entire body. Once the disease becomes more generalised, affected animals suffer from severe itchiness and secondary skin infection.
Fortunately sarcoptic mange is easily treated and there are several products that your vet can prescribe for your dogs. Foxes, however, are more problematic.
The problem in getting rid of “your” foxes is that other foxes will almost certainly move into the vacated territory, where they will likely access the source of infection so all you will do is perpetuate the problem. Unless they can be trapped, veterinary treatment is difficult, but the National Fox Welfare Society claims success in treating the condition using a homeopathic remedy containing arsenic and sulphur.
This article was originally published in 2020 and is kept updated.