By Arnold Plotnick, MS, DVM, ACVIM
People often complain about the “wet dog” smell that seeps out of a dog after a good romp in the rain. But we rarely hear complaints about the smell of a wet cat. Or a dry cat, for that matter. Cats are fastidious groomers and pride themselves on their cleanliness. Cat lovers know that no self-respecting cat would allow itself to be caught emitting an offensive odor.
Body odors do serve a purpose in animals. They are important in species recognition, mate selection, and social interaction. Interpreting the significance of a pet’s body odor can be challenging for veterinarians, as most clients insist on having a pleasant-smelling pet, or at worst, a pet with no smell at all. It is up to the veterinarian to determine whether the odor in question is a sign of disease, or whether it falls into the realm of normal. As a veterinarian specializing in cats, I find that the presence of a foul or unusual smell from a cat is almost always a sign that something is amiss.
In the latest edition of Ettinger’s Textbook of Veterinary Internal Medicine, Dr. Karen Moriello, Clinical Professor of Dermatology at the University of Wisconsin School of Veterinary Medicine, describes a scheme in which cats with problem body odors are divided into four broad categories based on the patient history and physical examination findings. There may be some overlap between groups. [See sidebar].
Category 1 would be a cat that the client feels is malodorous, but the veterinarian does not. Fortunately, this is less of an issue in cats than dogs. With no history or physical evidence of illness or skin disease, and the veterinarian failing to find what he considers to be any unusual odors during a head-to-tail, top-to-bottom-including-ears-and-paws “sniff test”, the cat is pronounced “normal”. Treatment is not required, although shampoo therapy with a pleasant-scented shampoo may be appropriate if the client insists. One notable exception is that of intact tomcats – they sometimes have a rather pungent aroma. Another notable (and common) exam-room scenario is the complaint that a foul odor appears “every now and then”. Usually clients will describe a funky, musky, “fishy” odor occasionally emanating from their cat. Often, when I examine the cat, the smell in question is gone. In this situation, anal sac expression is the most likely culprit. Cats (and dogs) have two small sac-like glands just inside the anus that produce a sharp-smelling secretion. Occasionally, this secretion will accumulate until the sacs become full. The sacs may then empty their contents onto the fur or into the immediate environment, especially if the cat becomes frightened or excited. Dr. Jacqueline Nenner, a veterinarian and colleague at East Side Animal Hospital in New York City, has her own fool-proof way to convince skeptical clients. “If I suspect that anal gland secretion is the cause of the mysterious odor, I will manually express the cat’s anal glands in the exam room”, she says. “A minute or two later, as the smell makes its way to the client’s nose, I’ll undoubtedly hear ‘Yes, that’s the smell!’”. Occasional expression of the anal sacs is nothing to worry about. Other anal sac diseases, however, such as abscesses or tumors, are clearly a concern, and can lead to constant odor.
The next category would be a stinky cat with an obvious cause. To become a member of this group, the veterinarian should be able to tell immediately what the cause of the smell is, whether it be urine, feces, halitosis (bad breath), or having been sprayed by a skunk. What happens next may vary, from simple recommendations on how to remove skunk odor, to detailed discussions as to whether further diagnostics may be necessary to elucidate the underlying cause, and which treatments might be appropriate once a diagnosis is made. In my experience, halitosis is the most common cause of obvious foul odor in cats. Dental disease, oral cancer, and kidney failure are the most common causes of foul breath seen in my feline practice.
The third category would be cats with a systemic illness as a cause of the foul odor. This is usually readily apparent to the veterinarian. Abscesses, and oral or dental diseases are common illnesses associated with odor. Urine and feces are common sources of odor in animals. Cats can either be soiling themselves due to urinary or fecal incontinence, or they may not be removing it from the haircoat due to an inability to groom properly. In my cat practice, I see many cats that are unable to groom their anal and genital region due to obesity. Arthritis is another reason for difficulty in grooming. In some instances, cats develop a foul odor because cats have simply stopped grooming themselves, resulting in a greasy, matted hair coat. This should be a warning flag for clients and veterinarians that a systemic illness (diabetes, hyperthyroidism) may be present.
The final category for fetid felines would be those with a skin problem. This would include cats with an obvious skin disease, or a skin disease discovered during a routine exam, or perhaps a history of past skin disorders. This is by far the most common cause of unpleasant odors in dogs. Fortunately, smelly skin diseases are much less common in cats. While bacterial and yeast infections of the skin and ears are the most common cause of foul odors in dogs, these types of infections are seen much less frequently in cats, and when present, rarely produce odors as offensive as that seen in dogs. “Ear infections are probably the biggest cause of foul odors coming from cats in my practice” says Dr. Heather Peikes, a board certified veterinary dermatologist at Animal Allergy and Dermatology in New York City. “Some cats have terribly infected ears that you can literally smell across the room, while others escape detection until you kiss the cat on the head or nuzzle up close to it, and then the odor becomes apparent”. Seborrhea, another familiar cause of foul doggie smell (think of your neighbor’s greasy, oily cocker spaniel), is relatively rare in cats. “Cats with autoimmune diseases, in which the immune system attacks the cat’s skin, will occasionally impart an unpleasant smell to the cat, but this is less common in cats than in dogs” notes Dr. Peikes. Whether cats as a species are naturally more resistant to skin disease, or whether their fastidious grooming habits provide a natural defense against skin infections isn’t clear. Regardless, skin disease in cats is not a significant cause of foul odor in cats as it is in dogs.
Being self-cleaning and being essentially odor-free are merely two of the millions of reasons why cats make great pets. The presence of an unusual or offensive odor could be a warning sign that your cat may have a problem such as a systemic illness or a skin disorder, and a veterinary visit is often necessary to determine the cause.
- Normal smell – it’s all in your head
- Foul smell due to an obvious cause – example: sprayed by a skunk
- Foul smell due to systemic illness – example: uremic breath from kidney failure
- Foul smell due to skin disease – example: a bacterial skin infection