WHAT IS MASTITIS?
Mastitis in dogs is an infection of the mammary glands. It usually occurs in female dogs who are nursing a new litter of puppies. The mammary glands swell and become very painful for the dog. Nursing puppies should not drink the milk from affected teats; the milk will be toxic to puppies.
In most cases, mastitis is caused by a bacterial infection. Trauma to the nipple or teat canal can allow bacteria to enter the teat canal, traveling up into the mammary gland and creating a bacterial infection. Even in the absence of trauma, a female dog living in unsanitary conditions may be exposed to large quantities of bacteria and other irritants, allowing this ascending infection to occur.
Less commonly, mastitis can be observed without evidence of infection. Trauma to the mammary gland, or prolonged periods of milk accumulation without milk removal, can lead to inflammation within the mammary gland.
Mastitis is most frequently seen in the postpartum period, after a dog gives birth. Many cases follow sudden weaning (which can lead to excessive milk accumulation within the gland) or the death of a puppy (leading to decreased milk removal from the glands).
SYMPTOMS OF MASTITIS IN DOGS
In mild or early cases of mastitis, the first sign of a problem may be that the nursing young are not gaining weight as quickly as expected. Careful examination may reveal slight swelling or inflammation of the affected mammary gland. In these stages, the affected dog often does not show any signs of illness and may show only minimal discomfort.
As mastitis progresses, the infected mammary gland will become increasingly swollen, inflamed, discoloured (frequently red or purple), and painful. The mammary glands also may become ulcerated, with open wounds and scabs visible on the mammary gland. Milk expressed from the affected mammary gland may contain visible blood or pus, or milk may appear visibly cloudy or thickened in consistency.
In severe cases, affected dogs may appear visibly ill. The affected mammary gland may appear dark purple or black in colour, as the tissues begin to die off due to overwhelming infection and decreased blood supply. Affected dogs may become lethargic, develop a fever, refuse to eat, or begin vomiting, as the infection enters the bloodstream and they develop signs of sepsis.
CAUSES OF MASTITIS IN DOGS
When pregnant, a dog’s body starts going through changes and milk production begins so she can nourish her pups when they are born. The puppies sometimes will scratch the mother’s nipples or the nipples can become cracked. This can allow a bacterial infection to begin in the milk ducts.
Dogs, females and males, can develop mastitis when not pregnant or nursing pups. If this is the case, your dog will need to see your veterinarian immediately. Mastitis that is occurring in a dog that is not nursing puppies can be caused by cancer of the mammary glands and needs urgent attention.
HOW IS MASTITIS DIAGNOSED?
In many cases, mastitis may be diagnosed based on physical examination alone. Occasionally, laboratory tests may be required to confirm the diagnosis and/or rule out other conditions.
Laboratory tests that may be recommended for mastitis include the following:
This blood test assesses the levels of red blood cells, white blood cells, and platelets in your dog’s blood. Changes in the white blood cell count indicate infection and the magnitude of change in the cell counts may help your veterinarian determine the severity of the infection.
In this test, a small sample of milk from the affected mammary gland is examined under the microscope. The presence of white blood cells (pus) or bacteria confirm a diagnosis of mastitis.
In some cases, especially when mastitis is attributed to infection and is not responding to commonly-used antibiotics, bacterial culture may be required. Milk will be collected from the mammary gland in a sterile manner and sent to a laboratory so that the bacteria can be isolated and characterized. Once the bacteria are isolated, antibiotic sensitivity testing can be used to determine the most effective antibiotic for treatment.
TYPES OF MASTITIS
Mastitis categorized into two different types.
Acute Septic Mastitis
The female has developed an infection or abscess within a mammary gland and has become very ill. Bacteria have entered the mammary gland and can be fatal if not treated quickly.
Otherwise referred to as caked breasts, galactostasis occurs during the later stages of pregnancy. The milk can start to accumulate and make the teats painful and distended. The mammary glands are not infected and therefore the female is not ill. This also happens when a female experiences a false pregnancy.
TREATMENT OF MASTITIS IN DOGS
Acute Septic Mastitis
A combination of treatments will most likely be prescribed by your veterinarian. Treatments can include aggressive antibiotics along with warm compresses applied to the affected teat. The infected teat will need to have the milk expressed to alleviate some of the pain and help prevent an abscess from forming.
Puppies should not be allowed to nurse from the affected teat. The puppies may need to be supplemented with formula while the female is recovering from acute septic mastitis. Just remember that milk production will stop after approximately three days if puppies do not nurse.
Your veterinarian may require that your dog’s water be withheld for 6-10 hours as well as food being withheld for up to 24 hours. Diuretics may also be prescribed as well as limited food intake. This treatment will not be helpful, and will likely be harmful, if this is not the cause of the problem.
Your dog may try to stimulate the teats by licking in the event of a false pregnancy. This can make it worse and your veterinarian may prescribe a hormonal therapy or a mild sedative to stop the behaviour.
HOME REMEDIES FOR MASTITIS
Cabbage leaf compresses also can also be used to decrease pain and inflammation. Cabbage leaves should be secured to the affected mammary gland using a bandage or fitted t-shirt. Once applied, they should be left in place for 2-4 hours. At this time, the cabbage leaves should be removed for 3-4 hours before reapplying for another 2-4 hours. The puppies can be allowed to nurse from the affected gland when it is uncovered.
Severe cases of mastitis may require hospitalization for intravenous fluid therapy and injectable medications. In some cases, your veterinarian may recommend surgical removal of necrotic or severely-infected glands. For this reason, it is important to treat mastitis as soon as signs are noted and give all medications as prescribed by your veterinarian.
RECOVERY OF MASTITIS IN DOGS
In the event of galactostasis mastitis, your dog is not at immediate risk but should still be examined by your veterinarian. Once hormone levels have become normal once again, the condition should go away.
Acute septic mastitis will require immediate and aggressive treatment to ensure a full recovery. Your veterinarian will set a treatment plan and all follow up visits to make sure that the infection is gone.
When mastitis is caused by something such as cancer, your veterinarian will speak with you regarding available treatments and your dog’s prognosis. Your veterinarian may refer you to a specialist.