Bacterial Infection Actinomycosis in Dogs: Causes & Treatment

Actinomycosis is a serious bacterial disease that affects dogs caused by Actinomyces or Arcanobacterium. This infection can lead to fistulous tracts, abscesses, and sulfur granules, common clinical signs of actinomycosis lesions in dogs. To diagnose this condition, cytologic examination of discharge or tissues is necessary. Actinomycosis can affect different tissues in dogs, including soft tissue and the anterior chamber of the eye, leading to septic endophthalmitis and ocular discharge in severe cases. Streptococcus infection may also be a contributing factor to Actinomycosis in dogs.

If you suspect your dog has actinomycosis disease, it’s important to seek veterinary Care immediately. This article will discuss canine Actinomycosis in detail, including its causes, symptoms, diagnosis, and treatment options. Actinomycosis can cause pneumonia and lesions, leading to abscess formation. So, let’s dive into Actinomycosis and learn how to protect our furry friends from this dangerous bacterial infection!

What Causes Actinomycosis in Dogs?

Actinomycosis is a bacterial disease that can affect dogs. The Actinomyces spp bacteria cause it, commonly found in the environment. Streptococcus and Arcanobacterium are other bacteria that can contribute to developing pneumonia in dogs.

Actinomyces spp is the primary bacteria that causes Actinomycosis in dogs.

Actinomyces spp are gram-positive bacteria that form branching filaments. They are anaerobic or microaerophilic, meaning they grow best in environments with low oxygen levels. These bacteria are commonly found in soil, water, and the mouths of animals and humans. Ampicillin is an antibiotic commonly used to treat Actinomyces infections. Some species of Actinomyces can cause bone infections, while others are found in the body cavity.

When a dog comes into contact with Actinomyces spp, either through ingestion or inhalation, the bacteria can enter its body and cause an infection. This can lead to pneumonia, a serious respiratory disease requiring immediate vet treatment. Cats are also at risk of contracting this disease if they come in contact with contaminated objects or inhale dust particles containing Actinomyces spp.

Infection can occur when Actinomyces bacteria enter the body through a wound or foreign body.

Another way that dogs can develop the disease actinomycosis is through wounds or foreign bodies that become infected with Actinomyces spp. This can lead to pneumonia and the need for veterinary Care. Cats can also be affected by this bacterial infection. For example, if a dog or cat gets a puncture wound from a stick contaminated with these bacteria, it could lead to an infection.

Foreign bodies such as splinters or grass awns can also introduce Actinomyces spp into a dog’s body and cause an infection. These foreign bodies may not be visible to the naked eye but can cause inflammation and irritation over time, leading to a disease that requires immediate attention from a vet. Cats are also susceptible to this type of infection if they have an untreated wound.

Streptococcus spp can also contribute to the development of Actinomycosis in dogs.

While Actinomyces spp and Streptococcus spp are the primary species that can cause actinomycosis disease in dogs, cats can also be affected. Antibiotic treatment, such as ampicillin, may be necessary to combat the infection.

Streptococcus spp are gram-positive bacteria that commonly inhabit animals’ and humans’ respiratory and gastrointestinal tracts. When these bacteria enter a wound or foreign body contaminated with Actinomyces spp, they can create an environment conducive to the growth and spread of both types of bacteria. Ampicillin may be used to treat infections caused by these species. In addition, Streptococcus spp and Actinomyces spp have been associated with endophthalmitis and Nocardiosis.

Symptoms of Actinomycosis in Dogs

Actinomycosis is a bacterial infection that affects dogs and cats. This condition can cause various symptoms, including swellingdraining tractsabscesses, and endophthalmitis. If your pet has a wound, it’s important to watch for signs of Actinomycosis or Nocardiosis.

Swelling is one of the most common symptoms of Actinomycosis caused by Actinomyces bacteria in dogs and cats. This can occur in various body parts, including the face and jaw. The swelling may be painful and tender to the touch. In rare cases, Actinomyces sp infection can lead to endophthalmitis.

Another symptom to watch out for is draining tracts. These small openings in the skin allow pus or other fluids to drain from an infection site, which can be caused by Actinomyces sp or Nocardiosis. These tracts may be visible on the surface of your dog’s skin or hidden underneath and may indicate the presence of endophthalmitis on the right side.

Abscesses are also a common sign of Actinomycosis in dogs caused by Actinomyces sp. These are pockets of pus that form when bacteria infect tissue beneath the skin. Abscesses can range from small lumps to large masses and can be painful. In severe cases, Actinomycosis may lead to endophthalmitis or inflammation of the inner eye and Nocardia infection on the right side of the body.

Diagnosis of Actinomycosis in Dogs

If you suspect your dog has Actinomycosis, it’s important to get them diagnosed immediately. A proper diagnosis involves a physical examination of the right area, biopsy, and culture for possible endophthalmitis caused by Nocardia.

During a physical examination, your veterinarian will look for signs of swelling, draining tracts, and abscesses. They may also take blood tests or perform imaging studies like X-rays or ultrasounds to detect actinomyces sp and Nocardia infections. In addition, they will check for any symptoms of endophthalmitis.

A biopsy involves taking a small tissue sample from an affected area and examining it under a microscope. This can help identify whether actinomyces sp bacteria is present and what type it is.

Finally, a culture involves growing bacteria from a sample taken during a biopsy or another procedure. This allows veterinarians to identify which specific strain of bacteria is causing the infection.

How Do Vets Diagnose Actinomycosis in Dogs?

To diagnose Actinomycosis in dogs, veterinarians rely on a combination of physical examination, biopsy, and culture. These methods allow them to identify the presence of Actinomyces sp bacteria and determine what type is causing the infection.

During a physical exam, your veterinarian will look for signs of swelling, draining tracts, and abscesses. They may also take blood tests or perform imaging studies like X-rays or ultrasounds to check for the presence of Actinomyces sp.

If they suspect Actinomycosis, they will likely perform a biopsy to confirm the diagnosis. This involves taking a small tissue sample from an affected area and examining it under a microscope.

Finally, they may perform a culture to identify which specific strain of bacteria is causing the infection. This information can help inform treatment decisions and ensure your dog receives appropriate Care.

How to Prevent Actinomycosis in Dogs

Actinomycosis is a bacterial infection caused by Actinomyces sp that can affect dogs, causing symptoms such as swelling, abscesses, and difficulty eating or swallowing. While treatment is available for Actinomycosis, it’s always better to prevent the infection from occurring in the first place. Here are some tips on how to prevent Actinomycosis in dogs.

Regular Dental Check-Ups and Cleaning

One of the most important steps to prevent Actinomycosis in your dog is to schedule regular dental check-ups and cleanings with your veterinarian. Poor oral hygiene can lead to bacterial infections like Actinomycosis, so keeping your dog’s teeth and gums healthy is essential. Your vet can also advise you on at-home dental Care for your dog.

Avoid Feeding Difficult-to-Chew Foods

Another way to help prevent Actinomycosis in dogs is by avoiding feeding them foods that are difficult or impossible for them to chew or swallow. This includes bones, which can splinter and cause damage to the mouth or throat. Instead, choose soft foods that are easy for your dog to eat without risking injury.

Keep Your Dog’s Environment Clean

Bacteria thrive in dirty environments, so keeping your dog’s living space clean is crucial. This means regularly cleaning their bedding, toys, food bowls, and any other items they encounter. It would be best to ensure that areas, where your dog spends time outside are kept clean and free of debris-freeeeVeterinary Care Immediately if Suspect Actinomycosis.

If you suspect your dog has Actinomycosis or any other bacterial infection, seek veterinary Care immediately. The sooner they receive treatment, the more likely they will recover fully. Symptoms of Actinomycosis can include swelling, abscesses, and difficulty eating or swallowing.

Treatment Options for Actinomycosis in Dogs

Actinomycosis is a bacterial infection that can affect dogs, and early detection and prompt treatment are crucial for successful management. In this article, we will discuss the different treatment options available to pet owners.


Antibiotics are the most common treatment option for Actinomycosis in dogs. The type of antibiotic prescribed will depend on the severity of the infection and the dog’s overall health. Generally, a course of antibiotics lasting several weeks is required to treat Actinomycosis effectively.

Some commonly prescribed antibiotics include penicillin, tetracyclines, and macrolides. These medications kill or inhibit the growth of bacteria in the body. It is important to follow your veterinarian’s instructions carefully when administering antibiotics to your dog.


Surgery may sometimes be necessary to remove infected tissue or abscesses caused by Actinomycosis. This option is usually reserved for more severe cases with unsuccessful treatments.

Surgical intervention can be risky and expensive, so it should only be considered a last resort after other options are exhausted. Your veterinarian can advise whether surgery is necessary for your dog’s condition.

Supportive Care

Supportive Care is an essential part of treating Actinomycosis in dogs. This includes providing adequate nutrition and hydration and managing any pain or discomfort associated with the infection.

Depending on your dog’s needs, your veterinarian may also recommend additional supportive therapies, such as wound care or physical therapy.

Vitreous Paracentesis

Vitreous paracentesis is a diagnostic procedure used to identify ocular Actinomycosis in dogs. During this procedure, a small sample of fluid from the eye is collected using a needle and syringe.

If ocular Actinomycosis is detected, treatment may involve a combination of antibiotics and supportive Care. In some cases, surgery may also be necessary to remove infected tissue from the eye.

Common Medications Used to Treat Actinomycosis in Dogs

Antimicrobial therapy is the primary treatment for Actinomycosis in dogs. This therapy involves using antibiotics to kill or inhibit the growth of bacteria that cause the infection. Several antibiotics can treat Actinomycosis in dogs, including penicillin, ampicillin, clavulanic acid, and enrofloxacin.


Penicillin is the most commonly used antibiotic for treating Actinomycosis in dogs. It works by inhibiting bacterial cell wall synthesis, ultimately leading to bacterial death. Penicillin is effective against a wide range of bacteria and has a relatively low risk of side effects.


Ampicillin is another antibiotic that can be used to treat Actinomycosis in dogs. Like penicillin, it works by inhibiting bacterial cell wall synthesis. However, ampicillin has a broader spectrum of activity than penicillin and may be more effective against certain types of bacteria.

Clavulanic Acid

Clavulanic acid is often added to amoxicillin to increase its effectiveness against Actinomycosis. Amoxicillin/clavulanate combination drugs are known as “augmentin” and are commonly used in veterinary medicine. Clavulanic acid works by inhibiting an enzyme some bacteria produce that can break down certain antibiotics.


Enrofloxacin is a broad-spectrum antibiotic that may be used in cases where other antibiotics are ineffective. It belongs to the fluoroquinolone class of antibiotics and inhibits bacterial DNA synthesis. Enrofloxacin should only be used under veterinary supervision due to its potential for serious side effects such as joint damage.

Other Possible Symptoms of Actinomycosis in Dogs

Actinomycosis in dogs can cause symptoms, including skin lesions slowly healing and swelling in the affected area. In addition to these common symptoms, several other signs may indicate your dog has Actinomycosis.

Degenerate Neutrophils

One possible sign of Actinomycosis is the presence of degenerate neutrophils in your dog’s bloodwork. Neutrophils are white blood cells that play an important role in fighting infections. When these cells become damaged or die off, they are called degenerate neutrophils.

If your veterinarian notices degenerate neutrophils on your dog’s bloodwork, it may indicate that they have an ongoing bacterial infection such as Actinomycosis.

Corneal Edema

In some cases, Actinomycosis can spread from the initial site of infection to other parts of the body. If the bacteria reaches the eye, it can cause corneal edema or cloudiness in the eye.

This symptom can be particularly concerning as it can affect your dog’s vision and lead to further complications if left untreated. Contact your veterinarian immediately if you notice any changes in your dog’s eyes or suspect they may have corneal edema.


Fever is a common symptom of many types of infections, including Actinomycosis. If your dog has a fever and other symptoms, such as lethargy or loss of appetite, it may indicate an underlying bacterial infection.

It’s important to note that fever alone is not necessarily indicative of Actinomycosis but rather a general sign that something is wrong with your pet’s health.

Loss of Appetite and Weight Loss

Another potential symptom of Actinomycosis in dogs is a loss of appetite and weight. If your dog is not interested in eating or has experienced a sudden drop in weight, it may indicate an underlying infection.

While these symptoms can be concerning, they are non-specific and could indicate various other health issues. Working with your veterinarian to determine the underlying cause of your dog’s symptoms and develop an appropriate treatment plan is important.

Raising Awareness About Actinomycosis in Dogs

Actinomycosis is a bacterial infection affecting dogs of all ages and breeds. It is caused by the bacterium Actinomyces, commonly found in soil and plant material. While it is not a common infection, it can cause serious health problems if left untreated.

To prevent Actinomycosis in dogs, keeping their environment clean and debris-free is important. Regular dental check-ups are also recommended to prevent oral infections, which can lead to Actinomycosis. If you suspect your dog has Actinomycosis, it’s important to seek veterinary Care immediately.

Symptoms of Actinomycosis include swelling, abscesses, and draining tracts on the skin or inside the mouth. Diagnosis typically involves a physical exam and laboratory tests such as blood work or imaging. Treatment for Actinomycosis usually involves antibiotics and surgical removal of any infected tissue. Common medications used include penicillin and tetracycline.

Dog owners need to be aware of the symptoms of Actinomycosis so they can seek prompt treatment for their pets. We can help keep our furry friends healthy and happy by taking preventative measures and seeking veterinary care when necessary. So, let’s spread awareness about this lesser-known bacterial infection among dog owners everywhere!

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