Scabies in dogs

When did we get scabies?

At the start of 2003 a mange epidemic in foxes at Sjælland broke out. They got exposed to mange mites (sarcoptes scabiei vulpus). The mite can be contagious towards many dogs. There has never been a definite epidemic of mange in foxes and dogs in Zealand (Sjælland). We have earlier had epidemics at Bornholm and in Jutland (1983/84). All foxes were eradicated at Bornholm and the population of foxes in Jutland were reduced by 70%.

In September 2003 an ill fox was put down at Amager. There was found a massive amount of mange during the autopsy. In the beginning of spring 2004 we saw many scruffy and ill foxes in the backyards at Amager. At the same time there was reported several cases of dogs itching. The itching turned into inflammation of the skin and even further itching. Foxes with mange mostly die. They change behavior and have trouble finding food. Of course, a fox is not seeing the vet. Dogs on the other hand can get cured with the right treatment.

How do sarcoptes mites live?

The scabies mite is a “burrow mite” which burrows its way 2-3 mm under the surface of the skin per day. It lays 2-5 eggs daily. Adult males look for females on the skin surface or in the “pockets” the females have dug. Examinations have shown that the mite dies after 17-21 days on the animal. A grown scabies mite is a microscopically animal that can’t be seen with the bare eye. The size is compared to a house-dust mite.

How is scabies transmitted?

If you live near a forest or other nature places where foxes are to be found, then you must avoid visiting these places in case the dog is a “magnet” for mange mites from the fox.

A dog can get infested if a scabies infested fox crosses the lawn during the night, maybe to find food. While it crosses the lawn, it scratches itself and some scabies mites fall to the ground. If the dog rolls on the grass afterwards, then it might get infested with mange.

Often the fox will climb through a hedge and leave mange mites om the leaves of the hedge. The dog senses right away that there has been a fox around and goes to the spot. The dog puts its snout into the hedge and it’s enough to get the mites on the tips of the ears or on the head.

Typically, the scabies gets on the ears. We will see hair loss on the ear margins, so the margins end with going bald (see symptoms later).

The experienced vet will without doubt take mange into consideration when the bald ear margins show.

Is a dog under suspicion for scabies and blood work has been done (see later: Diagnostic methods), and where the answer is still not in, then the dog owner ought to mention it to dog owners with a loose dog. They need to avoid “nose to nose” contact since the dog is under observation for scabies. Most certainly there is no reason to be embarrassed. It’s better to be honest. Many don’t like saying “My dog might have scabies”. To be honest with other dog owners is the way to fight the infestation of mange in dogs.

In short: Scabies transmits when in direct contact with another dog or fox infested with scabies. Scabies transmits as well in indirect contact. If a dog walks where an ill dog or fox has been recently, then the dog can get mange and become ill.

Who will get infested?

The fox has a special kind of scabies mite, which is not only attracted by foxes, but dogs as well. Some dogs smell in a way so the scabies mites of the fox can’t tell the difference whether it’s a dog or fox. It can happen, that you have a pack of several dogs but only one gets infested with scabies.

Why?: It’s about the smell. Some dogs attract the scabies mites from the fox, where others don’t carry the smell that the mites like. The “scent” can be because of the smell, tissue and temperature.

How to diagnose scabies?

Skin scraping

In the past scabies was diagnosed by taking a deep scraping from the skin with a scalpel. Even if the vet is experienced and great at doing skin scrapes, then the mite is still hard to find. If the mite can’t be found in the scraping, we still can’t rule out scabies being present. The scraping must be done so deep that the skin bleeds – a procedure thats not recommended  under any circumstances without some type of anaesthesia.

Bloodwork

The vet can take a blood sample and detect antibodies against scabies. The antibody values shall on paper be above 1o to set the diagnosis. You always compare the antibody value with the dogs symptoms, when setting the diagnosis.

One of the other possibilities, which gives similar symptoms as mange is an itching skin infection.

We used to se many allergic dogs, who had been diagnosed with multiply allergic disorder for years, when the problem is really scabies.

These dogs can have a count of antibodies, that is lower than 10.  Still, the dog has been infested by scabies for years. The value is this low because an immunity towards the mite occurs in the dog, where the symptoms have been kept down with a variety of medical treatments (Cortisone, antibiotics). The immunity means the mange count gets lower and lower, and when it’s under 10, it can still have started scratching due to scabies (years ago).

Why do some foxes survive mange? They get immune to the scabies mite, and we see the same with the dogs. The dog, which has a multiply allergic disorder, and which has been treated with Cortisone and antibiotics has a risk for developing fewer antibodies and (following give a false negative test result for mange).

Experiences from the vet clinic Artemis!

The highest count for mange we have seen was at 122. The dog couldn’t handle being inside its own body and got several epileptic seizures, which it never had had in the past. Post mange treatment no more epileptically seizures were seen.

In 2004 and the following 1½ years we did a research, where we examined how long the antibodies stay in the dog’s body. The examination showed that antibodies in some dogs remain in the blood up to a year (83.8%).

If a client suspects a new infestation of scabies, then it’s of no point to do a new blood test, since we can’t disclose the old antibodies being presence in the body.

It must be mentioned that the antibodies we measure, are not preventing antibodies, but only a reminder that we have had mange infestation at one point.

What are the symptoms of scabies?

If a dog gets infested by scabies mites, it will get itching at variable levels. The itching can be in a small area. Typically, the itching is seen behind the ears, on elbow- and tip of popliteal space or the groin. The scabies mites first infest the almost bald areas. You get the feeling that the dog wants to “chew off something”. It chews its hind legs and removes the hair and leave the thighs bald.

They do a self-traumatization, where skin infection and extensive hair loss are developed.

When the dog is in a warm room, the itching often gets worse since the mange mites are more active. It can happen in the bedroom in the morning or near the heater.

Some dogs never get the typical changes in the skin. It can be because the dogs respond differently to the mites. Mange mites deliver “secretions”. Some dogs are more sensitive towards these secretions, and feel it being very itching all over. The dog gets something we call an “allergic reaction” towards the mites, which leads to severer consequences.

Other dogs just scratch a bit. Due to the mild symptoms, then many dogs walk around being called “multi allergic”. The vet often prescribes  hormone therapy in a dose low enough to calm down the itching, but not remove the cause of the discomfort.

Many allergic dogs can be infested by scabies, but never have been diagnosed with the illness.

An allergic dog is allergic for life, where as a dog diagnosed with mange has an illness that can be fully cured.

How to treat scabies?

There are several methods. Some more effective than others.

The commonly used pills to prevent fleas- and ticks also treats scabies. Due to an increasing amount of dogs, who takes the pills, the cases of dogs with scabies are decreasing.