Veterinary Dentistry – a specialty more and more vets are interested in

107689090_586395245408237_9164811178664762081_oThe workshops organised by the Romanian Society of Orofacial Surgery and Veterinary Dentistry (RSVD) is becoming a tradition. The tiltle of the workshops that were organized in several cities of Romania was “Treatment options and prophyaxis in periodontal disease” (in dogs and cats, of course). As you already know, periodontal disease is the most common pathology in pets and it can have severe local and systemic complications that affect the quality of life of our beloved cats and dogs. Although it is very common, the disease is mostly treated in very advanced stages when the teeth cannot be saved anymore. The workshops lasted for 2 days. On the first day, the participants, both veterinarians and veterinary students, gained more knowledge regarding conscious oral examination, detailed oral examination under sedation, dental charting, specific instruments, scale and polish and oral homecare.

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The second day was dedicated to the more pragmatic treatment option in advanced stages of periodontal disease: the dental extraction. The participants learned a lot regarding indications and contraindications of dental extractions, dental blocks, simple extractions, surgical extractions and possible complications of dental extractions. Both days started with theoretical presentations and ended with the practical part so that the participants could exercise their new dental skills. The founding members of RSVD, Dr. Raluca Zvorasteanu, Dr. Iulia Milin, Dr. Dan Sebastian and Dr. Elena Nenciulescu, were also the speakers of the events. “The main purpose of the Romanian Society of Orofacial Surgery and Veterinary Dentistry is to bring together veterinarians, veterinary nurses and veterinary students to raise awareness of the importance of veterinary dentistry, to increase the professional level of veterinary dentistry in Romania and also to defend the values and interests of the Romanian veterinary community”, said Dr. Raluca Zvorasteanu, President of RSVD. According to Dr. Zvorasteanu, at least 9 out of 10 patients have some sort of dental disease and 100% of patients need oral homecare. “We like to promote prophylaxis as <the best treatment option> ”.

Learn and Travel ….. story from vets

67509335_393199464955171_7827241570955952128_nDr Elena Nenciulescu from Romania has done her externship with Ana Nemec, DVM, PhD, Dipl. AVDC, Dipl. EVDC at our project LEARN AND TRAVEL with Vets on The Balkans.

We would like to express our gratitude as well to The University of Ljubliana, Faculty of Veterinary Medicine in Slovenia for the opporunity!

 

Let her tell us her story:

Last week I had the amazing opportunity to assist Dr. Ana Nemec during dental procedures and dental consultations. It really was AMAZING!learn and travel

I arrived in Ljubljana on Sunday, July 27th. I had a little rest and the next day my journey in the Slovenian world of veterinary dentistry began. The weekly schedule is usually like this: Monday, Tuesday, Thursday and Friday are for dental procedures (2-3 cases per day) and Wednesday is only for consultations.

On the first day, Dr. Nemec showed me the clinic (very well equipped, with ultrasound machine, X-ray machine and CT). What really impressed me was the dentistry room. It is fantastic: dental unit, dental X-ray machine, dental table (custom made) and all dental instruments and materials that you need for dental materials for exodontics, endodontics, orthodontics, orthopaedics and oral surgery. It was like heaven for me!

All the dental procedures that I assisted had the following steps:

  1. Dental consultation under anaesthesia and filling the dental chart (using the periodontal probe, every tooth was examined – mobility, gingival retraction, furcation exposure, gingivitis, periodontal depth)
  2. Full mouth dental X-rays and interpretation
  3. Sonic scaling and polishing
  4. Surgical extractions (the teeth were extracted based on the clinical and radiological findings)

It is important to perform all steps correctly and not to miss any of them. 90% of dentistry cases in general practice are periodontal patients that need periodontal therapy, so this is what all vets should learn to do properly.

Dental chart for cats Dental table prepared for the patient Dental unit, dental table, intraoral X-ray and equipment for anaesthesia

I had the chance to see a wide range of cases: mild to severe periodontal disease, stomatitis, tooth resorption, tooth avulsion, crown fractures, chin eosinophilic granuloma, peripheral odontogenic fibroma, intraosseous squamacell carcinoma, endodontic treatment re-check, but also cases of no dental disease that came in only to learn oral homecare which is also a big must for maintaining the oral health of our pets. All cases were discussed in detail.

Dr. Nemec is such a positive person, teaching dentistry is something natural for her. She answered all my questions (and there were many of them). I consider myself very lucky to be given this opportunity. I learned a lot!

But it was not all dental work for me last week, I also visited the city. Ljubljana is beautiful: the castle, the city centre, the museums, the Tivoli Park. It is worth visiting. I enjoyed my stay there very much. On Saturday, August 3rd I traveled back home.

Vets on the Balkans and Luba Gancheva, thank you for giving me this opportunity. Learn and Travel is a fantastic chance to grow professionally. Dr. Ana Nemec, thank you so much sharing all you knowledge with me! I am really grateful for this experience.

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Pink teeth in a 10 months old Cane Corso

 

30595139_1823183557733595_5657871534119714816_nDr Elena Carmen Nenciulescu

Bucharest, Romania

 

 

 

Hera, a 10 months old female Cane Corso, was presented on the 15th of October 2018 for a dental consultation. She had pink teeth, a strong halitosis, „wasn’t eating like she used to” and showed signs of pain (didn’t let anyone touch her mouth or look at her teeth).

IMAGE 2

Crown fracture with pulp exposure 304 and 404

IMAGE 1

Image 1 – Abnomal density of the cortical bone

IMAGE 3

Image 3 – X-ray of the rostral maxilla

 

 

 

 

 

 

 

 

 

 

 

 

 

X-rays showed a very large pulp cavity in all teeth, very thin dentin and enamel, crown fracture with pulp exposure in 304 and 404 (Image 2), but also an abnomal density of the cortical bone in the mandible (Image 1) . The owner reported that the deciduous teeth were pink too.

 

 

 

 

 

 

 

 

 

 

 

 

The dog previosly had 2 surgeries in both elbows in another clinic (bilateral elbow dysplasia). Hera is also blind with both eyes (there is no vascularization in the eyes).

Antibiotics (amoxicillin with clavulanic acid 20 mg/kg/12 h) and analgesia (meloxicam 0.1 mg/kg/day) were immediately started and the patient was scheduled for a dental procedure a week later.  CBC and routine biochemistry were normal.

The dental examination under aneshesia revealed 6 crown fractures with pulp exposure (109, 110, 209, 210, 304, 404). We extracted these teeth and tried to seal  with the remaining ones. The dental extractions were very difficult, but the healing was good (as you can see in the images from the second dental procedure).

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Image 4 – Complicated fracture 304

IMAGE 5

Image 5-404 pulpar granuloma and 404 extraction

IMAGE 6

Image 6- 404 pulpar granuloma and 404 extraction

At this first dental procedure (Images 4 – 11), we took a blood sample to see what were the vitamine D3, calcium and parathoyroid hormone levels. When results came, we found out that Hera had hypoparathyroidism (PTH level was 1.2 pg/ml, almost 16 times lower then the physiologic range) and recomanded a thyroid ultrasound, which is not availiable unfortunately.

Also Vitamine B12 was low, so the patient recieved treatment for that too.

 

 

 

 

 

 

 

 

After the first procedure, the recovery was fast, the dog started to eat the next day, but only very soft food.

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Image 8- Clinical view of the right maxilla

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image 9-Clinical view of the right maxilla

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Image 10 – Clinical view of the right mandible

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Image 11 – Clinical view of the left maxilla

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

image 12

Image 12 – Clinical view of the right maxilla and mandible – tooth wear of all teeth is more pronounced

image 13

Image 13 – Clinical view of the lower incisors that are even „pinker” then the first time

The second dental procedure (Images 12 – 16) together with  the ovariohysterectomy took place on the 23rd of February 2019, when we performed extractions of 208 and 209 retained roots and full 405 was extracted for histopathological examination (that will be performed at Histovet by Dr. Teodoru Soare). The recovery was even better than the first one. Hera received clindamycin 11 mg/kg/day, 7 days and meloxicam 0.1 mg/kg/day, 4 days. Unfortunatelly, because a second set of radiographs were not available for this dental intervention.

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Image 14 – Closer look of the right maxilla

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Image 15 – Left upper premolars

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Image 16 – Left maxilla and mandible

 

 

 

 

 

 

 

 

 

 

 

The dental pathology of this patient might be a very rare congenital dental condition called „shell teeth”, in which teeth have large pulp chambers and insufficient coronal dentin. The treatment of this dental disease is full mouth extractions, but given the very high level of difficulty of the extractions, we chose to extract only the fractured teeth. It may be a consequence of a congenital hypoparathyroidism, which would also explain the other pathological signs (blindness, bilateral elbow dysplasia).

Hera is a very interesting case with high didactic value. She remains supervised for evaluation of her clinical evolution.

Both interventions took place at QincyVet and were performed together with Dr. Raluca Zvorasteanu.

Cat’s Tooth resorption case

pict 2Dr Yavor Stoyanov,

Veterinary clinic Bomed

Sofia, Bulgaria

A 6-year-old, neutered male domestic shorthair cat

was presented for dental cleaning due to “bed smell breath”.

No vaccinations history, irregular anthelmintic treatment.

No earlier dental care.

History of cystitis four years ago.

 

Clinical exam:

The cat was in good physical condition.

Normal temperature, auscultation, palpation.

 

Facial Exam:

Normal facial and eyes symmetry, no nose or eyes discharges.

No compression discomfort, no swollen regions, lymph nodes – normal, lips with black pigmented zones.

 

Conscious Oral exam:

The cat was cooperative.

Normal maxillomandibular joint mobility, without pain.

Normal buccal mucous membranes.  Lingual, sub lingual, caudal mouth space and  roof of the mouth was normal.

Moderate gingivitis, gingival recessions, missing all upper right premolars (106,107,108), left upper first premolar (206), first and third left mandibular premolars (307,308).

All canine teeth were with root exposure.

Many mobility teeth: 207,208,308,403, with root exposure and visual

root resorption and attachment loss.

Plaque index 2.

 

CBC, Biochemistry was in normal limits, except high globulins level.

 

Dental X-Ray was unavailable.

 

Oral exam and treatment under general anesthesia:

Missing all upper right premolars (106,107,108), left upper first premolar (206), first and third left mandibular premolars (307,308).

Moderate  gingivitis (gingival index 2).

Gingival and alveolar recessions.

No periodontal pockets. Stage 3 furcation (307, 308, 309, 208)

All canine teeth were with root exposure due to tooth extrusion.

Mobility teeth: 207(M3), 208(M2), 308(M3), 303(M3), 309(M3), 403(M3), with root exposure, visual root resorption and attachment loss.

1

Pic.1. Dental chart

Diagnosis:

 

Idiopathic Tooth Resorption

 

Treatment plan:

Multi teeth simple extraction

 

Treatment procedure:

Preoperative analgesia: Rheumocam

General anesthesia

Chlorhexidine Rinse 0.12% solution

Simple extraction with elevator and extraction forceps.

In this case because of severe attachment loss I just needed to section only one premolar.2

3

Postoperative treatment:

 

Rheumocam    24h/3 days

Stomorgil        24h/8 days

Stomodine      12h/14 days

 

Further treatment:

 

Dental and oral prophylaxis with Stomodine,

Regular examination every 3 months.

 

Discussion:

There are many theories about the etiology of Tooth resorption in domestic cats but main cause is still unknown.

Depends of the source, about 25–75% of domestic cats are affected.

There is an increasing prevalence of Tooth resorption as cats get older, with the first teeth becoming affected usually at four to six years of age.

Gender and neutering were not found to affect the prevalence of disease.

Cat owners may report halitosis, ptyalism, head shaking, dropping food

while eating, reluctance to eat hard food, excessive tongue movements,

repetitive lower jaw motions while eating, drinking or grooming,

sneezing, dysphagia, dehydration, anorexia, weight loss, and lethargy.

Clinical findings are various degrees of gingival inflammation, missing

or mobile teeth, gingival hyperplasia or recession, tooth extrusion, tooth

tissue destruction and others.

Earlier and most accurate diagnosis is made by dental X-Ray because

first changes are subgingival.

Depending on changes there are few classification based on severity

(stages 1–5) and radiographic appearance of the resorption (types 1–3).

Tooth resorption can develop with cementation and ankyloses or with

attachment loss and mobility of teeth. In case of attachment loss extraction

is easier.

 

Conclusion:

Tooth resorption is the most common progressive disease affecting the

dental tissues in domestic cats.

In every regular cat exam (with or without oral or dental abnormality)

Tooth resorption should be routinely suspected.

Choice of treatment – extraction of all affected teeth.

 

Feline chronic gingivostomatitis (FCGS): Case report

IMG_3022Stefani Sabrodin,

6th year veterinary student from Estonian University of Life Sciences

Animal data:

  • Donskoy cat
  • 6 years 10 months old
  • Spayed
  • Weight 3,66kg

Anamnesis morbi:

Owners came to visit, because of halitosis and cats’ loss of appetite. Cat has also lost some weight in previous months. Cat lives mostly inside and was not vaccinated for any diseases over 2 years.

Clinical examination:

Gingiva was very red, inflammatory and gums were bleeding when the mouth was opened. Opening a mouth was painful for the cat and ulcers on the tongue were visualised (Figure1). Cat had also a lot of calculus and she was hypersalivating. Due to the fact that cat was not vaccinated, a FeLv/FIV snap test was done, and it was negative. Also hematology and biochemistry were evaluated. In biochemistry liver and kidney values were mostly within normal limits (WNL) Only UREA was a bit low (4,5mmol/L) but it might be due to the starvation. Electrolytes were also controlled and they were WNL. In hematology only mild leukocytosis was seen.

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Treatment:

After the first visit, a dental appointment was planned. The cat got one subcutaneous injection of cefovencin (Convenia) 8mg/kg and went home with oral meloxicam 0,05mg/kg for 3 days. She came to tooth removal surgery in seven days. A cat was sedated with dexmedetomidine, butorphanol, and ketamine intramuscularly. TIVA with propofol was used during surgery. Cat got 5ml/kg/h of Ringer-Lactate during the procedure and free flow oxygen was given. Buprenorphine (0,01 mg/kg) intramuscularly and meloxicam (0,3 mg/kg) subcutaneously were given for analgesia and lidocaine was used for nerve blocks. Dental radiographs were made pre-and postoperatively (Figures 2). Figure 3 shows how important are dental radiographs. 301 was broken during the extractions but it was unclear if remnant got out or not. An x-ray was made and the root was visualised. Then the root remnant was removed and a new x-ray was taken.05 08 07 06

During the procedure, clinical picture (gingivitis II-III in all dens, 204 had gingival pocket of 2mm. 404 had gingival hyperplasia and also pocket of 2mm) and full mouth radiographs were evaluated. All teeth except canines were extracted. A cat went home with oral meloxicam (0,05 mg/kg) for 5 days. A new checkup was in 7 days. Figure 5 shows that gingiva is not so inflamed anymore. Cat started eating with a good appetite already the next day after the extractions.

 

 

 

09

This picture shows how much we actually need radiographs. 301 was broken during the extractions but we were not sure if we got the remnant out or not. We made an x-ray and saw the root. Then we removed root remnant but unfortunately I have no pictures of the last x-ray, but it was clean.

 

Figure 2. (a) 409 has a tooth resorption (TR). (b) 309 is missing. (c) and (d) are made after extractions.

Figure 4. was made right after the extractions.

Background

Feline chronic gingivostomatitis (FCGS) is a common syndrome, but its’ aeitology is unclear. FCGS causes inflammation and proliferation for the gingiva and oral mucosa. Inflammation can be mild to severe and it worsens with time. Mucosal ulcers are commonly seen in cats with FCGS. Ulcers are the most commonly on gingiva, tongue, buccal mucosa, lips, palatoglossal folds, and the lateral pharyngeal walls.

Aetiology is unclear, but it might be due to bacteria (usually from plaque Pasteurella spp↑, Prevotella spp↑), viruses or immune-mediated. Feline calicivirus (FCV), feline herpesvirus (FHV-1), feline immunodeficy virus (FIV), feline leukemia virus (FeLV), feline coronavirus (FeCoV) may cause FCGS.

The most obvious clinical changes are bilateral focal or diffuse chronic gingival and oral mucosal inflammation, ulcers and hyperplasia. Cats with FCGS has halitosis, dysphagia, ptyalism, bloody saliva, anorexia, and bleeding gingiva. Caudal part of the oral cavity is also with lesions. There is no sex, age or breed predilection.

For diagnostics, laboratory examinations are mandatory. Complete blood count (CBC), biochemistry (glucose and kidney values) and serological assays (FeLV/FIV) should be done.

Since the aetiology of the disease is unclear then treatment is empirical. In some cases, conservative treatment may help. Administration of antibiotics (amoxicillin/clavulanate, clindamycin, metronidazole), corticosteroids (not a good choice, because of side effects) , megestrol acetate (was used widely in the past, but now it’s not recommended due to the side effect), sodium salicylate, gold salts, lactoferrin (in mild cases, inflammation and salivation↓), interferon (poor results without extractions), professional tooth cleaning 3-4 times per year, chlorhexidine mouth rinses (usually not tolerated by cats for a long time) and teeth cleaning have been reported. The best cure is still full-mouth extractions.10

References

Holmstrom, S.E. Veterinary Dentistry: A Team Approach, 2nd edition. Elsevier 2012, 10:228- 230

Niemiec, B.A. Small Animal Dental, Oral & Maxillofacial Disease: A Colour Handbook. Manson Publishing 2012. 6:176-181

Correl C., Nind, F. Saunders Solutions in Veterinary Practice: Small Animal Dentistry. Saunders 2008. 12-15:79-97

Gorrel, C. Veterinary Dentistry for the General Practitioner 2nd Edition. Saunders, 2013

Tutt,C., Deeprose, J.& D.A. Crossley. BSAVA Manual of Canine and Feline Dentistry, 3rd edition. BSAVA. 2007.8:137-144

New opportunity! Learn and Travel with Dr Ana Nemec!

49539480_10156980124763851_4018716318076239872_nSuch a honor to have Ana Nemec, DVM, PhD, Dipl. AVDC, Dipl. EVDC at our project LEARN AND TRAVEL with Vets on The Balkans.
More about Dr Ana Nemec: https://www.ananemec.si/en/about-me/
We would like to express our gratitude as well to The University of Ljubliana, Faculty of Veterinary Medicine in Slovenia for the opporunity! https://www.vf.uni-lj.si/

who recognizes the need to educate students but also vets in veterinary dentistry!

Because of the huge interest about our new opportunity and limitated places, we decide to make a game! So in that way to choose who will attend the program with Dr Ana Nemec!
Send your clinical case and you can be the vet who will spend one week with such a teacher
We are waiting for you at gancheva.vet@gmal.com till 30 of April!
So your case should not be high level of knowledge and something specific. Can be regular case, avaible in you everyday practice. We would like to see only you are passionate about veterinary dentistry!learn and travel

Success to all of you!

Multimodal treatment approach to canine oral malignant melanoma: a clinical case

14199647_10154460495808851_4115072769610561786_n

Dr Ana Nemec

Ana Nemec, DVM, PhD, Dipl. AVDC, Dipl. EVDC; Ana Rejec, DVM, PhD, Resident, Veterinary dentistry

 

Animal Hospital Postojna, Cesta v Staro vas 20, 6230 Postojna, Slovenia

 

Case history and clinical signs

Fig. 1

Figure 1: Amelanotic malignant melanoma affecting right rostral maxilla in a 4-year-old female German shepherd at presentation.

A 4-year-old 30-kg female spayed German shepherd was presented due to rapidly growing rostral maxillary mass. At presentation, the proliferative mass, located around right maxillary third incisor and canine tooth was ulcerated and bleeding (Fig. 1). The patient was otherwise healthy with physical exam findings, CBC and biochemistry all within normal limits. Staging options were discussed and the client elected computed tomography (CT) of the head and neck as well as chest CT together with biopsy of the lesion and an abdominal ultrasound.

 

Imaging and histopathology findings

Fig. 2

Figure 2: A CT image taken at the level of maxillary canine teeth at presentation. Note an invasive lesion occupying majority of the right nasal cavity and crossing the midline

Pre- and post-contrast CT images revealed an invasive lesion, located primarily around the maxillary canine tooth and extending from the right maxillary second  incisor tooth to the mesial root of the right maxillary second premolar tooth, occupying majority of the right nasal cavity and crossing the midline (Fig. 2). CT of the neck and chest revealed no metastatic disease to the regional lymph nodes and lungs, and abdominal ultrasound was also within normal limits.

Histopathology of the lesion revealed spindle-cell neoplasm, with differential diagnoses being fibrosarcoma or spindle-cell amelanotic melanoma, and further immunohistochemistry using Melan A and PNL-2 antibodies was performed and was suggestive of amelanotic melanoma.

A stage III (with no detectable metastasis based on the diagnostics performed) amelanotic melanoma was diagnosed.

 

Treatment and follow-up

Fig. 3

Figure 3: With the dog under general anaesthesia in dorsal recumbency an incision is planned to remove the tumor with narrow margins (“debulking surgery”).

Fig. 4

Figure 4: Once the right rostral maxilla and left incisive bone are en-block removed together with the tumor, hemostasis is achieved by ligation of major palatine arteries. Note macroscopically-visible tumor remnants in the right nasal cavity.

Fig. 5

Figure 5: Immediate post-operative photograph of the 4 years old dog with OMM.

Due to an extensive involvement of the nasal cavity, wide resection was impossible to achieve without significantly impairing the cosmetic appearance and function of the animal, and the client elected palliative-intent extended unilateral rostral maxillectomy to reduce tumor burden (Figs. 3-5), followed by a course of adjuvant hypo-fractionated radiotherapy of the surgical area (6 x 6 Gy twice weekly) 3 weeks after the surgery (Figs. 6-9).

 

 

 

 

 

 

 

 

 

 

Fig. 6

Figure 6: Three weeks post surgery the mucosal flaps have healed and any remaining sutures are removed to minimize irritation and inflammation before radiation therapy is initiated

Fig. 7a

Figures 7: Radiotherapy is performed 3 weeks after surgical resection of amelanotic malignant melanoma with the dog under general anesthesia. Note a lead plate positioned in the mouth to prevent irradiation (exit dose) of the healthy mandibles. A bolus is used on the maxilla to achieve optimal dose distribution in the irradiation field.

Fig. 8

Figure 8: Radiation therapy technologist adjusting the patient and equipment to correctly apply the radiation treatment plan.

Fig. 9

Figure 9: Acute side affects of radiotherapy (radiomucosititis) 2 weeks after completion of radiotherapy, which diminished with supportive antibiotic, local antiseptic and anti-inflammatory treatment.

Melanoma vaccine treatment (4-dose, biweekly protocol, then boosters in 6-month intervals) was added to the treatment protocol as an immunotherapy approach to multimodal treatment approach. At all re-checks, the patient was clinically healthy and the most recent re-check head and neck and chest CT revealed no metastases 5 years after the diagnosis (Fig. 10). Fig. 7b

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion

Fig. 10b

Figure 10: 5-year follow up – no clinical nor CT evidence of local tumor recurrence

Malignant melanoma (OMM) is the most common nonodontogenic oral tumour in dogs. Clinical signs may vary greatly; the tumour is not necessarily pigmented (black). Histopathological diagnostics may be complicated as a tumour may present as amelanotic variant and/or as epithelioid-cell OMM, spindle-cell OMM or mixed-cell OMM. Therefore, immunohistochemistry is often needed to determine the diagnosis. OMM is locally invasive, with 50% of tumours being associated with surrounding bone invasion. Metastases are also common: in 74% of cases, OMM metastasise in regional lymph nodes and in up to 92% of cases in the lungs.

Hence, before any treatment is attempted, a patient with an OMM needs to be properly staged. To evaluate local disease, tumor location is noted and the lesion measured. Diagnostic imaging of the local lesion should include pre- and post-contrast CT of the head, as skull radiographs and/or intraoral dental radiographs will underestimate the extent of the lesion and especially invasion of maxillary tumor into adjacent structures. Magnetic resonance imaging (MRI) can also be considered and PET/CT is becoming available in veterinary medicine as well.

Evaluation of regional lymph nodes may be challenging. Although palpation of the mandibular lymph nodes should be routinely performed, it needs to be realized, that 40% of palpably normal lymph nodes contain metastases. Fine needle aspiration of the regional lymph nodes may be helpful, but reaching the main draining center of the head – retropharyngeal lymph nodes – requires ultrasound-guided approach. Also, it has recently been described, that consensus between cytology and histopathology for staging of lymph nodes in patients with melanocytic neoplasms is poor, and negative result does not rule out metastases. Evaluation of size and contrast-enhancement pattern on post-contrast CT images can be very helpful in evaluating regional lymph nodes for metastases, and PET/CT is also very promising. Excisional biopsy of the lymph nodes is debatable, as complete staging requires removal of all lymph nodes of the head and neck. Excisional biopsy of the sentinel lymph node – technique which is well developed in human medicine – is the goal and determination of the sentinel node will hopefully become easier with advanced imaging techniques.

Staging is completed with evaluation of distant organs for possible metastatic disease, where chest CT is much more sensitive to diagnose pulmonary metastases compared to thoracic radiographs. Full body CT may be recommended, if involvement of abdominal organs is suspected, which is rare in cases of canine OMM, and abdominal ultrasound is usually performed.

Once the stage of the OMM is determined, the treatment approach(es) and prognosis can be discussed with the client. It is worth mentioning here, that scientific data on treatment outcomes for specific stage OMM, especially when several treatment approaches are combined, are scarce. Hence, proper communication with the client is extremely important to present as much as possible information and keep realistic expectations. Generally, prognosis for animals, especially if the tumour arises from dentate areas, is guarded due to early and common metastases. Dogs with small OMM (smaller than 2 cm in diameter, stage I) located rostrally and those without metastases, have the best prognosis. With radical tumour resection (tumour with associated 1 cm of healthy tissues as determined by CT) median survival time was reported to be 723 days and related to tumor stage. It has also been reported, that even incomplete tumour resection (dirty margins) increases survival time. When complete resection cannot be achieved (as was expected in the presented case), or the client declines surgical treatment, or when surgery has resulted in incomplete removal of the tumor, or when regional metastases are present, other treatment options exist, although some studies questioned the benefits of adjuvant therapies. When recommending an adjuvant treatment, most commonly suggested is radiation therapy, which can also be the sole treatment for OMM (local and regional disease). The outcome of radiation therapy depends, as with surgery, on the stage of the tumor as well as on the radiation protocol; most commonly hypo-fractionated radiation protocols are recommended and, when used as a sole treatment of OMM, can result in median survival times a bit shorter than those achieved with surgical treatment. Acute side effects, such as radiomucositis are common, expected and usually resolve with supportive treatment, while late life-threatening side effects, such as osteoradionecrosis or secondary tumors, are rare, but need to be discussed with the client in advance, especially when long-term survival of irradiated patients is expected.

OMM is considered poorly responsive to chemotherapy, but is a highly immunogenic tumor. Although the exact immune mechanisms are not completely understood and are likely individually-specific, several immunotherapy and/or gene-electrotransfer therapy approaches have been suggested for canine OMM patients. Most (clinical) research has been performed on a canine melanoma vaccine (xenogeneic plasmid DNA with a cDNA insert encoding human tyrosinase), which has been shown to be safe, but data on its’ efficacy are conflicting. Although it remains unclear, what (if any) role melanoma vaccine and other treatments played in the prevention of metastatic disease in the case described in this report, it is important to realize, that the outcome of canine OMM treatment may not neccessary be poor. In addition, new multimodal approaches are being developed to treat canine OMM and are changing this disease with historically poor outocme into a chronic disease, at least in selected cases.Fig. 10a

 

Clinical study at Animal Hospital Postojna

At Animal Hospital Postojna we recently began a study titled “Evaluation of immune system response to hypo-fractionated radiotherapy in canine non-operable oral, cutaneous or digital melanoma’ together with the Oncovet Clinical Research Centre in France. The study aims to evaluate immune system response to hypo-fractionated radiotherapy in canine non-operable oral, cutaneous, or digital melanoma and to assess the ability of this therapy to improve the response to immunotherapy in combined treatment. With the client’s agreement, we include dogs (males and females) with malignant melanoma when the tumour cannot be surgically removed, either due to its localisation preventing the recommended wide excision, or the client’s refusal to approve such a procedure. In that case, hypo-fractionated radiotherapy remains the preferred treatment. If you or anyone you know are interested in participating in the study and would like to know more about the study protocol and obligations, risks and potential constraints as well as benefits that we offer if you decide to participate, please, contact us at info@ahp.si