Evaluation of cardiopulmonary and inflammatory markers in dogs with heartworm infection during treatment with the 2014 American Heartworm Society recommended treatment protocol

Improving access to melarsomine therapy: treating canine heartworm infection in a high-volume, outpatient community clinic setting

BACKGROUND

Models that provide high-quality veterinary care for more affordable prices are emerging, but not well documented outside of wellness and preventative care. Effective treatment guidelines for heartworm disease have been developed by the American Heartworm Society; however, not all owners are able to access treatment due to the high costs associated with sick and emergency care services.

METHODS

To increase access to high-quality adulticidal treatment of canine heartworm disease, we developed and implemented a technician-leveraged heartworm treatment protocol for high-volume, outpatient community clinic settings based on the American Heartworm Society guidelines. Modifications were few and included limited pre-treatment blood work, pre-injection sedation, post-injection pain medication, and a reduced exercise restriction period. We monitored retention rates for 556 dogs throughout treatment, evaluated treatment success (defined as no antigen detection 9 months post treatment) for patients that returned for post-treatment antigen testing, and reported on adverse reactions and therapy adherence throughout treatment.

RESULTS

Of the patients that began adulticide therapy, 539/556 (97%) successfully completed the three-injection series. No microfilariae were detected in 99% (428/433) of those who returned for post-injection microfilaria testing. Among those that returned for or reported the results of post-injection antigen testing, no antigen was detected for 99% (245/248) and no microfilariae were detected for 99.5% (200/201). During the course of treatment, 483/539 (90%) of patients experienced at least one adverse reaction, with the most frequently reported types being behavioral and injection site reactions. 25/539 (4.6%) of owners sought additional medical care for adverse reactions at some point during the treatment course. The overall mortality rate was 1.3% (7/556).

CONCLUSIONS

This study represents the first evaluation of a heartworm treatment protocol optimized for implementation in a high-volume, outpatient community clinic setting. Our findings align with those previously reported in private practice or tertiary referral centers, illustrating that through the inclusion of pre-treatment blood work, employing short-acting or reversible sedatives, ensuring proper analgesia, minimizing the use of ancillary diagnostics, reducing the duration of in-clinic monitoring while focusing on outpatient care, and maximizing technician involvement, we can deliver effective and safe melarsomine therapy at a more affordable cost to pet owners.

Therapeutic potential of virgin coconut oil in mitigating sodium benzoate- model of male infertility: Role of Nrf2/Hmox-1/NF-kB signaling pathway

Objectives

Male infertility is a major public health issue due to increased prevalence, so there is an urgent need for a therapeutic solution. The search for a natural dietary substance that could modulate redox balance and inflammation and protect testicular function is in demand. Virgin Coconut Oil (VCO) has found use in the treatment of diabetes, and cancer owing to the presence of polyphenols. However, there is a dearth of information on its effect on testicular toxicity. The present study investigated VCO as a possible treatment for testicular toxicity in the Sodium Benzoate (SB) model of male infertility by evaluating the oxidative and inflammatory status, circulating hormonal levels, and key sperm indices.

Materials and Methods

Twenty adult male rats were randomly assigned to four groups of 5 rats each and were treated with normal saline, sodium benzoate, sodium benzoate+5% VCO, and sodium benzoate+15% VCO for 30 days respectively. Biochemical analysis of reproductive hormones was assessed. Sperm parameters assessed include sperm function tests and sperm kinematics. One-way analysis of variance (ANOVA) followed by post hoc Tukey tests was performed.

Results

5% VCO reverts the deranged serum reproductive hormones caused by sodium benzoate. 5% VCO was more potent as an antioxidant and anti-inflammatory treatment than 15% VCO. However, both doses prevented SB's effect on the sperm function test and kinematics.

Conclusion

VCO-supplemented diet can ameliorate SB-induced testicular toxicity by inhibiting its mechanisms of toxicity that are related to oxidative stress, apoptosis, and inflammation.

Efficacy and tolerability of the American Heartworm Society therapeutic protocol in dogs affected by heartworm disease without caval syndrome

OBJECTIVES

The American Heartworm Society medical protocol represents the current standard of therapy for canine heartworm disease without caval syndrome. However, data on the tolerability of this protocol are limited. This study aimed to describe efficacy and prevalence of possible treatment-related side effects in dogs with heartworm disease treated using the American Heartworm Society protocol.

MATERIALS AND METHODS

For this retrospective multi-centre cohort study, dogs diagnosed with classes 1 to 3 heartworm disease that completed the American Heartworm Society medical protocol were searched in four medical databases. Demographic, clinical, diagnostic, therapeutic and outcome data, including the number and type of possible treatment-related side effects, were retrieved.

RESULTS

Thirty-five dogs were included. The median age and bodyweight were 6 years (1 to 13 years) and 17.3 kg (4.9 to 50 kg), respectively. Heartworm disease was classified as classes 1, 2 and 3 in 20 of 35, 11 of 35 and four of 35 dogs, respectively. In addition to the therapeutic recommendations of the American Heartworm Society, eight of 35 dogs underwent sedation to favour melarsomine administration, and 30 of 35 received ice at the injection site. After adulticide therapy, all dogs were hospitalised with cage rest [median time 12 hours (6 to 48 hours)]. All dogs survived the treatment. All dogs with long-term follow-up (32/35) became negative. Furthermore, treatment-related side effects were rare, mild and rapidly recovered without the need for supporting therapies; these included depression/lethargy (4/35 dogs), cough (2/35 dogs) and lameness, pain and gastrointestinal signs (1/35 dog each).

CLINICAL SIGNIFICANCE

The American Heartworm Society medical protocol is efficient and safe in dogs with classes 1 to 3 heartworm disease.

2022 Update of the Consensus on the Rational Use of Antithrombotics and Thrombolytics in Veterinary Critical Care (CURATIVE) Domain 1- Defining populations at risk

OBJECTIVES

To expand the number of conditions and interventions explored for their associations with thrombosis in the veterinary literature and to provide the basis for prescribing recommendations.

DESIGN

A population exposure comparison outcome format was used to represent patient, exposure, comparison, and outcome. Population Exposure Comparison Outcome questions were distributed to worksheet authors who performed comprehensive searches, summarized the evidence, and created guideline recommendations that were reviewed by domain chairs. The revised guidelines then underwent the Delphi survey process to reach consensus on the final guidelines. Diseases evaluated in this iteration included heartworm disease (dogs and cats), immune-mediated hemolytic anemia (cats), protein-losing nephropathy (cats), protein-losing enteropathy (dogs and cats), sepsis (cats), hyperadrenocorticism (cats), liver disease (dogs), congenital portosystemic shunts (dogs and cats) and the following interventions: IV catheters (dogs and cats), arterial catheters (dogs and cats), vascular access ports (dogs and cats), extracorporeal circuits (dogs and cats) and transvenous pacemakers (dogs and cats).

RESULTS

Of the diseases evaluated in this iteration, a high risk for thrombosis was defined as heartworm disease or protein-losing enteropathy. Low risk for thrombosis was defined as dogs with liver disease, cats with immune-mediated hemolytic anemia, protein-losing nephropathy, sepsis, or hyperadrenocorticism.

CONCLUSIONS

Associations with thrombosis are outlined for various conditions and interventions and provide the basis for management recommendations. Numerous knowledge gaps were identified that represent opportunities for future studies.

Occurrence of Dirofilaria immitis in Stray Dogs from Nepal

BACKGROUND

Nematodes of the genus Dirofilaria are widespread vector-borne helminths (VBH) of veterinary relevance. Dirofilariosis caused by D. immitis is frequently diagnosed in dogs often showing a severe clinical condition known as heartworm disease. Assessing the distribution pattern of canine dirofilariosis is pivotal to undertake appropriate control measures and define the risk of infection in animals and humans. This study provides original data on the occurrence of D. immitis in naive stray dogs from Nepal.

METHODS

An epidemiological study was performed on stray dogs from Siddharthanagar, Lumbini region, Nepal. Alive animals were blood sampled and examined for microfilariae using direct microscopy, buffy coat centrifugation and modified Knott's method. In addition, hematobiochemical parameters, including packed cell volume (PCV), alanine aminotransferase (SGPT), aspartate aminotransferase (SGOT), alkaline phosphate (ALP), creatinine, blood urea nitrogen (BUN), urea and total protein were analysed, along with a clinical scoring (body temperature and respiratory rate). During the observation period, data on autopsies performed on stray dogs showing canine heartworm disease were also included.

RESULTS

The overall prevalence of D. immitis in both alive and necropsied dogs was 22.49% (38/169). Out of 150 alive dogs, 29 (19.3%) were positive for D. immitis microfilariae. The prevalence of the infection varied according to the technique used, ranging from 16.0 to 19.3% based on direct blood smear microscopy and modified Knott's technique, respectively. The infection rate was significantly higher (p < 0.05) in dogs aging more than 3 years. A positive correlation was observed between SGPT and SGOT and the presence of microfilariae (p < 0.05). Among the 19 dead stray dogs, 9 animals showed adult D. immitis nematodes.

CONCLUSION

Results of this survey account for the presence of D. immitis in stray dogs from Nepal, thus supporting the existence of a local transmission cycle of diroflariosis in the region. Further investigations are warranted to accurately define the prevalence of the infection in the canine population and to undertake appropriate control measures to reduce the burden on the infection in dogs and, accordingly, the risk of transmission to humans.

An Accessible Alternative to Melarsomine: "Moxi-Doxy" for Treatment of Adult Heartworm Infection in Dogs

Canine heartworm infection, caused by the filarial parasite Dirofilaria immitis, represents a serious and expanding animal welfare concern that is expected to increase due to the effects of climate change and the COVID-19 pandemic. A body of evidence has emerged to support the use of a non-arsenical adulticide treatment protocol, using moxidectin and doxycycline to kill adult heartworms over a prolonged period. While a three-dose protocol using the arsenical drug melarsomine is currently the safest and most effective treatment for heartworm infection, this drug is not available in some countries and is inaccessible for many owners and animal shelters. Moxidectin-doxycycline (moxi-doxy) provides a viable alternative to no treatment at all, in cases where arsenical treatment is not possible. Based on current evidence, the most effective non-arsenical treatment regimen is doxycycline 10 mg/kg PO q 12 or 24 h for 28 days, combined with topical moxidectin at label dose. Moxidectin is repeated monthly until no antigen detected (NAD) status is confirmed. Sustained release injectable moxidectin, in combination with doxycycline, may provide an alternative in remote regions or in settings where significant compliance or accessibility concerns exist, but more studies are needed. In moxi-doxy protocols, doxycycline should be repeated annually until NAD. This review summarizes the safety and efficacy of moxi-doxy, addresses controversies surrounding this treatment approach, and provides detailed recommendations for treatment regimens and post-treatment testing.

Serum protein profiles and C-reactive protein in natural canine filariasis

Background and Aim:

Canine filariasis is caused by several species of filarial worms. The pathophysiological response to infection is mainly due to the filaria lifecycle. Laboratory detection methods to assess the pathological alterations characteristic of filariasis are needed urgently. Serum protein profiles and C-reactive protein (CRP) levels are used widely to diagnose several animal diseases. This study aimed to determine the serum protein profiles and CRP levels in dogs infected with Dirofilaria immitis or Brugia pahangi or both parasites.

Materials and Methods:

Blood samples were collected from 980 dogs presenting at animal hospitals and veterinary clinics in Bangkok and its vicinity. The presence of microfilaria in samples was determined using a buffy coat smear and staining with Wright–Giemsa. The sheathed and unsheathed microfilaria species were identified by acid phosphatase staining. Forty positive samples were tested. The serum protein profiles were identified by agarose gel electrophoresis. The CRP concentration was measured using a fluorescent immunoassay.

Results:

Albumin levels and albumin-to-globulin ratios were significantly lower, and total protein, β2 globulin, and γ globulin levels were significantly elevated in dogs infected with D. immitis and B. pahangi compared with reference values in normal dogs. The average CRP concentrations in dogs infected with D. immitis or B. pahangi were 69.9 and 12.9 mg/L, respectively.

Conclusion:

The total protein and γ globulin levels increased in canine filariasis compared with the normal reference range. The CRP concentration in dogs infected with D. immitis was extremely high, whereas that in dog infected with B. pahangi was normal.

Dogs with osteosarcoma have altered pro- and anti-inflammatory cytokine profiles

Background

Current advances in immunotherapy are an exciting area of study in canine osteosarcoma (OSA). The objective of this study was to determine the immune response in dogs with osteosarcoma by measuring stimulated leukocyte production of tumor necrosis factor (TNF), interleukin (IL)‐6, IL‐10 and TNF and IL‐6 to IL‐10 ratios.

Methods

Whole blood was collected from dogs with osteosarcoma receiving non‐steroidal anti‐inflammatory drugs (NSAIDs, n = 11), dogs with osteosarcoma not receiving NSAIDs (n = 14) and healthy dogs (n = 5).

Results

No difference in TNF production was found among healthy and OSA dogs regardless of NSAID administration following stimulation with lipopolysaccharide (LPS) (p = .410), lipoteichoic acid (LTA) (p = .693) or PBS (p = .120). Leukocyte IL‐6 production was greater in all dogs with OSA after stimulation with LPS (p = .015), LTA (p = .014) and PBS (p = .034) with no difference between OSA dogs receiving NSAIDs and those not. No differences in IL‐10 were found among healthy controls and dogs with OSA regardless of NSAID use. There was no difference among groups for LPS‐stimulated TNF to IL‐10 ratios (p = .407). For LTA‐stimulated leukocytes, the TNF to IL‐10 ratio was lower in dogs with OSA than in healthy dogs (p = .031) with no difference between OSA NSAID dogs compared to OSA non‐NSAID dogs (p = .059). No differences were found in LPS (p = .310)‐ or LTA (p = .265)‐stimulated leukocyte IL‐6 to IL‐10 production ratios among groups.

Conclusions

Dogs with osteosarcoma have an altered pro‐ and anti‐inflammatory immunologic profile compared to healthy dogs regardless of NSAID use. Further study is indicated to determine the potential prognostic and therapeutic implications of these findings.

The leukocytes of dogs with osteosarcoma had altered cytokine production in response to pathogen associated molecular pattern motifs compared to healthy dogs with increased IL‐6 production following LPS and LTA‐stimulation and decreased TNF‐to‐IL‐10 ratios following LTA‐stimulation. Future investigations should monitor leukocyte function through a defined treatment protocol and determine the prognostic significance and potential therapeutic targeting of these changes. These factors, with other immunologic parameters, should also be considered when investigating immunotherapy as potential predictive and prognostic markers.