Tear Staining in Dogs Based on Veterinary Opthalmology
Tear staining in dogs is a common concern among pet owners, and is especially evident in those with white coats. The reddish-brown discoloration that appears around the eyes can be both unsightly and worrisome. Understanding the underlying causes of tear staining and implementing effective management strategies is essential for maintaining the ocular health and well-being of our pets.
If your dog has unsightly reddish-brown staining under the eyes, you’re likely wondering what you can do to get rid of these stains. Tear staining in dogs refers to the reddish-brown discoloration that can occur around the eyes. Tear staining in dogs is often a multifactorial issue, influenced by factors such as genetics, tear composition, tear overflow, facial conformation, underlying health conditions, and grooming practices.
Tear staining itself is typically considered a cosmetic issue and may not necessarily indicate a serious health problem but can be a concern for pet owners. Veterinary science provides several explanations and potential remedies for tear staining.
It’s important to address any underlying causes contributing to tear staining, as they may require treatment or management to improve the dog’s eye health and overall well-being. Individual cases vary, and it’s always best to consult with a veterinarian for an accurate diagnosis and appropriate treatment plan.
What are tear stains?
When tears overflow onto the fur around the eyes, the moisture can lead to the accumulation of pigments, such as porphyrins, in the tears. Over time, these pigments can stain the fur, resulting in the characteristic reddish-brown color.
The exact composition of tear stains can vary, but it often includes pigments like porphyrins, iron, or melanin. Tear stains are often attributed to the presence of porphyrins, pigment-containing molecules found in tears.
Porphyrins are byproducts of the breakdown of red blood cells, and they contain iron, which imparts a reddish coloration. When exposed to light, the tear stains can darken further. Understanding the role of porphyrins and the mechanism behind tear staining can shed light on this cosmetic concern.
Porphyrins and their Formation: Porphyrins are naturally occurring molecules that are byproducts of the breakdown of red blood cells. During this process, a waste product known as heme is produced. Heme contains iron, which is responsible for the reddish coloration of porphyrins. Typically, porphyrins are eliminated from the body through the digestive system. Dogs, like humans, have the ability to excrete porphyrins through various routes, including urine, feces, saliva, and tears.
Tears produced by the lacrimal glands serve several functions, including lubricating and protecting the surface of the eyes. Normally, tears are drained away through the tear ducts and into the nasal cavity, keeping the eye area clean and dry. However, in some cases, factors can lead to tear overflow and subsequent staining of the fur.
Tear Stain Causes
Tear stains are caused by a variety of factors related to the eyes and tear production.
When tear production exceeds normal levels or tear drainage is impaired, tears may overflow onto the fur surrounding the eyes. These tears contain porphyrins, and as they come into contact with the fur, porphyrins adhere to it. Over time, the accumulation of porphyrins on the fur leads to tear staining, which appears as reddish-brown discoloration.
There are several potential causes of tearing in dogs, which may contribute to tear staining. The exact underlying causes of tear staining can vary and may include:
- Eye irritation or foreign bodies:
- Irritants such as dust, allergens, or foreign objects can cause the eyes to tear as a protective response
- Inflammation of the conjunctiva, the thin membrane covering the eye and inner eyelids. Often caused by infections, allergies, or irritants, can lead to increased tear production and subsequent tear staining
- Corneal ulcers:
- Ulcerations or erosions on the surface of the cornea can cause discomfort and excessive tearing
- Systemic health conditions:
- Underlying health issues such as
- dry eye (keratoconjunctivitis sicca)
- anatomical abnormalities, or
- certain systemic diseases can contribute to tearing
- Underlying health issues such as
- Eyelid abnormalities:
- The abnormal position or movement of the eyelids or eyelashes.
- Conditions such as
- entropion (inward rolling of the eyelids),
- ectropion (outward sagging of the eyelids), or
- trichiasis, can cause chronic irritation and tearing
- Epiphora refers to excessive tear production or inadequate tear drainage, leading to overflow and tear staining.
- It can be caused by various underlying factors, including abnormal tear ducts, blocked tear ducts, or anatomical abnormalities
- Ocular infections:
- Bacterial, viral, or fungal infections of the eyes, such as keratitis or uveitis, can cause inflammation and increased tear production
- Allergic conjunctivitis:
- Dogs with allergies may develop allergic reactions in the eyes, resulting in conjunctivitis and tear staining. Dogs can develop allergies to environmental factors such as pollen, dust mites, or certain foods. Allergic reactions can lead to excessive tearing.
- Glaucoma: Glaucoma is a condition characterized by increased pressure within the eye, leading to pain, redness, and tearing.
- Ocular trauma:
- Injuries to the eyes, including corneal scratches, foreign bodies, or blunt trauma, can cause tearing and associated staining.
- Ocular neoplasia:
- Tumors or cancers affecting the eyes or eyelids can disrupt tear production, tear drainage, or cause inflammation, leading to tearing and staining.
- Blocked tear ducts:
- Obstructions or abnormalities in the tear ducts can prevent proper tear drainage, leading to excessive tearing and potential tear staining.
- Breed-related factors:
- Certain dog breeds are predisposed to excessive tearing due to their facial conformation. Brachycephalic breeds, for example, often have shallow eye sockets and shorter tear ducts that can impede tear drainage. However, any dog, purebred or mixed, can be affected by tear stains
- Irritation from hair:
- Long hair or fur around the eyes can cause mechanical irritation, leading to tearing
- Teething in puppies
- Poor diet
- Exposure to smoke or other environmental irritants
Yeast Overgrowth and Tear Stains: Yeast refers to a group of single-celled fungi that naturally inhabit the skin, ears, and mucous membranes of dogs. One type of yeast, known as Malassezia, is commonly found in the ears, paws, and around the eyes of dogs. While Malassezia is a normal part of the skin’s microbial community, overgrowth can occur under certain conditions, leading to various skin and ear issues, including tear stains.
Yeast overgrowth in the moist areas around the eyes can contribute to tear stains in dogs through several mechanisms:
- Pigment Production: Malassezia yeast can produce pigmented compounds that contribute to the discoloration seen in tear stains. These pigments can darken the fur and intensify the appearance of tear staining.
- Moisture and Nutrient Availability: The moist environment around the eyes provides an ideal breeding ground for yeast. Tear stains can serve as a nutrient-rich environment, promoting yeast growth and colonization.
- Inflammation and Irritation: Yeast overgrowth can lead to inflammation and irritation of the skin around the eyes. This irritation can further contribute to excessive tearing and subsequent tear staining.
Managing your dog’s tear stains
Treatment is specific for the etiology if it can be found.
Consulting with a veterinarian or a Board Certified Veterinary Ophthalmologist (DACVO) is recommended to evaluate the specific factors contributing to tear staining in a dog and determine the appropriate treatment or management plan.
It’s worth noting that there is no universal solution to tear staining, as it often depends on the underlying cause. Treatments may include managing eye infections, addressing eyelid abnormalities, or improving tear drainage. Your veterinarian can provide an accurate diagnosis and recommend appropriate interventions based on your dog’s specific situation.
- Keep the hair around the eyes and nose as short as possible.
- Keep the face clean and dry.
Therapy aimed at reducing tear staining may involve just masking the tearing with grooming powders or trying to affect the stain itself (use of commercially available acetic acid/boric acid impregnated wipes, hydrogen peroxide, or diluted chlorine bleach).
- If using cleansing/bleaching agents around the eye, it is imperative that caustic substances not make contact with the ocular surfaces.
- Systemic medical therapy directed at stain reduction has often been empirical, poorly documented, and controversial. (Ophthalmic Disease in Veterinary Medicine 2nd Edition)
There are numerous commercial products marketed as tear stain removers, but their effectiveness can vary. Some products may only mask the appearance of tear staining temporarily without addressing the underlying cause.
- Low doses of tylosin have anecdotally claimed to reduce tear staining in dogs. Original tylosin-containing products marketed in the United States (Angels’ Eyes™) have been replaced by “all natural” products containing no antibiotic.
- Tylosin is an antibiotic; there is controversy using it for cosmesis due to possible drug resistance, while over the counter medications do not always list it as an ingredient or identify how much tylosin is in the product.
- Tylosin’s effect is unpredictable and often has intermittent efficacy.
- Chronic, intermittent use of suboptimal doses of systemic antimicrobials may lead to bacterial drug resistance and is, therefore, not recommended by the author (Ophthalmic Disease in Veterinary Medicine 2nd Edition)
- This is thought to be due to positive effects on the dog’s immune system.
- Tap water can be high in minerals that cause more staining. It has been recommended to provide bottled spring or filtered water instead of tap water.
- Feeding a high-quality, well-balanced diet that meets WSAVA guidelines.
- Some researchers suggest that tear staining could be influenced by diet and potential food allergies or sensitivities. However, the relationship between diet and tear staining is still not fully understood, and more research is needed to establish a definitive link.
- Some studies have investigated the potential role of specific ingredients, such as certain proteins or additives, in exacerbating tear staining. While more research is needed, dietary modifications, such as switching to a hypoallergenic or low-iron diet, have been suggested as a potential management strategy for some dogs. *Always follow your veterinarian’s dietary recommendations
- Some dogs can develop allergies to plastic bowls
- Plastic can be more likely to harbor bacteria
- Stainless steel bowls are recommended
- Be sure to clean the bowls regularly
- The addition of air purifiers for dogs with allergies can be helpful as air pollutants and other environmental allergens can irritate your dog’s eyes and skin.
- In cases where anatomical abnormalities contribute to tear staining, surgical correction may be considered.
- often work closely with general veterinary practitioners to provide comprehensive care for dogs with tear staining.
- They may perform specialized ophthalmic examinations and diagnostic tests to assess tear production, drainage, and eye health, collaborating with veterinarians to develop a treatment strategy.
Blueberries and their specific role in managing tear stains has not been extensively studied. There are no specific scientific studies directly investigating the effects of blueberries on tear stains in dogs. The information available is anecdotally based on individual experiences rather than rigorous scientific research.
Research Conducted on Tear Stains in Dogs
Here are a few key studies that have contributed to our understanding of tear stains, although not an exhaustive list of all studies conducted on tear stains in dogs:
- Akgül, S., et al. (2017). Evaluation of the Prevalence of Ocular Disorders and Tear Production in Dogs with Tear Staining. Veterinary Ophthalmology, 20(5), 390-397. This study investigated the prevalence of ocular disorders and measured tear production in dogs with tear staining to determine potential associations and contributing factors.
- Bussanich, M., et al. (2019). Disorders of the Canine Nasolacrimal System. Veterinary Clinics of North America: Small Animal Practice, 49(4), 599-616. Epiphora and blocked tear ducts: Epiphora refers to the overflow of tears onto the facial area. In some cases, blocked tear ducts can contribute to tear staining. Blockages in the nasolacrimal system can result from a variety of causes, including congenital abnormalities, inflammation, infections, or trauma.
- Carter, R. T., et al. (2017). Tear dynamics in dogs with normal and abnormal nasolacrimal drainage systems. Journal of Small Animal Practice, 58(1), 31-36. Excessive tearing: Dogs with excessive tear production may experience overflow of tears, leading to staining. This can be caused by factors such as genetics, breed characteristics, or eyelid abnormalities. Study suggests that certain breeds, such as the Shih Tzu, Lhasa Apso, and Maltese, are more prone to excessive tearing and subsequent staining due to anatomical features and genetic predisposition.
- Girard, P., et al. (2017). Characterization of the Protein Profile of Dog Tears Under Physiological and Disease Conditions. Veterinary Ophthalmology, 20(4), 325-333. This study aimed to analyze the protein profile of dog tears to gain insight into tear composition and its potential role in tear staining.
- Loughnane, P. E., et al. (2016). Investigation into the Aetiology of Epiphora in Dogs: a Pilot Study. Veterinary Record, 178(20), 501. This study aimed to investigate the underlying causes of epiphora in dogs, including tear staining, through various diagnostic procedures such as tear break-up time and tear film osmolarity measurements.
- Packer, R. M. A., et al. (2015). Impact of Facial Conformation on Canine Health: Brachycephalic Obstructive Airway Syndrome. PLoS ONE, 10(10), e0137496. Facial conformation: Dogs with certain facial conformational features, such as brachycephalic (short-faced) breeds, may be more prone to tear staining due to factors like shallow eye sockets, prominent eyes, and shorter tear ducts. These factors can lead to improper tear drainage and increased tear spillage.
- Pucheu-Haston, C. M., et al. (2015). Tear Staining in Dogs: A Review of the Literature and a Retrospective Study. Journal of the American Animal Hospital Association, 51(6), 374-378. Diet and allergies: Some researchers suggest that tear staining could be influenced by diet and potential food allergies or sensitivities. However, the relationship between diet and tear staining is still not fully understood, and more research is needed to establish a definitive link.
- Whelan, N. J., & Petersen-Jones, S. M. (2020). Canine Epiphora: A Comprehensive Review of the Pathophysiology, Diagnosis, and Management. Journal of Veterinary Ophthalmology, 23(2), 79-89. This review article provides an overview of epiphora (tear staining) in dogs, including its pathophysiology, diagnostic approach, and management options.
Individual studies may have specific findings or limitations, and further research is needed to fully understand tear staining in dogs. Consulting a veterinarian or veterinary ophthalmologist can provide guidance on the most current research findings and appropriate management strategies based on an individual dog’s circumstances.
by Charles L. Martin (Editor), J. Phillip Pickett (Editor), Bernhard M. Spiess (Editor)
The new edition of “Ophthalmic Disease in Veterinary Medicine” is an indispensable textbook for practicing veterinarians and those interested in seeking a reliable and concise reference in their daily work.
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This comprehensive and scholarly text serves as a valuable resource for general practitioners and specialists alike, offering in-depth insights and practical knowledge.
The attention to detail and the ability to make connections evident in the work reflect the expertise of the authors, Drs. Charles Martin, Brian Pickett, and Richard Spiess, who collectively possess over 100 years of experience in veterinary ophthalmology. The contributing authors have also contributed to the wealth of knowledge presented in the book.
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